[UI] Loop thread to main thread WindowedAppContext

premake5.lua

@@ -189,6 +189,12 @@ filter("platforms:Windows")
     "bcrypt",
   })
 
+-- Embed the manifest for things like dependencies and DPI awareness.
+filter({"platforms:Windows", "kind:ConsoleApp or WindowedApp"})
+  files({
+    "src/xenia/base/app_win32.manifest"
+  })
+
 -- Create scratch/ path
 if not os.isdir("scratch") then
   os.mkdir("scratch")
@@ -243,9 +249,13 @@ workspace("xenia")
     include("third_party/SDL2.lua")
   end
 
-  -- Disable treating warnings as fatal errors for all third party projects:
+  -- Disable treating warnings as fatal errors for all third party projects, as
+  -- well as other things relevant only to Xenia itself.
   for _, prj in ipairs(premake.api.scope.current.solution.projects) do
     project(prj.name)
+    removefiles({
+      "src/xenia/base/app_win32.manifest"
+    })
     removeflags({
       "FatalWarnings",
     })

src/xenia/app/emulator_window.cc

@@ -11,6 +11,7 @@
 
 #include "third_party/fmt/include/fmt/format.h"
 #include "third_party/imgui/imgui.h"
+#include "xenia/base/assert.h"
 #include "xenia/base/clock.h"
 #include "xenia/base/cvar.h"
 #include "xenia/base/debugging.h"
@@ -42,10 +43,11 @@ using xe::ui::UIEvent;
 
 const std::string kBaseTitle = "xenia";
 
-EmulatorWindow::EmulatorWindow(Emulator* emulator)
+EmulatorWindow::EmulatorWindow(Emulator* emulator,
+                               ui::WindowedAppContext& app_context)
     : emulator_(emulator),
-      loop_(ui::Loop::Create()),
+      app_context_(app_context),
-      window_(ui::Window::Create(loop_.get(), kBaseTitle)) {
+      window_(ui::Window::Create(app_context, kBaseTitle)) {
   base_title_ = kBaseTitle +
 #ifdef DEBUG
 #if _NO_DEBUG_HEAP == 1
@@ -63,23 +65,14 @@ EmulatorWindow::EmulatorWindow(Emulator* emulator)
                 ")";
 }
 
-EmulatorWindow::~EmulatorWindow() {
+std::unique_ptr<EmulatorWindow> EmulatorWindow::Create(
-  loop_->PostSynchronous([this]() { window_.reset(); });
+    Emulator* emulator, ui::WindowedAppContext& app_context) {
-}
+  assert_true(app_context.IsInUIThread());
-
+  std::unique_ptr<EmulatorWindow> emulator_window(
-std::unique_ptr<EmulatorWindow> EmulatorWindow::Create(Emulator* emulator) {
+      new EmulatorWindow(emulator, app_context));
-  std::unique_ptr<EmulatorWindow> emulator_window(new EmulatorWindow(emulator));
+  if (!emulator_window->Initialize()) {
-
+    return nullptr;
-  emulator_window->loop()->PostSynchronous([&emulator_window]() {
+  }
-    xe::threading::set_name("Windowing Loop");
-    xe::Profiler::ThreadEnter("Windowing Loop");
-
-    if (!emulator_window->Initialize()) {
-      xe::FatalError("Failed to initialize main window");
-      return;
-    }
-  });
-
   return emulator_window;
 }
 
@@ -91,8 +84,8 @@ bool EmulatorWindow::Initialize() {
 
   UpdateTitle();
 
-  window_->on_closed.AddListener([this](UIEvent* e) { loop_->Quit(); });
+  window_->on_closed.AddListener(
-  loop_->on_quit.AddListener([this](UIEvent* e) { window_.reset(); });
+      [this](UIEvent* e) { app_context_.QuitFromUIThread(); });
 
   window_->on_file_drop.AddListener(
       [this](FileDropEvent* e) { FileDrop(e->filename()); });
@@ -313,7 +306,7 @@ void EmulatorWindow::FileOpen() {
   file_picker->set_multi_selection(false);
   file_picker->set_title("Select Content Package");
   file_picker->set_extensions({
-      {"Supported Files", "*.iso;*.xex;*.xcp;*.*"},
+      {"Supported Files", "*.iso;*.xex;*.*"},
       {"Disc Image (*.iso)", "*.iso"},
       {"Xbox Executable (*.xex)", "*.xex"},
       //{"Content Package (*.xcp)", "*.xcp" },

src/xenia/app/emulator_window.h

@@ -13,9 +13,9 @@
 #include <memory>
 #include <string>
 
-#include "xenia/ui/loop.h"
 #include "xenia/ui/menu_item.h"
 #include "xenia/ui/window.h"
+#include "xenia/ui/windowed_app_context.h"
 #include "xenia/xbox.h"
 
 namespace xe {
@@ -27,12 +27,11 @@ namespace app {
 
 class EmulatorWindow {
  public:
-  virtual ~EmulatorWindow();
+  static std::unique_ptr<EmulatorWindow> Create(
-
+      Emulator* emulator, ui::WindowedAppContext& app_context);
-  static std::unique_ptr<EmulatorWindow> Create(Emulator* emulator);
 
   Emulator* emulator() const { return emulator_; }
-  ui::Loop* loop() const { return loop_.get(); }
+  ui::WindowedAppContext& app_context() const { return app_context_; }
   ui::Window* window() const { return window_.get(); }
 
   void UpdateTitle();
@@ -40,7 +39,8 @@ class EmulatorWindow {
   void SetInitializingShaderStorage(bool initializing);
 
  private:
-  explicit EmulatorWindow(Emulator* emulator);
+  explicit EmulatorWindow(Emulator* emulator,
+                          ui::WindowedAppContext& app_context);
 
   bool Initialize();
 
@@ -60,7 +60,7 @@ class EmulatorWindow {
   void ShowCommitID();
 
   Emulator* emulator_;
-  std::unique_ptr<ui::Loop> loop_;
+  ui::WindowedAppContext& app_context_;
   std::unique_ptr<ui::Window> window_;
   std::string base_title_;
   uint64_t cursor_hide_time_ = 0;

src/xenia/app/premake5.lua

@@ -52,8 +52,8 @@ project("xenia-app")
   local_platform_files()
   files({
     "xenia_main.cc",
-    "../base/main_"..platform_suffix..".cc",
     "../base/main_init_"..platform_suffix..".cc",
+    "../ui/windowed_app_main_"..platform_suffix..".cc",
   })
 
   resincludedirs({

src/xenia/app/xenia_main.cc

@@ -7,18 +7,29 @@
  ******************************************************************************
  */
 
+#include <atomic>
+#include <cstdlib>
+#include <functional>
+#include <memory>
+#include <string>
+#include <thread>
+#include <vector>
+
 #include "xenia/app/discord/discord_presence.h"
 #include "xenia/app/emulator_window.h"
 #include "xenia/base/cvar.h"
 #include "xenia/base/debugging.h"
 #include "xenia/base/logging.h"
-#include "xenia/base/main.h"
+#include "xenia/base/platform.h"
 #include "xenia/base/profiling.h"
 #include "xenia/base/threading.h"
 #include "xenia/config.h"
 #include "xenia/debug/ui/debug_window.h"
 #include "xenia/emulator.h"
 #include "xenia/ui/file_picker.h"
+#include "xenia/ui/window.h"
+#include "xenia/ui/windowed_app.h"
+#include "xenia/ui/windowed_app_context.h"
 #include "xenia/vfs/devices/host_path_device.h"
 
 // Available audio systems:
@@ -44,7 +55,6 @@
 #endif  // XE_PLATFORM_WIN32
 
 #include "third_party/fmt/include/fmt/format.h"
-#include "third_party/xbyak/xbyak/xbyak_util.h"
 
 DEFINE_string(apu, "any", "Audio system. Use: [any, nop, sdl, xaudio2]", "APU");
 DEFINE_string(gpu, "any", "Graphics system. Use: [any, d3d12, vulkan, null]",
@@ -91,83 +101,134 @@ DEFINE_bool(discord, true, "Enable Discord rich presence", "General");
 namespace xe {
 namespace app {
 
-template <typename T, typename... Args>
+class EmulatorApp final : public xe::ui::WindowedApp {
-class Factory {
+ public:
+  static std::unique_ptr<xe::ui::WindowedApp> Create(
+      xe::ui::WindowedAppContext& app_context) {
+    return std::unique_ptr<xe::ui::WindowedApp>(new EmulatorApp(app_context));
+  }
+
+  ~EmulatorApp();
+
+  bool OnInitialize() override;
+
+ protected:
+  void OnDestroy() override;
+
  private:
-  struct Creator {
+  template <typename T, typename... Args>
-    std::string name;
+  class Factory {
-    std::function<bool()> is_available;
+   private:
-    std::function<std::unique_ptr<T>(Args...)> instantiate;
+    struct Creator {
+      std::string name;
+      std::function<bool()> is_available;
+      std::function<std::unique_ptr<T>(Args...)> instantiate;
+    };
+
+    std::vector<Creator> creators_;
+
+   public:
+    void Add(const std::string_view name, std::function<bool()> is_available,
+             std::function<std::unique_ptr<T>(Args...)> instantiate) {
+      creators_.push_back({std::string(name), is_available, instantiate});
+    }
+
+    void Add(const std::string_view name,
+             std::function<std::unique_ptr<T>(Args...)> instantiate) {
+      auto always_available = []() { return true; };
+      Add(name, always_available, instantiate);
+    }
+
+    template <typename DT>
+    void Add(const std::string_view name) {
+      Add(name, DT::IsAvailable, [](Args... args) {
+        return std::make_unique<DT>(std::forward<Args>(args)...);
+      });
+    }
+
+    std::unique_ptr<T> Create(const std::string_view name, Args... args) {
+      if (!name.empty() && name != "any") {
+        auto it = std::find_if(
+            creators_.cbegin(), creators_.cend(),
+            [&name](const auto& f) { return name.compare(f.name) == 0; });
+        if (it != creators_.cend() && (*it).is_available()) {
+          return (*it).instantiate(std::forward<Args>(args)...);
+        }
+        return nullptr;
+      } else {
+        for (const auto& creator : creators_) {
+          if (!creator.is_available()) continue;
+          auto instance = creator.instantiate(std::forward<Args>(args)...);
+          if (!instance) continue;
+          return instance;
+        }
+        return nullptr;
+      }
+    }
+
+    std::vector<std::unique_ptr<T>> CreateAll(const std::string_view name,
+                                              Args... args) {
+      std::vector<std::unique_ptr<T>> instances;
+      if (!name.empty() && name != "any") {
+        auto it = std::find_if(
+            creators_.cbegin(), creators_.cend(),
+            [&name](const auto& f) { return name.compare(f.name) == 0; });
+        if (it != creators_.cend() && (*it).is_available()) {
+          auto instance = (*it).instantiate(std::forward<Args>(args)...);
+          if (instance) {
+            instances.emplace_back(std::move(instance));
+          }
+        }
+      } else {
+        for (const auto& creator : creators_) {
+          if (!creator.is_available()) continue;
+          auto instance = creator.instantiate(std::forward<Args>(args)...);
+          if (instance) {
+            instances.emplace_back(std::move(instance));
+          }
+        }
+      }
+      return instances;
+    }
   };
 
-  std::vector<Creator> creators_;
+  explicit EmulatorApp(xe::ui::WindowedAppContext& app_context);
 
- public:
+  static std::unique_ptr<apu::AudioSystem> CreateAudioSystem(
-  void Add(const std::string_view name, std::function<bool()> is_available,
+      cpu::Processor* processor);
-           std::function<std::unique_ptr<T>(Args...)> instantiate) {
+  static std::unique_ptr<gpu::GraphicsSystem> CreateGraphicsSystem();
-    creators_.push_back({std::string(name), is_available, instantiate});
+  static std::vector<std::unique_ptr<hid::InputDriver>> CreateInputDrivers(
-  }
+      ui::Window* window);
 
-  void Add(const std::string_view name,
+  void EmulatorThread();
-           std::function<std::unique_ptr<T>(Args...)> instantiate) {
+  void ShutdownEmulatorThreadFromUIThread();
-    auto always_available = []() { return true; };
-    Add(name, always_available, instantiate);
-  }
 
-  template <typename DT>
+  std::unique_ptr<Emulator> emulator_;
-  void Add(const std::string_view name) {
+  std::unique_ptr<EmulatorWindow> emulator_window_;
-    Add(name, DT::IsAvailable, [](Args... args) {
-      return std::make_unique<DT>(std::forward<Args>(args)...);
-    });
-  }
 
-  std::unique_ptr<T> Create(const std::string_view name, Args... args) {
+  // Created on demand, used by the emulator.
-    if (!name.empty() && name != "any") {
+  std::unique_ptr<xe::debug::ui::DebugWindow> debug_window_;
-      auto it = std::find_if(
-          creators_.cbegin(), creators_.cend(),
-          [&name](const auto& f) { return name.compare(f.name) == 0; });
-      if (it != creators_.cend() && (*it).is_available()) {
-        return (*it).instantiate(std::forward<Args>(args)...);
-      }
-      return nullptr;
-    } else {
-      for (const auto& creator : creators_) {
-        if (!creator.is_available()) continue;
-        auto instance = creator.instantiate(std::forward<Args>(args)...);
-        if (!instance) continue;
-        return instance;
-      }
-      return nullptr;
-    }
-  }
 
-  std::vector<std::unique_ptr<T>> CreateAll(const std::string_view name,
+  // Refreshing the emulator - placed after its dependencies.
-                                            Args... args) {
+  std::atomic<bool> emulator_thread_quit_requested_;
-    std::vector<std::unique_ptr<T>> instances;
+  std::unique_ptr<xe::threading::Event> emulator_thread_event_;
-    if (!name.empty() && name != "any") {
+  std::thread emulator_thread_;
-      auto it = std::find_if(
-          creators_.cbegin(), creators_.cend(),
-          [&name](const auto& f) { return name.compare(f.name) == 0; });
-      if (it != creators_.cend() && (*it).is_available()) {
-        auto instance = (*it).instantiate(std::forward<Args>(args)...);
-        if (instance) {
-          instances.emplace_back(std::move(instance));
-        }
-      }
-    } else {
-      for (const auto& creator : creators_) {
-        if (!creator.is_available()) continue;
-        auto instance = creator.instantiate(std::forward<Args>(args)...);
-        if (instance) {
-          instances.emplace_back(std::move(instance));
-        }
-      }
-    }
-    return instances;
-  }
 };
 
-std::unique_ptr<apu::AudioSystem> CreateAudioSystem(cpu::Processor* processor) {
+EmulatorApp::EmulatorApp(xe::ui::WindowedAppContext& app_context)
+    : xe::ui::WindowedApp(app_context, "xenia", "[Path to .iso/.xex]") {
+  AddPositionalOption("target");
+}
+
+EmulatorApp::~EmulatorApp() {
+  // Should be shut down from OnDestroy if OnInitialize has ever been done, but
+  // for the most safety as a running thread may be destroyed only after
+  // joining.
+  ShutdownEmulatorThreadFromUIThread();
+}
+
+std::unique_ptr<apu::AudioSystem> EmulatorApp::CreateAudioSystem(
+    cpu::Processor* processor) {
   Factory<apu::AudioSystem, cpu::Processor*> factory;
 #if XE_PLATFORM_WIN32
   factory.Add<apu::xaudio2::XAudio2AudioSystem>("xaudio2");
@@ -177,7 +238,7 @@ std::unique_ptr<apu::AudioSystem> CreateAudioSystem(cpu::Processor* processor) {
   return factory.Create(cvars::apu, processor);
 }
 
-std::unique_ptr<gpu::GraphicsSystem> CreateGraphicsSystem() {
+std::unique_ptr<gpu::GraphicsSystem> EmulatorApp::CreateGraphicsSystem() {
   Factory<gpu::GraphicsSystem> factory;
 #if XE_PLATFORM_WIN32
   factory.Add<gpu::d3d12::D3D12GraphicsSystem>("d3d12");
@@ -187,7 +248,7 @@ std::unique_ptr<gpu::GraphicsSystem> CreateGraphicsSystem() {
   return factory.Create(cvars::gpu);
 }
 
-std::vector<std::unique_ptr<hid::InputDriver>> CreateInputDrivers(
+std::vector<std::unique_ptr<hid::InputDriver>> EmulatorApp::CreateInputDrivers(
     ui::Window* window) {
   std::vector<std::unique_ptr<hid::InputDriver>> drivers;
   if (cvars::hid.compare("nop") == 0) {
@@ -215,9 +276,9 @@ std::vector<std::unique_ptr<hid::InputDriver>> CreateInputDrivers(
   return drivers;
 }
 
-int xenia_main(const std::vector<std::string>& args) {
+bool EmulatorApp::OnInitialize() {
   Profiler::Initialize();
-  Profiler::ThreadEnter("main");
+  Profiler::ThreadEnter("Main");
 
   // Figure out where internal files and content should go.
   std::filesystem::path storage_root = cvars::storage_root;
@@ -275,20 +336,55 @@ int xenia_main(const std::vector<std::string>& args) {
   }
 
   // Create the emulator but don't initialize so we can setup the window.
-  auto emulator =
+  emulator_ =
       std::make_unique<Emulator>("", storage_root, content_root, cache_root);
 
   // Main emulator display window.
-  auto emulator_window = EmulatorWindow::Create(emulator.get());
+  emulator_window_ = EmulatorWindow::Create(emulator_.get(), app_context());
+  if (!emulator_window_) {
+    XELOGE("Failed to create the main emulator window");
+    return false;
+  }
+
+  // Setup the emulator and run its loop in a separate thread.
+  emulator_thread_quit_requested_.store(false, std::memory_order_relaxed);
+  emulator_thread_event_ = xe::threading::Event::CreateAutoResetEvent(false);
+  emulator_thread_ = std::thread(&EmulatorApp::EmulatorThread, this);
+
+  return true;
+}
+
+void EmulatorApp::OnDestroy() {
+  ShutdownEmulatorThreadFromUIThread();
+
+  if (cvars::discord) {
+    discord::DiscordPresence::Shutdown();
+  }
+
+  Profiler::Dump();
+  // The profiler needs to shut down before the graphics context.
+  Profiler::Shutdown();
+
+  // TODO(DrChat): Remove this code and do a proper exit.
+  XELOGI("Cheap-skate exit!");
+  std::quick_exit(EXIT_SUCCESS);
+}
+
+void EmulatorApp::EmulatorThread() {
+  assert_not_null(emulator_thread_event_);
+
+  xe::threading::set_name("Emulator");
+  Profiler::ThreadEnter("Emulator");
 
   // Setup and initialize all subsystems. If we can't do something
   // (unsupported system, memory issues, etc) this will fail early.
   X_STATUS result =
-      emulator->Setup(emulator_window->window(), CreateAudioSystem,
+      emulator_->Setup(emulator_window_->window(), CreateAudioSystem,
-                      CreateGraphicsSystem, CreateInputDrivers);
+                       CreateGraphicsSystem, CreateInputDrivers);
   if (XFAILED(result)) {
     XELOGE("Failed to setup emulator: {:08X}", result);
-    return 1;
+    app_context().RequestDeferredQuit();
+    return;
   }
 
   if (cvars::mount_scratch) {
@@ -297,10 +393,11 @@ int xenia_main(const std::vector<std::string>& args) {
     if (!scratch_device->Initialize()) {
       XELOGE("Unable to scan scratch path");
     } else {
-      if (!emulator->file_system()->RegisterDevice(std::move(scratch_device))) {
+      if (!emulator_->file_system()->RegisterDevice(
+              std::move(scratch_device))) {
         XELOGE("Unable to register scratch path");
       } else {
-        emulator->file_system()->RegisterSymbolicLink("scratch:", "\\SCRATCH");
+        emulator_->file_system()->RegisterSymbolicLink("scratch:", "\\SCRATCH");
       }
     }
   }
@@ -311,10 +408,10 @@ int xenia_main(const std::vector<std::string>& args) {
     if (!cache0_device->Initialize()) {
       XELOGE("Unable to scan cache0 path");
     } else {
-      if (!emulator->file_system()->RegisterDevice(std::move(cache0_device))) {
+      if (!emulator_->file_system()->RegisterDevice(std::move(cache0_device))) {
         XELOGE("Unable to register cache0 path");
       } else {
-        emulator->file_system()->RegisterSymbolicLink("cache0:", "\\CACHE0");
+        emulator_->file_system()->RegisterSymbolicLink("cache0:", "\\CACHE0");
       }
     }
 
@@ -323,10 +420,10 @@ int xenia_main(const std::vector<std::string>& args) {
     if (!cache1_device->Initialize()) {
       XELOGE("Unable to scan cache1 path");
     } else {
-      if (!emulator->file_system()->RegisterDevice(std::move(cache1_device))) {
+      if (!emulator_->file_system()->RegisterDevice(std::move(cache1_device))) {
         XELOGE("Unable to register cache1 path");
       } else {
-        emulator->file_system()->RegisterSymbolicLink("cache1:", "\\CACHE1");
+        emulator_->file_system()->RegisterSymbolicLink("cache1:", "\\CACHE1");
       }
     }
 
@@ -339,79 +436,62 @@ int xenia_main(const std::vector<std::string>& args) {
     if (!cache_device->Initialize()) {
       XELOGE("Unable to scan cache path");
     } else {
-      if (!emulator->file_system()->RegisterDevice(std::move(cache_device))) {
+      if (!emulator_->file_system()->RegisterDevice(std::move(cache_device))) {
         XELOGE("Unable to register cache path");
       } else {
-        emulator->file_system()->RegisterSymbolicLink("cache:", "\\CACHE");
+        emulator_->file_system()->RegisterSymbolicLink("cache:", "\\CACHE");
       }
     }
   }
 
   // Set a debug handler.
   // This will respond to debugging requests so we can open the debug UI.
-  std::unique_ptr<xe::debug::ui::DebugWindow> debug_window;
   if (cvars::debug) {
-    emulator->processor()->set_debug_listener_request_handler(
+    emulator_->processor()->set_debug_listener_request_handler(
-        [&](xe::cpu::Processor* processor) {
+        [this](xe::cpu::Processor* processor) {
-          if (debug_window) {
+          if (debug_window_) {
-            return debug_window.get();
+            return debug_window_.get();
           }
-          emulator_window->loop()->PostSynchronous([&]() {
+          app_context().CallInUIThreadSynchronous([this]() {
-            debug_window = xe::debug::ui::DebugWindow::Create(
+            debug_window_ = xe::debug::ui::DebugWindow::Create(emulator_.get(),
-                emulator.get(), emulator_window->loop());
+                                                               app_context());
-            debug_window->window()->on_closed.AddListener(
+            debug_window_->window()->on_closed.AddListener(
-                [&](xe::ui::UIEvent* e) {
+                [this](xe::ui::UIEvent* e) {
-                  emulator->processor()->set_debug_listener(nullptr);
+                  emulator_->processor()->set_debug_listener(nullptr);
-                  emulator_window->loop()->Post(
+                  app_context().CallInUIThread(
-                      [&]() { debug_window.reset(); });
+                      [this]() { debug_window_.reset(); });
                 });
           });
-          return debug_window.get();
+          // If failed to enqueue the UI thread call, this will just be null.
+          return debug_window_.get();
         });
   }
 
-  auto evt = xe::threading::Event::CreateAutoResetEvent(false);
+  emulator_->on_launch.AddListener([&](auto title_id, const auto& game_title) {
-  emulator->on_launch.AddListener([&](auto title_id, const auto& game_title) {
     if (cvars::discord) {
       discord::DiscordPresence::PlayingTitle(
           game_title.empty() ? "Unknown Title" : std::string(game_title));
     }
-    emulator_window->UpdateTitle();
+    app_context().CallInUIThread([this]() { emulator_window_->UpdateTitle(); });
-    evt->Set();
+    emulator_thread_event_->Set();
   });
 
-  emulator->on_shader_storage_initialization.AddListener(
+  emulator_->on_shader_storage_initialization.AddListener(
-      [&](bool initializing) {
+      [this](bool initializing) {
-        emulator_window->SetInitializingShaderStorage(initializing);
+        app_context().CallInUIThread([this, initializing]() {
+          emulator_window_->SetInitializingShaderStorage(initializing);
+        });
       });
 
-  emulator->on_terminate.AddListener([&]() {
+  emulator_->on_terminate.AddListener([]() {
     if (cvars::discord) {
       discord::DiscordPresence::NotPlaying();
     }
   });
 
-  emulator_window->window()->on_closing.AddListener([&](ui::UIEvent* e) {
-    // This needs to shut down before the graphics context.
-    Profiler::Shutdown();
-  });
-
-  bool exiting = false;
-  emulator_window->loop()->on_quit.AddListener([&](ui::UIEvent* e) {
-    exiting = true;
-    evt->Set();
-
-    if (cvars::discord) {
-      discord::DiscordPresence::Shutdown();
-    }
-
-    // TODO(DrChat): Remove this code and do a proper exit.
-    XELOGI("Cheap-skate exit!");
-    exit(0);
-  });
-
   // Enable the main menu now that the emulator is properly loaded
-  emulator_window->window()->EnableMainMenu();
+  app_context().CallInUIThread(
+      [this]() { emulator_window_->window()->EnableMainMenu(); });
 
   // Grab path from the flag or unnamed argument.
   std::filesystem::path path;
@@ -420,50 +500,56 @@ int xenia_main(const std::vector<std::string>& args) {
   }
 
   // Toggles fullscreen
-  if (cvars::fullscreen) emulator_window->ToggleFullscreen();
+  if (cvars::fullscreen) {
+    app_context().CallInUIThread(
+        [this]() { emulator_window_->ToggleFullscreen(); });
+  }
 
   if (!path.empty()) {
     // Normalize the path and make absolute.
     auto abs_path = std::filesystem::absolute(path);
-    result = emulator->LaunchPath(abs_path);
+    result = emulator_->LaunchPath(abs_path);
     if (XFAILED(result)) {
       xe::FatalError(fmt::format("Failed to launch target: {:08X}", result));
-      emulator.reset();
+      app_context().RequestDeferredQuit();
-      emulator_window.reset();
+      return;
-      return 1;
     }
   }
 
-  // Now, we're going to use the main thread to drive events related to
+  // Now, we're going to use this thread to drive events related to emulation.
-  // emulation.
+  while (!emulator_thread_quit_requested_.load(std::memory_order_relaxed)) {
-  while (!exiting) {
+    xe::threading::Wait(emulator_thread_event_.get(), false);
-    xe::threading::Wait(evt.get(), false);
-
     while (true) {
-      emulator->WaitUntilExit();
+      emulator_->WaitUntilExit();
-      if (emulator->TitleRequested()) {
+      if (emulator_->TitleRequested()) {
-        emulator->LaunchNextTitle();
+        emulator_->LaunchNextTitle();
       } else {
         break;
       }
     }
   }
+}
 
-  debug_window.reset();
+void EmulatorApp::ShutdownEmulatorThreadFromUIThread() {
-  emulator.reset();
+  // TODO(Triang3l): Proper shutdown of the emulator (relying on std::quick_exit
-
+  // for now) - currently WaitUntilExit loops forever otherwise (plus possibly
-  if (cvars::discord) {
+  // lots of other things not shutting down correctly now). Some parts of the
-    discord::DiscordPresence::Shutdown();
+  // code call the regular std::exit, which seems to be calling destructors (at
+  // least on Linux), so the entire join is currently commented out.
+#if 0
+  // Same thread as the one created it, to make sure there's zero possibility of
+  // a race with the creation of the emulator thread.
+  assert_true(app_context().IsInUIThread());
+  emulator_thread_quit_requested_.store(true, std::memory_order_relaxed);
+  if (!emulator_thread_.joinable()) {
+    return;
   }
-
+  emulator_thread_event_->Set();
-  Profiler::Dump();
+  emulator_thread_.join();
-  Profiler::Shutdown();
+#endif
-  emulator_window.reset();
-  return 0;
 }
 
 }  // namespace app
 }  // namespace xe
 
-DEFINE_ENTRY_POINT("xenia", xe::app::xenia_main, "[Path to .iso/.xex]",
+XE_DEFINE_WINDOWED_APP(xenia, xe::app::EmulatorApp::Create);
-                   "target");

src/xenia/apu/xaudio2/xaudio2_audio_driver.cc

@@ -9,13 +9,14 @@
 
 #include "xenia/apu/xaudio2/xaudio2_audio_driver.h"
 
-// Must be included before xaudio2.h so we get the right windows.h include.
-#include "xenia/base/platform_win.h"
-
 #include "xenia/apu/apu_flags.h"
 #include "xenia/apu/conversion.h"
+#include "xenia/apu/xaudio2/xaudio2_api.h"
+#include "xenia/base/assert.h"
 #include "xenia/base/clock.h"
 #include "xenia/base/logging.h"
+#include "xenia/base/platform_win.h"
+#include "xenia/base/threading.h"
 
 namespace xe {
 namespace apu {
@@ -73,11 +74,6 @@ bool XAudio2AudioDriver::Initialize() {
     }
   }
 
-  // First CPU (2.8 default). XAUDIO2_ANY_PROCESSOR (2.7 default) steals too
-  // much time from other things. Ideally should process audio on what roughly
-  // represents thread 4 (5th) on the Xbox 360 (2.7 default on the console), or
-  // even beyond the 6 guest cores.
-  api::XAUDIO2_PROCESSOR processor = 0x00000001;
   if (api_minor_version_ >= 8) {
     union {
       // clang-format off
@@ -94,7 +90,7 @@ bool XAudio2AudioDriver::Initialize() {
       assert_always();
       return false;
     }
-    hr = xaudio2_create(&objects_.api_2_8.audio, 0, processor);
+    hr = xaudio2_create(&objects_.api_2_8.audio, 0, kProcessor);
     if (FAILED(hr)) {
       XELOGE("XAudio2Create failed with {:08X}", hr);
       assert_always();
@@ -102,20 +98,38 @@ bool XAudio2AudioDriver::Initialize() {
     }
     return InitializeObjects(objects_.api_2_8);
   } else {
-    hr = CoCreateInstance(__uuidof(api::XAudio2_7), NULL, CLSCTX_INPROC_SERVER,
+    // We need to be able to accept frames from any non-STA thread - primarily
-                          IID_PPV_ARGS(&objects_.api_2_7.audio));
+    // from any guest thread, so MTA needs to be used. The AudioDriver, however,
-    if (FAILED(hr)) {
+    // may be initialized from the UI thread, which has the STA concurrency
-      XELOGE("CoCreateInstance for XAudio2 failed with {:08X}", hr);
+    // model, or from another thread regardless of its concurrency model. So,
-      assert_always();
+    // all management of the objects needs to be performed in MTA. Launch the
+    // lifecycle management thread, which will handle initialization and
+    // shutdown, and also provide a scope for implicit MTA in threads that have
+    // never initialized COM explicitly, which lasts until all threads that have
+    // initialized MTA explicitly have uninitialized it - the thread that holds
+    // the MTA scope needs to be running while other threads are able to submit
+    // frames as they might have not initialized MTA explicitly.
+    // https://devblogs.microsoft.com/oldnewthing/?p=4613
+    assert_false(mta_thread_.joinable());
+    mta_thread_initialization_attempt_completed_ = false;
+    mta_thread_shutdown_requested_ = false;
+    mta_thread_ = std::thread(&XAudio2AudioDriver::MTAThread, this);
+    {
+      std::unique_lock<std::mutex> mta_thread_initialization_completion_lock(
+          mta_thread_initialization_completion_mutex_);
+      while (true) {
+        if (mta_thread_initialization_attempt_completed_) {
+          break;
+        }
+        mta_thread_initialization_completion_cond_.wait(
+            mta_thread_initialization_completion_lock);
+      }
+    }
+    if (!mta_thread_initialization_completion_result_) {
+      mta_thread_.join();
       return false;
     }
-    hr = objects_.api_2_7.audio->Initialize(0, processor);
+    return true;
-    if (FAILED(hr)) {
-      XELOGE("IXAudio2::Initialize failed with {:08X}", hr);
-      assert_always();
-      return false;
-    }
-    return InitializeObjects(objects_.api_2_7);
   }
 }
 
@@ -249,7 +263,16 @@ void XAudio2AudioDriver::Shutdown() {
   if (api_minor_version_ >= 8) {
     ShutdownObjects(objects_.api_2_8);
   } else {
-    ShutdownObjects(objects_.api_2_7);
+    // XAudio 2.7 lifecycle is managed by the MTA thread.
+    if (mta_thread_.joinable()) {
+      {
+        std::unique_lock<std::mutex> mta_thread_shutdown_request_lock(
+            mta_thread_shutdown_request_mutex_);
+        mta_thread_shutdown_requested_ = true;
+      }
+      mta_thread_shutdown_request_cond_.notify_all();
+      mta_thread_.join();
+    }
   }
 
   if (xaudio2_module_) {
@@ -283,6 +306,82 @@ void XAudio2AudioDriver::ShutdownObjects(Objects& objects) {
   }
 }
 
+void XAudio2AudioDriver::MTAThread() {
+  xe::threading::set_name("XAudio 2.7 MTA");
+
+  assert_false(mta_thread_initialization_attempt_completed_);
+
+  bool initialized = false;
+
+  // Initializing MTA COM in this thread, as well making other (guest) threads
+  // that don't explicitly call CoInitializeEx implicitly MTA for the period of
+  // time when they can interact with XAudio 2.7 through the XAudio2AudioDriver,
+  // until the CoUninitialize (to be more precise, the CoUninitialize for the
+  // last remaining MTA thread, but we need implicit MTA for the audio here).
+  // https://devblogs.microsoft.com/oldnewthing/?p=4613
+  HRESULT hr = CoInitializeEx(nullptr, COINIT_MULTITHREADED);
+  if (FAILED(hr)) {
+    XELOGE("XAudio 2.7 MTA thread CoInitializeEx failed with {:08X}", hr);
+  } else {
+    hr = CoCreateInstance(__uuidof(api::XAudio2_7), nullptr,
+                          CLSCTX_INPROC_SERVER,
+                          IID_PPV_ARGS(&objects_.api_2_7.audio));
+    if (FAILED(hr)) {
+      XELOGE("CoCreateInstance for XAudio2 failed with {:08X}", hr);
+    } else {
+      hr = objects_.api_2_7.audio->Initialize(0, kProcessor);
+      if (FAILED(hr)) {
+        XELOGE("IXAudio2::Initialize failed with {:08X}", hr);
+      } else {
+        if (InitializeObjects(objects_.api_2_7)) {
+          initialized = true;
+
+          // Initialized successfully, await a shutdown request while keeping an
+          // implicit COM MTA scope.
+
+          mta_thread_initialization_completion_result_ = true;
+          {
+            std::unique_lock<std::mutex>
+                mta_thread_initialization_completion_lock(
+                    mta_thread_initialization_completion_mutex_);
+            mta_thread_initialization_attempt_completed_ = true;
+          }
+          mta_thread_initialization_completion_cond_.notify_all();
+
+          {
+            std::unique_lock<std::mutex> mta_thread_shutdown_request_lock(
+                mta_thread_shutdown_request_mutex_);
+            while (true) {
+              if (mta_thread_shutdown_requested_) {
+                break;
+              }
+              mta_thread_shutdown_request_cond_.wait(
+                  mta_thread_shutdown_request_lock);
+            }
+          }
+        }
+
+        // Even if InitializeObjects has failed, need to clean up with
+        // ShutdownObjects.
+        ShutdownObjects(objects_.api_2_7);
+      }
+    }
+    CoUninitialize();
+  }
+
+  if (!initialized) {
+    mta_thread_initialization_completion_result_ = false;
+    {
+      // Failed to initialize - notify the threads waiting for the
+      // initialization.
+      std::unique_lock<std::mutex> mta_thread_initialization_completion_lock(
+          mta_thread_initialization_completion_mutex_);
+      mta_thread_initialization_attempt_completed_ = true;
+    }
+    mta_thread_initialization_completion_cond_.notify_all();
+  }
+}
+
 }  // namespace xaudio2
 }  // namespace apu
 }  // namespace xe

src/xenia/apu/xaudio2/xaudio2_audio_driver.h

@@ -10,8 +10,13 @@
 #ifndef XENIA_APU_XAUDIO2_XAUDIO2_AUDIO_DRIVER_H_
 #define XENIA_APU_XAUDIO2_XAUDIO2_AUDIO_DRIVER_H_
 
+#include <condition_variable>
+#include <mutex>
+#include <thread>
+
 #include "xenia/apu/audio_driver.h"
 #include "xenia/apu/xaudio2/xaudio2_api.h"
+#include "xenia/base/platform.h"
 #include "xenia/base/threading.h"
 
 struct IXAudio2;
@@ -28,17 +33,45 @@ class XAudio2AudioDriver : public AudioDriver {
   ~XAudio2AudioDriver() override;
 
   bool Initialize();
+  // Must not be called from COM STA threads as MTA XAudio 2.7 may be used. It's
+  // fine to call this from threads that have never initialized COM as
+  // initializing MTA for any thread implicitly initializes it for all threads
+  // not explicitly requesting STA (until COM is uninitialized all threads that
+  // have initialized MTA).
+  // https://devblogs.microsoft.com/oldnewthing/?p=4613
   void SubmitFrame(uint32_t frame_ptr) override;
   void Shutdown();
 
  private:
+  // First CPU (2.8 default). XAUDIO2_ANY_PROCESSOR (2.7 default) steals too
+  // much time from other things. Ideally should process audio on what roughly
+  // represents thread 4 (5th) on the Xbox 360 (2.7 default on the console), or
+  // even beyond the 6 guest cores.
+  api::XAUDIO2_PROCESSOR kProcessor = 0x00000001;
+
+  // For XAudio 2.7, InitializeObjects and ShutdownObjects must be called only
+  // in the lifecycle management thread with COM MTA initialized.
   template <typename Objects>
   bool InitializeObjects(Objects& objects);
   template <typename Objects>
   void ShutdownObjects(Objects& objects);
 
+  void MTAThread();
+
   void* xaudio2_module_ = nullptr;
   uint32_t api_minor_version_ = 7;
+
+  bool mta_thread_initialization_completion_result_;
+  std::mutex mta_thread_initialization_completion_mutex_;
+  std::condition_variable mta_thread_initialization_completion_cond_;
+  bool mta_thread_initialization_attempt_completed_;
+
+  std::mutex mta_thread_shutdown_request_mutex_;
+  std::condition_variable mta_thread_shutdown_request_cond_;
+  bool mta_thread_shutdown_requested_;
+
+  std::thread mta_thread_;
+
   union {
     struct {
       api::IXAudio2_7* audio;

src/xenia/base/app_win32.manifest

@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<assembly xmlns="urn:schemas-microsoft-com:asm.v1" xmlns:asmv3="urn:schemas-microsoft-com:asm.v3" manifestVersion="1.0">
+  <dependency>
+    <dependentAssembly>
+      <assemblyIdentity type="win32" name="Microsoft.Windows.Common-Controls" version="6.0.0.0" processorArchitecture="*" publicKeyToken="6595b64144ccf1df" language="*" />
+    </dependentAssembly>
+  </dependency>
+  <asmv3:application>
+    <asmv3:windowsSettings>
+      <dpiAware xmlns="http://schemas.microsoft.com/SMI/2005/WindowsSettings">True/PM</dpiAware>
+      <dpiAwareness xmlns="http://schemas.microsoft.com/SMI/2016/WindowsSettings">PerMonitor</dpiAwareness>
+    </asmv3:windowsSettings>
+  </asmv3:application>
+</assembly>

src/xenia/base/console.h

@@ -0,0 +1,22 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2021 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#ifndef XENIA_BASE_CONSOLE_H_
+#define XENIA_BASE_CONSOLE_H_
+
+namespace xe {
+
+// Returns true if there is a user-visible console attached to receive stdout.
+bool has_console_attached();
+
+void AttachConsole();
+
+}  // namespace xe
+
+#endif  // XENIA_BASE_CONSOLE_H_

src/xenia/base/console_app_main.h

@@ -2,54 +2,50 @@
  ******************************************************************************
  * Xenia : Xbox 360 Emulator Research Project                                 *
  ******************************************************************************
- * Copyright 2020 Ben Vanik. All rights reserved.                             *
+ * Copyright 2021 Ben Vanik. All rights reserved.                             *
  * Released under the BSD license - see LICENSE in the root for more details. *
  ******************************************************************************
  */
 
-#ifndef XENIA_BASE_MAIN_H_
+#ifndef XENIA_BASE_CONSOLE_APP_MAIN_H_
-#define XENIA_BASE_MAIN_H_
+#define XENIA_BASE_CONSOLE_APP_MAIN_H_
 
-#include <optional>
 #include <string>
 #include <vector>
 
-#include "xenia/base/cvar.h"
-#include "xenia/base/platform.h"
-
 namespace xe {
 
-// Returns true if there is a user-visible console attached to receive stdout.
-bool has_console_attached();
-
-void AttachConsole();
-
 // Extern defined by user code. This must be present for the application to
 // launch.
-struct EntryInfo {
+struct ConsoleAppEntryInfo {
   std::string name;
   int (*entry_point)(const std::vector<std::string>& args);
   bool transparent_options;  // no argument parsing
-  std::optional<std::string> positional_usage;
+  std::string positional_usage;
-  std::optional<std::vector<std::string>> positional_options;
+  std::vector<std::string> positional_options;
 };
-EntryInfo GetEntryInfo();
+ConsoleAppEntryInfo GetConsoleAppEntryInfo();
 
-#define DEFINE_ENTRY_POINT(name, entry_point, positional_usage, ...)       \
+// TODO(Triang3l): Multiple console app entry points on Android when a console
-  xe::EntryInfo xe::GetEntryInfo() {                                       \
+// activity is added. This is currently for individual executables running on
+// Termux.
+
+#define XE_DEFINE_CONSOLE_APP(name, entry_point, positional_usage, ...)    \
+  xe::ConsoleAppEntryInfo xe::GetConsoleAppEntryInfo() {                   \
     std::initializer_list<std::string> positional_options = {__VA_ARGS__}; \
-    return xe::EntryInfo{                                                  \
+    return xe::ConsoleAppEntryInfo{                                        \
         name, entry_point, false, positional_usage,                        \
         std::vector<std::string>(std::move(positional_options))};          \
   }
 
 // TODO(Joel Linn): Add some way to filter consumed arguments in
 // cvar::ParseLaunchArguments()
-#define DEFINE_ENTRY_POINT_TRANSPARENT(name, entry_point)                      \
+#define XE_DEFINE_CONSOLE_APP_TRANSPARENT(name, entry_point)               \
-  xe::EntryInfo xe::GetEntryInfo() {                                           \
+  xe::ConsoleAppEntryInfo xe::GetConsoleAppEntryInfo() {                   \
-    return xe::EntryInfo{name, entry_point, true, std::nullopt, std::nullopt}; \
+    return xe::ConsoleAppEntryInfo{name, entry_point, true, std::string(), \
+                                   std::vector<std::string>()};            \
   }
 
 }  // namespace xe
 
-#endif  // XENIA_BASE_MAIN_H_
+#endif  // XENIA_BASE_CONSOLE_APP_MAIN_H_

src/xenia/base/console_app_main_android.cc

@@ -0,0 +1,10 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2021 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#include "xenia/base/console_app_posix.cc"

src/xenia/base/console_app_main_posix.cc

@@ -7,42 +7,32 @@
  ******************************************************************************
  */
 
-#include <stdio.h>
+#include <string>
-#include <unistd.h>
+#include <vector>
 
+#include "xenia/base/console_app_main.h"
 #include "xenia/base/cvar.h"
-#include "xenia/base/main.h"
-
-#include "xenia/base/filesystem.h"
 #include "xenia/base/logging.h"
-#include "xenia/base/string.h"
-
-namespace xe {
-
-bool has_console_attached() { return isatty(fileno(stdin)) == 1; }
-
-void AttachConsole() {}
-
-}  // namespace xe
 
 extern "C" int main(int argc, char** argv) {
-  auto entry_info = xe::GetEntryInfo();
+  xe::ConsoleAppEntryInfo entry_info = xe::GetConsoleAppEntryInfo();
 
   if (!entry_info.transparent_options) {
-    cvar::ParseLaunchArguments(argc, argv, entry_info.positional_usage.value(),
+    cvar::ParseLaunchArguments(argc, argv, entry_info.positional_usage,
-                               entry_info.positional_options.value());
+                               entry_info.positional_options);
   }
 
+  // Initialize logging. Needs parsed cvars.
+  xe::InitializeLogging(entry_info.name);
+
   std::vector<std::string> args;
   for (int n = 0; n < argc; n++) {
-    args.push_back(argv[n]);
+    args.emplace_back(argv[n]);
   }
 
-  // Initialize logging. Needs parsed FLAGS.
-  xe::InitializeLogging(entry_info.name);
-
-  // Call app-provided entry point.
   int result = entry_info.entry_point(args);
 
+  xe::ShutdownLogging();
+
   return result;
 }

src/xenia/base/console_app_main_win.cc

@@ -0,0 +1,36 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2021 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#include <cstdlib>
+#include <vector>
+
+#include "xenia/base/console_app_main.h"
+#include "xenia/base/main_win.h"
+
+int main(int argc_ignored, char** argv_ignored) {
+  xe::ConsoleAppEntryInfo entry_info = xe::GetConsoleAppEntryInfo();
+
+  std::vector<std::string> args;
+  if (!xe::ParseWin32LaunchArguments(entry_info.transparent_options,
+                                     entry_info.positional_usage,
+                                     entry_info.positional_options, &args)) {
+    return EXIT_FAILURE;
+  }
+
+  int result = xe::InitializeWin32App(entry_info.name);
+  if (result) {
+    return result;
+  }
+
+  result = entry_info.entry_point(args);
+
+  xe::ShutdownWin32App();
+
+  return result;
+}

src/xenia/base/console_posix.cc

@@ -0,0 +1,21 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2021 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+
+#include "xenia/base/console.h"
+
+namespace xe {
+
+bool has_console_attached() { return isatty(fileno(stdin)) == 1; }
+
+void AttachConsole() {}
+
+}  // namespace xe

src/xenia/base/console_win.cc

@@ -0,0 +1,60 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2021 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#include <fcntl.h>
+#include <io.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "xenia/base/console.h"
+#include "xenia/base/platform_win.h"
+
+namespace xe {
+
+// TODO(Triang3l): Set the default depending on the actual subsystem. Currently
+// it inhibits message boxes.
+static bool has_console_attached_ = true;
+
+bool has_console_attached() { return has_console_attached_; }
+
+static bool has_shell_environment_variable() {
+  size_t size = 0;
+  // Check if SHELL exists
+  // If it doesn't, then we are in a Windows Terminal
+  auto error = getenv_s(&size, nullptr, 0, "SHELL");
+  if (error) {
+    return false;
+  }
+  return !!size;
+}
+
+void AttachConsole() {
+  bool has_console = ::AttachConsole(ATTACH_PARENT_PROCESS) == TRUE;
+  if (!has_console || !has_shell_environment_variable()) {
+    // We weren't launched from a console, so just return.
+    has_console_attached_ = false;
+    return;
+  }
+
+  AllocConsole();
+
+  has_console_attached_ = true;
+
+  auto std_handle = (intptr_t)GetStdHandle(STD_OUTPUT_HANDLE);
+  auto con_handle = _open_osfhandle(std_handle, _O_TEXT);
+  auto fp = _fdopen(con_handle, "w");
+  freopen_s(&fp, "CONOUT$", "w", stdout);
+
+  std_handle = (intptr_t)GetStdHandle(STD_ERROR_HANDLE);
+  con_handle = _open_osfhandle(std_handle, _O_TEXT);
+  fp = _fdopen(con_handle, "w");
+  freopen_s(&fp, "CONOUT$", "w", stderr);
+}
+
+}  // namespace xe

src/xenia/base/cvar.cc

@@ -14,8 +14,8 @@
 #define UTF_CPP_CPLUSPLUS 201703L
 #include "third_party/utfcpp/source/utf8.h"
 
+#include "xenia/base/console.h"
 #include "xenia/base/logging.h"
-#include "xenia/base/main.h"
 #include "xenia/base/system.h"
 
 namespace utfcpp = utf8;

src/xenia/base/logging.cc

@@ -18,10 +18,10 @@
 #include "third_party/disruptorplus/include/disruptorplus/sequence_barrier.hpp"
 #include "third_party/disruptorplus/include/disruptorplus/spin_wait_strategy.hpp"
 #include "xenia/base/atomic.h"
+#include "xenia/base/console.h"
 #include "xenia/base/cvar.h"
 #include "xenia/base/debugging.h"
 #include "xenia/base/filesystem.h"
-#include "xenia/base/main.h"
 #include "xenia/base/math.h"
 #include "xenia/base/memory.h"
 #include "xenia/base/ring_buffer.h"

src/xenia/base/main_init_android.cc

@@ -0,0 +1,10 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2021 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+// Nothing. Stub.

src/xenia/base/main_init_posix.cc

@@ -2,13 +2,9 @@
  ******************************************************************************
  * Xenia : Xbox 360 Emulator Research Project                                 *
  ******************************************************************************
- * Copyright 2014 Ben Vanik. All rights reserved.                             *
+ * Copyright 2021 Ben Vanik. All rights reserved.                             *
  * Released under the BSD license - see LICENSE in the root for more details. *
  ******************************************************************************
  */
 
-#include "xenia/base/main.h"
-
-#include <cstdlib>
-
 // Nothing. Stub.

src/xenia/base/main_init_win.cc

@@ -7,10 +7,11 @@
  ******************************************************************************
  */
 
-#include "xenia/base/main.h"
+#include "xenia/base/platform_win.h"
 
 #include <cstdlib>
 
+// Includes Windows headers, so it goes after platform_win.h.
 #include "third_party/xbyak/xbyak/xbyak_util.h"
 
 class StartupAvxCheck {

src/xenia/base/main_win.cc

@@ -7,14 +7,12 @@
  ******************************************************************************
  */
 
-#include <fcntl.h>
+#include <malloc.h>
-#include <io.h>
+#include <cstring>
-
-#include <cstdlib>
 
 #include "xenia/base/cvar.h"
 #include "xenia/base/logging.h"
-#include "xenia/base/main.h"
+#include "xenia/base/main_win.h"
 #include "xenia/base/platform_win.h"
 #include "xenia/base/string.h"
 
@@ -24,54 +22,11 @@
 // For RequestHighPerformance.
 #include <winternl.h>
 
-// Includes Windows headers, so it goes here.
-#include "third_party/xbyak/xbyak/xbyak_util.h"
-
 DEFINE_bool(win32_high_freq, true,
             "Requests high performance from the NT kernel", "Kernel");
-DEFINE_bool(enable_console, false, "Open a console window with the main window",
-            "General");
 
 namespace xe {
 
-bool has_console_attached_ = true;
-
-bool has_console_attached() { return has_console_attached_; }
-
-bool has_shell_environment_variable() {
-  size_t size = 0;
-  // Check if SHELL exists
-  // If it doesn't, then we are in a Windows Terminal
-  auto error = getenv_s(&size, nullptr, 0, "SHELL");
-  if (error) {
-    return false;
-  }
-  return !!size;
-}
-
-void AttachConsole() {
-  bool has_console = ::AttachConsole(ATTACH_PARENT_PROCESS) == TRUE;
-  if (!has_console || !has_shell_environment_variable()) {
-    // We weren't launched from a console, so just return.
-    has_console_attached_ = false;
-    return;
-  }
-
-  AllocConsole();
-
-  has_console_attached_ = true;
-
-  auto std_handle = (intptr_t)GetStdHandle(STD_OUTPUT_HANDLE);
-  auto con_handle = _open_osfhandle(std_handle, _O_TEXT);
-  auto fp = _fdopen(con_handle, "w");
-  freopen_s(&fp, "CONOUT$", "w", stdout);
-
-  std_handle = (intptr_t)GetStdHandle(STD_ERROR_HANDLE);
-  con_handle = _open_osfhandle(std_handle, _O_TEXT);
-  fp = _fdopen(con_handle, "w");
-  freopen_s(&fp, "CONOUT$", "w", stderr);
-}
-
 static void RequestHighPerformance() {
 #if XE_PLATFORM_WIN32
   NTSTATUS(*NtQueryTimerResolution)
@@ -97,8 +52,10 @@ static void RequestHighPerformance() {
 #endif
 }
 
-static bool parse_launch_arguments(const xe::EntryInfo& entry_info,
+bool ParseWin32LaunchArguments(
-                                   std::vector<std::string>& args) {
+    bool transparent_options, const std::string_view positional_usage,
+    const std::vector<std::string>& positional_options,
+    std::vector<std::string>* args_out) {
   auto command_line = GetCommandLineW();
 
   int wargc;
@@ -118,48 +75,24 @@ static bool parse_launch_arguments(const xe::EntryInfo& entry_info,
 
   LocalFree(wargv);
 
-  if (!entry_info.transparent_options) {
+  if (!transparent_options) {
-    cvar::ParseLaunchArguments(argc, argv, entry_info.positional_usage.value(),
+    cvar::ParseLaunchArguments(argc, argv, positional_usage,
-                               entry_info.positional_options.value());
+                               positional_options);
   }
 
-  args.clear();
+  if (args_out) {
-  for (int n = 0; n < argc; n++) {
+    args_out->clear();
-    args.push_back(std::string(argv[n]));
+    for (int n = 0; n < argc; n++) {
+      args_out->push_back(std::string(argv[n]));
+    }
   }
 
   return true;
 }
 
-int Main() {
+int InitializeWin32App(const std::string_view app_name) {
-  auto entry_info = xe::GetEntryInfo();
-
-  std::vector<std::string> args;
-  if (!parse_launch_arguments(entry_info, args)) {
-    return 1;
-  }
-
-  // Attach a console so we can write output to stdout. If the user hasn't
-  // redirected output themselves it'll pop up a window.
-  if (cvars::enable_console) {
-    xe::AttachConsole();
-  }
-
-  // Setup COM on the main thread.
-  // NOTE: this may fail if COM has already been initialized - that's OK.
-#pragma warning(suppress : 6031)
-  CoInitializeEx(nullptr, COINIT_MULTITHREADED);
-
   // Initialize logging. Needs parsed FLAGS.
-  xe::InitializeLogging(entry_info.name);
+  xe::InitializeLogging(app_name);
-
-  Xbyak::util::Cpu cpu;
-  if (!cpu.has(Xbyak::util::Cpu::tAVX)) {
-    xe::FatalError(
-        "Your CPU does not support AVX, which is required by Xenia. See the "
-        "FAQ for system requirements at https://xenia.jp");
-    return -1;
-  }
 
   // Print version info.
   XELOGI(
@@ -175,38 +108,9 @@ int Main() {
     RequestHighPerformance();
   }
 
-  // Call app-provided entry point.
+  return 0;
-  int result = entry_info.entry_point(args);
-
-  xe::ShutdownLogging();
-  return result;
 }
 
+void ShutdownWin32App() { xe::ShutdownLogging(); }
+
 }  // namespace xe
-
-// Used in console mode apps; automatically picked based on subsystem.
-int main(int argc_ignored, char** argv_ignored) { return xe::Main(); }
-
-// Used in windowed apps; automatically picked based on subsystem.
-int WINAPI wWinMain(HINSTANCE, HINSTANCE, LPWSTR command_line, int) {
-  // Run normal entry point.
-  return xe::Main();
-}
-
-#if defined _M_IX86
-#pragma comment( \
-    linker,      \
-    "/manifestdependency:\"type='win32' name='Microsoft.Windows.Common-Controls' version='6.0.0.0' processorArchitecture='x86' publicKeyToken='6595b64144ccf1df' language='*'\"")  // NOLINT(whitespace/line_length)
-#elif defined _M_IA64
-#pragma comment( \
-    linker,      \
-    "/manifestdependency:\"type='win32' name='Microsoft.Windows.Common-Controls' version='6.0.0.0' processorArchitecture='ia64' publicKeyToken='6595b64144ccf1df' language='*'\"")  // NOLINT(whitespace/line_length)
-#elif defined _M_X64
-#pragma comment( \
-    linker,      \
-    "/manifestdependency:\"type='win32' name='Microsoft.Windows.Common-Controls' version='6.0.0.0' processorArchitecture='amd64' publicKeyToken='6595b64144ccf1df' language='*'\"")  // NOLINT(whitespace/line_length)
-#else
-#pragma comment( \
-    linker,      \
-    "/manifestdependency:\"type='win32' name='Microsoft.Windows.Common-Controls' version='6.0.0.0' processorArchitecture='*' publicKeyToken='6595b64144ccf1df' language='*'\"")  // NOLINT(whitespace/line_length)
-#endif

src/xenia/base/main_win.h

@@ -0,0 +1,29 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2021 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#ifndef XENIA_BASE_MAIN_WIN_H_
+#define XENIA_BASE_MAIN_WIN_H_
+
+#include <string>
+#include <vector>
+
+namespace xe {
+
+// Functions for calling in both windowed and console entry points.
+bool ParseWin32LaunchArguments(
+    bool transparent_options, const std::string_view positional_usage,
+    const std::vector<std::string>& positional_options,
+    std::vector<std::string>* args_out);
+// InitializeWin32App uses cvars, call ParseWin32LaunchArguments before.
+int InitializeWin32App(const std::string_view app_name);
+void ShutdownWin32App();
+
+}  // namespace xe
+
+#endif  // XENIA_BASE_MAIN_WIN_H_

src/xenia/base/premake5.lua

@@ -11,7 +11,8 @@ project("xenia-base")
   defines({
   })
   local_platform_files()
-  removefiles({"main_*.cc"})
+  removefiles({"console_app_main_*.cc"})
+  removefiles({"main_init_*.cc"})
   files({
     "debug_visualizers.natvis",
   })

src/xenia/cpu/ppc/testing/ppc_testing_main.cc

@@ -7,10 +7,10 @@
  ******************************************************************************
  */
 
+#include "xenia/base/console_app_main.h"
 #include "xenia/base/cvar.h"
 #include "xenia/base/filesystem.h"
 #include "xenia/base/logging.h"
-#include "xenia/base/main.h"
 #include "xenia/base/math.h"
 #include "xenia/base/platform.h"
 #include "xenia/base/string_buffer.h"
@@ -483,5 +483,5 @@ int main(const std::vector<std::string>& args) {
 }  // namespace cpu
 }  // namespace xe
 
-DEFINE_ENTRY_POINT("xenia-cpu-ppc-test", xe::cpu::test::main, "[test name]",
+XE_DEFINE_CONSOLE_APP("xenia-cpu-ppc-test", xe::cpu::test::main, "[test name]",
-                   "test_name");
+                      "test_name");

src/xenia/cpu/ppc/testing/ppc_testing_native_main.cc

@@ -7,6 +7,8 @@
  ******************************************************************************
  */
 
+#include "xenia/base/console_app_main.h"
+#include "xenia/base/cvar.h"
 #include "xenia/base/filesystem.h"
 #include "xenia/base/logging.h"
 #include "xenia/base/main.h"
@@ -23,6 +25,7 @@ DEFINE_string(test_path, "src/xenia/cpu/ppc/testing/",
               "Directory scanned for test files.");
 DEFINE_string(test_bin_path, "src/xenia/cpu/ppc/testing/bin/",
               "Directory with binary outputs of the test files.");
+DEFINE_transient_string(test_name, "", "Test suite name.", "General");
 
 extern "C" void xe_call_native(void* context, void* fn);
 
@@ -505,19 +508,13 @@ bool RunTests(const std::wstring& test_name) {
   return failed_count ? false : true;
 }
 
-int main(const std::vector<std::wstring>& args) {
+int main(const std::vector<std::string>& args) {
-  // Grab test name, if present.
+  return RunTests(cvars::test_name) ? 0 : 1;
-  std::wstring test_name;
-  if (args.size() >= 2) {
-    test_name = args[1];
-  }
-
-  return RunTests(test_name) ? 0 : 1;
 }
 
 }  // namespace test
 }  // namespace cpu
 }  // namespace xe
 
-DEFINE_ENTRY_POINT(L"xenia-cpu-ppc-test", L"xenia-cpu-ppc-test [test name]",
+XE_DEFINE_CONSOLE_APP("xenia-cpu-ppc-test", xe::cpu::test::main, "[test name]",
-                   xe::cpu::test::main);
+                      "test_name");

src/xenia/cpu/ppc/testing/premake5.lua

@@ -17,7 +17,7 @@ project("xenia-cpu-ppc-tests")
   })
   files({
     "ppc_testing_main.cc",
-    "../../../base/main_"..platform_suffix..".cc",
+    "../../../base/console_app_main_"..platform_suffix..".cc",
   })
   files({
     "*.s",
@@ -46,7 +46,7 @@ project("xenia-cpu-ppc-nativetests")
   })
   files({
     "ppc_testing_native_main.cc",
-    "../../../base/main_"..platform_suffix..".cc",
+    "../../../base/console_app_main_"..platform_suffix..".cc",
   })
   files({
     "instr_*.s",

src/xenia/cpu/testing/sandbox_main.cc

@@ -7,7 +7,7 @@
  ******************************************************************************
  */
 
-#include "xenia/base/main.h"
+#include "xenia/base/console_app_main.h"
 #include "xenia/cpu/backend/x64/x64_backend.h"
 #include "xenia/cpu/cpu.h"
 #include "xenia/cpu/ppc/ppc_context.h"
@@ -23,10 +23,10 @@ using xe::cpu::ppc::PPCContext;
 
 // TODO(benvanik): simple memory? move more into core?
 
-int main(std::vector<std::wstring>& args) {
+int main(std::vector<std::string>& args) {
 #if XE_OPTION_PROFILING
   xe::Profiler::Initialize();
-  xe::Profiler::ThreadEnter("main");
+  xe::Profiler::ThreadEnter("Main");
 #endif  // XE_OPTION_PROFILING
 
   size_t memory_size = 16 * 1024 * 1024;
@@ -79,4 +79,4 @@ int main(std::vector<std::wstring>& args) {
 }  // namespace cpu
 }  // namespace xe
 
-DEFINE_ENTRY_POINT(L"xenia-cpu-sandbox", L"?", xe::cpu::sandbox::main);
+XE_DEFINE_CONSOLE_APP("xenia-cpu-sandbox", xe::cpu::sandbox::main, "");

src/xenia/cpu/testing/util.h

@@ -12,7 +12,6 @@
 
 #include <vector>
 
-#include "xenia/base/main.h"
 #include "xenia/cpu/backend/x64/x64_backend.h"
 #include "xenia/cpu/hir/hir_builder.h"
 #include "xenia/cpu/ppc/ppc_context.h"

src/xenia/debug/ui/debug_window.cc

@@ -32,6 +32,7 @@
 #include "xenia/kernel/xthread.h"
 #include "xenia/ui/graphics_provider.h"
 #include "xenia/ui/imgui_drawer.h"
+#include "xenia/ui/windowed_app_context.h"
 
 DEFINE_bool(imgui_debug, false, "Show ImGui debugging tools.", "UI");
 
@@ -50,11 +51,12 @@ using xe::ui::UIEvent;
 
 const std::string kBaseTitle = "Xenia Debugger";
 
-DebugWindow::DebugWindow(Emulator* emulator, xe::ui::Loop* loop)
+DebugWindow::DebugWindow(Emulator* emulator,
+                         xe::ui::WindowedAppContext& app_context)
     : emulator_(emulator),
       processor_(emulator->processor()),
-      loop_(loop),
+      app_context_(app_context),
-      window_(xe::ui::Window::Create(loop_, kBaseTitle)) {
+      window_(xe::ui::Window::Create(app_context_, kBaseTitle)) {
   if (cs_open(CS_ARCH_X86, CS_MODE_64, &capstone_handle_) != CS_ERR_OK) {
     assert_always("Failed to initialize capstone");
   }
@@ -63,16 +65,18 @@ DebugWindow::DebugWindow(Emulator* emulator, xe::ui::Loop* loop)
 }
 
 DebugWindow::~DebugWindow() {
-  loop_->PostSynchronous([this]() { window_.reset(); });
+  // Make sure pending functions referencing the DebugWindow are executed.
+  app_context_.ExecutePendingFunctionsFromUIThread();
 
   if (capstone_handle_) {
     cs_close(&capstone_handle_);
   }
 }
 
-std::unique_ptr<DebugWindow> DebugWindow::Create(Emulator* emulator,
+std::unique_ptr<DebugWindow> DebugWindow::Create(
-                                                 xe::ui::Loop* loop) {
+    Emulator* emulator, xe::ui::WindowedAppContext& app_context) {
-  std::unique_ptr<DebugWindow> debug_window(new DebugWindow(emulator, loop));
+  std::unique_ptr<DebugWindow> debug_window(
+      new DebugWindow(emulator, app_context));
   if (!debug_window->Initialize()) {
     xe::FatalError("Failed to initialize debug window");
     return nullptr;
@@ -87,8 +91,6 @@ bool DebugWindow::Initialize() {
     return false;
   }
 
-  loop_->on_quit.AddListener([this](UIEvent* e) { window_.reset(); });
-
   // Main menu.
   auto main_menu = MenuItem::Create(MenuItem::Type::kNormal);
   auto file_menu = MenuItem::Create(MenuItem::Type::kPopup, "&File");
@@ -1425,7 +1427,7 @@ void DebugWindow::UpdateCache() {
   auto kernel_state = emulator_->kernel_state();
   auto object_table = kernel_state->object_table();
 
-  loop_->Post([this]() {
+  app_context_.CallInUIThread([this]() {
     std::string title = kBaseTitle;
     switch (processor_->execution_state()) {
       case cpu::ExecutionState::kEnded:
@@ -1531,9 +1533,7 @@ Breakpoint* DebugWindow::LookupBreakpointAtAddress(
   }
 }
 
-void DebugWindow::OnFocus() {
+void DebugWindow::OnFocus() { Focus(); }
-  loop_->Post([this]() { window_->set_focus(true); });
-}
 
 void DebugWindow::OnDetached() {
   UpdateCache();
@@ -1546,30 +1546,34 @@ void DebugWindow::OnDetached() {
 
 void DebugWindow::OnExecutionPaused() {
   UpdateCache();
-  loop_->Post([this]() { window_->set_focus(true); });
+  Focus();
 }
 
 void DebugWindow::OnExecutionContinued() {
   UpdateCache();
-  loop_->Post([this]() { window_->set_focus(true); });
+  Focus();
 }
 
 void DebugWindow::OnExecutionEnded() {
   UpdateCache();
-  loop_->Post([this]() { window_->set_focus(true); });
+  Focus();
 }
 
 void DebugWindow::OnStepCompleted(cpu::ThreadDebugInfo* thread_info) {
   UpdateCache();
   SelectThreadStackFrame(thread_info, 0, true);
-  loop_->Post([this]() { window_->set_focus(true); });
+  Focus();
 }
 
 void DebugWindow::OnBreakpointHit(Breakpoint* breakpoint,
                                   cpu::ThreadDebugInfo* thread_info) {
   UpdateCache();
   SelectThreadStackFrame(thread_info, 0, true);
-  loop_->Post([this]() { window_->set_focus(true); });
+  Focus();
+}
+
+void DebugWindow::Focus() const {
+  app_context_.CallInUIThread([this]() { window_->set_focus(true); });
 }
 
 }  // namespace ui

src/xenia/debug/ui/debug_window.h

@@ -18,9 +18,9 @@
 #include "xenia/cpu/debug_listener.h"
 #include "xenia/cpu/processor.h"
 #include "xenia/emulator.h"
-#include "xenia/ui/loop.h"
 #include "xenia/ui/menu_item.h"
 #include "xenia/ui/window.h"
+#include "xenia/ui/windowed_app_context.h"
 #include "xenia/xbox.h"
 
 namespace xe {
@@ -31,11 +31,11 @@ class DebugWindow : public cpu::DebugListener {
  public:
   ~DebugWindow();
 
-  static std::unique_ptr<DebugWindow> Create(Emulator* emulator,
+  static std::unique_ptr<DebugWindow> Create(
-                                             xe::ui::Loop* loop);
+      Emulator* emulator, xe::ui::WindowedAppContext& app_context);
 
   Emulator* emulator() const { return emulator_; }
-  xe::ui::Loop* loop() const { return loop_; }
+  xe::ui::WindowedAppContext& app_context() const { return app_context_; }
   xe::ui::Window* window() const { return window_.get(); }
 
   void OnFocus() override;
@@ -48,7 +48,8 @@ class DebugWindow : public cpu::DebugListener {
                        cpu::ThreadDebugInfo* thread_info) override;
 
  private:
-  explicit DebugWindow(Emulator* emulator, xe::ui::Loop* loop);
+  explicit DebugWindow(Emulator* emulator,
+                       xe::ui::WindowedAppContext& app_context);
   bool Initialize();
 
   void DrawFrame();
@@ -86,9 +87,11 @@ class DebugWindow : public cpu::DebugListener {
   cpu::Breakpoint* LookupBreakpointAtAddress(
       cpu::Breakpoint::AddressType address_type, uint64_t address);
 
+  void Focus() const;
+
   Emulator* emulator_ = nullptr;
   cpu::Processor* processor_ = nullptr;
-  xe::ui::Loop* loop_ = nullptr;
+  xe::ui::WindowedAppContext& app_context_;
   std::unique_ptr<xe::ui::Window> window_;
   uint64_t last_draw_tick_count_ = 0;
 

src/xenia/emulator.cc

@@ -40,6 +40,8 @@
 #include "xenia/kernel/xboxkrnl/xboxkrnl_module.h"
 #include "xenia/memory.h"
 #include "xenia/ui/imgui_dialog.h"
+#include "xenia/ui/window.h"
+#include "xenia/ui/windowed_app_context.h"
 #include "xenia/vfs/devices/disc_image_device.h"
 #include "xenia/vfs/devices/host_path_device.h"
 #include "xenia/vfs/devices/null_device.h"
@@ -233,7 +235,7 @@ X_STATUS Emulator::Setup(
 
   if (display_window_) {
     // Finish initializing the display.
-    display_window_->loop()->PostSynchronous([this]() {
+    display_window_->app_context().CallInUIThreadSynchronous([this]() {
       xe::ui::GraphicsContextLock context_lock(display_window_->context());
       Profiler::set_window(display_window_);
     });
@@ -583,7 +585,7 @@ bool Emulator::ExceptionCallback(Exception* ex) {
   }
 
   // Display a dialog telling the user the guest has crashed.
-  display_window()->loop()->PostSynchronous([&]() {
+  display_window()->app_context().CallInUIThreadSynchronous([this]() {
     xe::ui::ImGuiDialog::ShowMessageBox(
         display_window(), "Uh-oh!",
         "The guest has crashed.\n\n"

src/xenia/gpu/d3d12/d3d12_graphics_system.cc

@@ -49,7 +49,7 @@ std::string D3D12GraphicsSystem::name() const {
 X_STATUS D3D12GraphicsSystem::Setup(cpu::Processor* processor,
                                     kernel::KernelState* kernel_state,
                                     ui::Window* target_window) {
-  provider_ = xe::ui::d3d12::D3D12Provider::Create(target_window);
+  provider_ = xe::ui::d3d12::D3D12Provider::Create();
   auto d3d12_provider = static_cast<xe::ui::d3d12::D3D12Provider*>(provider());
   auto device = d3d12_provider->GetDevice();
 

src/xenia/gpu/d3d12/d3d12_trace_dump_main.cc

@@ -7,8 +7,8 @@
  ******************************************************************************
  */
 
+#include "xenia/base/console_app_main.h"
 #include "xenia/base/logging.h"
-#include "xenia/base/main.h"
 #include "xenia/gpu/d3d12/d3d12_command_processor.h"
 #include "xenia/gpu/d3d12/d3d12_graphics_system.h"
 #include "xenia/gpu/trace_dump.h"
@@ -54,6 +54,6 @@ int trace_dump_main(const std::vector<std::string>& args) {
 }  // namespace gpu
 }  // namespace xe
 
-DEFINE_ENTRY_POINT("xenia-gpu-d3d12-trace-dump",
+XE_DEFINE_CONSOLE_APP("xenia-gpu-d3d12-trace-dump",
-                   xe::gpu::d3d12::trace_dump_main, "some.trace",
+                      xe::gpu::d3d12::trace_dump_main, "some.trace",
-                   "target_trace_file");
+                      "target_trace_file");

src/xenia/gpu/d3d12/d3d12_trace_viewer_main.cc

@@ -2,13 +2,15 @@
  ******************************************************************************
  * Xenia : Xbox 360 Emulator Research Project                                 *
  ******************************************************************************
- * Copyright 2020 Ben Vanik. All rights reserved.                             *
+ * Copyright 2021 Ben Vanik. All rights reserved.                             *
  * Released under the BSD license - see LICENSE in the root for more details. *
  ******************************************************************************
  */
 
+#include <memory>
+#include <string>
+
 #include "xenia/base/logging.h"
-#include "xenia/base/main.h"
 #include "xenia/gpu/d3d12/d3d12_command_processor.h"
 #include "xenia/gpu/d3d12/d3d12_graphics_system.h"
 #include "xenia/gpu/trace_viewer.h"
@@ -17,10 +19,13 @@ namespace xe {
 namespace gpu {
 namespace d3d12 {
 
-using namespace xe::gpu::xenos;
+class D3D12TraceViewer final : public TraceViewer {
-
-class D3D12TraceViewer : public TraceViewer {
  public:
+  static std::unique_ptr<WindowedApp> Create(
+      xe::ui::WindowedAppContext& app_context) {
+    return std::unique_ptr<WindowedApp>(new D3D12TraceViewer(app_context));
+  }
+
   std::unique_ptr<gpu::GraphicsSystem> CreateGraphicsSystem() override {
     return std::unique_ptr<gpu::GraphicsSystem>(new D3D12GraphicsSystem());
   }
@@ -45,17 +50,15 @@ class D3D12TraceViewer : public TraceViewer {
     // TextureInfo/SamplerInfo which are going away.
     return 0;
   }
-};
 
-int trace_viewer_main(const std::vector<std::string>& args) {
+ private:
-  D3D12TraceViewer trace_viewer;
+  explicit D3D12TraceViewer(xe::ui::WindowedAppContext& app_context)
-  return trace_viewer.Main(args);
+      : TraceViewer(app_context, "xenia-gpu-d3d12-trace-viewer") {}
-}
+};
 
 }  // namespace d3d12
 }  // namespace gpu
 }  // namespace xe
 
-DEFINE_ENTRY_POINT("xenia-gpu-d3d12-trace-viewer",
+XE_DEFINE_WINDOWED_APP(xenia_gpu_d3d12_trace_viewer,
-                   xe::gpu::d3d12::trace_viewer_main, "some.trace",
+                       xe::gpu::d3d12::D3D12TraceViewer::Create);
-                   "target_trace_file");

src/xenia/gpu/d3d12/premake5.lua

@@ -54,7 +54,7 @@ project("xenia-gpu-d3d12-trace-viewer")
   })
   files({
     "d3d12_trace_viewer_main.cc",
-    "../../base/main_"..platform_suffix..".cc",
+    "../../ui/windowed_app_main_"..platform_suffix..".cc",
   })
   -- Only create the .user file if it doesn't already exist.
   local user_file = project_root.."/build/xenia-gpu-d3d12-trace-viewer.vcxproj.user"
@@ -101,7 +101,7 @@ project("xenia-gpu-d3d12-trace-dump")
   })
   files({
     "d3d12_trace_dump_main.cc",
-    "../../base/main_"..platform_suffix..".cc",
+    "../../base/console_app_main_"..platform_suffix..".cc",
   })
   -- Only create the .user file if it doesn't already exist.
   local user_file = project_root.."/build/xenia-gpu-d3d12-trace-dump.vcxproj.user"

src/xenia/gpu/graphics_system.cc

@@ -18,7 +18,8 @@
 #include "xenia/gpu/command_processor.h"
 #include "xenia/gpu/gpu_flags.h"
 #include "xenia/ui/graphics_provider.h"
-#include "xenia/ui/loop.h"
+#include "xenia/ui/window.h"
+#include "xenia/ui/windowed_app_context.h"
 
 DEFINE_bool(
     store_shaders, true,
@@ -57,22 +58,24 @@ X_STATUS GraphicsSystem::Setup(cpu::Processor* processor,
   // This must happen on the UI thread.
   std::unique_ptr<xe::ui::GraphicsContext> processor_context = nullptr;
   if (provider_) {
-    if (target_window_) {
+    // Setup the context the command processor will do all its drawing in.
-      target_window_->loop()->PostSynchronous([&]() {
+    bool contexts_initialized = true;
-        // Create the context used for presentation.
+    processor_context = provider()->CreateOffscreenContext();
-        assert_null(target_window->context());
+    if (processor_context) {
-        target_window_->set_context(provider_->CreateContext(target_window_));
+      if (target_window_) {
-
+        if (!target_window_->app_context().CallInUIThreadSynchronous([&]() {
-        // Setup the context the command processor will do all its drawing in.
+              // Create the context used for presentation.
-        // It's shared with the display context so that we can resolve
+              assert_null(target_window->context());
-        // framebuffers from it.
+              target_window_->set_context(
-        processor_context = provider()->CreateOffscreenContext();
+                  provider_->CreateContext(target_window_));
-      });
+            })) {
+          contexts_initialized = false;
+        }
+      }
     } else {
-      processor_context = provider()->CreateOffscreenContext();
+      contexts_initialized = false;
     }
-
+    if (!contexts_initialized) {
-    if (!processor_context) {
       xe::FatalError(
           "Unable to initialize graphics context. Xenia requires Vulkan "
           "support.\n"

src/xenia/gpu/null/null_graphics_system.cc

@@ -26,7 +26,7 @@ X_STATUS NullGraphicsSystem::Setup(cpu::Processor* processor,
                                    ui::Window* target_window) {
   // This is a null graphics system, but we still setup vulkan because UI needs
   // it through us :|
-  provider_ = xe::ui::vulkan::VulkanProvider::Create(target_window);
+  provider_ = xe::ui::vulkan::VulkanProvider::Create();
 
   return GraphicsSystem::Setup(processor, kernel_state, target_window);
 }

src/xenia/gpu/premake5.lua

@@ -45,7 +45,7 @@ project("xenia-gpu-shader-compiler")
   })
   files({
     "shader_compiler_main.cc",
-    "../base/main_"..platform_suffix..".cc",
+    "../base/console_app_main_"..platform_suffix..".cc",
   })
 
   filter("platforms:Windows")

src/xenia/gpu/shader_compiler_main.cc

@@ -13,9 +13,9 @@
 #include <vector>
 
 #include "xenia/base/assert.h"
+#include "xenia/base/console_app_main.h"
 #include "xenia/base/cvar.h"
 #include "xenia/base/logging.h"
-#include "xenia/base/main.h"
 #include "xenia/base/platform.h"
 #include "xenia/base/string.h"
 #include "xenia/base/string_buffer.h"
@@ -229,5 +229,6 @@ int shader_compiler_main(const std::vector<std::string>& args) {
 }  // namespace gpu
 }  // namespace xe
 
-DEFINE_ENTRY_POINT("xenia-gpu-shader-compiler", xe::gpu::shader_compiler_main,
+XE_DEFINE_CONSOLE_APP("xenia-gpu-shader-compiler",
-                   "shader.bin", "shader_input");
+                      xe::gpu::shader_compiler_main, "shader.bin",
+                      "shader_input");

src/xenia/gpu/trace_dump.cc

@@ -100,7 +100,7 @@ bool TraceDump::Setup() {
     return false;
   }
   graphics_system_ = emulator_->graphics_system();
-  player_ = std::make_unique<TracePlayer>(nullptr, graphics_system_);
+  player_ = std::make_unique<TracePlayer>(graphics_system_);
   return true;
 }
 

src/xenia/gpu/trace_player.cc

@@ -17,9 +17,8 @@
 namespace xe {
 namespace gpu {
 
-TracePlayer::TracePlayer(xe::ui::Loop* loop, GraphicsSystem* graphics_system)
+TracePlayer::TracePlayer(GraphicsSystem* graphics_system)
-    : loop_(loop),
+    : graphics_system_(graphics_system),
-      graphics_system_(graphics_system),
       current_frame_index_(0),
       current_command_index_(-1) {
   // Need to allocate all of physical memory so that we can write to it during

src/xenia/gpu/trace_player.h

@@ -16,7 +16,6 @@
 #include "xenia/base/threading.h"
 #include "xenia/gpu/trace_protocol.h"
 #include "xenia/gpu/trace_reader.h"
-#include "xenia/ui/loop.h"
 
 namespace xe {
 namespace gpu {
@@ -30,7 +29,7 @@ enum class TracePlaybackMode {
 
 class TracePlayer : public TraceReader {
  public:
-  TracePlayer(xe::ui::Loop* loop, GraphicsSystem* graphics_system);
+  TracePlayer(GraphicsSystem* graphics_system);
   ~TracePlayer() override;
 
   GraphicsSystem* graphics_system() const { return graphics_system_; }
@@ -54,7 +53,6 @@ class TracePlayer : public TraceReader {
   void PlayTraceOnThread(const uint8_t* trace_data, size_t trace_size,
                          TracePlaybackMode playback_mode, bool clear_caches);
 
-  xe::ui::Loop* loop_;
   GraphicsSystem* graphics_system_;
   int current_frame_index_;
   int current_command_index_;

src/xenia/gpu/trace_viewer.cc

@@ -2,7 +2,7 @@
  ******************************************************************************
  * Xenia : Xbox 360 Emulator Research Project                                 *
  ******************************************************************************
- * Copyright 2020 Ben Vanik. All rights reserved.                             *
+ * Copyright 2021 Ben Vanik. All rights reserved.                             *
  * Released under the BSD license - see LICENSE in the root for more details. *
  ******************************************************************************
  */
@@ -13,10 +13,12 @@
 
 #include "third_party/half/include/half.hpp"
 #include "third_party/imgui/imgui.h"
+#include "xenia/base/assert.h"
 #include "xenia/base/clock.h"
 #include "xenia/base/logging.h"
 #include "xenia/base/math.h"
 #include "xenia/base/string.h"
+#include "xenia/base/system.h"
 #include "xenia/base/threading.h"
 #include "xenia/gpu/command_processor.h"
 #include "xenia/gpu/gpu_flags.h"
@@ -30,6 +32,7 @@
 #include "xenia/ui/imgui_drawer.h"
 #include "xenia/ui/virtual_key.h"
 #include "xenia/ui/window.h"
+#include "xenia/ui/windowed_app_context.h"
 #include "xenia/xbox.h"
 
 DEFINE_path(target_trace_file, "", "Specifies the trace file to load.", "GPU");
@@ -46,22 +49,16 @@ static const ImVec4 kColorComment =
 static const ImVec4 kColorIgnored =
     ImVec4(100 / 255.0f, 100 / 255.0f, 100 / 255.0f, 255 / 255.0f);
 
-TraceViewer::TraceViewer() = default;
+TraceViewer::TraceViewer(xe::ui::WindowedAppContext& app_context,
+                         const std::string_view name)
+    : xe::ui::WindowedApp(app_context, name, "some.trace") {
+  AddPositionalOption("target_trace_file");
+}
 
 TraceViewer::~TraceViewer() = default;
 
-int TraceViewer::Main(const std::vector<std::string>& args) {
+bool TraceViewer::OnInitialize() {
-  // Grab path from the flag or unnamed argument.
+  std::filesystem::path path = cvars::target_trace_file;
-  std::filesystem::path path;
-  if (!cvars::target_trace_file.empty()) {
-    // Passed as a named argument.
-    // TODO(benvanik): find something better than gflags that supports
-    // unicode.
-    path = cvars::target_trace_file;
-  } else if (args.size() >= 2) {
-    // Passed as an unnamed argument.
-    path = xe::to_path(args[1]);
-  }
 
   // If no path passed, ask the user.
   if (path.empty()) {
@@ -83,42 +80,37 @@ int TraceViewer::Main(const std::vector<std::string>& args) {
   }
 
   if (path.empty()) {
-    xe::FatalError("No trace file specified");
+    xe::ShowSimpleMessageBox(xe::SimpleMessageBoxType::Warning,
-    return 1;
+                             "No trace file specified");
+    return false;
   }
 
   // Normalize the path and make absolute.
   auto abs_path = std::filesystem::absolute(path);
 
   if (!Setup()) {
-    xe::FatalError("Unable to setup trace viewer");
+    xe::ShowSimpleMessageBox(xe::SimpleMessageBoxType::Error,
-    return 1;
+                             "Unable to setup trace viewer");
+    return false;
   }
   if (!Load(std::move(abs_path))) {
-    xe::FatalError("Unable to load trace file; not found?");
+    xe::ShowSimpleMessageBox(xe::SimpleMessageBoxType::Error,
-    return 1;
+                             "Unable to load trace file; not found?");
+    return false;
   }
-  Run();
+  return true;
-  return 0;
 }
 
 bool TraceViewer::Setup() {
   // Main display window.
-  loop_ = ui::Loop::Create();
+  assert_true(app_context().IsInUIThread());
-  window_ = xe::ui::Window::Create(loop_.get(), "xenia-gpu-trace-viewer");
+  window_ = xe::ui::Window::Create(app_context(), "xenia-gpu-trace-viewer");
-  loop_->PostSynchronous([&]() {
+  if (!window_->Initialize()) {
-    xe::threading::set_name("Win32 Loop");
+    XELOGE("Failed to initialize main window");
-    if (!window_->Initialize()) {
+    return false;
-      xe::FatalError("Failed to initialize main window");
+  }
-      return;
+  window_->on_closed.AddListener(
-    }
+      [this](xe::ui::UIEvent* e) { app_context().QuitFromUIThread(); });
-  });
-  window_->on_closed.AddListener([&](xe::ui::UIEvent* e) {
-    loop_->Quit();
-    XELOGI("User-initiated death!");
-    exit(1);
-  });
-  loop_->on_quit.AddListener([&](xe::ui::UIEvent* e) { window_.reset(); });
   window_->Resize(1920, 1200);
 
   // Create the emulator but don't initialize so we can setup the window.
@@ -142,9 +134,9 @@ bool TraceViewer::Setup() {
     }
   });
 
-  player_ = std::make_unique<TracePlayer>(loop_.get(), graphics_system_);
+  player_ = std::make_unique<TracePlayer>(graphics_system_);
 
-  window_->on_painting.AddListener([&](xe::ui::UIEvent* e) {
+  window_->on_painting.AddListener([this](xe::ui::UIEvent* e) {
     DrawUI();
 
     // Continuous paint.
@@ -167,16 +159,6 @@ bool TraceViewer::Load(const std::filesystem::path& trace_file_path) {
   return true;
 }
 
-void TraceViewer::Run() {
-  // Wait until we are exited.
-  loop_->AwaitQuit();
-
-  player_.reset();
-  emulator_.reset();
-  window_.reset();
-  loop_.reset();
-}
-
 void TraceViewer::DrawMultilineString(const std::string_view str) {
   size_t i = 0;
   bool done = false;

src/xenia/gpu/trace_viewer.h

@@ -2,7 +2,7 @@
  ******************************************************************************
  * Xenia : Xbox 360 Emulator Research Project                                 *
  ******************************************************************************
- * Copyright 2020 Ben Vanik. All rights reserved.                             *
+ * Copyright 2021 Ben Vanik. All rights reserved.                             *
  * Released under the BSD license - see LICENSE in the root for more details. *
  ******************************************************************************
  */
@@ -18,13 +18,8 @@
 #include "xenia/gpu/trace_protocol.h"
 #include "xenia/gpu/xenos.h"
 #include "xenia/memory.h"
-
+#include "xenia/ui/window.h"
-namespace xe {
+#include "xenia/ui/windowed_app.h"
-namespace ui {
-class Loop;
-class Window;
-}  // namespace ui
-}  // namespace xe
 
 namespace xe {
 namespace gpu {
@@ -32,14 +27,15 @@ namespace gpu {
 struct SamplerInfo;
 struct TextureInfo;
 
-class TraceViewer {
+class TraceViewer : public xe::ui::WindowedApp {
  public:
   virtual ~TraceViewer();
 
-  int Main(const std::vector<std::string>& args);
+  bool OnInitialize() override;
 
  protected:
-  TraceViewer();
+  explicit TraceViewer(xe::ui::WindowedAppContext& app_context,
+                       const std::string_view name);
 
   virtual std::unique_ptr<gpu::GraphicsSystem> CreateGraphicsSystem() = 0;
 
@@ -60,7 +56,6 @@ class TraceViewer {
 
   virtual bool Setup();
 
-  std::unique_ptr<xe::ui::Loop> loop_;
   std::unique_ptr<xe::ui::Window> window_;
   std::unique_ptr<Emulator> emulator_;
   Memory* memory_ = nullptr;
@@ -75,7 +70,6 @@ class TraceViewer {
   };
 
   bool Load(const std::filesystem::path& trace_file_path);
-  void Run();
 
   void DrawUI();
   void DrawControllerUI();

src/xenia/gpu/vulkan/premake5.lua

@@ -62,7 +62,7 @@ project("xenia-gpu-vulkan-trace-viewer")
   })
   files({
     "vulkan_trace_viewer_main.cc",
-    "../../base/main_"..platform_suffix..".cc",
+    "../../ui/windowed_app_main_"..platform_suffix..".cc",
   })
 
   filter("platforms:Linux")
@@ -128,7 +128,7 @@ project("xenia-gpu-vulkan-trace-dump")
   })
   files({
     "vulkan_trace_dump_main.cc",
-    "../../base/main_"..platform_suffix..".cc",
+    "../../base/console_app_main_"..platform_suffix..".cc",
   })
 
   filter("platforms:Linux")

src/xenia/gpu/vulkan/vulkan_graphics_system.cc

@@ -37,7 +37,7 @@ X_STATUS VulkanGraphicsSystem::Setup(cpu::Processor* processor,
                                      kernel::KernelState* kernel_state,
                                      ui::Window* target_window) {
   // Must create the provider so we can create contexts.
-  auto provider = xe::ui::vulkan::VulkanProvider::Create(target_window);
+  auto provider = xe::ui::vulkan::VulkanProvider::Create();
   device_ = provider->device();
   provider_ = std::move(provider);
 

src/xenia/gpu/vulkan/vulkan_trace_dump_main.cc

@@ -7,8 +7,8 @@
  ******************************************************************************
  */
 
+#include "xenia/base/console_app_main.h"
 #include "xenia/base/logging.h"
-#include "xenia/base/main.h"
 #include "xenia/gpu/trace_dump.h"
 #include "xenia/gpu/vulkan/vulkan_command_processor.h"
 #include "xenia/gpu/vulkan/vulkan_graphics_system.h"
@@ -55,6 +55,6 @@ int trace_dump_main(const std::vector<std::string>& args) {
 }  // namespace gpu
 }  // namespace xe
 
-DEFINE_ENTRY_POINT("xenia-gpu-vulkan-trace-dump",
+XE_DEFINE_CONSOLE_APP("xenia-gpu-vulkan-trace-dump",
-                   xe::gpu::vulkan::trace_dump_main, "some.trace",
+                      xe::gpu::vulkan::trace_dump_main, "some.trace",
-                   "target_trace_file");
+                      "target_trace_file");

src/xenia/gpu/vulkan/vulkan_trace_viewer_main.cc

@@ -2,13 +2,15 @@
  ******************************************************************************
  * Xenia : Xbox 360 Emulator Research Project                                 *
  ******************************************************************************
- * Copyright 2020 Ben Vanik. All rights reserved.                             *
+ * Copyright 2021 Ben Vanik. All rights reserved.                             *
  * Released under the BSD license - see LICENSE in the root for more details. *
  ******************************************************************************
  */
 
+#include <memory>
+#include <string>
+
 #include "xenia/base/logging.h"
-#include "xenia/base/main.h"
 #include "xenia/gpu/trace_viewer.h"
 #include "xenia/gpu/vulkan/vulkan_command_processor.h"
 #include "xenia/gpu/vulkan/vulkan_graphics_system.h"
@@ -19,8 +21,13 @@ namespace vulkan {
 
 using namespace xe::gpu::xenos;
 
-class VulkanTraceViewer : public TraceViewer {
+class VulkanTraceViewer final : public TraceViewer {
  public:
+  static std::unique_ptr<WindowedApp> Create(
+      xe::ui::WindowedAppContext& app_context) {
+    return std::unique_ptr<WindowedApp>(new VulkanTraceViewer(app_context));
+  }
+
   std::unique_ptr<gpu::GraphicsSystem> CreateGraphicsSystem() override {
     return std::unique_ptr<gpu::GraphicsSystem>(new VulkanGraphicsSystem());
   }
@@ -60,17 +67,15 @@ class VulkanTraceViewer : public TraceViewer {
     // return static_cast<uintptr_t>(texture->handle);
     return 0;
   }
-};
 
-int trace_viewer_main(const std::vector<std::string>& args) {
+ private:
-  VulkanTraceViewer trace_viewer;
+  explicit VulkanTraceViewer(xe::ui::WindowedAppContext& app_context)
-  return trace_viewer.Main(args);
+      : TraceViewer(app_context, "xenia-gpu-vulkan-trace-viewer") {}
-}
+};
 
 }  // namespace vulkan
 }  // namespace gpu
 }  // namespace xe
 
-DEFINE_ENTRY_POINT("xenia-gpu-vulkan-trace-viewer",
+XE_DEFINE_WINDOWED_APP(xenia_gpu_vulkan_trace_viewer,
-                   xe::gpu::vulkan::trace_viewer_main, "some.trace",
+                       xe::gpu::vulkan::VulkanTraceViewer::Create);
-                   "target_trace_file");

src/xenia/hid/hid_demo.cc

@@ -10,15 +10,17 @@
 #include <array>
 #include <cstring>
 #include <forward_list>
+#include <memory>
+#include <string>
 #include <tuple>
 #include <unordered_map>
+#include <vector>
 
 #include "third_party/fmt/include/fmt/format.h"
 #include "third_party/imgui/imgui.h"
 #include "xenia/base/clock.h"
 #include "xenia/base/cvar.h"
 #include "xenia/base/logging.h"
-#include "xenia/base/main.h"
 #include "xenia/base/threading.h"
 #include "xenia/hid/hid_flags.h"
 #include "xenia/hid/input_system.h"
@@ -26,6 +28,7 @@
 #include "xenia/ui/virtual_key.h"
 #include "xenia/ui/vulkan/vulkan_provider.h"
 #include "xenia/ui/window.h"
+#include "xenia/ui/windowed_app.h"
 
 // Available input drivers:
 #include "xenia/hid/nop/nop_hid.h"
@@ -46,10 +49,36 @@ DEFINE_string(hid, "any", "Input system. Use: [any, nop, sdl, winkey, xinput]",
 namespace xe {
 namespace hid {
 
-std::unique_ptr<xe::hid::InputSystem> input_system_;
+class HidDemoApp final : public ui::WindowedApp {
-bool is_active = true;
+ public:
+  static std::unique_ptr<ui::WindowedApp> Create(
+      ui::WindowedAppContext& app_context) {
+    return std::unique_ptr<ui::WindowedApp>(new HidDemoApp(app_context));
+  }
 
-std::vector<std::unique_ptr<hid::InputDriver>> CreateInputDrivers(
+  bool OnInitialize() override;
+
+ private:
+  explicit HidDemoApp(ui::WindowedAppContext& app_context)
+      : ui::WindowedApp(app_context, "xenia-hid-demo") {}
+
+  static std::vector<std::unique_ptr<hid::InputDriver>> CreateInputDrivers(
+      ui::Window* window);
+
+  void DrawUserInputGetState(uint32_t user_index) const;
+  void DrawInputGetState() const;
+  void DrawUserInputGetKeystroke(uint32_t user_index, bool poll,
+                                 bool hide_repeats, bool clear_log) const;
+  void DrawInputGetKeystroke(bool poll, bool hide_repeats,
+                             bool clear_log) const;
+
+  std::unique_ptr<ui::GraphicsProvider> graphics_provider_;
+  std::unique_ptr<ui::Window> window_;
+  std::unique_ptr<InputSystem> input_system_;
+  bool is_active_ = true;
+};
+
+std::vector<std::unique_ptr<hid::InputDriver>> HidDemoApp::CreateInputDrivers(
     ui::Window* window) {
   std::vector<std::unique_ptr<hid::InputDriver>> drivers;
   if (cvars::hid.compare("nop") == 0) {
@@ -94,60 +123,46 @@ std::vector<std::unique_ptr<hid::InputDriver>> CreateInputDrivers(
   return drivers;
 }
 
-std::unique_ptr<xe::ui::GraphicsProvider> CreateDemoGraphicsProvider(
+bool HidDemoApp::OnInitialize() {
-    xe::ui::Window* window) {
+  // Create graphics provider that provides the context for the window.
-  return xe::ui::vulkan::VulkanProvider::Create(window);
+  graphics_provider_ = xe::ui::vulkan::VulkanProvider::Create();
-}
+  if (!graphics_provider_) {
+    return false;
+  }
 
-void DrawInputGetState();
+  // Create the window.
-void DrawInputGetKeystroke(bool poll, bool hide_repeats, bool clear_log);
+  window_ = xe::ui::Window::Create(app_context(), GetName());
-
+  if (!window_->Initialize()) {
-int hid_demo_main(const std::vector<std::string>& args) {
+    XELOGE("Failed to initialize main window");
-  // Create run loop and the window.
+    return false;
-  auto loop = ui::Loop::Create();
+  }
-  auto window = xe::ui::Window::Create(loop.get(), GetEntryInfo().name);
+  window_->on_closed.AddListener([this](xe::ui::UIEvent* e) {
-  loop->PostSynchronous([&window]() {
-    xe::threading::set_name("Win32 Loop");
-    if (!window->Initialize()) {
-      FatalError("Failed to initialize main window");
-      return;
-    }
-  });
-  window->on_closed.AddListener([&loop](xe::ui::UIEvent* e) {
-    loop->Quit();
     XELOGI("User-initiated death!");
-    exit(1);
+    app_context().QuitFromUIThread();
   });
-  loop->on_quit.AddListener([&window](xe::ui::UIEvent* e) { window.reset(); });
 
   // Initial size setting, done here so that it knows the menu exists.
-  window->Resize(COL_WIDTH_STATE + COL_WIDTH_STROKE, ROW_HEIGHT_GENERAL + 500);
+  window_->Resize(COL_WIDTH_STATE + COL_WIDTH_STROKE, ROW_HEIGHT_GENERAL + 500);
 
-  // Create the graphics context used for drawing and setup the window.
+  // Create the graphics context for the window. The window will finish
-  std::unique_ptr<xe::ui::GraphicsProvider> graphics_provider;
+  // initialization with the context (loading resources, etc).
-  loop->PostSynchronous([&window, &graphics_provider]() {
+  window_->set_context(graphics_provider_->CreateContext(window_.get()));
-    // Create context and give it to the window.
-    // The window will finish initialization wtih the context (loading
-    // resources, etc).
-    graphics_provider = CreateDemoGraphicsProvider(window.get());
-    window->set_context(graphics_provider->CreateContext(window.get()));
 
-    // Initialize input system and all drivers.
+  // Initialize input system and all drivers.
-    input_system_ = std::make_unique<xe::hid::InputSystem>(window.get());
+  input_system_ = std::make_unique<xe::hid::InputSystem>(window_.get());
-    auto drivers = CreateInputDrivers(window.get());
+  auto drivers = CreateInputDrivers(window_.get());
-    for (size_t i = 0; i < drivers.size(); ++i) {
+  for (size_t i = 0; i < drivers.size(); ++i) {
-      auto& driver = drivers[i];
+    auto& driver = drivers[i];
-      driver->set_is_active_callback([]() -> bool { return is_active; });
+    driver->set_is_active_callback([this]() -> bool { return is_active_; });
-      input_system_->AddDriver(std::move(driver));
+    input_system_->AddDriver(std::move(driver));
-    }
+  }
 
-    window->Invalidate();
+  window_->Invalidate();
-  });
 
-  window->set_imgui_input_enabled(true);
+  window_->set_imgui_input_enabled(true);
 
-  window->on_painting.AddListener([&](xe::ui::UIEvent* e) {
+  window_->on_painting.AddListener([this](xe::ui::UIEvent* e) {
-    auto& io = window->imgui_drawer()->GetIO();
+    auto& io = window_->imgui_drawer()->GetIO();
 
     const ImGuiWindowFlags wflags =
         ImGuiWindowFlags_NoResize | ImGuiWindowFlags_NoMove |
@@ -161,7 +176,7 @@ int hid_demo_main(const std::vector<std::string>& args) {
           ImVec2(COL_WIDTH_STATE + COL_WIDTH_STROKE, ROW_HEIGHT_GENERAL));
 
       ImGui::Text("Input System (hid) = \"%s\"", cvars::hid.c_str());
-      ImGui::Checkbox("is_active", &is_active);
+      ImGui::Checkbox("is_active", &is_active_);
     }
     ImGui::End();
 
@@ -201,21 +216,13 @@ int hid_demo_main(const std::vector<std::string>& args) {
     ImGui::End();
 
     // Continuous paint.
-    window->Invalidate();
+    window_->Invalidate();
   });
 
-  // Wait until we are exited.
+  return true;
-  loop->AwaitQuit();
-
-  input_system_.reset();
-
-  loop->PostSynchronous([&graphics_provider]() { graphics_provider.reset(); });
-  window.reset();
-  loop.reset();
-  return 0;
 }
 
-void DrawUserInputGetState(uint32_t user_index) {
+void HidDemoApp::DrawUserInputGetState(uint32_t user_index) const {
   ImGui::Text("User %u:", user_index);
 
   X_INPUT_STATE state;
@@ -274,7 +281,7 @@ void DrawUserInputGetState(uint32_t user_index) {
   ImGui::Text(" ");
 }
 
-void DrawInputGetState() {
+void HidDemoApp::DrawInputGetState() const {
   ImGui::BeginChild("##input_get_state_scroll");
   for (uint32_t user_index = 0; user_index < MAX_USERS; ++user_index) {
     DrawUserInputGetState(user_index);
@@ -282,46 +289,48 @@ void DrawInputGetState() {
   ImGui::EndChild();
 }
 
-static const std::unordered_map<ui::VirtualKey, const std::string> kVkPretty = {
+void HidDemoApp::DrawUserInputGetKeystroke(uint32_t user_index, bool poll,
-    {ui::VirtualKey::kXInputPadA, "A"},
+                                           bool hide_repeats,
-    {ui::VirtualKey::kXInputPadB, "B"},
+                                           bool clear_log) const {
-    {ui::VirtualKey::kXInputPadX, "X"},
+  static const std::unordered_map<ui::VirtualKey, const std::string> kVkPretty =
-    {ui::VirtualKey::kXInputPadY, "Y"},
+      {
-    {ui::VirtualKey::kXInputPadRShoulder, "R Shoulder"},
+          {ui::VirtualKey::kXInputPadA, "A"},
-    {ui::VirtualKey::kXInputPadLShoulder, "L Shoulder"},
+          {ui::VirtualKey::kXInputPadB, "B"},
-    {ui::VirtualKey::kXInputPadLTrigger, "L Trigger"},
+          {ui::VirtualKey::kXInputPadX, "X"},
-    {ui::VirtualKey::kXInputPadRTrigger, "R Trigger"},
+          {ui::VirtualKey::kXInputPadY, "Y"},
+          {ui::VirtualKey::kXInputPadRShoulder, "R Shoulder"},
+          {ui::VirtualKey::kXInputPadLShoulder, "L Shoulder"},
+          {ui::VirtualKey::kXInputPadLTrigger, "L Trigger"},
+          {ui::VirtualKey::kXInputPadRTrigger, "R Trigger"},
 
-    {ui::VirtualKey::kXInputPadDpadUp, "DPad up"},
+          {ui::VirtualKey::kXInputPadDpadUp, "DPad up"},
-    {ui::VirtualKey::kXInputPadDpadDown, "DPad down"},
+          {ui::VirtualKey::kXInputPadDpadDown, "DPad down"},
-    {ui::VirtualKey::kXInputPadDpadLeft, "DPad left"},
+          {ui::VirtualKey::kXInputPadDpadLeft, "DPad left"},
-    {ui::VirtualKey::kXInputPadDpadRight, "DPad right"},
+          {ui::VirtualKey::kXInputPadDpadRight, "DPad right"},
-    {ui::VirtualKey::kXInputPadStart, "Start"},
+          {ui::VirtualKey::kXInputPadStart, "Start"},
-    {ui::VirtualKey::kXInputPadBack, "Back"},
+          {ui::VirtualKey::kXInputPadBack, "Back"},
-    {ui::VirtualKey::kXInputPadLThumbPress, "L Thumb press"},
+          {ui::VirtualKey::kXInputPadLThumbPress, "L Thumb press"},
-    {ui::VirtualKey::kXInputPadRThumbPress, "R Thumb press"},
+          {ui::VirtualKey::kXInputPadRThumbPress, "R Thumb press"},
 
-    {ui::VirtualKey::kXInputPadLThumbUp, "L Thumb up"},
+          {ui::VirtualKey::kXInputPadLThumbUp, "L Thumb up"},
-    {ui::VirtualKey::kXInputPadLThumbDown, "L Thumb down"},
+          {ui::VirtualKey::kXInputPadLThumbDown, "L Thumb down"},
-    {ui::VirtualKey::kXInputPadLThumbRight, "L Thumb right"},
+          {ui::VirtualKey::kXInputPadLThumbRight, "L Thumb right"},
-    {ui::VirtualKey::kXInputPadLThumbLeft, "L Thumb left"},
+          {ui::VirtualKey::kXInputPadLThumbLeft, "L Thumb left"},
-    {ui::VirtualKey::kXInputPadLThumbUpLeft, "L Thumb up & left"},
+          {ui::VirtualKey::kXInputPadLThumbUpLeft, "L Thumb up & left"},
-    {ui::VirtualKey::kXInputPadLThumbUpRight, "L Thumb up & right"},
+          {ui::VirtualKey::kXInputPadLThumbUpRight, "L Thumb up & right"},
-    {ui::VirtualKey::kXInputPadLThumbDownRight, "L Thumb down & right"},
+          {ui::VirtualKey::kXInputPadLThumbDownRight, "L Thumb down & right"},
-    {ui::VirtualKey::kXInputPadLThumbDownLeft, "L Thumb down & left"},
+          {ui::VirtualKey::kXInputPadLThumbDownLeft, "L Thumb down & left"},
 
-    {ui::VirtualKey::kXInputPadRThumbUp, "R Thumb up"},
+          {ui::VirtualKey::kXInputPadRThumbUp, "R Thumb up"},
-    {ui::VirtualKey::kXInputPadRThumbDown, "R Thumb down"},
+          {ui::VirtualKey::kXInputPadRThumbDown, "R Thumb down"},
-    {ui::VirtualKey::kXInputPadRThumbRight, "R Thumb right"},
+          {ui::VirtualKey::kXInputPadRThumbRight, "R Thumb right"},
-    {ui::VirtualKey::kXInputPadRThumbLeft, "R Thumb left"},
+          {ui::VirtualKey::kXInputPadRThumbLeft, "R Thumb left"},
-    {ui::VirtualKey::kXInputPadRThumbUpLeft, "R Thumb up & left"},
+          {ui::VirtualKey::kXInputPadRThumbUpLeft, "R Thumb up & left"},
-    {ui::VirtualKey::kXInputPadRThumbUpRight, "R Thumb up & right"},
+          {ui::VirtualKey::kXInputPadRThumbUpRight, "R Thumb up & right"},
-    {ui::VirtualKey::kXInputPadRThumbDownRight, "R Thumb down & right"},
+          {ui::VirtualKey::kXInputPadRThumbDownRight, "R Thumb down & right"},
-    {ui::VirtualKey::kXInputPadRThumbDownLeft, "R Thumb down & left"},
+          {ui::VirtualKey::kXInputPadRThumbDownLeft, "R Thumb down & left"},
-};
+      };
 
-void DrawUserInputGetKeystroke(uint32_t user_index, bool poll,
-                               bool hide_repeats, bool clear_log) {
   const size_t maxLog = 128;
   static std::array<std::forward_list<std::string>, MAX_USERS> event_logs;
   static std::array<uint64_t, MAX_USERS> last_event_times = {};
@@ -400,7 +409,8 @@ void DrawUserInputGetKeystroke(uint32_t user_index, bool poll,
   }
 }
 
-void DrawInputGetKeystroke(bool poll, bool hide_repeats, bool clear_log) {
+void HidDemoApp::DrawInputGetKeystroke(bool poll, bool hide_repeats,
+                                       bool clear_log) const {
   bool tab_bar = ImGui::BeginTabBar("DrawInputGetKeystroke");
   for (uint32_t user_index = 0; user_index < MAX_USERS; ++user_index) {
     DrawUserInputGetKeystroke(user_index, poll, hide_repeats, clear_log);
@@ -411,4 +421,4 @@ void DrawInputGetKeystroke(bool poll, bool hide_repeats, bool clear_log) {
 }  // namespace hid
 }  // namespace xe
 
-DEFINE_ENTRY_POINT("xenia-hid-demo", xe::hid::hid_demo_main, "");
+XE_DEFINE_WINDOWED_APP(xenia_hid_demo, xe::hid::HidDemoApp::Create);

src/xenia/hid/premake5.lua

@@ -32,7 +32,7 @@ project("xenia-hid-demo")
   })
   files({
     "hid_demo.cc",
-    "../base/main_"..platform_suffix..".cc",
+    "../ui/windowed_app_main_"..platform_suffix..".cc",
   })
   resincludedirs({
     project_root,

src/xenia/hid/sdl/sdl_input_driver.cc

@@ -22,6 +22,7 @@
 #include "xenia/hid/hid_flags.h"
 #include "xenia/ui/virtual_key.h"
 #include "xenia/ui/window.h"
+#include "xenia/ui/windowed_app_context.h"
 
 // TODO(joellinn) make this path relative to the config folder.
 DEFINE_path(mappings_file, "gamecontrollerdb.txt",
@@ -43,6 +44,12 @@ SDLInputDriver::SDLInputDriver(xe::ui::Window* window)
       keystroke_states_() {}
 
 SDLInputDriver::~SDLInputDriver() {
+  // Make sure the CallInUIThread is executed before destroying the references.
+  if (sdl_pumpevents_queued_) {
+    window()->app_context().CallInUIThreadSynchronous([this]() {
+      window()->app_context().ExecutePendingFunctionsFromUIThread();
+    });
+  }
   for (size_t i = 0; i < controllers_.size(); i++) {
     if (controllers_.at(i).sdl) {
       SDL_GameControllerClose(controllers_.at(i).sdl);
@@ -65,8 +72,9 @@ X_STATUS SDLInputDriver::Setup() {
   }
 
   // SDL_PumpEvents should only be run in the thread that initialized SDL - we
-  // are hijacking the window loop thread for that.
+  // are hijacking the UI thread for that. If this function fails to be queued,
-  window()->loop()->PostSynchronous([&]() {
+  // the "initialized" variables will be false - that's handled safely.
+  window()->app_context().CallInUIThreadSynchronous([this]() {
     if (!xe::helper::sdl::SDLHelper::Prepare()) {
       return;
     }
@@ -129,7 +137,9 @@ X_STATUS SDLInputDriver::Setup() {
       }
     }
   });
-  return sdl_events_initialized_ && sdl_gamecontroller_initialized_;
+  return (sdl_events_initialized_ && sdl_gamecontroller_initialized_)
+             ? X_STATUS_SUCCESS
+             : X_STATUS_UNSUCCESSFUL;
 }
 
 X_RESULT SDLInputDriver::GetCapabilities(uint32_t user_index, uint32_t flags,
@@ -693,7 +703,7 @@ void SDLInputDriver::QueueControllerUpdate() {
   bool is_queued = false;
   sdl_pumpevents_queued_.compare_exchange_strong(is_queued, true);
   if (!is_queued) {
-    window()->loop()->Post([this]() {
+    window()->app_context().CallInUIThread([this]() {
       SDL_PumpEvents();
       sdl_pumpevents_queued_ = false;
     });

src/xenia/kernel/xam/xam_nui.cc

@@ -15,6 +15,7 @@
 #include "xenia/kernel/xam/xam_private.h"
 #include "xenia/ui/imgui_dialog.h"
 #include "xenia/ui/window.h"
+#include "xenia/ui/windowed_app_context.h"
 #include "xenia/xbox.h"
 
 namespace xe {
@@ -50,15 +51,16 @@ dword_result_t XamShowNuiTroubleshooterUI(unknown_t unk1, unknown_t unk2,
 
   auto display_window = kernel_state()->emulator()->display_window();
   xe::threading::Fence fence;
-  display_window->loop()->PostSynchronous([&]() {
+  if (display_window->app_context().CallInUIThreadSynchronous([&]() {
-    xe::ui::ImGuiDialog::ShowMessageBox(
+        xe::ui::ImGuiDialog::ShowMessageBox(
-        display_window, "NUI Troubleshooter",
+            display_window, "NUI Troubleshooter",
-        "The game has indicated there is a problem with NUI (Kinect).")
+            "The game has indicated there is a problem with NUI (Kinect).")
-        ->Then(&fence);
+            ->Then(&fence);
-  });
+      })) {
-  ++xam_dialogs_shown_;
+    ++xam_dialogs_shown_;
-  fence.Wait();
+    fence.Wait();
-  --xam_dialogs_shown_;
+    --xam_dialogs_shown_;
+  }
 
   return 0;
 }

src/xenia/kernel/xam/xam_ui.cc

@@ -17,6 +17,7 @@
 #include "xenia/kernel/xam/xam_private.h"
 #include "xenia/ui/imgui_dialog.h"
 #include "xenia/ui/window.h"
+#include "xenia/ui/windowed_app_context.h"
 #include "xenia/xbox.h"
 
 namespace xe {
@@ -76,11 +77,16 @@ X_RESULT xeXamDispatchDialog(T* dialog,
       result = close_callback(dialog);
     });
     xe::threading::Fence fence;
-    kernel_state()->emulator()->display_window()->loop()->PostSynchronous(
+    xe::ui::WindowedAppContext& app_context =
-        [&dialog, &fence]() { dialog->Then(&fence); });
+        kernel_state()->emulator()->display_window()->app_context();
-    ++xam_dialogs_shown_;
+    if (app_context.CallInUIThreadSynchronous(
-    fence.Wait();
+            [&dialog, &fence]() { dialog->Then(&fence); })) {
-    --xam_dialogs_shown_;
+      ++xam_dialogs_shown_;
+      fence.Wait();
+      --xam_dialogs_shown_;
+    } else {
+      delete dialog;
+    }
     // dialog should be deleted at this point!
     return result;
   };
@@ -117,11 +123,14 @@ X_RESULT xeXamDispatchDialogEx(
           result = close_callback(dialog, extended_error, length);
         });
     xe::threading::Fence fence;
-    display_window->loop()->PostSynchronous(
+    if (display_window->app_context().CallInUIThreadSynchronous(
-        [&dialog, &fence]() { dialog->Then(&fence); });
+            [&dialog, &fence]() { dialog->Then(&fence); })) {
-    ++xam_dialogs_shown_;
+      ++xam_dialogs_shown_;
-    fence.Wait();
+      fence.Wait();
-    --xam_dialogs_shown_;
+      --xam_dialogs_shown_;
+    } else {
+      delete dialog;
+    }
     // dialog should be deleted at this point!
     return result;
   };

src/xenia/kernel/xthread.cc

@@ -11,10 +11,6 @@
 
 #include <cstring>
 
-#ifdef XE_PLATFORM_WIN32
-#include <objbase.h>
-#endif
-
 #include "third_party/fmt/include/fmt/format.h"
 #include "xenia/base/byte_stream.h"
 #include "xenia/base/clock.h"
@@ -383,20 +379,6 @@ X_STATUS XThread::Create() {
     // Set name immediately, if we have one.
     thread_->set_name(thread_name_);
 
-#ifdef XE_PLATFORM_WIN32
-    // Setup COM on this thread.
-    //
-    // https://devblogs.microsoft.com/oldnewthing/?p=4613
-    //
-    // "If any thread in the process calls CoInitialize[Ex] with the
-    // COINIT_MULTITHREADED flag, then that not only initializes the current
-    // thread as a member of the multi-threaded apartment, but it also says,
-    // "Any thread which has never called CoInitialize[Ex] is also part of the
-    // multi-threaded apartment."
-#pragma warning(suppress : 6031)
-    CoInitializeEx(nullptr, COINIT_MULTITHREADED);
-#endif
-
     // Profiler needs to know about the thread.
     xe::Profiler::ThreadEnter(thread_name_.c_str());
 

src/xenia/tools/api-scanner/api_scanner_loader.h

@@ -7,11 +7,12 @@
  ******************************************************************************
  */
 
+#include <cstddef>
+#include <cstdint>
+#include <memory>
 #include <vector>
 
-#include "xenia/base/main.h"
 #include "xenia/base/math.h"
-#include "xenia/base/string.h"
 #include "xenia/cpu/export_resolver.h"
 #include "xenia/kernel/fs/filesystem.h"
 #include "xenia/kernel/objects/xfile.h"

src/xenia/tools/api-scanner/api_scanner_main.cc

@@ -7,17 +7,25 @@
  ******************************************************************************
  */
 
-#include "api_scanner_loader.h"
+#include <cstdio>
+#include <string>
+#include <vector>
+
+#include "xenia/base/console_app_main.h"
+#include "xenia/base/cvar.h"
+#include "xenia/base/string.h"
+#include "xenia/tools/api_scanner_loader.h"
 
 namespace xe {
 namespace tools {
 
-DEFINE_string(target, "", "List of file to extract imports from");
+DEFINE_transient_string(target, "", "List of file to extract imports from");
 
+// TODO(Triang3l): Change to std::string (currently doesn't even compile).
 int api_scanner_main(std::vector<std::wstring>& args) {
   // XXX we need gflags to split multiple flags into arrays for us
 
-  if (args.size() == 2 || !FLAGS_target.empty()) {
+  if (args.size() == 2 || !cvars::target.empty()) {
     apiscanner_loader loader_;
     std::wstring target(cvars::target.empty() ? args[1]
                                               : xe::to_wstring(cvars::target));
@@ -41,5 +49,5 @@ int api_scanner_main(std::vector<std::wstring>& args) {
 }  // namespace tools
 }  // namespace xe
 
-DEFINE_ENTRY_POINT(L"api-scanner", L"api-scanner --target=<target file>",
+XE_DEFINE_CONSOLE_APP("api-scanner", xe::tools::api_scanner_main,
-                   xe::tools::api_scanner_main);
+                      "[target file]", "target");

src/xenia/ui/d3d12/d3d12_provider.cc

@@ -47,8 +47,8 @@ bool D3D12Provider::IsD3D12APIAvailable() {
   return true;
 }
 
-std::unique_ptr<D3D12Provider> D3D12Provider::Create(Window* main_window) {
+std::unique_ptr<D3D12Provider> D3D12Provider::Create() {
-  std::unique_ptr<D3D12Provider> provider(new D3D12Provider(main_window));
+  std::unique_ptr<D3D12Provider> provider(new D3D12Provider);
   if (!provider->Initialize()) {
     xe::FatalError(
         "Unable to initialize Direct3D 12 graphics subsystem.\n"
@@ -63,9 +63,6 @@ std::unique_ptr<D3D12Provider> D3D12Provider::Create(Window* main_window) {
   return provider;
 }
 
-D3D12Provider::D3D12Provider(Window* main_window)
-    : GraphicsProvider(main_window) {}
-
 D3D12Provider::~D3D12Provider() {
   if (graphics_analysis_ != nullptr) {
     graphics_analysis_->Release();

src/xenia/ui/d3d12/d3d12_provider.h

@@ -27,7 +27,7 @@ class D3D12Provider : public GraphicsProvider {
 
   static bool IsD3D12APIAvailable();
 
-  static std::unique_ptr<D3D12Provider> Create(Window* main_window);
+  static std::unique_ptr<D3D12Provider> Create();
 
   std::unique_ptr<GraphicsContext> CreateContext(
       Window* target_window) override;
@@ -147,7 +147,7 @@ class D3D12Provider : public GraphicsProvider {
   }
 
  private:
-  explicit D3D12Provider(Window* main_window);
+  D3D12Provider() = default;
 
   static bool EnableIncreaseBasePriorityPrivilege();
   bool Initialize();

src/xenia/ui/d3d12/d3d12_window_demo.cc

@@ -2,28 +2,44 @@
  ******************************************************************************
  * Xenia : Xbox 360 Emulator Research Project                                 *
  ******************************************************************************
- * Copyright 2020 Ben Vanik. All rights reserved.                             *
+ * Copyright 2021 Ben Vanik. All rights reserved.                             *
  * Released under the BSD license - see LICENSE in the root for more details. *
  ******************************************************************************
  */
 
+#include <memory>
 #include <string>
-#include <vector>
 
-#include "xenia/base/main.h"
 #include "xenia/ui/d3d12/d3d12_provider.h"
-#include "xenia/ui/window.h"
+#include "xenia/ui/window_demo.h"
+#include "xenia/ui/windowed_app.h"
 
 namespace xe {
 namespace ui {
+namespace d3d12 {
 
-int window_demo_main(const std::vector<std::string>& args);
+class D3D12WindowDemoApp final : public WindowDemoApp {
+ public:
+  static std::unique_ptr<WindowedApp> Create(WindowedAppContext& app_context) {
+    return std::unique_ptr<WindowedApp>(new D3D12WindowDemoApp(app_context));
+  }
 
-std::unique_ptr<GraphicsProvider> CreateDemoGraphicsProvider(Window* window) {
+ protected:
-  return xe::ui::d3d12::D3D12Provider::Create(window);
+  std::unique_ptr<GraphicsProvider> CreateGraphicsProvider() const override;
+
+ private:
+  explicit D3D12WindowDemoApp(WindowedAppContext& app_context)
+      : WindowDemoApp(app_context, "xenia-ui-window-d3d12-demo") {}
+};
+
+std::unique_ptr<GraphicsProvider> D3D12WindowDemoApp::CreateGraphicsProvider()
+    const {
+  return D3D12Provider::Create();
 }
 
+}  // namespace d3d12
 }  // namespace ui
 }  // namespace xe
 
-DEFINE_ENTRY_POINT("xenia-ui-window-d3d12-demo", xe::ui::window_demo_main, "");
+XE_DEFINE_WINDOWED_APP(xenia_ui_window_d3d12_demo,
+                       xe::ui::d3d12::D3D12WindowDemoApp::Create);

src/xenia/ui/d3d12/premake5.lua

@@ -30,7 +30,7 @@ project("xenia-ui-window-d3d12-demo")
   files({
     "../window_demo.cc",
     "d3d12_window_demo.cc",
-    project_root.."/src/xenia/base/main_"..platform_suffix..".cc",
+    project_root.."/src/xenia/ui/windowed_app_main_"..platform_suffix..".cc",
   })
   resincludedirs({
     project_root,

src/xenia/ui/file_picker_win.cc

@@ -12,6 +12,9 @@
 #include "xenia/base/string.h"
 #include "xenia/ui/file_picker.h"
 
+// Microsoft headers after platform_win.h.
+#include <wrl/client.h>
+
 namespace xe {
 namespace ui {
 
@@ -106,32 +109,16 @@ Win32FilePicker::Win32FilePicker() = default;
 
 Win32FilePicker::~Win32FilePicker() = default;
 
-template <typename T>
-struct com_ptr {
-  com_ptr() : value(nullptr) {}
-  ~com_ptr() { reset(); }
-  void reset() {
-    if (value) {
-      value->Release();
-      value = nullptr;
-    }
-  }
-  operator T*() { return value; }
-  T* operator->() const { return value; }
-  T** addressof() { return &value; }
-  T* value;
-};
-
 bool Win32FilePicker::Show(void* parent_window_handle) {
   // TODO(benvanik): FileSaveDialog.
   assert_true(mode() == Mode::kOpen);
   // TODO(benvanik): folder dialogs.
   assert_true(type() == Type::kFile);
 
-  com_ptr<IFileDialog> file_dialog;
+  Microsoft::WRL::ComPtr<IFileDialog> file_dialog;
   HRESULT hr =
       CoCreateInstance(CLSID_FileOpenDialog, NULL, CLSCTX_INPROC_SERVER,
-                       IID_PPV_ARGS(file_dialog.addressof()));
+                       IID_PPV_ARGS(&file_dialog));
   if (!SUCCEEDED(hr)) {
     return false;
   }
@@ -180,14 +167,13 @@ bool Win32FilePicker::Show(void* parent_window_handle) {
   }
 
   // Create an event handling object, and hook it up to the dialog.
-  com_ptr<IFileDialogEvents> file_dialog_events;
+  Microsoft::WRL::ComPtr<IFileDialogEvents> file_dialog_events;
-  hr = CDialogEventHandler_CreateInstance(
+  hr = CDialogEventHandler_CreateInstance(IID_PPV_ARGS(&file_dialog_events));
-      IID_PPV_ARGS(file_dialog_events.addressof()));
   if (!SUCCEEDED(hr)) {
     return false;
   }
   DWORD cookie;
-  hr = file_dialog->Advise(file_dialog_events, &cookie);
+  hr = file_dialog->Advise(file_dialog_events.Get(), &cookie);
   if (!SUCCEEDED(hr)) {
     return false;
   }
@@ -201,8 +187,8 @@ bool Win32FilePicker::Show(void* parent_window_handle) {
 
   // Obtain the result once the user clicks the 'Open' button.
   // The result is an IShellItem object.
-  com_ptr<IShellItem> shell_item;
+  Microsoft::WRL::ComPtr<IShellItem> shell_item;
-  hr = file_dialog->GetResult(shell_item.addressof());
+  hr = file_dialog->GetResult(&shell_item);
   if (!SUCCEEDED(hr)) {
     return false;
   }

src/xenia/ui/graphics_provider.h

@@ -36,9 +36,6 @@ class GraphicsProvider {
 
   virtual ~GraphicsProvider() = default;
 
-  // The 'main' window of an application, used to query provider information.
-  Window* main_window() const { return main_window_; }
-
   // Creates a new graphics context and swapchain for presenting to a window.
   virtual std::unique_ptr<GraphicsContext> CreateContext(
       Window* target_window) = 0;
@@ -48,9 +45,7 @@ class GraphicsProvider {
   virtual std::unique_ptr<GraphicsContext> CreateOffscreenContext() = 0;
 
  protected:
-  explicit GraphicsProvider(Window* main_window) : main_window_(main_window) {}
+  GraphicsProvider() = default;
-
-  Window* main_window_ = nullptr;
 };
 
 }  // namespace ui

src/xenia/ui/loop.cc

@@ -1,37 +0,0 @@
-/**
- ******************************************************************************
- * Xenia : Xbox 360 Emulator Research Project                                 *
- ******************************************************************************
- * Copyright 2014 Ben Vanik. All rights reserved.                             *
- * Released under the BSD license - see LICENSE in the root for more details. *
- ******************************************************************************
- */
-
-#include "xenia/ui/loop.h"
-
-#include "xenia/base/assert.h"
-#include "xenia/base/threading.h"
-
-namespace xe {
-namespace ui {
-
-Loop::Loop() = default;
-
-Loop::~Loop() = default;
-
-void Loop::PostSynchronous(std::function<void()> fn) {
-  if (is_on_loop_thread()) {
-    // Prevent deadlock if we are executing on ourselves.
-    fn();
-    return;
-  }
-  xe::threading::Fence fence;
-  Post([&fn, &fence]() {
-    fn();
-    fence.Signal();
-  });
-  fence.Wait();
-}
-
-}  // namespace ui
-}  // namespace xe

src/xenia/ui/loop.h

@@ -1,45 +0,0 @@
-/**
- ******************************************************************************
- * Xenia : Xbox 360 Emulator Research Project                                 *
- ******************************************************************************
- * Copyright 2014 Ben Vanik. All rights reserved.                             *
- * Released under the BSD license - see LICENSE in the root for more details. *
- ******************************************************************************
- */
-
-#ifndef XENIA_UI_LOOP_H_
-#define XENIA_UI_LOOP_H_
-
-#include <functional>
-#include <memory>
-
-#include "xenia/base/delegate.h"
-#include "xenia/ui/ui_event.h"
-
-namespace xe {
-namespace ui {
-
-class Loop {
- public:
-  static std::unique_ptr<Loop> Create();
-
-  Loop();
-  virtual ~Loop();
-
-  // Returns true if the currently executing code is within the loop thread.
-  virtual bool is_on_loop_thread() = 0;
-
-  virtual void Post(std::function<void()> fn) = 0;
-  virtual void PostDelayed(std::function<void()> fn, uint64_t delay_millis) = 0;
-  void PostSynchronous(std::function<void()> fn);
-
-  virtual void Quit() = 0;
-  virtual void AwaitQuit() = 0;
-
-  Delegate<UIEvent*> on_quit;
-};
-
-}  // namespace ui
-}  // namespace xe
-
-#endif  // XENIA_UI_LOOP_H_

src/xenia/ui/loop_gtk.cc

@@ -1,81 +0,0 @@
-/**
- ******************************************************************************
- * Xenia : Xbox 360 Emulator Research Project                                 *
- ******************************************************************************
- * Copyright 2020 Ben Vanik. All rights reserved.                             *
- * Released under the BSD license - see LICENSE in the root for more details. *
- ******************************************************************************
- */
-
-#include "xenia/ui/loop_gtk.h"
-
-#include <gdk/gdkx.h>
-#include <gtk/gtk.h>
-
-#include "xenia/base/assert.h"
-
-namespace xe {
-namespace ui {
-
-std::unique_ptr<Loop> Loop::Create() { return std::make_unique<GTKLoop>(); }
-
-GTKLoop::GTKLoop() : thread_id_() {
-  gtk_init(nullptr, nullptr);
-  xe::threading::Fence init_fence;
-  thread_ = std::thread([&init_fence, this]() {
-    xe::threading::set_name("GTK Loop");
-
-    thread_id_ = std::this_thread::get_id();
-    init_fence.Signal();
-
-    ThreadMain();
-
-    quit_fence_.Signal();
-  });
-  init_fence.Wait();
-}
-
-GTKLoop::~GTKLoop() {
-  Quit();
-  thread_.join();
-}
-
-void GTKLoop::ThreadMain() { gtk_main(); }
-
-bool GTKLoop::is_on_loop_thread() {
-  return thread_id_ == std::this_thread::get_id();
-}
-
-gboolean _posted_fn_thunk(gpointer posted_fn) {
-  // convert gpointer back to std::function, call it, then free std::function
-  std::function<void()>* f =
-      reinterpret_cast<std::function<void()>*>(posted_fn);
-  std::function<void()>& func = *f;
-  func();
-  delete f;
-  // Tells GDK we don't want to run this again
-  return G_SOURCE_REMOVE;
-}
-
-void GTKLoop::Post(std::function<void()> fn) {
-  assert_true(thread_id_ != std::thread::id());
-  // converting std::function to a generic pointer for gdk
-  gdk_threads_add_idle(_posted_fn_thunk, reinterpret_cast<gpointer>(
-                                             new std::function<void()>(fn)));
-}
-
-void GTKLoop::PostDelayed(std::function<void()> fn, uint64_t delay_millis) {
-  gdk_threads_add_timeout(
-      delay_millis, _posted_fn_thunk,
-      reinterpret_cast<gpointer>(new std::function<void()>(fn)));
-}
-
-void GTKLoop::Quit() {
-  assert_true(thread_id_ != std::thread::id());
-  Post([]() { gtk_main_quit(); });
-}
-
-void GTKLoop::AwaitQuit() { quit_fence_.Wait(); }
-
-}  // namespace ui
-}  // namespace xe

src/xenia/ui/loop_win.cc

@@ -1,131 +0,0 @@
-/**
- ******************************************************************************
- * Xenia : Xbox 360 Emulator Research Project                                 *
- ******************************************************************************
- * Copyright 2014 Ben Vanik. All rights reserved.                             *
- * Released under the BSD license - see LICENSE in the root for more details. *
- ******************************************************************************
- */
-
-#include "xenia/ui/loop_win.h"
-
-#include "xenia/base/assert.h"
-
-namespace xe {
-namespace ui {
-
-std::unique_ptr<Loop> Loop::Create() { return std::make_unique<Win32Loop>(); }
-
-Win32Loop::Win32Loop() : thread_id_(0) {
-  timer_queue_ = CreateTimerQueue();
-
-  xe::threading::Fence init_fence;
-  thread_ = std::thread([&init_fence, this]() {
-    xe::threading::set_name("Win32 Loop");
-    thread_id_ = GetCurrentThreadId();
-
-    // Make a Win32 call to enable the thread queue.
-    MSG msg;
-    PeekMessage(&msg, NULL, WM_USER, WM_USER, PM_NOREMOVE);
-
-    init_fence.Signal();
-
-    ThreadMain();
-
-    quit_fence_.Signal();
-  });
-  init_fence.Wait();
-}
-
-Win32Loop::~Win32Loop() {
-  Quit();
-  thread_.join();
-
-  DeleteTimerQueueEx(timer_queue_, INVALID_HANDLE_VALUE);
-  std::lock_guard<std::mutex> lock(pending_timers_mutex_);
-  while (!pending_timers_.empty()) {
-    auto timer = pending_timers_.back();
-    pending_timers_.pop_back();
-    delete timer;
-  }
-}
-
-void Win32Loop::ThreadMain() {
-  MSG msg;
-  while (!should_exit_ && GetMessage(&msg, NULL, 0, 0)) {
-    TranslateMessage(&msg);
-    DispatchMessage(&msg);
-
-    // Process queued functions.
-    std::lock_guard<std::recursive_mutex> lock(posted_functions_mutex_);
-    for (auto it = posted_functions_.begin(); it != posted_functions_.end();) {
-      (*it).Call();
-      it = posted_functions_.erase(it);
-    }
-  }
-
-  UIEvent e(nullptr);
-  on_quit(&e);
-}
-
-bool Win32Loop::is_on_loop_thread() {
-  return thread_id_ == GetCurrentThreadId();
-}
-
-void Win32Loop::Post(std::function<void()> fn) {
-  assert_true(thread_id_ != 0);
-  {
-    std::lock_guard<std::recursive_mutex> lock(posted_functions_mutex_);
-    PostedFn posted_fn(fn);
-    posted_functions_.push_back(posted_fn);
-  }
-
-  while (!PostThreadMessage(thread_id_, WM_NULL, 0, 0)) {
-    Sleep(1);
-  }
-}
-
-void Win32Loop::TimerQueueCallback(void* context, uint8_t) {
-  auto timer = reinterpret_cast<PendingTimer*>(context);
-  auto loop = timer->loop;
-  auto fn = std::move(timer->fn);
-  DeleteTimerQueueTimer(timer->timer_queue, timer->timer_handle, NULL);
-  {
-    std::lock_guard<std::mutex> lock(loop->pending_timers_mutex_);
-    loop->pending_timers_.remove(timer);
-  }
-  delete timer;
-  loop->Post(std::move(fn));
-}
-
-void Win32Loop::PostDelayed(std::function<void()> fn, uint64_t delay_millis) {
-  if (!delay_millis) {
-    Post(std::move(fn));
-    return;
-  }
-  auto timer = new PendingTimer();
-  timer->loop = this;
-  timer->timer_queue = timer_queue_;
-  timer->fn = std::move(fn);
-  {
-    std::lock_guard<std::mutex> lock(pending_timers_mutex_);
-    pending_timers_.push_back(timer);
-  }
-  CreateTimerQueueTimer(&timer->timer_handle, timer_queue_,
-                        WAITORTIMERCALLBACK(TimerQueueCallback), timer,
-                        DWORD(delay_millis), 0,
-                        WT_EXECUTEINTIMERTHREAD | WT_EXECUTEONLYONCE);
-}
-
-void Win32Loop::Quit() {
-  assert_true(thread_id_ != 0);
-  should_exit_ = true;
-  while (!PostThreadMessage(thread_id_, WM_NULL, 0, 0)) {
-    Sleep(1);
-  }
-}
-
-void Win32Loop::AwaitQuit() { quit_fence_.Wait(); }
-
-}  // namespace ui
-}  // namespace xe

src/xenia/ui/loop_win.h

@@ -1,74 +0,0 @@
-/**
- ******************************************************************************
- * Xenia : Xbox 360 Emulator Research Project                                 *
- ******************************************************************************
- * Copyright 2014 Ben Vanik. All rights reserved.                             *
- * Released under the BSD license - see LICENSE in the root for more details. *
- ******************************************************************************
- */
-
-#ifndef XENIA_UI_LOOP_WIN_H_
-#define XENIA_UI_LOOP_WIN_H_
-
-#include <list>
-#include <mutex>
-#include <thread>
-
-#include "xenia/base/platform_win.h"
-#include "xenia/base/threading.h"
-#include "xenia/ui/loop.h"
-
-namespace xe {
-namespace ui {
-
-class Win32Loop : public Loop {
- public:
-  Win32Loop();
-  ~Win32Loop() override;
-
-  bool is_on_loop_thread() override;
-
-  void Post(std::function<void()> fn) override;
-  void PostDelayed(std::function<void()> fn, uint64_t delay_millis) override;
-
-  void Quit() override;
-  void AwaitQuit() override;
-
- private:
-  struct PendingTimer {
-    Win32Loop* loop;
-    HANDLE timer_queue;
-    HANDLE timer_handle;
-    std::function<void()> fn;
-  };
-
-  class PostedFn {
-   public:
-    explicit PostedFn(std::function<void()> fn) : fn_(std::move(fn)) {}
-    void Call() { fn_(); }
-
-   private:
-    std::function<void()> fn_;
-  };
-
-  void ThreadMain();
-
-  static void TimerQueueCallback(void* context, uint8_t);
-
-  std::thread thread_;
-  DWORD thread_id_;
-  bool should_exit_ = false;
-  xe::threading::Fence quit_fence_;
-
-  HANDLE timer_queue_;
-  std::mutex pending_timers_mutex_;
-  std::list<PendingTimer*> pending_timers_;
-
-  std::recursive_mutex posted_functions_mutex_;
-  std::list<PostedFn> posted_functions_;
-};
-
-}  // namespace ui
-}  // namespace xe
-
-#endif  // XENIA_UI_LOOP_WIN_H_

src/xenia/ui/premake5.lua

@@ -13,3 +13,4 @@ project("xenia-ui")
   })
   local_platform_files()
   removefiles({"*_demo.cc"})
+  removefiles({"windowed_app_main_*.cc"})

src/xenia/ui/vulkan/premake5.lua

@@ -45,7 +45,7 @@ project("xenia-ui-window-vulkan-demo")
   files({
     "../window_demo.cc",
     "vulkan_window_demo.cc",
-    project_root.."/src/xenia/base/main_"..platform_suffix..".cc",
+    project_root.."/src/xenia/ui/windowed_app_main_"..platform_suffix..".cc",
   })
   resincludedirs({
     project_root,

src/xenia/ui/vulkan/vulkan_provider.cc

@@ -24,8 +24,8 @@ namespace xe {
 namespace ui {
 namespace vulkan {
 
-std::unique_ptr<VulkanProvider> VulkanProvider::Create(Window* main_window) {
+std::unique_ptr<VulkanProvider> VulkanProvider::Create() {
-  std::unique_ptr<VulkanProvider> provider(new VulkanProvider(main_window));
+  std::unique_ptr<VulkanProvider> provider(new VulkanProvider);
   if (!provider->Initialize()) {
     xe::FatalError(
         "Unable to initialize Vulkan graphics subsystem.\n"
@@ -40,9 +40,6 @@ std::unique_ptr<VulkanProvider> VulkanProvider::Create(Window* main_window) {
   return provider;
 }
 
-VulkanProvider::VulkanProvider(Window* main_window)
-    : GraphicsProvider(main_window) {}
-
 VulkanProvider::~VulkanProvider() {
   device_.reset();
   instance_.reset();

src/xenia/ui/vulkan/vulkan_provider.h

@@ -25,7 +25,7 @@ class VulkanProvider : public GraphicsProvider {
  public:
   ~VulkanProvider() override;
 
-  static std::unique_ptr<VulkanProvider> Create(Window* main_window);
+  static std::unique_ptr<VulkanProvider> Create();
 
   VulkanInstance* instance() const { return instance_.get(); }
   VulkanDevice* device() const { return device_.get(); }
@@ -35,7 +35,7 @@ class VulkanProvider : public GraphicsProvider {
   std::unique_ptr<GraphicsContext> CreateOffscreenContext() override;
 
  protected:
-  explicit VulkanProvider(Window* main_window);
+  VulkanProvider() = default;
 
   bool Initialize();
 

src/xenia/ui/vulkan/vulkan_window_demo.cc

@@ -2,28 +2,44 @@
  ******************************************************************************
  * Xenia : Xbox 360 Emulator Research Project                                 *
  ******************************************************************************
- * Copyright 2020 Ben Vanik. All rights reserved.                             *
+ * Copyright 2021 Ben Vanik. All rights reserved.                             *
  * Released under the BSD license - see LICENSE in the root for more details. *
  ******************************************************************************
  */
 
+#include <memory>
 #include <string>
-#include <vector>
 
-#include "xenia/base/main.h"
 #include "xenia/ui/vulkan/vulkan_provider.h"
-#include "xenia/ui/window.h"
+#include "xenia/ui/window_demo.h"
+#include "xenia/ui/windowed_app.h"
 
 namespace xe {
 namespace ui {
+namespace vulkan {
 
-int window_demo_main(const std::vector<std::string>& args);
+class VulkanWindowDemoApp final : public WindowDemoApp {
+ public:
+  static std::unique_ptr<WindowedApp> Create(WindowedAppContext& app_context) {
+    return std::unique_ptr<WindowedApp>(new VulkanWindowDemoApp(app_context));
+  }
 
-std::unique_ptr<GraphicsProvider> CreateDemoGraphicsProvider(Window* window) {
+ protected:
-  return xe::ui::vulkan::VulkanProvider::Create(window);
+  std::unique_ptr<GraphicsProvider> CreateGraphicsProvider() const override;
+
+ private:
+  explicit VulkanWindowDemoApp(WindowedAppContext& app_context)
+      : WindowDemoApp(app_context, "xenia-ui-window-vulkan-demo") {}
+};
+
+std::unique_ptr<GraphicsProvider> VulkanWindowDemoApp::CreateGraphicsProvider()
+    const {
+  return VulkanProvider::Create();
 }
 
+}  // namespace vulkan
 }  // namespace ui
 }  // namespace xe
 
-DEFINE_ENTRY_POINT("xenia-ui-window-vulkan-demo", xe::ui::window_demo_main, "");
+XE_DEFINE_WINDOWED_APP(xenia_ui_window_vulkan_demo,
+                       xe::ui::vulkan::VulkanWindowDemoApp::Create);

src/xenia/ui/window.cc

@@ -31,8 +31,8 @@ constexpr double kDoubleClickDistance = 5;
 
 constexpr int32_t kMouseWheelDetent = 120;
 
-Window::Window(Loop* loop, const std::string& title)
+Window::Window(WindowedAppContext& app_context, const std::string& title)
-    : loop_(loop), title_(title) {}
+    : app_context_(app_context), title_(title) {}
 
 Window::~Window() {
   // Context must have been cleaned up already in OnDestroy.

src/xenia/ui/window.h

@@ -16,10 +16,10 @@
 #include "xenia/base/delegate.h"
 #include "xenia/base/platform.h"
 #include "xenia/ui/graphics_context.h"
-#include "xenia/ui/loop.h"
 #include "xenia/ui/menu_item.h"
 #include "xenia/ui/ui_event.h"
 #include "xenia/ui/window_listener.h"
+#include "xenia/ui/windowed_app_context.h"
 
 namespace xe {
 namespace ui {
@@ -31,11 +31,13 @@ class ImGuiDrawer;
 
 class Window {
  public:
-  static std::unique_ptr<Window> Create(Loop* loop, const std::string& title);
+  static std::unique_ptr<Window> Create(WindowedAppContext& app_context_,
+                                        const std::string& title);
 
   virtual ~Window();
 
-  Loop* loop() const { return loop_; }
+  WindowedAppContext& app_context() const { return app_context_; }
+
   virtual NativePlatformHandle native_platform_handle() const = 0;
   virtual NativeWindowHandle native_handle() const = 0;
 
@@ -69,8 +71,11 @@ class Window {
   virtual bool is_bordered() const { return false; }
   virtual void set_bordered(bool enabled) {}
 
-  virtual int get_dpi() const { return 96; }
+  virtual int get_medium_dpi() const { return 96; }
-  virtual float get_dpi_scale() const { return get_dpi() / 96.f; }
+  virtual int get_dpi() const { return get_medium_dpi(); }
+  virtual float get_dpi_scale() const {
+    return float(get_dpi()) / float(get_medium_dpi());
+  }
 
   bool has_focus() const { return has_focus_; }
   virtual void set_focus(bool value) { has_focus_ = value; }
@@ -78,6 +83,8 @@ class Window {
   bool is_cursor_visible() const { return is_cursor_visible_; }
   virtual void set_cursor_visible(bool value) { is_cursor_visible_ = value; }
 
+  // TODO(Triang3l): Don't scale for guest output - use physical pixels. Use
+  // logical pixels only for the immediate drawer.
   int32_t width() const { return width_; }
   int32_t height() const { return height_; }
   int32_t scaled_width() const { return int32_t(width_ * get_dpi_scale()); }
@@ -135,7 +142,7 @@ class Window {
   Delegate<MouseEvent*> on_mouse_wheel;
 
  protected:
-  Window(Loop* loop, const std::string& title);
+  Window(WindowedAppContext& app_context, const std::string& title);
 
   void ForEachListener(std::function<void(WindowListener*)> fn);
   void TryForEachListener(std::function<bool(WindowListener*)> fn);
@@ -170,7 +177,7 @@ class Window {
 
   void OnKeyPress(KeyEvent* e, bool is_down, bool is_char);
 
-  Loop* loop_ = nullptr;
+  WindowedAppContext& app_context_;
   std::unique_ptr<MenuItem> main_menu_;
   std::string title_;
 #ifdef XE_PLATFORM_GNU_LINUX

src/xenia/ui/window_demo.cc

@@ -2,7 +2,7 @@
  ******************************************************************************
  * Xenia : Xbox 360 Emulator Research Project                                 *
  ******************************************************************************
- * Copyright 2020 Ben Vanik. All rights reserved.                             *
+ * Copyright 2021 Ben Vanik. All rights reserved.                             *
  * Released under the BSD license - see LICENSE in the root for more details. *
  ******************************************************************************
  */
@@ -12,7 +12,6 @@
 #include "third_party/imgui/imgui.h"
 #include "xenia/base/clock.h"
 #include "xenia/base/logging.h"
-#include "xenia/base/main.h"
 #include "xenia/base/profiling.h"
 #include "xenia/base/threading.h"
 #include "xenia/ui/graphics_provider.h"
@@ -20,28 +19,29 @@
 #include "xenia/ui/imgui_drawer.h"
 #include "xenia/ui/virtual_key.h"
 #include "xenia/ui/window.h"
+#include "xenia/ui/window_demo.h"
 
 namespace xe {
 namespace ui {
 
-// Implemented in one of the window_*_demo.cc files under a subdir.
+WindowDemoApp::~WindowDemoApp() { Profiler::Shutdown(); }
-std::unique_ptr<GraphicsProvider> CreateDemoGraphicsProvider(Window* window);
 
-int window_demo_main(const std::vector<std::string>& args) {
+bool WindowDemoApp::OnInitialize() {
   Profiler::Initialize();
-  Profiler::ThreadEnter("main");
+  Profiler::ThreadEnter("Main");
 
-  // Create run loop and the window.
+  // Create graphics provider that provides the context for the window.
-  auto loop = ui::Loop::Create();
+  graphics_provider_ = CreateGraphicsProvider();
-  auto window = xe::ui::Window::Create(loop.get(), GetEntryInfo().name);
+  if (!graphics_provider_) {
-  loop->PostSynchronous([&window]() {
+    return false;
-    xe::threading::set_name("Win32 Loop");
+  }
-    xe::Profiler::ThreadEnter("Win32 Loop");
+
-    if (!window->Initialize()) {
+  // Create the window.
-      FatalError("Failed to initialize main window");
+  window_ = xe::ui::Window::Create(app_context(), GetName());
-      return;
+  if (!window_->Initialize()) {
-    }
+    XELOGE("Failed to initialize main window");
-  });
+    return false;
+  }
 
   // Main menu.
   auto main_menu = MenuItem::Create(MenuItem::Type::kNormal);
@@ -49,7 +49,7 @@ int window_demo_main(const std::vector<std::string>& args) {
   {
     file_menu->AddChild(MenuItem::Create(MenuItem::Type::kString, "&Close",
                                          "Alt+F4",
-                                         [&window]() { window->Close(); }));
+                                         [this]() { window_->Close(); }));
   }
   main_menu->AddChild(std::move(file_menu));
   auto debug_menu = MenuItem::Create(MenuItem::Type::kPopup, "&Debug");
@@ -62,37 +62,28 @@ int window_demo_main(const std::vector<std::string>& args) {
                                           []() { Profiler::TogglePause(); }));
   }
   main_menu->AddChild(std::move(debug_menu));
-  window->set_main_menu(std::move(main_menu));
+  window_->set_main_menu(std::move(main_menu));
 
   // Initial size setting, done here so that it knows the menu exists.
-  window->Resize(1920, 1200);
+  window_->Resize(1920, 1200);
 
-  // Create the graphics context used for drawing and setup the window.
+  // Create the graphics context for the window. The window will finish
-  std::unique_ptr<GraphicsProvider> graphics_provider;
+  // initialization with the context (loading resources, etc).
-  loop->PostSynchronous([&window, &graphics_provider]() {
+  window_->set_context(graphics_provider_->CreateContext(window_.get()));
-    // Create graphics provider and an initial context for the window.
-    // The window will finish initialization with the context (loading
-    // resources, etc).
-    graphics_provider = CreateDemoGraphicsProvider(window.get());
-    window->set_context(graphics_provider->CreateContext(window.get()));
 
-    // Setup the profiler display.
+  // Setup the profiler display.
-    GraphicsContextLock context_lock(window->context());
+  GraphicsContextLock context_lock(window_->context());
-    Profiler::set_window(window.get());
+  Profiler::set_window(window_.get());
 
-    // Enable imgui input.
+  // Enable imgui input.
-    window->set_imgui_input_enabled(true);
+  window_->set_imgui_input_enabled(true);
+
+  window_->on_closed.AddListener([this](xe::ui::UIEvent* e) {
+    XELOGI("User-initiated death!");
+    app_context().QuitFromUIThread();
   });
 
-  window->on_closed.AddListener(
+  window_->on_key_down.AddListener([](xe::ui::KeyEvent* e) {
-      [&loop, &window, &graphics_provider](xe::ui::UIEvent* e) {
-        loop->Quit();
-        Profiler::Shutdown();
-        XELOGI("User-initiated death!");
-      });
-  loop->on_quit.AddListener([&window](xe::ui::UIEvent* e) { window.reset(); });
-
-  window->on_key_down.AddListener([](xe::ui::KeyEvent* e) {
     switch (e->virtual_key()) {
       case VirtualKey::kF3:
         Profiler::ToggleDisplay();
@@ -102,23 +93,19 @@ int window_demo_main(const std::vector<std::string>& args) {
     }
   });
 
-  window->on_painting.AddListener([&](xe::ui::UIEvent* e) {
+  window_->on_painting.AddListener([this](xe::ui::UIEvent* e) {
-    auto& io = window->imgui_drawer()->GetIO();
+    auto& io = window_->imgui_drawer()->GetIO();
 
     ImGui::ShowDemoWindow();
     ImGui::ShowMetricsWindow();
 
+    Profiler::Flip();
+
     // Continuous paint.
-    window->Invalidate();
+    window_->Invalidate();
   });
 
-  // Wait until we are exited.
+  return true;
-  loop->AwaitQuit();
-
-  window.reset();
-  loop.reset();
-  graphics_provider.reset();
-  return 0;
 }
 
 }  // namespace ui

src/xenia/ui/window_demo.h

@@ -0,0 +1,44 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2021 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#ifndef XENIA_UI_WINDOW_DEMO_H_
+#define XENIA_UI_WINDOW_DEMO_H_
+
+#include <memory>
+#include <string>
+
+#include "xenia/ui/graphics_provider.h"
+#include "xenia/ui/window.h"
+#include "xenia/ui/windowed_app.h"
+
+namespace xe {
+namespace ui {
+
+class WindowDemoApp : public WindowedApp {
+ public:
+  ~WindowDemoApp();
+
+  bool OnInitialize() override;
+
+ protected:
+  explicit WindowDemoApp(WindowedAppContext& app_context,
+                         const std::string_view name)
+      : WindowedApp(app_context, name) {}
+
+  virtual std::unique_ptr<GraphicsProvider> CreateGraphicsProvider() const = 0;
+
+ private:
+  std::unique_ptr<GraphicsProvider> graphics_provider_;
+  std::unique_ptr<Window> window_;
+};
+
+}  // namespace ui
+}  // namespace xe
+
+#endif  // XENIA_UI_WINDOW_DEMO_H_

src/xenia/ui/window_gtk.cc

@@ -22,12 +22,13 @@
 namespace xe {
 namespace ui {
 
-std::unique_ptr<Window> Window::Create(Loop* loop, const std::string& title) {
+std::unique_ptr<Window> Window::Create(WindowedAppContext& app_context,
-  return std::make_unique<GTKWindow>(loop, title);
+                                       const std::string& title) {
+  return std::make_unique<GTKWindow>(app_context, title);
 }
 
-GTKWindow::GTKWindow(Loop* loop, const std::string& title)
+GTKWindow::GTKWindow(WindowedAppContext& app_context, const std::string& title)
-    : Window(loop, title) {}
+    : Window(app_context, title) {}
 
 GTKWindow::~GTKWindow() {
   OnDestroy();
@@ -92,7 +93,7 @@ gboolean close_callback(GtkWidget* widget, gpointer data) {
   return G_SOURCE_CONTINUE;
 }
 
-void GTKWindow::Create() {
+bool GTKWindow::OnCreate() {
   // GTK optionally allows passing argv and argc here for parsing gtk specific
   // options. We won't bother
   window_ = gtk_window_new(GTK_WINDOW_TOPLEVEL);
@@ -129,10 +130,7 @@ void GTKWindow::Create() {
   gtk_box_pack_end(GTK_BOX(box_), drawing_area_, TRUE, TRUE, 0);
   gtk_container_add(GTK_CONTAINER(window_), box_);
   gtk_widget_show_all(window_);
-}
 
-bool GTKWindow::OnCreate() {
-  loop()->PostSynchronous([this]() { this->Create(); });
   return super::OnCreate();
 }
 

src/xenia/ui/window_gtk.h

@@ -28,7 +28,7 @@ class GTKWindow : public Window {
   using super = Window;
 
  public:
-  GTKWindow(Loop* loop, const std::string& title);
+  GTKWindow(WindowedAppContext& app_context, const std::string& title);
   ~GTKWindow() override;
 
   NativePlatformHandle native_platform_handle() const override {
@@ -74,7 +74,6 @@ class GTKWindow : public Window {
   void OnResize(UIEvent* e) override;
 
  private:
-  void Create();
   GtkWidget* window_;
   GtkWidget* box_;
   GtkWidget* drawing_area_;

src/xenia/ui/window_win.cc

@@ -18,16 +18,19 @@
 #include "xenia/base/logging.h"
 #include "xenia/base/platform_win.h"
 #include "xenia/ui/virtual_key.h"
+#include "xenia/ui/windowed_app_context_win.h"
 
 namespace xe {
 namespace ui {
 
-std::unique_ptr<Window> Window::Create(Loop* loop, const std::string& title) {
+std::unique_ptr<Window> Window::Create(WindowedAppContext& app_context,
-  return std::make_unique<Win32Window>(loop, title);
+                                       const std::string& title) {
+  return std::make_unique<Win32Window>(app_context, title);
 }
 
-Win32Window::Win32Window(Loop* loop, const std::string& title)
+Win32Window::Win32Window(WindowedAppContext& app_context,
-    : Window(loop, title) {}
+                         const std::string& title)
+    : Window(app_context, title) {}
 
 Win32Window::~Win32Window() {
   OnDestroy();
@@ -43,37 +46,32 @@ Win32Window::~Win32Window() {
 }
 
 NativePlatformHandle Win32Window::native_platform_handle() const {
-  return ::GetModuleHandle(nullptr);
+  return static_cast<const Win32WindowedAppContext&>(app_context()).hinstance();
 }
 
 bool Win32Window::Initialize() { return OnCreate(); }
 
 bool Win32Window::OnCreate() {
-  HINSTANCE hInstance = GetModuleHandle(nullptr);
+  HINSTANCE hInstance =
+      static_cast<const Win32WindowedAppContext&>(app_context()).hinstance();
 
-  if (!SetProcessDpiAwareness_ || !GetDpiForMonitor_) {
+  // Per-monitor DPI awareness is expected to be enabled via the manifest, as
+  // that's the recommended way, which also doesn't require calling
+  // SetProcessDpiAwareness before doing anything that may depend on DPI
+  // awareness (so it's safe to use any Windows APIs before this code).
+  // TODO(Triang3l): Safe handling of per-monitor DPI awareness v2, with
+  // automatic scaling on DPI change.
+  if (!GetDpiForMonitor_) {
     auto shcore = GetModuleHandleW(L"shcore.dll");
     if (shcore) {
-      SetProcessDpiAwareness_ =
-          GetProcAddress(shcore, "SetProcessDpiAwareness");
       GetDpiForMonitor_ = GetProcAddress(shcore, "GetDpiForMonitor");
     }
   }
 
   static bool has_registered_class = false;
   if (!has_registered_class) {
-    // Tell Windows that we're DPI aware.
+    WNDCLASSEXW wcex;
-    if (SetProcessDpiAwareness_) {
+    wcex.cbSize = sizeof(wcex);
-      auto spda = (decltype(&SetProcessDpiAwareness))SetProcessDpiAwareness_;
-      auto res = spda(PROCESS_PER_MONITOR_DPI_AWARE);
-      if (res != S_OK) {
-        XELOGW("Failed to set process DPI awareness. (code = 0x{:08X})",
-               static_cast<uint32_t>(res));
-      }
-    }
-
-    WNDCLASSEX wcex;
-    wcex.cbSize = sizeof(WNDCLASSEX);
     wcex.style = CS_HREDRAW | CS_VREDRAW | CS_OWNDC;
     wcex.lpfnWndProc = Win32Window::WndProcThunk;
     wcex.cbClsExtra = 0;
@@ -85,7 +83,7 @@ bool Win32Window::OnCreate() {
     wcex.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
     wcex.lpszMenuName = nullptr;
     wcex.lpszClassName = L"XeniaWindowClass";
-    if (!RegisterClassEx(&wcex)) {
+    if (!RegisterClassExW(&wcex)) {
       XELOGE("RegisterClassEx failed");
       return false;
     }
@@ -216,7 +214,9 @@ bool Win32Window::SetIcon(const void* buffer, size_t size) {
   }
 
   // Reset icon to default.
-  auto default_icon = LoadIconW(GetModuleHandle(nullptr), L"MAINICON");
+  auto default_icon = LoadIconW(
+      static_cast<const Win32WindowedAppContext&>(app_context()).hinstance(),
+      L"MAINICON");
   SendMessageW(hwnd_, WM_SETICON, ICON_BIG,
                reinterpret_cast<LPARAM>(default_icon));
   SendMessageW(hwnd_, WM_SETICON, ICON_SMALL,
@@ -316,13 +316,22 @@ void Win32Window::set_bordered(bool enabled) {
 }
 
 int Win32Window::get_dpi() const {
+  // TODO(Triang3l): Cache until WM_DPICHANGED is received (which, with
+  // per-monitor awareness v2 will also receive the new suggested window size).
+  // According to MSDN, x and y are identical.
+
   if (!GetDpiForMonitor_) {
-    return 96;
+    HDC screen_hdc = GetDC(nullptr);
+    if (!screen_hdc) {
+      return get_medium_dpi();
+    }
+    int logical_pixels_x = GetDeviceCaps(screen_hdc, LOGPIXELSX);
+    ReleaseDC(nullptr, screen_hdc);
+    return logical_pixels_x;
   }
 
   HMONITOR monitor = MonitorFromWindow(hwnd_, MONITOR_DEFAULTTOPRIMARY);
 
-  // According to msdn, x and y are identical...
   UINT dpi_x, dpi_y;
   auto gdfm = (decltype(&GetDpiForMonitor))GetDpiForMonitor_;
   gdfm(monitor, MDT_DEFAULT, &dpi_x, &dpi_y);

src/xenia/ui/window_win.h

@@ -24,7 +24,7 @@ class Win32Window : public Window {
   using super = Window;
 
  public:
-  Win32Window(Loop* loop, const std::string& title);
+  Win32Window(WindowedAppContext& app_context, const std::string& title);
   ~Win32Window() override;
 
   NativePlatformHandle native_platform_handle() const override;
@@ -90,7 +90,6 @@ class Win32Window : public Window {
   WINDOWPLACEMENT windowed_pos_ = {0};
   POINT last_mouse_pos_ = {0};
 
-  void* SetProcessDpiAwareness_ = nullptr;
   void* GetDpiForMonitor_ = nullptr;
 };
 

src/xenia/ui/windowed_app.h

@@ -0,0 +1,129 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2021 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#ifndef XENIA_UI_WINDOWED_APP_H_
+#define XENIA_UI_WINDOWED_APP_H_
+
+#include <cstddef>
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "xenia/base/platform.h"
+#include "xenia/ui/windowed_app_context.h"
+
+#if XE_PLATFORM_ANDROID
+#include <android/native_activity.h>
+
+#include "xenia/ui/windowed_app_context_android.h"
+#endif
+
+namespace xe {
+namespace ui {
+
+// Interface between the platform's entry points (in the main, UI, thread that
+// also runs the message loop) and the app that implements it.
+class WindowedApp {
+ public:
+  // WindowedApps are expected to provide a static creation function, for
+  // creating an instance of the class (which may be called before
+  // initialization of platform-specific parts, should preferably be as simple
+  // as possible).
+
+  WindowedApp(const WindowedApp& app) = delete;
+  WindowedApp& operator=(const WindowedApp& app) = delete;
+  virtual ~WindowedApp() = default;
+
+  WindowedAppContext& app_context() const { return app_context_; }
+
+  // Same as the executable (project), xenia-library-app.
+  const std::string& GetName() const { return name_; }
+  const std::string& GetPositionalOptionsUsage() const {
+    return positional_options_usage_;
+  }
+  const std::vector<std::string>& GetPositionalOptions() const {
+    return positional_options_;
+  }
+
+  // Called once before receiving other lifecycle callback invocations. Cvars
+  // will be initialized with the launch arguments. Returns whether the app has
+  // been initialized successfully (otherwise platform-specific code must call
+  // OnDestroy and refuse to continue running the app).
+  virtual bool OnInitialize() = 0;
+  // See OnDestroy for more info.
+  void InvokeOnDestroy() {
+    // For safety and convenience of referencing objects owned by the app in
+    // pending functions queued in or after OnInitialize, make sure they are
+    // executed before telling the app that destruction needs to happen.
+    app_context().ExecutePendingFunctionsFromUIThread();
+    OnDestroy();
+  }
+
+ protected:
+  // Positional options should be initialized in the constructor if needed.
+  // Cvars will not have been initialized with the arguments at the moment of
+  // construction (as the result depends on construction).
+  explicit WindowedApp(
+      WindowedAppContext& app_context, const std::string_view name,
+      const std::string_view positional_options_usage = std::string_view())
+      : app_context_(app_context),
+        name_(name),
+        positional_options_usage_(positional_options_usage) {}
+
+  // For calling from the constructor.
+  void AddPositionalOption(const std::string_view option) {
+    positional_options_.emplace_back(option);
+  }
+
+  // OnDestroy entry point may be called (through InvokeOnDestroy) by the
+  // platform-specific lifecycle interface at request of either the app itself
+  // or the OS - thus should be possible for the lifecycle interface to call at
+  // any moment (not from inside other lifecycle callbacks though). The app will
+  // also be destroyed when that happens, so the destructor will also be called
+  // (but this is more safe with respect to exceptions). This is only guaranteed
+  // to be called if OnInitialize has already happened (successfully or not) -
+  // in case of an error before initialization, the destructor may be called
+  // alone as well. Context's pending functions will be executed before the
+  // call, so it's safe to destroy dependencies of them here (though it may
+  // still be possible to add more pending functions here depending on whether
+  // the context was explicitly shut down before this is invoked).
+  virtual void OnDestroy() {}
+
+ private:
+  WindowedAppContext& app_context_;
+
+  std::string name_;
+  std::string positional_options_usage_;
+  std::vector<std::string> positional_options_;
+};
+
+#if XE_PLATFORM_ANDROID
+// Multiple apps in a single library. ANativeActivity_onCreate chosen via
+// android.app.func_name of the NativeActivity of each app.
+#define XE_DEFINE_WINDOWED_APP(export_name, creator)                           \
+  __attribute__((visibility("default"))) extern "C" void export_name(          \
+      ANativeActivity* activity, void* saved_state, size_t saved_state_size) { \
+    xe::ui::AndroidWindowedAppContext::StartAppOnNativeActivityCreate(         \
+        activity, saved_state, saved_state_size, creator);                     \
+  }
+#else
+// Separate executables for each app.
+std::unique_ptr<WindowedApp> (*GetWindowedAppCreator())(
+    WindowedAppContext& app_context);
+#define XE_DEFINE_WINDOWED_APP(export_name, creator)                       \
+  std::unique_ptr<xe::ui::WindowedApp> (*xe::ui::GetWindowedAppCreator())( \
+      xe::ui::WindowedAppContext & app_context) {                          \
+    return creator;                                                        \
+  }
+#endif
+
+}  // namespace ui
+}  // namespace xe
+
+#endif  // XENIA_UI_WINDOWED_APP_H_

src/xenia/ui/windowed_app_context.cc

@@ -0,0 +1,180 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2021 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#include "xenia/ui/windowed_app_context.h"
+
+#include <utility>
+
+#include "xenia/base/assert.h"
+#include "xenia/base/threading.h"
+
+namespace xe {
+namespace ui {
+
+WindowedAppContext::~WindowedAppContext() {
+  // The UI thread is responsible for managing the lifetime of the context.
+  assert_true(IsInUIThread());
+
+  // It's okay to destroy the context from a platform's internal UI loop
+  // callback, primarily on platforms where the loop is run by the OS itself,
+  // and the context can't be created and destroyed in a RAII way, rather, it's
+  // created in an initialization handler and destroyed in a shutdown handler
+  // called by the OS. However, destruction must not be done from within the
+  // queued functions - as in this case, the pending function container, the
+  // mutex, will be accessed after having been destroyed already.
+
+  // Make sure CallInUIThreadDeferred doesn't call
+  // NotifyUILoopOfPendingFunctions, which is virtual.
+  is_in_destructor_ = true;
+  // Make sure the final ExecutePendingFunctionsFromUIThread doesn't call
+  // PlatformQuitFromUIThread, which is virtual.
+  has_quit_ = true;
+
+  // Platform-specific quit is expected to be performed by the subclass (the
+  // order of it vs. the final ExecutePendingFunctionsFromUIThread shouldn't
+  // matter anymore, the implementation may assume that no pending functions
+  // will be requested for execution specifically via the platform-specific
+  // loop, as there should be no more references to the context in other
+  // threads), can't call the virtual PlatformQuitFromUIThread anymore.
+  ExecutePendingFunctionsFromUIThread(true);
+}
+
+bool WindowedAppContext::CallInUIThreadDeferred(
+    std::function<void()> function) {
+  {
+    std::unique_lock<std::mutex> pending_functions_lock(
+        pending_functions_mutex_);
+    if (!pending_functions_accepted_) {
+      // Will not be called as the loop will not be executed anymore.
+      return false;
+    }
+    pending_functions_.emplace_back(std::move(function));
+  }
+  // Notify unconditionally, even if currently running pending functions. It's
+  // possible for pending functions themselves to run inner platform message
+  // loops, such as when displaying dialogs - in this case, the notification is
+  // needed to run the new function from such an inner loop. A modal loop can be
+  // started even in leftovers happening during the quit, where there's still
+  // opportunity for enqueueing and executing new pending functions - so only
+  // checking if called in the destructor (it's safe to check this without
+  // locking a mutex as it's assumed that if the object is already being
+  // destroyed, no other threads can have references to it - any access would
+  // result in a race condition anyway) as the subclass has already been
+  // destroyed. Having pending_functions_mutex_ unlocked also means that
+  // NotifyUILoopOfPendingFunctions may be done while the UI thread is calling
+  // or has already called PlatformQuitFromUIThread - but it's better than
+  // keeping pending_functions_mutex_ locked as NotifyUILoopOfPendingFunctions
+  // may be implemented as pushing to a fixed-size pipe, in which case it will
+  // have to wait until free space is available, but if the UI thread tries to
+  // lock the mutex afterwards to execute pending functions (and encouters
+  // contention), nothing will be able to receive from the pipe anymore and thus
+  // free the space, causing a deadlock.
+  if (!is_in_destructor_) {
+    NotifyUILoopOfPendingFunctions();
+  }
+  return true;
+}
+
+bool WindowedAppContext::CallInUIThread(std::function<void()> function) {
+  if (IsInUIThread()) {
+    // The intention is just to make sure the code is executed in the UI thread,
+    // don't defer execution if no need to.
+    function();
+    return true;
+  }
+  return CallInUIThreadDeferred(std::move(function));
+}
+
+bool WindowedAppContext::CallInUIThreadSynchronous(
+    std::function<void()> function) {
+  if (IsInUIThread()) {
+    // Prevent deadlock if called from the UI thread.
+    function();
+    return true;
+  }
+  xe::threading::Fence fence;
+  if (!CallInUIThreadDeferred([&function, &fence]() {
+        function();
+        fence.Signal();
+      })) {
+    return false;
+  }
+  fence.Wait();
+  return true;
+}
+
+void WindowedAppContext::QuitFromUIThread() {
+  assert_true(IsInUIThread());
+  bool has_quit_previously = has_quit_;
+  // Make sure PlatformQuitFromUIThread is called only once, not from nested
+  // pending function execution during the quit - otherwise it will be called
+  // when it's still possible to add new pending functions. This isn't as wrong
+  // as calling PlatformQuitFromUIThread from the destructor, but still a part
+  // of the contract for simplicity.
+  has_quit_ = true;
+  // Executing pending function unconditionally because it's the contract of
+  // this method that functions are executed immediately.
+  ExecutePendingFunctionsFromUIThread(true);
+  if (has_quit_previously) {
+    // Potentially calling QuitFromUIThread from inside a pending function (in
+    // the worst and dangerous case, from a pending function executed in the
+    // destructor - and PlatformQuitFromUIThread is virtual).
+    return;
+  }
+  // Call the platform-specific shutdown while letting it assume that no new
+  // functions will be queued anymore (but NotifyUILoopOfPendingFunctions may
+  // still be called after PlatformQuitFromUIThread as the two are not
+  // interlocked). This is different than the order in the destruction, but
+  // there this assumption is ensured by the expectation that there should be no
+  // more references to the context in other threads that would allow queueing
+  // new functions with calling NotifyUILoopOfPendingFunctions.
+  PlatformQuitFromUIThread();
+}
+
+void WindowedAppContext::ExecutePendingFunctionsFromUIThread(bool is_final) {
+  assert_true(IsInUIThread());
+  std::unique_lock<std::mutex> pending_functions_lock(pending_functions_mutex_);
+  while (!pending_functions_.empty()) {
+    // Removing the function from the queue before executing it, as the function
+    // itself may call ExecutePendingFunctionsFromUIThread - if it's kept, the
+    // inner loop will try to execute it again, resulting in potentially endless
+    // recursion, and even if it's terminated, each level will be trying to
+    // remove the same function from the queue - instead, actually removing
+    // other functions, or even beyond the end of the queue.
+    std::function<void()> function = std::move(pending_functions_.front());
+    pending_functions_.pop_front();
+    // Call the function with the lock released as it may take an indefinitely
+    // long time to execute if it opens some dialog (possibly with its own
+    // platform message loop), and in that case, without unlocking, no other
+    // thread would be able to add new pending functions (which would result in
+    // unintended waits for user input). This also allows using std::mutex
+    // instead of std::recursive_mutex.
+    pending_functions_lock.unlock();
+    function();
+    pending_functions_lock.lock();
+  }
+  if (is_final) {
+    // Atomically with completion of the pending functions loop, disallow adding
+    // new functions after executing the existing ones - it was possible to
+    // enqueue new functions from the leftover ones as there still was
+    // opportunity to call them, so it wasn't necessary to disallow adding
+    // before executing, but now new functions will potentially never be
+    // executed. This is done even if this is just an inner pending functions
+    // execution and there's still potential possibility of adding and executing
+    // new functions in the outer loops - for simplicity and consistency (so
+    // QuitFromUIThread's behavior doesn't depend as much on the location of the
+    // call - inside a pending function or from some system callback of the
+    // window), assuming after a PlatformQuitFromUIThread call, it's not
+    // possible to add new pending functions anymore.
+    pending_functions_accepted_ = false;
+  }
+}
+
+}  // namespace ui
+}  // namespace xe

src/xenia/ui/windowed_app_context.h

@@ -0,0 +1,184 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2021 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#ifndef XENIA_UI_WINDOWED_APP_CONTEXT_H_
+#define XENIA_UI_WINDOWED_APP_CONTEXT_H_
+
+#include <cstdint>
+#include <deque>
+#include <functional>
+#include <mutex>
+#include <thread>
+
+#include "xenia/base/assert.h"
+
+namespace xe {
+namespace ui {
+
+// Context for inputs provided by the entry point and interacting with the
+// platform's UI loop, to be implemented by platforms.
+class WindowedAppContext {
+ public:
+  WindowedAppContext(const WindowedAppContext& context) = delete;
+  WindowedAppContext& operator=(const WindowedAppContext& context) = delete;
+  virtual ~WindowedAppContext();
+
+  // The thread where the object is created will be assumed to be the UI thread,
+  // for the purpose of being able to perform CallInUIThreadSynchronous before
+  // running the loop.
+  bool IsInUIThread() const {
+    return std::this_thread::get_id() == ui_thread_id_;
+  }
+
+  // CallInUIThreadDeferred and CallInUIThread are fire and forget - will be
+  // executed at some point the future when the UI thread is running the loop
+  // and is not busy doing other things.
+  // Therefore, references to objects in the function may outlive the owners of
+  // those objects, so use-after-free is very easy to create if not being
+  // careful enough.
+  // There are two solutions to this issue:
+  // - Signaling a fence in the function, awaiting it before destroying objects
+  //   referenced by the function (works for shutdown from non-UI threads, or
+  //   for CallInUIThread, but not CallInUIThreadDeferred, in the UI thread).
+  // - Calling ExecutePendingFunctionsFromUIThread in the UI thread before
+  //   destroying objects referenced by the function (works for shutdown from
+  //   the UI thread, though CallInUIThreadSynchronous doing
+  //   ExecutePendingFunctionsFromUIThread is also an option for shutdown from
+  //   any thread).
+  // (These are not required if all the called function is doing is triggering a
+  // quit with the context pointer captured by value, as the only object
+  // involved will be the context itself, with a pointer that is valid until
+  // it's destroyed - the most late location of the pending function execution
+  // possible.)
+  // Returning true if the function has been enqueued (it will be called at some
+  // point, at worst, before exiting the loop) or called immediately, false if
+  // it was dropped (if calling after exiting the loop).
+  // It's okay to enqueue functions from queued functions already being
+  // executed. As execution may be happening during the destruction of the
+  // context as well, in this case, CallInUIThreadDeferred must make sure it
+  // doesn't call anything virtual in the destructor.
+
+  // Enqueues the function regardless of the current thread. Won't necessarily
+  // be executed directly from the platform main loop as
+  // ExecutePendingFunctionsFromUIThread may be called anywhere (for instance,
+  // to await pending functions before destroying what they are referencing).
+  bool CallInUIThreadDeferred(std::function<void()> function);
+  // Executes the function immediately if already in the UI thread, enqueues it
+  // otherwise.
+  bool CallInUIThread(std::function<void()> function);
+  bool CallInUIThreadSynchronous(std::function<void()> function);
+  // It's okay to call this function from the queued functions themselves (such
+  // as in the case of waiting for a pending async CallInUIThreadDeferred
+  // described above - the wait may be done inside a CallInUIThreadSynchronous
+  // function safely).
+  void ExecutePendingFunctionsFromUIThread() {
+    ExecutePendingFunctionsFromUIThread(false);
+  }
+
+  // If on the target platform, the program itself is supposed to run the UI
+  // loop, this may be checked before doing blocking message waits as an
+  // additional safety measure beyond what PlatformQuitFromUIThread guarantees,
+  // and if true, the loop should be terminated (pending function will already
+  // have been executed). This doesn't imply that pending functions have been
+  // executed in all contexts, however - they can be executing from quitting
+  // itself (in the worst case, in the destructor where virtual methods can't be
+  // called), and in this case, this will be returning true.
+  bool HasQuitFromUIThread() const {
+    assert_true(IsInUIThread());
+    return has_quit_;
+  }
+
+  // Immediately disallows adding new pending UI functions, executes the already
+  // queued ones, and makes sure that the UI loop is aware that it was asked to
+  // stop running. This must not destroy the context or the app directly - the
+  // actual app shutdown will be initiated at some point outside the scope of
+  // app's callbacks. May call virtual functions - invoke
+  // ExecutePendingFunctionsFromUIThread(true) in the destructor instead, and
+  // use the platform-specific destructor to invoke the needed
+  // PlatformQuitFromUIThread logic (it should be safe, in case of destruction,
+  // to perform platform-specific quit request logic before the common part -
+  // NotifyUILoopOfPendingFunctions won't be called after the platform-specific
+  // quit request logic in this case anyway as destruction expects that there
+  // are no references to the object in other threads). Safe to call from within
+  // pending functions - requesting quit from non-UI threads is possible via
+  // methods like CallInUIThreadSynchronous. For deferred, rather than
+  // immediate, quitting from the UI thread, CallInUIThreadDeferred may be used
+  // (but the context pointer should be captured by value not to require
+  // explicit completion forcing in case the storage of the pointer is lost
+  // before the function is called).
+  void QuitFromUIThread();
+  // Callable from any thread. This is a special case where a completely
+  // fire-and-forget CallInUIThreadDeferred is safe, as the function only
+  // references nonvirtual functions of the context itself, and will be called
+  // at most from the destructor. No need to return the result - it doesn't
+  // matter if has quit already or not, as that's the intention anyway.
+  void RequestDeferredQuit() {
+    CallInUIThreadDeferred([this] { QuitFromUIThread(); });
+  }
+
+ protected:
+  WindowedAppContext() : ui_thread_id_(std::this_thread::get_id()) {}
+
+  // Can be called from any thread (including the UI thread) to ask the OS to
+  // run an iteration of the UI loop (with or without processing internal UI
+  // messages, this is platform-dependent) so pending functions will be executed
+  // at some point. pending_functions_mutex_ will not be locked when this is
+  // called (to make sure that, for example, the caller, waiting for space in
+  // the OS's message queue, such as in case of a Linux pipe, won't be blocking
+  // the UI thread that has started executing pending messages while pumping
+  // that pipe, resulting in a deadlock) - implementations don't directly see
+  // anything protected by it anyway, and a spurious notification shouldn't be
+  // causing any damage, this is similar to how condition variables can be
+  // signaled outside the critical section (signaling inside the critical
+  // section may also cause contention if the thread waiting is woken up quickly
+  // enough). This, however, means that NotifyUILoopOfPendingFunctions may be
+  // called in a non-UI thread after the final pending message processing
+  // followed by PlatformQuitFromUIThread in the UI thread - so it can still be
+  // called after a quit.
+  virtual void NotifyUILoopOfPendingFunctions() = 0;
+
+  // Called when requesting a quit in the UI thread to tell the platform that
+  // the UI loop needs to be terminated. The pending function queue is assumed
+  // to be empty before this is called, and no new pending functions can be
+  // added (but NotifyUILoopOfPendingFunctions may still be called as it's not
+  // mutually exclusive with PlatformQuitFromUIThread - if this matters, the
+  // platform implementation itself should be resolving this case).
+  virtual void PlatformQuitFromUIThread() = 0;
+
+  std::thread::id ui_thread_id_;
+
+ private:
+  // May be called with is_final == true from the destructor - must not call
+  // anything virtual in this case.
+  void ExecutePendingFunctionsFromUIThread(bool is_final);
+
+  // Accessible by the UI thread.
+  bool has_quit_ = false;
+  bool is_in_destructor_ = false;
+
+  // Synchronizes producers with each other and with the consumer, as well as
+  // all of them with the pending_functions_accepted_ variable which indicates
+  // whether shutdown has not been performed yet, as after the shutdown, no new
+  // functions will be executed anymore, therefore no new function should be
+  // queued, as it will never be called (thus CallInUIThreadSynchronous for it
+  // will never return, for instance).
+  std::mutex pending_functions_mutex_;
+  std::deque<std::function<void()>> pending_functions_;
+  // Protected by pending_functions_mutex_, writable by the UI thread, readable
+  // by any thread. Must be set to false before exiting the main platform loop,
+  // but before that, all pending functions must be executed no matter what, as
+  // they may need to signal fences currently being awaited (like the
+  // CallInUIThreadSynchronous fence).
+  bool pending_functions_accepted_ = true;
+};
+
+}  // namespace ui
+}  // namespace xe
+
+#endif  // XENIA_UI_WINDOWED_APP_CONTEXT_H_

src/xenia/ui/windowed_app_context_android.cc

@@ -0,0 +1,67 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2021 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#include "xenia/ui/windowed_app_context_android.h"
+
+#include <android/native_activity.h>
+
+#include "xenia/base/assert.h"
+#include "xenia/ui/windowed_app.h"
+
+namespace xe {
+namespace ui {
+
+void AndroidWindowedAppContext::StartAppOnNativeActivityCreate(
+    ANativeActivity* activity, [[maybe_unused]] void* saved_state,
+    [[maybe_unused]] size_t saved_state_size,
+    std::unique_ptr<WindowedApp> (*app_creator)(
+        WindowedAppContext& app_context)) {
+  AndroidWindowedAppContext* app_context =
+      new AndroidWindowedAppContext(activity);
+  // The pointer is now held by the Activity as its ANativeActivity::instance,
+  // until the destruction.
+  if (!app_context->InitializeApp(app_creator)) {
+    delete app_context;
+    ANativeActivity_finish(activity);
+  }
+}
+
+AndroidWindowedAppContext::~AndroidWindowedAppContext() {
+  // TODO(Triang3l): Unregister activity callbacks.
+  activity_->instance = nullptr;
+}
+
+void AndroidWindowedAppContext::NotifyUILoopOfPendingFunctions() {
+  // TODO(Triang3l): Request message processing in the UI thread.
+}
+
+void AndroidWindowedAppContext::PlatformQuitFromUIThread() {
+  ANativeActivity_finish(activity);
+}
+
+AndroidWindowedAppContext::AndroidWindowedAppContext(ANativeActivity* activity)
+    : activity_(activity) {
+  activity_->instance = this;
+  // TODO(Triang3l): Register activity callbacks.
+}
+
+bool AndroidWindowedAppContext::InitializeApp(std::unique_ptr<WindowedApp> (
+    *app_creator)(WindowedAppContext& app_context)) {
+  assert_null(app_);
+  app_ = app_creator(this);
+  if (!app_->OnInitialize()) {
+    app_->InvokeOnDestroy();
+    app_.reset();
+    return false;
+  }
+  return true;
+}
+
+}  // namespace ui
+}  // namespace xe

src/xenia/ui/windowed_app_context_android.h

@@ -0,0 +1,61 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2021 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#ifndef XENIA_UI_WINDOWED_APP_CONTEXT_ANDROID_H_
+#define XENIA_UI_WINDOWED_APP_CONTEXT_ANDROID_H_
+
+#include <android/native_activity.h>
+#include <memory>
+
+#include "xenia/ui/windowed_app_context.h"
+
+namespace xe {
+namespace ui {
+
+class WindowedApp;
+
+class AndroidWindowedAppContext final : public WindowedAppContext {
+ public:
+  // For calling from android.app.func_name exports.
+  static void StartAppOnNativeActivityCreate(
+      ANativeActivity* activity, void* saved_state, size_t saved_state_size,
+      std::unique_ptr<WindowedApp> (*app_creator)(
+          WindowedAppContext& app_context));
+
+  // Defined in the translation unit where WindowedApp is complete because of
+  // std::unique_ptr.
+  ~AndroidWindowedAppContext();
+
+  ANativeActivity* activity() const { return activity_; }
+  WindowedApp* app() const { return app_.get(); }
+
+  void NotifyUILoopOfPendingFunctions() override;
+
+  void PlatformQuitFromUIThread() override;
+
+ private:
+  explicit AndroidWindowedAppContext(ANativeActivity* activity);
+  bool InitializeApp(std::unique_ptr<WindowedApp> (*app_creator)(
+      WindowedAppContext& app_context));
+
+  // TODO(Triang3l): Switch from ANativeActivity to the context itself being the
+  // object for communication with the Java code when NativeActivity isn't used
+  // anymore as its functionality is heavily limited.
+  ANativeActivity* activity_;
+  std::unique_ptr<WindowedApp> app_;
+
+  // TODO(Triang3l): The rest of the context, including quit handler (and the
+  // destructor) calling `finish` on the activity, UI looper notification
+  // posting, etc.
+};
+
+}  // namespace ui
+}  // namespace xe
+
+#endif  // XENIA_UI_WINDOWED_APP_CONTEXT_ANDROID_H_

src/xenia/ui/windowed_app_context_gtk.cc

@@ -0,0 +1,112 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2021 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#include "xenia/ui/windowed_app_context_gtk.h"
+
+#include <gdk/gdk.h>
+#include <glib.h>
+#include <gtk/gtk.h>
+
+namespace xe {
+namespace ui {
+
+GTKWindowedAppContext::~GTKWindowedAppContext() {
+  // Remove the idle sources as their data pointer (to this context) is now
+  // outdated.
+  if (quit_idle_pending_) {
+    g_source_remove(quit_idle_pending_);
+  }
+  {
+    // Lock the mutex for a pending_functions_idle_pending_ access memory
+    // barrier, even though no other threads can access this object anymore.
+    std::lock_guard<std::mutex> pending_functions_idle_pending_lock(
+        pending_functions_idle_pending_mutex_);
+    if (pending_functions_idle_pending_) {
+      g_source_remove(pending_functions_idle_pending_);
+    }
+  }
+}
+
+void GTKWindowedAppContext::NotifyUILoopOfPendingFunctions() {
+  std::lock_guard<std::mutex> pending_functions_idle_pending_lock(
+      pending_functions_idle_pending_mutex_);
+  if (!pending_functions_idle_pending_) {
+    pending_functions_idle_pending_ =
+        gdk_threads_add_idle(PendingFunctionsSourceFunc, this);
+  }
+}
+
+void GTKWindowedAppContext::PlatformQuitFromUIThread() {
+  if (quit_idle_pending_ || !gtk_main_level()) {
+    return;
+  }
+  gtk_main_quit();
+  // Quit from all loops in the context, current inner, upcoming inner (this is
+  // why the idle function is added even at the main level of 1), until we can
+  // return to the tail of RunMainGTKLoop.
+  quit_idle_pending_ = gdk_threads_add_idle(QuitSourceFunc, this);
+}
+
+void GTKWindowedAppContext::RunMainGTKLoop() {
+  // For safety, in case the quit request somehow happened before the loop.
+  if (HasQuitFromUIThread()) {
+    return;
+  }
+  assert_zero(gtk_main_level());
+  gtk_main();
+  // Something else - not QuitFromUIThread - might have done gtk_main_quit for
+  // the outer loop. If it has exited for some reason, let the context know, so
+  // pending function won't be added pointlessly.
+  QuitFromUIThread();
+  // Don't interfere with main loops of other contexts that will possibly be
+  // executed in this thread later (if this is not the only app that will be
+  // executed in this process, for example, or if some WindowedAppContext-less
+  // dialog is opened after the windowed app has quit) - cancel the scheduled
+  // quit chain as we have quit already.
+  if (quit_idle_pending_) {
+    g_source_remove(quit_idle_pending_);
+    quit_idle_pending_ = 0;
+  }
+}
+
+gboolean GTKWindowedAppContext::PendingFunctionsSourceFunc(gpointer data) {
+  auto& app_context = *static_cast<GTKWindowedAppContext*>(data);
+  // Allow new pending function notifications to be made, and stop tracking the
+  // lifetime of the idle source that is already being executed and thus
+  // removed. This must be done before executing the functions (if done after,
+  // notifications may be missed if they happen between the execution of the
+  // functions and the reset of pending_functions_idle_pending_).
+  {
+    std::lock_guard<std::mutex> pending_functions_idle_pending_lock(
+        app_context.pending_functions_idle_pending_mutex_);
+    app_context.pending_functions_idle_pending_ = 0;
+  }
+  app_context.ExecutePendingFunctionsFromUIThread();
+  return G_SOURCE_REMOVE;
+}
+
+gboolean GTKWindowedAppContext::QuitSourceFunc(gpointer data) {
+  auto app_context = static_cast<GTKWindowedAppContext*>(data);
+  guint main_level = gtk_main_level();
+  assert_not_zero(main_level);
+  if (!main_level) {
+    app_context->quit_idle_pending_ = 0;
+    return G_SOURCE_REMOVE;
+  }
+  gtk_main_quit();
+  // Quit from all loops in the context, current inner, upcoming inner (this is
+  // why the idle function is added even at the main level of 1), until we can
+  // return to the tail of RunMainGTKLoop.
+  app_context->quit_idle_pending_ =
+      gdk_threads_add_idle(QuitSourceFunc, app_context);
+  return G_SOURCE_REMOVE;
+}
+
+}  // namespace ui
+}  // namespace xe

src/xenia/ui/windowed_app_context_gtk.h

@@ -0,0 +1,46 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2021 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#ifndef XENIA_UI_WINDOWED_APP_CONTEXT_GTK_H_
+#define XENIA_UI_WINDOWED_APP_CONTEXT_GTK_H_
+
+#include <glib.h>
+#include <mutex>
+
+#include "xenia/ui/windowed_app_context.h"
+
+namespace xe {
+namespace ui {
+
+class GTKWindowedAppContext final : public WindowedAppContext {
+ public:
+  GTKWindowedAppContext() = default;
+  ~GTKWindowedAppContext();
+
+  void NotifyUILoopOfPendingFunctions() override;
+
+  void PlatformQuitFromUIThread() override;
+
+  void RunMainGTKLoop();
+
+ private:
+  static gboolean PendingFunctionsSourceFunc(gpointer data);
+
+  static gboolean QuitSourceFunc(gpointer data);
+
+  std::mutex pending_functions_idle_pending_mutex_;
+  guint pending_functions_idle_pending_ = 0;
+
+  guint quit_idle_pending_ = 0;
+};
+
+}  // namespace ui
+}  // namespace xe
+
+#endif  // XENIA_UI_WINDOWED_APP_CONTEXT_GTK_H_

src/xenia/ui/windowed_app_context_win.cc

@@ -0,0 +1,130 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2021 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#include "xenia/ui/windowed_app_context_win.h"
+
+#include <cstdlib>
+
+#include "xenia/base/platform_win.h"
+
+namespace xe {
+namespace ui {
+
+bool Win32WindowedAppContext::pending_functions_window_class_registered_;
+
+Win32WindowedAppContext::~Win32WindowedAppContext() {
+  if (pending_functions_hwnd_) {
+    DestroyWindow(pending_functions_hwnd_);
+  }
+}
+
+bool Win32WindowedAppContext::Initialize() {
+  // Logging possibly not initialized in this function yet.
+  // Create the message-only window for executing pending functions - using a
+  // window instead of executing them between iterations so non-main message
+  // loops, such as Windows modals, can execute pending functions too.
+  static const WCHAR kPendingFunctionsWindowClassName[] =
+      L"XeniaPendingFunctionsWindowClass";
+  if (!pending_functions_window_class_registered_) {
+    WNDCLASSEXW pending_functions_window_class = {};
+    pending_functions_window_class.cbSize =
+        sizeof(pending_functions_window_class);
+    pending_functions_window_class.lpfnWndProc = PendingFunctionsWndProc;
+    pending_functions_window_class.hInstance = hinstance_;
+    pending_functions_window_class.lpszClassName =
+        kPendingFunctionsWindowClassName;
+    if (!RegisterClassExW(&pending_functions_window_class)) {
+      return false;
+    }
+    pending_functions_window_class_registered_ = true;
+  }
+  pending_functions_hwnd_ = CreateWindowExW(
+      0, kPendingFunctionsWindowClassName, L"Xenia Pending Functions",
+      WS_OVERLAPPED, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT,
+      HWND_MESSAGE, nullptr, hinstance_, this);
+  if (!pending_functions_hwnd_) {
+    return false;
+  }
+  return true;
+}
+
+void Win32WindowedAppContext::NotifyUILoopOfPendingFunctions() {
+  while (!PostMessageW(pending_functions_hwnd_,
+                       kPendingFunctionsWindowClassMessageExecute, 0, 0)) {
+    Sleep(1);
+  }
+}
+
+void Win32WindowedAppContext::PlatformQuitFromUIThread() {
+  // Send WM_QUIT to whichever loop happens to process it - may be the loop of a
+  // built-in modal window, which is unaware of HasQuitFromUIThread, don't let
+  // it delay quitting indefinitely.
+  PostQuitMessage(EXIT_SUCCESS);
+}
+
+int Win32WindowedAppContext::RunMainMessageLoop() {
+  int result = EXIT_SUCCESS;
+  MSG message;
+  // The HasQuitFromUIThread check is not absolutely required, but for
+  // additional safety in case WM_QUIT is not received for any reason.
+  while (!HasQuitFromUIThread()) {
+    BOOL message_result = GetMessageW(&message, nullptr, 0, 0);
+    if (message_result == 0 || message_result == -1) {
+      // WM_QUIT (0 - this is the primary message loop, no need to resend, also
+      // contains the result from PostQuitMessage in wParam) or an error
+      // (-1). Quitting the context will run the pending functions. Getting
+      // WM_QUIT doesn't imply that QuitFromUIThread has been called already, it
+      // may originate in some place other than PlatformQuitFromUIThread as
+      // well - call it to finish everything including the pending functions.
+      QuitFromUIThread();
+      result = message_result ? EXIT_FAILURE : int(message.wParam);
+      break;
+    }
+    TranslateMessage(&message);
+    DispatchMessageW(&message);
+  }
+  return result;
+}
+
+LRESULT CALLBACK Win32WindowedAppContext::PendingFunctionsWndProc(
+    HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam) {
+  if (message == WM_CLOSE) {
+    // Need the window for the entire context's lifetime, don't allow anything
+    // to close it.
+    return 0;
+  }
+  if (message == WM_NCCREATE) {
+    SetWindowLongPtrW(
+        hwnd, GWLP_USERDATA,
+        reinterpret_cast<LONG_PTR>(
+            reinterpret_cast<const CREATESTRUCTW*>(lparam)->lpCreateParams));
+  } else {
+    auto app_context = reinterpret_cast<Win32WindowedAppContext*>(
+        GetWindowLongPtrW(hwnd, GWLP_USERDATA));
+    if (app_context) {
+      switch (message) {
+        case WM_DESTROY:
+          // The message-only window owned by the context is being destroyed,
+          // thus the context won't be able to execute pending functions
+          // anymore - can't continue functioning normally.
+          app_context->QuitFromUIThread();
+          break;
+        case kPendingFunctionsWindowClassMessageExecute:
+          app_context->ExecutePendingFunctionsFromUIThread();
+          break;
+        default:
+          break;
+      }
+    }
+  }
+  return DefWindowProcW(hwnd, message, wparam, lparam);
+}
+
+}  // namespace ui
+}  // namespace xe

src/xenia/ui/windowed_app_context_win.h

@@ -0,0 +1,58 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2021 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#ifndef XENIA_UI_WINDOWED_APP_CONTEXT_WIN_H_
+#define XENIA_UI_WINDOWED_APP_CONTEXT_WIN_H_
+
+#include <memory>
+
+#include "xenia/base/platform_win.h"
+#include "xenia/ui/windowed_app_context.h"
+
+namespace xe {
+namespace ui {
+
+class Win32WindowedAppContext final : public WindowedAppContext {
+ public:
+  // Must call Initialize and check its result after creating to be able to
+  // perform pending function calls.
+  explicit Win32WindowedAppContext(HINSTANCE hinstance, int show_cmd)
+      : hinstance_(hinstance), show_cmd_(show_cmd) {}
+  ~Win32WindowedAppContext();
+
+  bool Initialize();
+
+  HINSTANCE hinstance() const { return hinstance_; }
+  int show_cmd() const { return show_cmd_; }
+
+  void NotifyUILoopOfPendingFunctions() override;
+
+  void PlatformQuitFromUIThread() override;
+
+  int RunMainMessageLoop();
+
+ private:
+  enum : UINT {
+    kPendingFunctionsWindowClassMessageExecute = WM_USER,
+  };
+
+  static LRESULT CALLBACK PendingFunctionsWndProc(HWND hwnd, UINT message,
+                                                  WPARAM wparam, LPARAM lparam);
+
+  HINSTANCE hinstance_;
+  int show_cmd_;
+  HWND pending_functions_hwnd_ = nullptr;
+
+  static bool pending_functions_window_class_registered_;
+};
+
+}  // namespace ui
+}  // namespace xe
+
+#endif  // XENIA_UI_WINDOWED_APP_CONTEXT_WIN_H_

src/xenia/ui/windowed_app_main_posix.cc

@@ -0,0 +1,64 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2021 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#include <gtk/gtk.h>
+#include <cstdio>
+#include <cstdlib>
+#include <memory>
+
+#include "xenia/base/cvar.h"
+#include "xenia/base/logging.h"
+#include "xenia/ui/windowed_app.h"
+#include "xenia/ui/windowed_app_context_gtk.h"
+
+extern "C" int main(int argc_pre_gtk, char** argv_pre_gtk) {
+  // Initialize GTK+, which will handle and remove its own arguments from argv.
+  // Both GTK+ and Xenia use --option=value argument format (see man
+  // gtk-options), however, it's meaningless to try to parse the same argument
+  // both as a GTK+ one and as a cvar. Make GTK+ options take precedence in case
+  // of a name collision, as there's an alternative way of setting Xenia options
+  // (the config).
+  int argc_post_gtk = argc_pre_gtk;
+  char** argv_post_gtk = argv_pre_gtk;
+  if (!gtk_init_check(&argc_post_gtk, &argv_post_gtk)) {
+    // Logging has not been initialized yet.
+    std::fputs("Failed to initialize GTK+\n", stderr);
+    return EXIT_FAILURE;
+  }
+
+  int result;
+
+  {
+    xe::ui::GTKWindowedAppContext app_context;
+
+    std::unique_ptr<xe::ui::WindowedApp> app =
+        xe::ui::GetWindowedAppCreator()(app_context);
+
+    cvar::ParseLaunchArguments(argc_post_gtk, argv_post_gtk,
+                               app->GetPositionalOptionsUsage(),
+                               app->GetPositionalOptions());
+
+    // Initialize logging. Needs parsed cvars.
+    xe::InitializeLogging(app->GetName());
+
+    if (app->OnInitialize()) {
+      app_context.RunMainGTKLoop();
+      result = EXIT_SUCCESS;
+    } else {
+      result = EXIT_FAILURE;
+    }
+
+    app->InvokeOnDestroy();
+  }
+
+  // Logging may still be needed in the destructors.
+  xe::ShutdownLogging();
+
+  return result;
+}

src/xenia/ui/windowed_app_main_win.cc

@@ -0,0 +1,70 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2021 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#include <cstdlib>
+#include <memory>
+
+#include "xenia/base/console.h"
+#include "xenia/base/cvar.h"
+#include "xenia/base/main_win.h"
+#include "xenia/base/platform_win.h"
+#include "xenia/ui/windowed_app.h"
+#include "xenia/ui/windowed_app_context_win.h"
+
+DEFINE_bool(enable_console, false, "Open a console window with the main window",
+            "General");
+
+int WINAPI wWinMain(HINSTANCE hinstance, HINSTANCE hinstance_prev,
+                    LPWSTR command_line, int show_cmd) {
+  int result;
+
+  {
+    xe::ui::Win32WindowedAppContext app_context(hinstance, show_cmd);
+    // TODO(Triang3l): Initialize creates a window. Set DPI awareness via the
+    // manifest.
+    if (!app_context.Initialize()) {
+      return EXIT_FAILURE;
+    }
+
+    std::unique_ptr<xe::ui::WindowedApp> app =
+        xe::ui::GetWindowedAppCreator()(app_context);
+
+    if (!xe::ParseWin32LaunchArguments(false, app->GetPositionalOptionsUsage(),
+                                       app->GetPositionalOptions(), nullptr)) {
+      return EXIT_FAILURE;
+    }
+
+    // TODO(Triang3l): Rework this, need to initialize the console properly,
+    // disable has_console_attached_ by default in windowed apps, and attach
+    // only if needed.
+    if (cvars::enable_console) {
+      xe::AttachConsole();
+    }
+
+    // Initialize COM on the UI thread with the apartment-threaded concurrency
+    // model, so dialogs can be used.
+    if (FAILED(CoInitializeEx(nullptr, COINIT_APARTMENTTHREADED))) {
+      return EXIT_FAILURE;
+    }
+
+    xe::InitializeWin32App(app->GetName());
+
+    result =
+        app->OnInitialize() ? app_context.RunMainMessageLoop() : EXIT_FAILURE;
+
+    app->InvokeOnDestroy();
+  }
+
+  // Logging may still be needed in the destructors.
+  xe::ShutdownWin32App();
+
+  CoUninitialize();
+
+  return result;
+}

src/xenia/vfs/premake5.lua

@@ -27,7 +27,7 @@ project("xenia-vfs-dump")
 
   files({
     "vfs_dump.cc",
-    project_root.."/src/xenia/base/main_"..platform_suffix..".cc",
+    project_root.."/src/xenia/base/console_app_main_"..platform_suffix..".cc",
   })
   resincludedirs({
     project_root,

src/xenia/vfs/vfs_dump.cc

@@ -2,7 +2,7 @@
  ******************************************************************************
  * Xenia : Xbox 360 Emulator Research Project                                 *
  ******************************************************************************
- * Copyright 2020 Ben Vanik. All rights reserved.                             *
+ * Copyright 2021 Ben Vanik. All rights reserved.                             *
  * Released under the BSD license - see LICENSE in the root for more details. *
  ******************************************************************************
  */
@@ -11,8 +11,9 @@
 #include <string>
 #include <vector>
 
+#include "xenia/base/console_app_main.h"
+#include "xenia/base/cvar.h"
 #include "xenia/base/logging.h"
-#include "xenia/base/main.h"
 #include "xenia/base/math.h"
 
 #include "xenia/vfs/devices/stfs_container_device.h"
@@ -113,5 +114,5 @@ int vfs_dump_main(const std::vector<std::string>& args) {
 }  // namespace vfs
 }  // namespace xe
 
-DEFINE_ENTRY_POINT("xenia-vfs-dump", xe::vfs::vfs_dump_main,
+XE_DEFINE_CONSOLE_APP("xenia-vfs-dump", xe::vfs::vfs_dump_main,
-                   "[source] [dump_path]", "source", "dump_path");
+                      "[source] [dump_path]", "source", "dump_path");

tools/build/scripts/test_suite.lua

@@ -31,7 +31,7 @@ local function combined_test_suite(test_suite_name, project_root, base_path, con
     })
     files({
       project_root.."/"..build_tools_src.."/test_suite_main.cc",
-      project_root.."/src/xenia/base/main_"..platform_suffix..".cc",
+      project_root.."/src/xenia/base/console_app_main_"..platform_suffix..".cc",
       base_path.."/**_test.cc",
     })
     filter("toolset:msc")

tools/build/src/test_suite_main.cc

@@ -13,8 +13,8 @@
 #include <string>
 #include <vector>
 
+#include "xenia/base/console_app_main.h"
 #include "xenia/base/cvar.h"
-#include "xenia/base/main.h"
 
 #define CATCH_CONFIG_RUNNER
 #include "third_party/catch/single_include/catch2/catch.hpp"
@@ -43,5 +43,5 @@ int test_suite_main(const std::vector<std::string>& args) {
 #error XE_TEST_SUITE_NAME is undefined!
 #endif
 
-DEFINE_ENTRY_POINT_TRANSPARENT(XE_TEST_SUITE_NAME,
+XE_DEFINE_CONSOLE_APP_TRANSPARENT(XE_TEST_SUITE_NAME,
-                               xe::test_suite::test_suite_main);
+                                  xe::test_suite::test_suite_main);