Merge pull request #11822 from AdmiralCurtiss/win-large-memarena

Common/MemArenaWin: Improve file mapping logic.

Source/Core/Common/MemArena.h

@@ -4,6 +4,7 @@
 #pragma once
 
 #include <cstddef>
+#include <string_view>
 #include <vector>
 
 #include "Common/CommonTypes.h"
@@ -34,8 +35,10 @@ public:
   /// CreateView() and ReleaseView(). Used to make a mappable region for emulated memory.
   ///
   /// @param size The amount of bytes that should be allocated in this region.
+  /// @param base_name A base name for the shared memory region, if applicable for this platform.
+  /// Will be extended with the process ID.
   ///
-  void GrabSHMSegment(size_t size);
+  void GrabSHMSegment(size_t size, std::string_view base_name);
 
   ///
   /// Release the memory segment previously allocated with GrabSHMSegment().

Source/Core/Common/MemArenaAndroid.cpp

@@ -10,6 +10,8 @@
 #include <set>
 #include <string>
 
+#include <fmt/format.h>
+
 #include <dlfcn.h>
 #include <fcntl.h>
 #include <linux/ashmem.h>
@@ -62,9 +64,10 @@ static int AshmemCreateFileMapping(const char* name, size_t size)
 MemArena::MemArena() = default;
 MemArena::~MemArena() = default;
 
-void MemArena::GrabSHMSegment(size_t size)
+void MemArena::GrabSHMSegment(size_t size, std::string_view base_name)
 {
-  m_shm_fd = AshmemCreateFileMapping(("dolphin-emu." + std::to_string(getpid())).c_str(), size);
+  const std::string name = fmt::format("{}.{}", base_name, getpid());
+  m_shm_fd = AshmemCreateFileMapping(name.c_str(), size);
   if (m_shm_fd < 0)
     NOTICE_LOG_FMT(MEMMAP, "Ashmem allocation failed");
 }

Source/Core/Common/MemArenaUnix.cpp

@@ -10,6 +10,8 @@
 #include <set>
 #include <string>
 
+#include <fmt/format.h>
+
 #include <fcntl.h>
 #include <sys/mman.h>
 #include <unistd.h>
@@ -25,9 +27,9 @@ namespace Common
 MemArena::MemArena() = default;
 MemArena::~MemArena() = default;
 
-void MemArena::GrabSHMSegment(size_t size)
+void MemArena::GrabSHMSegment(size_t size, std::string_view base_name)
 {
-  const std::string file_name = "/dolphin-emu." + std::to_string(getpid());
+  const std::string file_name = fmt::format("/{}.{}", base_name, getpid());
   m_shm_fd = shm_open(file_name.c_str(), O_RDWR | O_CREAT | O_EXCL, 0600);
   if (m_shm_fd == -1)
   {

Source/Core/Common/MemArenaWin.cpp

@@ -8,6 +8,8 @@
 #include <cstdlib>
 #include <string>
 
+#include <fmt/format.h>
+
 #include <windows.h>
 
 #include "Common/Assert.h"
@@ -97,11 +99,22 @@ MemArena::~MemArena()
   ReleaseSHMSegment();
 }
 
-void MemArena::GrabSHMSegment(size_t size)
+static DWORD GetHighDWORD(u64 value)
 {
-  const std::string name = "dolphin-emu." + std::to_string(GetCurrentProcessId());
-  m_memory_handle = CreateFileMapping(INVALID_HANDLE_VALUE, nullptr, PAGE_READWRITE, 0,
-                                      static_cast<DWORD>(size), UTF8ToTStr(name).c_str());
+  return static_cast<DWORD>(value >> 32);
+}
+
+static DWORD GetLowDWORD(u64 value)
+{
+  return static_cast<DWORD>(value);
+}
+
+void MemArena::GrabSHMSegment(size_t size, std::string_view base_name)
+{
+  const std::string name = fmt::format("{}.{}", base_name, GetCurrentProcessId());
+  m_memory_handle =
+      CreateFileMapping(INVALID_HANDLE_VALUE, nullptr, PAGE_READWRITE, GetHighDWORD(size),
+                        GetLowDWORD(size), UTF8ToTStr(name).c_str());
 }
 
 void MemArena::ReleaseSHMSegment()
@@ -114,8 +127,9 @@ void MemArena::ReleaseSHMSegment()
 
 void* MemArena::CreateView(s64 offset, size_t size)
 {
-  return MapViewOfFileEx(m_memory_handle, FILE_MAP_ALL_ACCESS, 0, (DWORD)((u64)offset), size,
-                         nullptr);
+  const u64 off = static_cast<u64>(offset);
+  return MapViewOfFileEx(m_memory_handle, FILE_MAP_ALL_ACCESS, GetHighDWORD(off), GetLowDWORD(off),
+                         size, nullptr);
 }
 
 void MemArena::ReleaseView(void* view, size_t size)

Source/Core/Core/HW/Memmap.cpp

@@ -121,7 +121,7 @@ void MemoryManager::Init()
     region.active = true;
     mem_size += region.size;
   }
-  m_arena.GrabSHMSegment(mem_size);
+  m_arena.GrabSHMSegment(mem_size, "dolphin-emu");
 
   m_physical_page_mappings.fill(nullptr);