pcsx2/3rdparty/winwil/include/wil/com_apartment_variable.h

490 lines
19 KiB
C++

//*********************************************************
//
// Copyright (c) Microsoft. All rights reserved.
// This code is licensed under the MIT License.
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
// ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
// TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
// PARTICULAR PURPOSE AND NONINFRINGEMENT.
//
//*********************************************************
//! @file
//! Smart pointers and other thin usability pattern wrappers over COM patterns.
#ifndef __WIL_COM_APARTMENT_VARIABLE_INCLUDED
#define __WIL_COM_APARTMENT_VARIABLE_INCLUDED
#include <any>
#include <objidl.h>
#include <roapi.h>
#include <type_traits>
#include <unordered_map>
#include <winrt/Windows.Foundation.h>
#include "com.h"
#include "cppwinrt.h"
#include "result_macros.h"
#include "win32_helpers.h"
#ifndef WIL_ENABLE_EXCEPTIONS
#error This header requires exceptions
#endif
namespace wil
{
// Determine if apartment variables are supported in the current process context.
// Prior to build 22365, the APIs needed to create apartment variables (e.g. RoGetApartmentIdentifier)
// failed for unpackaged processes. For MS people, see http://task.ms/31861017 for details.
// APIs needed to implement apartment variables did not work in non-packaged processes.
inline bool are_apartment_variables_supported()
{
unsigned long long apartmentId{};
return RoGetApartmentIdentifier(&apartmentId) != HRESULT_FROM_WIN32(ERROR_API_UNAVAILABLE);
}
// COM will implicitly rundown the apartment registration when it invokes a handler
// and blocks calling unregister when executing the callback. So be careful to release()
// this when callback is invoked to avoid a double free of the cookie.
using unique_apartment_shutdown_registration =
unique_any<APARTMENT_SHUTDOWN_REGISTRATION_COOKIE, decltype(&::RoUnregisterForApartmentShutdown), ::RoUnregisterForApartmentShutdown>;
struct apartment_variable_platform
{
static unsigned long long GetApartmentId()
{
unsigned long long apartmentId{};
FAIL_FAST_IF_FAILED(RoGetApartmentIdentifier(&apartmentId));
return apartmentId;
}
static auto RegisterForApartmentShutdown(IApartmentShutdown* observer)
{
unsigned long long id{};
shutdown_type cookie;
THROW_IF_FAILED(RoRegisterForApartmentShutdown(observer, &id, cookie.put()));
return cookie;
}
static void UnRegisterForApartmentShutdown(APARTMENT_SHUTDOWN_REGISTRATION_COOKIE cookie)
{
FAIL_FAST_IF_FAILED(RoUnregisterForApartmentShutdown(cookie));
}
static auto CoInitializeEx(DWORD coinitFlags = 0 /*COINIT_MULTITHREADED*/)
{
return wil::CoInitializeEx(coinitFlags);
}
// disable the test hook
inline static constexpr unsigned long AsyncRundownDelayForTestingRaces = INFINITE;
using shutdown_type = wil::unique_apartment_shutdown_registration;
};
enum class apartment_variable_leak_action
{
fail_fast,
ignore
};
// "pins" the current module in memory by incrementing the module reference count and leaking that.
inline void ensure_module_stays_loaded()
{
static INIT_ONCE s_initLeakModule{}; // avoiding magic statics
wil::init_once_failfast(s_initLeakModule, []() {
HMODULE result{};
FAIL_FAST_IF(!GetModuleHandleExW(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS | GET_MODULE_HANDLE_EX_FLAG_PIN, L"", &result));
return S_OK;
});
}
/// @cond
namespace details
{
// For the address of data, you can detect global variables by the ability to resolve the module from the address.
inline bool IsGlobalVariable(const void* moduleAddress) noexcept
{
wil::unique_hmodule moduleHandle;
return GetModuleHandleExW(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS, static_cast<PCWSTR>(moduleAddress), &moduleHandle) != FALSE;
}
struct any_maker_base
{
std::any (*adapter)(void*);
void* inner;
WI_NODISCARD std::any operator()() const
{
return adapter(inner);
}
};
template <typename T>
struct any_maker : any_maker_base
{
any_maker()
{
adapter = [](auto) -> std::any {
return T{};
};
}
any_maker(T (*maker)())
{
adapter = [](auto maker) -> std::any {
return reinterpret_cast<T (*)()>(maker)();
};
inner = reinterpret_cast<void*>(maker);
}
template <typename F>
any_maker(F&& f)
{
adapter = [](auto maker) -> std::any {
return reinterpret_cast<F*>(maker)[0]();
};
inner = std::addressof(f);
}
};
template <apartment_variable_leak_action leak_action = apartment_variable_leak_action::fail_fast, typename test_hook = apartment_variable_platform>
struct apartment_variable_base
{
inline static winrt::slim_mutex s_lock;
struct apartment_variable_storage
{
apartment_variable_storage(apartment_variable_storage&& other) noexcept = default;
apartment_variable_storage(const apartment_variable_storage& other) = delete;
apartment_variable_storage(typename test_hook::shutdown_type&& cookie_) : cookie(std::move(cookie_))
{
}
winrt::apartment_context context;
typename test_hook::shutdown_type cookie;
// Variables are stored using the address of the apartment_variable_base<> as the key.
std::unordered_map<apartment_variable_base<leak_action, test_hook>*, std::any> variables;
};
// Apartment id -> variables storage.
inline static wil::object_without_destructor_on_shutdown<std::unordered_map<unsigned long long, apartment_variable_storage>> s_apartmentStorage;
constexpr apartment_variable_base() = default;
~apartment_variable_base()
{
// Global variables (object with static storage duration)
// are run down when the process is shutting down or when the
// dll is unloaded. At these points it is not possible to start
// an async operation and the work performed is not needed,
// the apartments with variable have been run down already.
const auto isGlobal = details::IsGlobalVariable(this);
if (!isGlobal)
{
clear_all_apartments_async();
}
if constexpr (leak_action == apartment_variable_leak_action::fail_fast)
{
if (isGlobal && !ProcessShutdownInProgress())
{
// If you hit this fail fast it means the storage in s_apartmentStorage will be leaked.
// For apartment variables used in .exes, this is expected and
// this fail fast should be disabled using
// wil::apartment_variable<T, wil::apartment_variable_leak_action::ignore>
//
// For DLLs, if this is expected, disable this fail fast using
// wil::apartment_variable<T, wil::apartment_variable_leak_action::ignore>
//
// Use of apartment variables in DLLs only loaded by COM will never hit this case
// as COM will unload DLLs before apartments are rundown,
// providing the opportunity to empty s_apartmentStorage.
//
// But DLLs loaded and unloaded to call DLL entry points (outside of COM) may
// create variable storage that can't be cleaned up as the DLL lifetime is
// shorter that the COM lifetime. In these cases either
// 1) accept the leaks and disable the fail fast as describe above
// 2) disable module unloading by calling wil::ensure_module_stays_loaded
// 3) CoCreate an object from this DLL to make COM aware of the DLL
FAIL_FAST_IF(!s_apartmentStorage.get().empty());
}
}
}
// non-copyable, non-assignable
apartment_variable_base(apartment_variable_base const&) = delete;
void operator=(apartment_variable_base const&) = delete;
// get current value or throw if no value has been set
std::any& get_existing()
{
auto any = get_if();
if (!any)
{
THROW_HR(E_NOT_SET);
}
return *any;
}
static apartment_variable_storage* get_current_apartment_variable_storage()
{
auto storage = s_apartmentStorage.get().find(test_hook::GetApartmentId());
if (storage != s_apartmentStorage.get().end())
{
return &storage->second;
}
return nullptr;
}
apartment_variable_storage* ensure_current_apartment_variables()
{
auto variables = get_current_apartment_variable_storage();
if (variables)
{
return variables;
}
struct ApartmentObserver : public winrt::implements<ApartmentObserver, IApartmentShutdown>
{
void STDMETHODCALLTYPE OnUninitialize(unsigned long long apartmentId) noexcept override
{
// This code runs at apartment rundown so be careful to avoid deadlocks by
// extracting the variables under the lock then release them outside.
auto variables = [apartmentId]() {
auto lock = winrt::slim_lock_guard(s_lock);
return s_apartmentStorage.get().extract(apartmentId);
}();
WI_ASSERT(variables.key() == apartmentId);
// The system implicitly releases the shutdown observer
// after invoking the callback and does not allow calling unregister
// in the callback. So release the reference to the registration.
variables.mapped().cookie.release();
}
};
auto shutdownRegistration = test_hook::RegisterForApartmentShutdown(winrt::make<ApartmentObserver>().get());
return &s_apartmentStorage.get()
.insert({test_hook::GetApartmentId(), apartment_variable_storage(std::move(shutdownRegistration))})
.first->second;
}
// get current value or custom-construct one on demand
template <typename T>
std::any& get_or_create(any_maker<T>&& creator)
{
apartment_variable_storage* variable_storage = nullptr;
{ // scope for lock
auto lock = winrt::slim_lock_guard(s_lock);
variable_storage = ensure_current_apartment_variables();
auto variable = variable_storage->variables.find(this);
if (variable != variable_storage->variables.end())
{
return variable->second;
}
} // drop the lock
// create the object outside the lock to avoid reentrant deadlock
auto value = creator();
auto insert_lock = winrt::slim_lock_guard(s_lock);
// The insertion may fail if creator() recursively caused itself to be created,
// in which case we return the existing object and the falsely-created one is discarded.
return variable_storage->variables.insert({this, std::move(value)}).first->second;
}
// get pointer to current value or nullptr if no value has been set
std::any* get_if()
{
auto lock = winrt::slim_lock_guard(s_lock);
if (auto variable_storage = get_current_apartment_variable_storage())
{
auto variable = variable_storage->variables.find(this);
if (variable != variable_storage->variables.end())
{
return &(variable->second);
}
}
return nullptr;
}
// replace or create the current value, fail fasts if the value is not already stored
void set(std::any value)
{
// release value, with the swapped value, outside of the lock
{
auto lock = winrt::slim_lock_guard(s_lock);
auto storage = s_apartmentStorage.get().find(test_hook::GetApartmentId());
FAIL_FAST_IF(storage == s_apartmentStorage.get().end());
auto& variable_storage = storage->second;
auto variable = variable_storage.variables.find(this);
FAIL_FAST_IF(variable == variable_storage.variables.end());
variable->second.swap(value);
}
}
// remove any current value
void clear()
{
auto lock = winrt::slim_lock_guard(s_lock);
if (auto variable_storage = get_current_apartment_variable_storage())
{
variable_storage->variables.erase(this);
if (variable_storage->variables.size() == 0)
{
s_apartmentStorage.get().erase(test_hook::GetApartmentId());
}
}
}
winrt::Windows::Foundation::IAsyncAction clear_all_apartments_async()
{
// gather all the apartments that hold objects we need to destruct
// (do not gather the objects themselves, because the apartment might
// destruct before we get around to it, and we should let the apartment
// destruct the object while it still can).
std::vector<winrt::apartment_context> contexts;
{ // scope for lock
auto lock = winrt::slim_lock_guard(s_lock);
for (auto& [id, storage] : s_apartmentStorage.get())
{
auto variable = storage.variables.find(this);
if (variable != storage.variables.end())
{
contexts.push_back(storage.context);
}
}
}
if (contexts.empty())
{
co_return;
}
wil::unique_mta_usage_cookie mta_reference; // need to extend the MTA due to async cleanup
FAIL_FAST_IF_FAILED(CoIncrementMTAUsage(mta_reference.put()));
// From a background thread hop into each apartment to run down the object
// if it's still there.
co_await winrt::resume_background();
// This hook enables testing the case where execution of this method loses the race with
// apartment rundown by other means.
if constexpr (test_hook::AsyncRundownDelayForTestingRaces != INFINITE)
{
Sleep(test_hook::AsyncRundownDelayForTestingRaces);
}
for (auto&& context : contexts)
{
try
{
co_await context;
clear();
}
catch (winrt::hresult_error const& e)
{
// Ignore failure if apartment ran down before we could clean it up.
// The object already ran down as part of apartment cleanup.
if ((e.code() != RPC_E_SERVER_DIED_DNE) && (e.code() != RPC_E_DISCONNECTED))
{
throw;
}
}
catch (...)
{
FAIL_FAST();
}
}
}
static const auto& storage()
{
return s_apartmentStorage.get();
}
static size_t current_apartment_variable_count()
{
auto lock = winrt::slim_lock_guard(s_lock);
if (auto variable_storage = get_current_apartment_variable_storage())
{
return variable_storage->variables.size();
}
return 0;
}
};
} // namespace details
/// @endcond
// Apartment variables enable storing COM objects safely in globals
// (objects with static storage duration) by creating a unique copy
// in each apartment and managing their lifetime based on apartment rundown
// notifications.
// They can also be used for automatic or dynamic storage duration but those
// cases are less common.
// This type is also useful for storing references to apartment affine objects.
//
// Note, that apartment variables hosted in a COM DLL need to integrate with
// the DllCanUnloadNow() function to include the ref counts contributed by
// C++ WinRT objects. This is automatic for DLLs that host C++ WinRT objects
// but WRL projects will need to be updated to call winrt::get_module_lock().
template <typename T, apartment_variable_leak_action leak_action = apartment_variable_leak_action::fail_fast, typename test_hook = wil::apartment_variable_platform>
struct apartment_variable : details::apartment_variable_base<leak_action, test_hook>
{
using base = details::apartment_variable_base<leak_action, test_hook>;
constexpr apartment_variable() = default;
// Get current value or throw if no value has been set.
T& get_existing()
{
return std::any_cast<T&>(base::get_existing());
}
// Get current value or default-construct one on demand.
T& get_or_create()
{
return std::any_cast<T&>(base::get_or_create(details::any_maker<T>()));
}
// Get current value or custom-construct one on demand.
template <typename F>
T& get_or_create(F&& f)
{
return std::any_cast<T&>(base::get_or_create(details::any_maker<T>(std::forward<F>(f))));
}
// get pointer to current value or nullptr if no value has been set
T* get_if()
{
return std::any_cast<T>(base::get_if());
}
// replace or create the current value, fail fasts if the value is not already stored
template <typename V>
void set(V&& value)
{
return base::set(std::forward<V>(value));
}
// Clear the value in the current apartment.
using base::clear;
// Asynchronously clear the value in all apartments it is present in.
using base::clear_all_apartments_async;
// For testing only.
// 1) To observe the state of the storage in the debugger assign this to
// a temporary variable (const&) and watch its contents.
// 2) Use this to test the implementation.
using base::storage;
// For testing only. The number of variables in the current apartment.
using base::current_apartment_variable_count;
};
} // namespace wil
#endif // __WIL_COM_APARTMENT_VARIABLE_INCLUDED