gecko-dev/ipc/mscom/MainThreadInvoker.cpp

135 строки
3.7 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "mozilla/mscom/MainThreadInvoker.h"
#include "GeckoProfiler.h"
#include "MainThreadUtils.h"
#include "mozilla/Assertions.h"
#include "mozilla/ClearOnShutdown.h"
#include "mozilla/DebugOnly.h"
#include "mozilla/HangMonitor.h"
#include "mozilla/RefPtr.h"
#include "private/prpriv.h" // For PR_GetThreadID
#include "WinUtils.h"
namespace {
class SyncRunnable : public mozilla::Runnable
{
public:
SyncRunnable(HANDLE aEvent, already_AddRefed<nsIRunnable>&& aRunnable)
: mDoneEvent(aEvent)
, mRunnable(aRunnable)
{
MOZ_ASSERT(aEvent);
MOZ_ASSERT(mRunnable);
}
NS_IMETHOD Run() override
{
mRunnable->Run();
::SetEvent(mDoneEvent);
return NS_OK;
}
private:
HANDLE mDoneEvent;
nsCOMPtr<nsIRunnable> mRunnable;
};
} // anonymous namespace
namespace mozilla {
namespace mscom {
HANDLE MainThreadInvoker::sMainThread = nullptr;
/* static */ bool
MainThreadInvoker::InitStatics()
{
nsCOMPtr<nsIThread> mainThread;
nsresult rv = ::NS_GetMainThread(getter_AddRefs(mainThread));
if (NS_FAILED(rv)) {
return false;
}
PRThread* mainPrThread = nullptr;
rv = mainThread->GetPRThread(&mainPrThread);
if (NS_FAILED(rv)) {
return false;
}
PRUint32 tid = ::PR_GetThreadID(mainPrThread);
sMainThread = ::OpenThread(SYNCHRONIZE | THREAD_SET_CONTEXT, FALSE, tid);
return !!sMainThread;
}
MainThreadInvoker::MainThreadInvoker()
: mDoneEvent(::CreateEventW(nullptr, FALSE, FALSE, nullptr))
{
static const bool gotStatics = InitStatics();
MOZ_ASSERT(gotStatics);
}
MainThreadInvoker::~MainThreadInvoker()
{
if (mDoneEvent) {
::CloseHandle(mDoneEvent);
}
}
bool
MainThreadInvoker::WaitForCompletion(DWORD aTimeout)
{
HANDLE handles[] = {mDoneEvent, sMainThread};
DWORD waitResult = ::WaitForMultipleObjects(ArrayLength(handles), handles,
FALSE, aTimeout);
return waitResult == WAIT_OBJECT_0;
}
bool
MainThreadInvoker::Invoke(already_AddRefed<nsIRunnable>&& aRunnable,
DWORD aTimeout)
{
nsCOMPtr<nsIRunnable> runnable(Move(aRunnable));
if (!runnable) {
return false;
}
if (NS_IsMainThread()) {
runnable->Run();
return true;
}
RefPtr<SyncRunnable> wrappedRunnable(new SyncRunnable(mDoneEvent,
runnable.forget()));
// Make sure that wrappedRunnable remains valid while sitting in the APC queue
wrappedRunnable->AddRef();
if (!::QueueUserAPC(&MainThreadAPC, sMainThread,
reinterpret_cast<UINT_PTR>(wrappedRunnable.get()))) {
// Enqueue failed so cancel the above AddRef
wrappedRunnable->Release();
return false;
}
// We should ensure a call to NtTestAlert() is made on the main thread so
// that the main thread will check for APCs during event processing. If we
// omit this then the main thread will not check its APC queue until it is
// idle.
widget::WinUtils::SetAPCPending();
return WaitForCompletion(aTimeout);
}
/* static */ VOID CALLBACK
MainThreadInvoker::MainThreadAPC(ULONG_PTR aParam)
{
GeckoProfilerWakeRAII wakeProfiler;
mozilla::HangMonitor::NotifyActivity(mozilla::HangMonitor::kGeneralActivity);
MOZ_ASSERT(NS_IsMainThread());
RefPtr<SyncRunnable> runnable(already_AddRefed<SyncRunnable>(
reinterpret_cast<SyncRunnable*>(aParam)));
runnable->Run();
}
} // namespace mscom
} // namespace mozilla