gecko-dev/ipc/glue/CrossProcessSemaphore_windo...

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/* -*- 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 <windows.h>
#include "base/process_util.h"
#include "CrossProcessSemaphore.h"
#include "nsDebug.h"
#include "nsISupportsImpl.h"
#include "ProtocolUtils.h"
using base::GetCurrentProcessHandle;
using base::ProcessHandle;
namespace mozilla {
/* static */
CrossProcessSemaphore* CrossProcessSemaphore::Create(const char*,
uint32_t aInitialValue) {
// We explicitly share this using DuplicateHandle, we do -not- want this to
// be inherited by child processes by default! So no security attributes are
// given.
HANDLE semaphore =
::CreateSemaphoreA(nullptr, aInitialValue, 0x7fffffff, nullptr);
if (!semaphore) {
return nullptr;
}
return new CrossProcessSemaphore(semaphore);
}
/* static */
CrossProcessSemaphore* CrossProcessSemaphore::Create(
CrossProcessSemaphoreHandle aHandle) {
DWORD flags;
if (!::GetHandleInformation(aHandle.get(), &flags)) {
return nullptr;
}
return new CrossProcessSemaphore(aHandle.release());
}
CrossProcessSemaphore::CrossProcessSemaphore(HANDLE aSemaphore)
: mSemaphore(aSemaphore) {
MOZ_COUNT_CTOR(CrossProcessSemaphore);
}
CrossProcessSemaphore::~CrossProcessSemaphore() {
MOZ_ASSERT(mSemaphore, "Improper construction of semaphore or double free.");
::CloseHandle(mSemaphore);
MOZ_COUNT_DTOR(CrossProcessSemaphore);
}
bool CrossProcessSemaphore::Wait(const Maybe<TimeDuration>& aWaitTime) {
MOZ_ASSERT(mSemaphore, "Improper construction of semaphore.");
HRESULT hr = ::WaitForSingleObject(
mSemaphore, aWaitTime.isSome() ? aWaitTime->ToMilliseconds() : INFINITE);
return hr == WAIT_OBJECT_0;
}
void CrossProcessSemaphore::Signal() {
MOZ_ASSERT(mSemaphore, "Improper construction of semaphore.");
::ReleaseSemaphore(mSemaphore, 1, nullptr);
}
CrossProcessSemaphoreHandle CrossProcessSemaphore::ShareToProcess(
base::ProcessId aTargetPid) {
HANDLE newHandle;
bool succeeded =
::DuplicateHandle(GetCurrentProcess(), mSemaphore, GetCurrentProcess(),
&newHandle, 0, false, DUPLICATE_SAME_ACCESS);
if (!succeeded) {
return nullptr;
}
return UniqueFileHandle(newHandle);
}
void CrossProcessSemaphore::CloseHandle() {}
} // namespace mozilla