зеркало из https://github.com/mozilla/gecko-dev.git
119 строки
3.2 KiB
C++
119 строки
3.2 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/. */
|
|
|
|
#ifndef mozilla_CrossProcessSemaphore_h
|
|
#define mozilla_CrossProcessSemaphore_h
|
|
|
|
#include "base/process.h"
|
|
#include "mozilla/TimeStamp.h"
|
|
#include "mozilla/Maybe.h"
|
|
|
|
#if defined(OS_WIN)
|
|
# include "mozilla/UniquePtrExtensions.h"
|
|
#endif
|
|
#if !defined(OS_WIN) && !defined(OS_MACOSX)
|
|
# include <pthread.h>
|
|
# include <semaphore.h>
|
|
# include "mozilla/ipc/SharedMemoryBasic.h"
|
|
# include "mozilla/Atomics.h"
|
|
#endif
|
|
|
|
namespace IPC {
|
|
template <typename T>
|
|
struct ParamTraits;
|
|
} // namespace IPC
|
|
|
|
//
|
|
// Provides:
|
|
//
|
|
// - CrossProcessSemaphore, a semaphore that can be shared across processes
|
|
namespace mozilla {
|
|
|
|
template <typename T>
|
|
inline bool IsHandleValid(const T& handle) {
|
|
return bool(handle);
|
|
}
|
|
|
|
#if defined(OS_WIN)
|
|
typedef mozilla::UniqueFileHandle CrossProcessSemaphoreHandle;
|
|
#elif !defined(OS_MACOSX)
|
|
typedef mozilla::ipc::SharedMemoryBasic::Handle CrossProcessSemaphoreHandle;
|
|
|
|
template <>
|
|
inline bool IsHandleValid<CrossProcessSemaphoreHandle>(
|
|
const CrossProcessSemaphoreHandle& handle) {
|
|
return !(handle == mozilla::ipc::SharedMemoryBasic::NULLHandle());
|
|
}
|
|
#else
|
|
// Stub for other platforms. We can't use uintptr_t here since different
|
|
// processes could disagree on its size.
|
|
typedef uintptr_t CrossProcessSemaphoreHandle;
|
|
#endif
|
|
|
|
class CrossProcessSemaphore {
|
|
public:
|
|
/**
|
|
* CrossProcessSemaphore
|
|
* @param name A name which can reference this lock (currently unused)
|
|
**/
|
|
static CrossProcessSemaphore* Create(const char* aName,
|
|
uint32_t aInitialValue);
|
|
|
|
/**
|
|
* CrossProcessSemaphore
|
|
* @param handle A handle of an existing cross process semaphore that can be
|
|
* opened.
|
|
*/
|
|
static CrossProcessSemaphore* Create(CrossProcessSemaphoreHandle aHandle);
|
|
|
|
~CrossProcessSemaphore();
|
|
|
|
/**
|
|
* Decrements the current value of the semaphore. This will block if the
|
|
* current value of the semaphore is 0, up to a maximum of aWaitTime (if
|
|
* specified).
|
|
* Returns true if the semaphore was succesfully decremented, false otherwise.
|
|
**/
|
|
bool Wait(const Maybe<TimeDuration>& aWaitTime = Nothing());
|
|
|
|
/**
|
|
* Increments the current value of the semaphore.
|
|
**/
|
|
void Signal();
|
|
|
|
/**
|
|
* CloneHandle
|
|
* This function is called to generate a serializable structure that can
|
|
* be sent to the specified process and opened on the other side.
|
|
*
|
|
* @returns A handle that can be shared to another process
|
|
*/
|
|
CrossProcessSemaphoreHandle CloneHandle();
|
|
|
|
void CloseHandle();
|
|
|
|
private:
|
|
friend struct IPC::ParamTraits<CrossProcessSemaphore>;
|
|
|
|
CrossProcessSemaphore();
|
|
CrossProcessSemaphore(const CrossProcessSemaphore&);
|
|
CrossProcessSemaphore& operator=(const CrossProcessSemaphore&);
|
|
|
|
#if defined(OS_WIN)
|
|
explicit CrossProcessSemaphore(HANDLE aSemaphore);
|
|
|
|
HANDLE mSemaphore;
|
|
#elif !defined(OS_MACOSX)
|
|
RefPtr<mozilla::ipc::SharedMemoryBasic> mSharedBuffer;
|
|
sem_t* mSemaphore;
|
|
mozilla::Atomic<int32_t>* mRefCount;
|
|
#endif
|
|
};
|
|
|
|
} // namespace mozilla
|
|
|
|
#endif
|