mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-11-01 14:45:29 +00:00
114 lines
3.1 KiB
C++
114 lines
3.1 KiB
C++
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
|
|
* 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_CrossProcessMutex_h
|
|
#define mozilla_CrossProcessMutex_h
|
|
|
|
#include "base/process.h"
|
|
#include "mozilla/Mutex.h"
|
|
|
|
#if defined(OS_LINUX)
|
|
#include <pthread.h>
|
|
#include "SharedMemoryBasic.h"
|
|
#include "mozilla/Atomics.h"
|
|
#endif
|
|
|
|
namespace IPC {
|
|
template<typename T>
|
|
struct ParamTraits;
|
|
}
|
|
|
|
//
|
|
// Provides:
|
|
//
|
|
// - CrossProcessMutex, a non-recursive mutex that can be shared across processes
|
|
// - CrossProcessMutexAutoLock, an RAII class for ensuring that Mutexes are
|
|
// properly locked and unlocked
|
|
//
|
|
// Using CrossProcessMutexAutoLock/CrossProcessMutexAutoUnlock is MUCH
|
|
// preferred to making bare calls to CrossProcessMutex.Lock and Unlock.
|
|
//
|
|
namespace mozilla {
|
|
#ifdef XP_WIN
|
|
typedef HANDLE CrossProcessMutexHandle;
|
|
#elif defined(OS_LINUX)
|
|
typedef mozilla::ipc::SharedMemoryBasic::Handle CrossProcessMutexHandle;
|
|
#else
|
|
// Stub for other platforms. We can't use uintptr_t here since different
|
|
// processes could disagree on its size.
|
|
typedef uintptr_t CrossProcessMutexHandle;
|
|
#endif
|
|
|
|
class NS_COM_GLUE CrossProcessMutex
|
|
{
|
|
public:
|
|
/**
|
|
* CrossProcessMutex
|
|
* @param name A name which can reference this lock (currently unused)
|
|
**/
|
|
CrossProcessMutex(const char* aName);
|
|
/**
|
|
* CrossProcessMutex
|
|
* @param handle A handle of an existing cross process mutex that can be
|
|
* opened.
|
|
*/
|
|
CrossProcessMutex(CrossProcessMutexHandle aHandle);
|
|
|
|
/**
|
|
* ~CrossProcessMutex
|
|
**/
|
|
~CrossProcessMutex();
|
|
|
|
/**
|
|
* Lock
|
|
* This will lock the mutex. Any other thread in any other process that
|
|
* has access to this mutex calling lock will block execution until the
|
|
* initial caller of lock has made a call to Unlock.
|
|
*
|
|
* If the owning process is terminated unexpectedly the mutex will be
|
|
* released.
|
|
**/
|
|
void Lock();
|
|
|
|
/**
|
|
* Unlock
|
|
* This will unlock the mutex. A single thread currently waiting on a lock
|
|
* call will resume execution and aquire ownership of the lock. No
|
|
* guarantees are made as to the order in which waiting threads will resume
|
|
* execution.
|
|
**/
|
|
void Unlock();
|
|
|
|
/**
|
|
* ShareToProcess
|
|
* 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
|
|
*/
|
|
CrossProcessMutexHandle ShareToProcess(base::ProcessHandle aTarget);
|
|
|
|
private:
|
|
friend struct IPC::ParamTraits<CrossProcessMutex>;
|
|
|
|
CrossProcessMutex();
|
|
CrossProcessMutex(const CrossProcessMutex&);
|
|
CrossProcessMutex &operator=(const CrossProcessMutex&);
|
|
|
|
#ifdef XP_WIN
|
|
HANDLE mMutex;
|
|
#elif defined(OS_LINUX)
|
|
mozilla::ipc::SharedMemoryBasic* mSharedBuffer;
|
|
pthread_mutex_t* mMutex;
|
|
mozilla::Atomic<int32_t>* mCount;
|
|
#endif
|
|
};
|
|
|
|
typedef BaseAutoLock<CrossProcessMutex> CrossProcessMutexAutoLock;
|
|
typedef BaseAutoUnlock<CrossProcessMutex> CrossProcessMutexAutoUnlock;
|
|
|
|
}
|
|
#endif
|