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comparison: ipc/glue/CrossProcessMutex_posix.cpp
ipc/glue/CrossProcessMutex_posix.cpp
- branch
- TOR_BUG_3246
- changeset 5
- 4ab42b5ab56c
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| -1:000000000000 | 0:320dc750304f |
|---|---|
| 1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- | |
| 2 * This Source Code Form is subject to the terms of the Mozilla Public | |
| 3 * License, v. 2.0. If a copy of the MPL was not distributed with this | |
| 4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ | |
| 5 | |
| 6 #include "CrossProcessMutex.h" | |
| 7 #include "mozilla/unused.h" | |
| 8 #include "nsDebug.h" | |
| 9 #include "nsISupportsImpl.h" | |
| 10 | |
| 11 namespace { | |
| 12 | |
| 13 struct MutexData { | |
| 14 pthread_mutex_t mMutex; | |
| 15 mozilla::Atomic<int32_t> mCount; | |
| 16 }; | |
| 17 | |
| 18 } | |
| 19 | |
| 20 namespace mozilla { | |
| 21 | |
| 22 CrossProcessMutex::CrossProcessMutex(const char*) | |
| 23 : mSharedBuffer(nullptr) | |
| 24 , mMutex(nullptr) | |
| 25 , mCount(nullptr) | |
| 26 { | |
| 27 mSharedBuffer = new ipc::SharedMemoryBasic; | |
| 28 if (!mSharedBuffer->Create(sizeof(MutexData))) { | |
| 29 MOZ_CRASH(); | |
| 30 } | |
| 31 | |
| 32 if (!mSharedBuffer->Map(sizeof(MutexData))) { | |
| 33 MOZ_CRASH(); | |
| 34 } | |
| 35 | |
| 36 MutexData* data = static_cast<MutexData*>(mSharedBuffer->memory()); | |
| 37 | |
| 38 if (!data) { | |
| 39 MOZ_CRASH(); | |
| 40 } | |
| 41 | |
| 42 mMutex = &(data->mMutex); | |
| 43 mCount = &(data->mCount); | |
| 44 | |
| 45 *mCount = 1; | |
| 46 | |
| 47 pthread_mutexattr_t mutexAttributes; | |
| 48 pthread_mutexattr_init(&mutexAttributes); | |
| 49 // Make the mutex reentrant so it behaves the same as a win32 mutex | |
| 50 if (pthread_mutexattr_settype(&mutexAttributes, PTHREAD_MUTEX_RECURSIVE)) { | |
| 51 MOZ_CRASH(); | |
| 52 } | |
| 53 if (pthread_mutexattr_setpshared(&mutexAttributes, PTHREAD_PROCESS_SHARED)) { | |
| 54 MOZ_CRASH(); | |
| 55 } | |
| 56 | |
| 57 if (pthread_mutex_init(mMutex, &mutexAttributes)) { | |
| 58 MOZ_CRASH(); | |
| 59 } | |
| 60 | |
| 61 MOZ_COUNT_CTOR(CrossProcessMutex); | |
| 62 } | |
| 63 | |
| 64 CrossProcessMutex::CrossProcessMutex(CrossProcessMutexHandle aHandle) | |
| 65 : mSharedBuffer(nullptr) | |
| 66 , mMutex(nullptr) | |
| 67 , mCount(nullptr) | |
| 68 { | |
| 69 if (!ipc::SharedMemoryBasic::IsHandleValid(aHandle)) { | |
| 70 MOZ_CRASH(); | |
| 71 } | |
| 72 | |
| 73 mSharedBuffer = new ipc::SharedMemoryBasic(aHandle); | |
| 74 | |
| 75 if (!mSharedBuffer->Map(sizeof(MutexData))) { | |
| 76 MOZ_CRASH(); | |
| 77 } | |
| 78 | |
| 79 MutexData* data = static_cast<MutexData*>(mSharedBuffer->memory()); | |
| 80 | |
| 81 if (!data) { | |
| 82 MOZ_CRASH(); | |
| 83 } | |
| 84 | |
| 85 mMutex = &(data->mMutex); | |
| 86 mCount = &(data->mCount); | |
| 87 (*mCount)++; | |
| 88 | |
| 89 MOZ_COUNT_CTOR(CrossProcessMutex); | |
| 90 } | |
| 91 | |
| 92 CrossProcessMutex::~CrossProcessMutex() | |
| 93 { | |
| 94 int32_t count = --(*mCount); | |
| 95 | |
| 96 if (count == 0) { | |
| 97 // Nothing can be done if the destroy fails so ignore return code. | |
| 98 unused << pthread_mutex_destroy(mMutex); | |
| 99 } | |
| 100 | |
| 101 delete mSharedBuffer; | |
| 102 MOZ_COUNT_DTOR(CrossProcessMutex); | |
| 103 } | |
| 104 | |
| 105 void | |
| 106 CrossProcessMutex::Lock() | |
| 107 { | |
| 108 MOZ_ASSERT(*mCount > 0, "Attempting to lock mutex with zero ref count"); | |
| 109 pthread_mutex_lock(mMutex); | |
| 110 } | |
| 111 | |
| 112 void | |
| 113 CrossProcessMutex::Unlock() | |
| 114 { | |
| 115 MOZ_ASSERT(*mCount > 0, "Attempting to unlock mutex with zero ref count"); | |
| 116 pthread_mutex_unlock(mMutex); | |
| 117 } | |
| 118 | |
| 119 CrossProcessMutexHandle | |
| 120 CrossProcessMutex::ShareToProcess(base::ProcessHandle aHandle) | |
| 121 { | |
| 122 CrossProcessMutexHandle result = ipc::SharedMemoryBasic::NULLHandle(); | |
| 123 | |
| 124 if (mSharedBuffer && !mSharedBuffer->ShareToProcess(aHandle, &result)) { | |
| 125 MOZ_CRASH(); | |
| 126 } | |
| 127 | |
| 128 return result; | |
| 129 } | |
| 130 | |
| 131 } |
