ipc/glue/CrossProcessMutex_posix.cpp@6474c204b198 (annotated)
ipc/glue/CrossProcessMutex_posix.cpp
Wed, 31 Dec 2014 06:09:35 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Wed, 31 Dec 2014 06:09:35 +0100
- changeset 0
- 6474c204b198
- permissions
- -rw-r--r--
Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.
| michael@0 | 1 | /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- |
| michael@0 | 2 | * This Source Code Form is subject to the terms of the Mozilla Public |
| michael@0 | 3 | * License, v. 2.0. If a copy of the MPL was not distributed with this |
| michael@0 | 4 | * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ |
| michael@0 | 5 | |
| michael@0 | 6 | #include "CrossProcessMutex.h" |
| michael@0 | 7 | #include "mozilla/unused.h" |
| michael@0 | 8 | #include "nsDebug.h" |
| michael@0 | 9 | #include "nsISupportsImpl.h" |
| michael@0 | 10 | |
| michael@0 | 11 | namespace { |
| michael@0 | 12 | |
| michael@0 | 13 | struct MutexData { |
| michael@0 | 14 | pthread_mutex_t mMutex; |
| michael@0 | 15 | mozilla::Atomic<int32_t> mCount; |
| michael@0 | 16 | }; |
| michael@0 | 17 | |
| michael@0 | 18 | } |
| michael@0 | 19 | |
| michael@0 | 20 | namespace mozilla { |
| michael@0 | 21 | |
| michael@0 | 22 | CrossProcessMutex::CrossProcessMutex(const char*) |
| michael@0 | 23 | : mSharedBuffer(nullptr) |
| michael@0 | 24 | , mMutex(nullptr) |
| michael@0 | 25 | , mCount(nullptr) |
| michael@0 | 26 | { |
| michael@0 | 27 | mSharedBuffer = new ipc::SharedMemoryBasic; |
| michael@0 | 28 | if (!mSharedBuffer->Create(sizeof(MutexData))) { |
| michael@0 | 29 | MOZ_CRASH(); |
| michael@0 | 30 | } |
| michael@0 | 31 | |
| michael@0 | 32 | if (!mSharedBuffer->Map(sizeof(MutexData))) { |
| michael@0 | 33 | MOZ_CRASH(); |
| michael@0 | 34 | } |
| michael@0 | 35 | |
| michael@0 | 36 | MutexData* data = static_cast<MutexData*>(mSharedBuffer->memory()); |
| michael@0 | 37 | |
| michael@0 | 38 | if (!data) { |
| michael@0 | 39 | MOZ_CRASH(); |
| michael@0 | 40 | } |
| michael@0 | 41 | |
| michael@0 | 42 | mMutex = &(data->mMutex); |
| michael@0 | 43 | mCount = &(data->mCount); |
| michael@0 | 44 | |
| michael@0 | 45 | *mCount = 1; |
| michael@0 | 46 | |
| michael@0 | 47 | pthread_mutexattr_t mutexAttributes; |
| michael@0 | 48 | pthread_mutexattr_init(&mutexAttributes); |
| michael@0 | 49 | // Make the mutex reentrant so it behaves the same as a win32 mutex |
| michael@0 | 50 | if (pthread_mutexattr_settype(&mutexAttributes, PTHREAD_MUTEX_RECURSIVE)) { |
| michael@0 | 51 | MOZ_CRASH(); |
| michael@0 | 52 | } |
| michael@0 | 53 | if (pthread_mutexattr_setpshared(&mutexAttributes, PTHREAD_PROCESS_SHARED)) { |
| michael@0 | 54 | MOZ_CRASH(); |
| michael@0 | 55 | } |
| michael@0 | 56 | |
| michael@0 | 57 | if (pthread_mutex_init(mMutex, &mutexAttributes)) { |
| michael@0 | 58 | MOZ_CRASH(); |
| michael@0 | 59 | } |
| michael@0 | 60 | |
| michael@0 | 61 | MOZ_COUNT_CTOR(CrossProcessMutex); |
| michael@0 | 62 | } |
| michael@0 | 63 | |
| michael@0 | 64 | CrossProcessMutex::CrossProcessMutex(CrossProcessMutexHandle aHandle) |
| michael@0 | 65 | : mSharedBuffer(nullptr) |
| michael@0 | 66 | , mMutex(nullptr) |
| michael@0 | 67 | , mCount(nullptr) |
| michael@0 | 68 | { |
| michael@0 | 69 | if (!ipc::SharedMemoryBasic::IsHandleValid(aHandle)) { |
| michael@0 | 70 | MOZ_CRASH(); |
| michael@0 | 71 | } |
| michael@0 | 72 | |
| michael@0 | 73 | mSharedBuffer = new ipc::SharedMemoryBasic(aHandle); |
| michael@0 | 74 | |
| michael@0 | 75 | if (!mSharedBuffer->Map(sizeof(MutexData))) { |
| michael@0 | 76 | MOZ_CRASH(); |
| michael@0 | 77 | } |
| michael@0 | 78 | |
| michael@0 | 79 | MutexData* data = static_cast<MutexData*>(mSharedBuffer->memory()); |
| michael@0 | 80 | |
| michael@0 | 81 | if (!data) { |
| michael@0 | 82 | MOZ_CRASH(); |
| michael@0 | 83 | } |
| michael@0 | 84 | |
| michael@0 | 85 | mMutex = &(data->mMutex); |
| michael@0 | 86 | mCount = &(data->mCount); |
| michael@0 | 87 | (*mCount)++; |
| michael@0 | 88 | |
| michael@0 | 89 | MOZ_COUNT_CTOR(CrossProcessMutex); |
| michael@0 | 90 | } |
| michael@0 | 91 | |
| michael@0 | 92 | CrossProcessMutex::~CrossProcessMutex() |
| michael@0 | 93 | { |
| michael@0 | 94 | int32_t count = --(*mCount); |
| michael@0 | 95 | |
| michael@0 | 96 | if (count == 0) { |
| michael@0 | 97 | // Nothing can be done if the destroy fails so ignore return code. |
| michael@0 | 98 | unused << pthread_mutex_destroy(mMutex); |
| michael@0 | 99 | } |
| michael@0 | 100 | |
| michael@0 | 101 | delete mSharedBuffer; |
| michael@0 | 102 | MOZ_COUNT_DTOR(CrossProcessMutex); |
| michael@0 | 103 | } |
| michael@0 | 104 | |
| michael@0 | 105 | void |
| michael@0 | 106 | CrossProcessMutex::Lock() |
| michael@0 | 107 | { |
| michael@0 | 108 | MOZ_ASSERT(*mCount > 0, "Attempting to lock mutex with zero ref count"); |
| michael@0 | 109 | pthread_mutex_lock(mMutex); |
| michael@0 | 110 | } |
| michael@0 | 111 | |
| michael@0 | 112 | void |
| michael@0 | 113 | CrossProcessMutex::Unlock() |
| michael@0 | 114 | { |
| michael@0 | 115 | MOZ_ASSERT(*mCount > 0, "Attempting to unlock mutex with zero ref count"); |
| michael@0 | 116 | pthread_mutex_unlock(mMutex); |
| michael@0 | 117 | } |
| michael@0 | 118 | |
| michael@0 | 119 | CrossProcessMutexHandle |
| michael@0 | 120 | CrossProcessMutex::ShareToProcess(base::ProcessHandle aHandle) |
| michael@0 | 121 | { |
| michael@0 | 122 | CrossProcessMutexHandle result = ipc::SharedMemoryBasic::NULLHandle(); |
| michael@0 | 123 | |
| michael@0 | 124 | if (mSharedBuffer && !mSharedBuffer->ShareToProcess(aHandle, &result)) { |
| michael@0 | 125 | MOZ_CRASH(); |
| michael@0 | 126 | } |
| michael@0 | 127 | |
| michael@0 | 128 | return result; |
| michael@0 | 129 | } |
| michael@0 | 130 | |
| michael@0 | 131 | } |
