henrike@webrtc.org | f7795df | 2014-05-13 18:00:26 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2004 The WebRTC Project Authors. All rights reserved. |
| 3 | * |
| 4 | * Use of this source code is governed by a BSD-style license |
| 5 | * that can be found in the LICENSE file in the root of the source |
| 6 | * tree. An additional intellectual property rights grant can be found |
| 7 | * in the file PATENTS. All contributing project authors may |
| 8 | * be found in the AUTHORS file in the root of the source tree. |
| 9 | */ |
| 10 | |
| 11 | #include "webrtc/base/signalthread.h" |
| 12 | |
| 13 | #include "webrtc/base/common.h" |
| 14 | |
| 15 | namespace rtc { |
| 16 | |
| 17 | /////////////////////////////////////////////////////////////////////////////// |
| 18 | // SignalThread |
| 19 | /////////////////////////////////////////////////////////////////////////////// |
| 20 | |
| 21 | SignalThread::SignalThread() |
| 22 | : main_(Thread::Current()), |
| 23 | worker_(this), |
| 24 | state_(kInit), |
| 25 | refcount_(1) { |
| 26 | main_->SignalQueueDestroyed.connect(this, |
| 27 | &SignalThread::OnMainThreadDestroyed); |
| 28 | worker_.SetName("SignalThread", this); |
| 29 | } |
| 30 | |
| 31 | SignalThread::~SignalThread() { |
| 32 | ASSERT(refcount_ == 0); |
| 33 | } |
| 34 | |
| 35 | bool SignalThread::SetName(const std::string& name, const void* obj) { |
| 36 | EnterExit ee(this); |
| 37 | ASSERT(main_->IsCurrent()); |
| 38 | ASSERT(kInit == state_); |
| 39 | return worker_.SetName(name, obj); |
| 40 | } |
| 41 | |
| 42 | bool SignalThread::SetPriority(ThreadPriority priority) { |
| 43 | EnterExit ee(this); |
| 44 | ASSERT(main_->IsCurrent()); |
| 45 | ASSERT(kInit == state_); |
| 46 | return worker_.SetPriority(priority); |
| 47 | } |
| 48 | |
| 49 | void SignalThread::Start() { |
| 50 | EnterExit ee(this); |
| 51 | ASSERT(main_->IsCurrent()); |
| 52 | if (kInit == state_ || kComplete == state_) { |
| 53 | state_ = kRunning; |
| 54 | OnWorkStart(); |
| 55 | worker_.Start(); |
| 56 | } else { |
| 57 | ASSERT(false); |
| 58 | } |
| 59 | } |
| 60 | |
| 61 | void SignalThread::Destroy(bool wait) { |
| 62 | EnterExit ee(this); |
| 63 | ASSERT(main_->IsCurrent()); |
| 64 | if ((kInit == state_) || (kComplete == state_)) { |
| 65 | refcount_--; |
| 66 | } else if (kRunning == state_ || kReleasing == state_) { |
| 67 | state_ = kStopping; |
| 68 | // OnWorkStop() must follow Quit(), so that when the thread wakes up due to |
| 69 | // OWS(), ContinueWork() will return false. |
| 70 | worker_.Quit(); |
| 71 | OnWorkStop(); |
| 72 | if (wait) { |
| 73 | // Release the thread's lock so that it can return from ::Run. |
| 74 | cs_.Leave(); |
| 75 | worker_.Stop(); |
| 76 | cs_.Enter(); |
| 77 | refcount_--; |
| 78 | } |
| 79 | } else { |
| 80 | ASSERT(false); |
| 81 | } |
| 82 | } |
| 83 | |
| 84 | void SignalThread::Release() { |
| 85 | EnterExit ee(this); |
| 86 | ASSERT(main_->IsCurrent()); |
| 87 | if (kComplete == state_) { |
| 88 | refcount_--; |
| 89 | } else if (kRunning == state_) { |
| 90 | state_ = kReleasing; |
| 91 | } else { |
| 92 | // if (kInit == state_) use Destroy() |
| 93 | ASSERT(false); |
| 94 | } |
| 95 | } |
| 96 | |
| 97 | bool SignalThread::ContinueWork() { |
| 98 | EnterExit ee(this); |
| 99 | ASSERT(worker_.IsCurrent()); |
| 100 | return worker_.ProcessMessages(0); |
| 101 | } |
| 102 | |
| 103 | void SignalThread::OnMessage(Message *msg) { |
| 104 | EnterExit ee(this); |
| 105 | if (ST_MSG_WORKER_DONE == msg->message_id) { |
| 106 | ASSERT(main_->IsCurrent()); |
| 107 | OnWorkDone(); |
| 108 | bool do_delete = false; |
| 109 | if (kRunning == state_) { |
| 110 | state_ = kComplete; |
| 111 | } else { |
| 112 | do_delete = true; |
| 113 | } |
| 114 | if (kStopping != state_) { |
| 115 | // Before signaling that the work is done, make sure that the worker |
| 116 | // thread actually is done. We got here because DoWork() finished and |
| 117 | // Run() posted the ST_MSG_WORKER_DONE message. This means the worker |
| 118 | // thread is about to go away anyway, but sometimes it doesn't actually |
| 119 | // finish before SignalWorkDone is processed, and for a reusable |
| 120 | // SignalThread this makes an assert in thread.cc fire. |
| 121 | // |
| 122 | // Calling Stop() on the worker ensures that the OS thread that underlies |
| 123 | // the worker will finish, and will be set to NULL, enabling us to call |
| 124 | // Start() again. |
| 125 | worker_.Stop(); |
| 126 | SignalWorkDone(this); |
| 127 | } |
| 128 | if (do_delete) { |
| 129 | refcount_--; |
| 130 | } |
| 131 | } |
| 132 | } |
| 133 | |
| 134 | void SignalThread::Run() { |
| 135 | DoWork(); |
| 136 | { |
| 137 | EnterExit ee(this); |
| 138 | if (main_) { |
| 139 | main_->Post(this, ST_MSG_WORKER_DONE); |
| 140 | } |
| 141 | } |
| 142 | } |
| 143 | |
| 144 | void SignalThread::OnMainThreadDestroyed() { |
| 145 | EnterExit ee(this); |
| 146 | main_ = NULL; |
| 147 | } |
| 148 | |
| 149 | } // namespace rtc |