1 /*
2 * libjingle
3 * Copyright 2004--2009, Google Inc.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright notice,
9 * this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright notice,
11 * this list of conditions and the following disclaimer in the documentation
12 * and/or other materials provided with the distribution.
13 * 3. The name of the author may not be used to endorse or promote products
14 * derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
17 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
18 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
19 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28 #include "talk/base/signalthread.h"
29
30 #include "talk/base/common.h"
31
32 namespace talk_base {
33
34 ///////////////////////////////////////////////////////////////////////////////
35 // SignalThread
36 ///////////////////////////////////////////////////////////////////////////////
37
SignalThread()38 SignalThread::SignalThread() : main_(Thread::Current()), state_(kInit) {
39 main_->SignalQueueDestroyed.connect(this,
40 &SignalThread::OnMainThreadDestroyed);
41 refcount_ = 1;
42 worker_.parent_ = this;
43 worker_.SetName("SignalThread", this);
44 }
45
~SignalThread()46 SignalThread::~SignalThread() {
47 ASSERT(refcount_ == 0);
48 }
49
SetName(const std::string & name,const void * obj)50 bool SignalThread::SetName(const std::string& name, const void* obj) {
51 EnterExit ee(this);
52 ASSERT(main_->IsCurrent());
53 ASSERT(kInit == state_);
54 return worker_.SetName(name, obj);
55 }
56
SetPriority(ThreadPriority priority)57 bool SignalThread::SetPriority(ThreadPriority priority) {
58 EnterExit ee(this);
59 ASSERT(main_->IsCurrent());
60 ASSERT(kInit == state_);
61 return worker_.SetPriority(priority);
62 }
63
Start()64 void SignalThread::Start() {
65 EnterExit ee(this);
66 ASSERT(main_->IsCurrent());
67 if (kInit == state_ || kComplete == state_) {
68 state_ = kRunning;
69 OnWorkStart();
70 worker_.Start();
71 } else {
72 ASSERT(false);
73 }
74 }
75
Destroy(bool wait)76 void SignalThread::Destroy(bool wait) {
77 EnterExit ee(this);
78 ASSERT(main_->IsCurrent());
79 if ((kInit == state_) || (kComplete == state_)) {
80 refcount_--;
81 } else if (kRunning == state_ || kReleasing == state_) {
82 state_ = kStopping;
83 // OnWorkStop() must follow Quit(), so that when the thread wakes up due to
84 // OWS(), ContinueWork() will return false.
85 worker_.Quit();
86 OnWorkStop();
87 if (wait) {
88 // Release the thread's lock so that it can return from ::Run.
89 cs_.Leave();
90 worker_.Stop();
91 cs_.Enter();
92 refcount_--;
93 }
94 } else {
95 ASSERT(false);
96 }
97 }
98
Release()99 void SignalThread::Release() {
100 EnterExit ee(this);
101 ASSERT(main_->IsCurrent());
102 if (kComplete == state_) {
103 refcount_--;
104 } else if (kRunning == state_) {
105 state_ = kReleasing;
106 } else {
107 // if (kInit == state_) use Destroy()
108 ASSERT(false);
109 }
110 }
111
ContinueWork()112 bool SignalThread::ContinueWork() {
113 EnterExit ee(this);
114 ASSERT(worker_.IsCurrent());
115 return worker_.ProcessMessages(0);
116 }
117
OnMessage(Message * msg)118 void SignalThread::OnMessage(Message *msg) {
119 EnterExit ee(this);
120 if (ST_MSG_WORKER_DONE == msg->message_id) {
121 ASSERT(main_->IsCurrent());
122 OnWorkDone();
123 bool do_delete = false;
124 if (kRunning == state_) {
125 state_ = kComplete;
126 } else {
127 do_delete = true;
128 }
129 if (kStopping != state_) {
130 // Before signaling that the work is done, make sure that the worker
131 // thread actually is done. We got here because DoWork() finished and
132 // Run() posted the ST_MSG_WORKER_DONE message. This means the worker
133 // thread is about to go away anyway, but sometimes it doesn't actually
134 // finish before SignalWorkDone is processed, and for a reusable
135 // SignalThread this makes an assert in thread.cc fire.
136 //
137 // Calling Stop() on the worker ensures that the OS thread that underlies
138 // the worker will finish, and will be set to NULL, enabling us to call
139 // Start() again.
140 worker_.Stop();
141 SignalWorkDone(this);
142 }
143 if (do_delete) {
144 refcount_--;
145 }
146 }
147 }
148
Run()149 void SignalThread::Run() {
150 DoWork();
151 {
152 EnterExit ee(this);
153 if (main_) {
154 main_->Post(this, ST_MSG_WORKER_DONE);
155 }
156 }
157 }
158
OnMainThreadDestroyed()159 void SignalThread::OnMainThreadDestroyed() {
160 EnterExit ee(this);
161 main_ = NULL;
162 }
163
164 } // namespace talk_base
165