1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/ipc/chromium/src/base/thread.cc Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,188 @@
1.4 +// Copyright (c) 2006-2009 The Chromium Authors. All rights reserved.
1.5 +// Use of this source code is governed by a BSD-style license that can be
1.6 +// found in the LICENSE file.
1.7 +
1.8 +#include "base/thread.h"
1.9 +
1.10 +#include "base/lazy_instance.h"
1.11 +#include "base/string_util.h"
1.12 +#include "base/thread_local.h"
1.13 +#include "base/waitable_event.h"
1.14 +#include "GeckoProfiler.h"
1.15 +#include "mozilla/IOInterposer.h"
1.16 +
1.17 +#ifdef MOZ_TASK_TRACER
1.18 +#include "GeckoTaskTracer.h"
1.19 +#endif
1.20 +
1.21 +namespace base {
1.22 +
1.23 +// This task is used to trigger the message loop to exit.
1.24 +class ThreadQuitTask : public Task {
1.25 + public:
1.26 + virtual void Run() {
1.27 + MessageLoop::current()->Quit();
1.28 + Thread::SetThreadWasQuitProperly(true);
1.29 + }
1.30 +};
1.31 +
1.32 +// Used to pass data to ThreadMain. This structure is allocated on the stack
1.33 +// from within StartWithOptions.
1.34 +struct Thread::StartupData {
1.35 + // We get away with a const reference here because of how we are allocated.
1.36 + const Thread::Options& options;
1.37 +
1.38 + // Used to synchronize thread startup.
1.39 + WaitableEvent event;
1.40 +
1.41 + explicit StartupData(const Options& opt)
1.42 + : options(opt),
1.43 + event(false, false) {}
1.44 +};
1.45 +
1.46 +Thread::Thread(const char *name)
1.47 + : startup_data_(NULL),
1.48 + thread_(0),
1.49 + message_loop_(NULL),
1.50 + thread_id_(0),
1.51 + name_(name) {
1.52 +}
1.53 +
1.54 +Thread::~Thread() {
1.55 + Stop();
1.56 +}
1.57 +
1.58 +namespace {
1.59 +
1.60 +// We use this thread-local variable to record whether or not a thread exited
1.61 +// because its Stop method was called. This allows us to catch cases where
1.62 +// MessageLoop::Quit() is called directly, which is unexpected when using a
1.63 +// Thread to setup and run a MessageLoop.
1.64 +base::LazyInstance<base::ThreadLocalBoolean> lazy_tls_bool(
1.65 + base::LINKER_INITIALIZED);
1.66 +
1.67 +} // namespace
1.68 +
1.69 +void Thread::SetThreadWasQuitProperly(bool flag) {
1.70 + lazy_tls_bool.Pointer()->Set(flag);
1.71 +}
1.72 +
1.73 +bool Thread::GetThreadWasQuitProperly() {
1.74 + bool quit_properly = true;
1.75 +#ifndef NDEBUG
1.76 + quit_properly = lazy_tls_bool.Pointer()->Get();
1.77 +#endif
1.78 + return quit_properly;
1.79 +}
1.80 +
1.81 +bool Thread::Start() {
1.82 + return StartWithOptions(Options());
1.83 +}
1.84 +
1.85 +bool Thread::StartWithOptions(const Options& options) {
1.86 + DCHECK(!message_loop_);
1.87 +
1.88 + SetThreadWasQuitProperly(false);
1.89 +
1.90 + StartupData startup_data(options);
1.91 + startup_data_ = &startup_data;
1.92 +
1.93 + if (!PlatformThread::Create(options.stack_size, this, &thread_)) {
1.94 + DLOG(ERROR) << "failed to create thread";
1.95 + startup_data_ = NULL; // Record that we failed to start.
1.96 + return false;
1.97 + }
1.98 +
1.99 + // Wait for the thread to start and initialize message_loop_
1.100 + startup_data.event.Wait();
1.101 +
1.102 + DCHECK(message_loop_);
1.103 + return true;
1.104 +}
1.105 +
1.106 +void Thread::Stop() {
1.107 + if (!thread_was_started())
1.108 + return;
1.109 +
1.110 + // We should only be called on the same thread that started us.
1.111 + DCHECK_NE(thread_id_, PlatformThread::CurrentId());
1.112 +
1.113 + // StopSoon may have already been called.
1.114 + if (message_loop_)
1.115 + message_loop_->PostTask(FROM_HERE, new ThreadQuitTask());
1.116 +
1.117 + // Wait for the thread to exit. It should already have terminated but make
1.118 + // sure this assumption is valid.
1.119 + //
1.120 + // TODO(darin): Unfortunately, we need to keep message_loop_ around until
1.121 + // the thread exits. Some consumers are abusing the API. Make them stop.
1.122 + //
1.123 + PlatformThread::Join(thread_);
1.124 +
1.125 + // The thread can't receive messages anymore.
1.126 + message_loop_ = NULL;
1.127 +
1.128 + // The thread no longer needs to be joined.
1.129 + startup_data_ = NULL;
1.130 +}
1.131 +
1.132 +void Thread::StopSoon() {
1.133 + if (!message_loop_)
1.134 + return;
1.135 +
1.136 + // We should only be called on the same thread that started us.
1.137 + DCHECK_NE(thread_id_, PlatformThread::CurrentId());
1.138 +
1.139 + // We had better have a message loop at this point! If we do not, then it
1.140 + // most likely means that the thread terminated unexpectedly, probably due
1.141 + // to someone calling Quit() on our message loop directly.
1.142 + DCHECK(message_loop_);
1.143 +
1.144 + message_loop_->PostTask(FROM_HERE, new ThreadQuitTask());
1.145 +}
1.146 +
1.147 +void Thread::ThreadMain() {
1.148 + char aLocal;
1.149 + profiler_register_thread(name_.c_str(), &aLocal);
1.150 + mozilla::IOInterposer::RegisterCurrentThread();
1.151 +
1.152 + // The message loop for this thread.
1.153 + MessageLoop message_loop(startup_data_->options.message_loop_type);
1.154 +
1.155 + // Complete the initialization of our Thread object.
1.156 + thread_id_ = PlatformThread::CurrentId();
1.157 + PlatformThread::SetName(name_.c_str());
1.158 + message_loop.set_thread_name(name_);
1.159 + message_loop.set_hang_timeouts(startup_data_->options.transient_hang_timeout,
1.160 + startup_data_->options.permanent_hang_timeout);
1.161 + message_loop_ = &message_loop;
1.162 +
1.163 + // Let the thread do extra initialization.
1.164 + // Let's do this before signaling we are started.
1.165 + Init();
1.166 +
1.167 + startup_data_->event.Signal();
1.168 + // startup_data_ can't be touched anymore since the starting thread is now
1.169 + // unlocked.
1.170 +
1.171 + message_loop.Run();
1.172 +
1.173 + // Let the thread do extra cleanup.
1.174 + CleanUp();
1.175 +
1.176 + // Assert that MessageLoop::Quit was called by ThreadQuitTask.
1.177 + DCHECK(GetThreadWasQuitProperly());
1.178 +
1.179 + mozilla::IOInterposer::UnregisterCurrentThread();
1.180 + profiler_unregister_thread();
1.181 +
1.182 +#ifdef MOZ_TASK_TRACER
1.183 + mozilla::tasktracer::FreeTraceInfo();
1.184 +#endif
1.185 +
1.186 + // We can't receive messages anymore.
1.187 + message_loop_ = NULL;
1.188 + thread_id_ = 0;
1.189 +}
1.190 +
1.191 +} // namespace base
