1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200
|
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
// Copyright (c) 2006-2009 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "base/thread.h"
#include "base/string_util.h"
#include "base/thread_local.h"
#include "base/waitable_event.h"
#include "GeckoProfiler.h"
#include "mozilla/IOInterposer.h"
#include "nsThreadUtils.h"
#ifdef MOZ_TASK_TRACER
#include "GeckoTaskTracer.h"
#endif
namespace base {
// This task is used to trigger the message loop to exit.
class ThreadQuitTask : public mozilla::Runnable {
public:
NS_IMETHOD Run() override {
MessageLoop::current()->Quit();
Thread::SetThreadWasQuitProperly(true);
return NS_OK;
}
};
// Used to pass data to ThreadMain. This structure is allocated on the stack
// from within StartWithOptions.
struct Thread::StartupData {
// We get away with a const reference here because of how we are allocated.
const Thread::Options& options;
// Used to synchronize thread startup.
WaitableEvent event;
explicit StartupData(const Options& opt)
: options(opt),
event(false, false) {}
};
Thread::Thread(const char *name)
: startup_data_(NULL),
thread_(0),
message_loop_(NULL),
thread_id_(0),
name_(name) {
MOZ_COUNT_CTOR(base::Thread);
}
Thread::~Thread() {
MOZ_COUNT_DTOR(base::Thread);
Stop();
}
namespace {
// We use this thread-local variable to record whether or not a thread exited
// because its Stop method was called. This allows us to catch cases where
// MessageLoop::Quit() is called directly, which is unexpected when using a
// Thread to setup and run a MessageLoop.
static base::ThreadLocalBoolean& get_tls_bool() {
static base::ThreadLocalBoolean tls_ptr;
return tls_ptr;
}
} // namespace
void Thread::SetThreadWasQuitProperly(bool flag) {
get_tls_bool().Set(flag);
}
bool Thread::GetThreadWasQuitProperly() {
bool quit_properly = true;
#ifndef NDEBUG
quit_properly = get_tls_bool().Get();
#endif
return quit_properly;
}
bool Thread::Start() {
return StartWithOptions(Options());
}
bool Thread::StartWithOptions(const Options& options) {
DCHECK(!message_loop_);
SetThreadWasQuitProperly(false);
StartupData startup_data(options);
startup_data_ = &startup_data;
if (!PlatformThread::Create(options.stack_size, this, &thread_)) {
DLOG(ERROR) << "failed to create thread";
startup_data_ = NULL; // Record that we failed to start.
return false;
}
// Wait for the thread to start and initialize message_loop_
startup_data.event.Wait();
DCHECK(message_loop_);
return true;
}
void Thread::Stop() {
if (!thread_was_started())
return;
// We should only be called on the same thread that started us.
DCHECK_NE(thread_id_, PlatformThread::CurrentId());
// StopSoon may have already been called.
if (message_loop_) {
RefPtr<ThreadQuitTask> task = new ThreadQuitTask();
message_loop_->PostTask(task.forget());
}
// Wait for the thread to exit. It should already have terminated but make
// sure this assumption is valid.
//
// TODO(darin): Unfortunately, we need to keep message_loop_ around until
// the thread exits. Some consumers are abusing the API. Make them stop.
//
PlatformThread::Join(thread_);
// The thread can't receive messages anymore.
message_loop_ = NULL;
// The thread no longer needs to be joined.
startup_data_ = NULL;
}
void Thread::StopSoon() {
if (!message_loop_)
return;
// We should only be called on the same thread that started us.
DCHECK_NE(thread_id_, PlatformThread::CurrentId());
// We had better have a message loop at this point! If we do not, then it
// most likely means that the thread terminated unexpectedly, probably due
// to someone calling Quit() on our message loop directly.
DCHECK(message_loop_);
RefPtr<ThreadQuitTask> task = new ThreadQuitTask();
message_loop_->PostTask(task.forget());
}
void Thread::ThreadMain() {
char aLocal;
profiler_register_thread(name_.c_str(), &aLocal);
mozilla::IOInterposer::RegisterCurrentThread();
// The message loop for this thread.
MessageLoop message_loop(startup_data_->options.message_loop_type,
NS_GetCurrentThread());
// Complete the initialization of our Thread object.
thread_id_ = PlatformThread::CurrentId();
PlatformThread::SetName(name_.c_str());
message_loop.set_thread_name(name_);
message_loop.set_hang_timeouts(startup_data_->options.transient_hang_timeout,
startup_data_->options.permanent_hang_timeout);
message_loop_ = &message_loop;
// Let the thread do extra initialization.
// Let's do this before signaling we are started.
Init();
startup_data_->event.Signal();
// startup_data_ can't be touched anymore since the starting thread is now
// unlocked.
message_loop.Run();
// Let the thread do extra cleanup.
CleanUp();
// Assert that MessageLoop::Quit was called by ThreadQuitTask.
DCHECK(GetThreadWasQuitProperly());
mozilla::IOInterposer::UnregisterCurrentThread();
profiler_unregister_thread();
#ifdef MOZ_TASK_TRACER
mozilla::tasktracer::FreeTraceInfo();
#endif
// We can't receive messages anymore.
message_loop_ = NULL;
thread_id_ = 0;
}
} // namespace base
|