root/content/child/webthread_impl.cc

DEFINITIONS

1. TaskObserverAdapter
2. WillProcessTask
3. DidProcessTask
4. addTaskObserver
5. removeTaskObserver
6. postTask
7. postDelayedTask
8. enterRunLoop
9. exitRunLoop
10. isCurrentThread
11. postTask
12. postDelayedTask
13. enterRunLoop
14. exitRunLoop
15. isCurrentThread

// Copyright 2014 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.

// An implementation of WebThread in terms of base::MessageLoop and
// base::Thread

#include "content/child/webthread_impl.h"

#include "base/bind.h"
#include "base/bind_helpers.h"
#include "base/message_loop/message_loop.h"
#include "base/pending_task.h"
#include "base/threading/platform_thread.h"

namespace content {

WebThreadBase::WebThreadBase() {}
WebThreadBase::~WebThreadBase() {}

class WebThreadBase::TaskObserverAdapter
    : public base::MessageLoop::TaskObserver {
 public:
  TaskObserverAdapter(WebThread::TaskObserver* observer)
      : observer_(observer) {}

  virtual void WillProcessTask(const base::PendingTask& pending_task) OVERRIDE {
    observer_->willProcessTask();
  }

  virtual void DidProcessTask(const base::PendingTask& pending_task) OVERRIDE {
    observer_->didProcessTask();
  }

private:
  WebThread::TaskObserver* observer_;
};

void WebThreadBase::addTaskObserver(TaskObserver* observer) {
  CHECK(isCurrentThread());
  std::pair<TaskObserverMap::iterator, bool> result = task_observer_map_.insert(
      std::make_pair(observer, static_cast<TaskObserverAdapter*>(NULL)));
  if (result.second)
    result.first->second = new TaskObserverAdapter(observer);
  base::MessageLoop::current()->AddTaskObserver(result.first->second);
}

void WebThreadBase::removeTaskObserver(TaskObserver* observer) {
  CHECK(isCurrentThread());
  TaskObserverMap::iterator iter = task_observer_map_.find(observer);
  if (iter == task_observer_map_.end())
    return;
  base::MessageLoop::current()->RemoveTaskObserver(iter->second);
  delete iter->second;
  task_observer_map_.erase(iter);
}

WebThreadImpl::WebThreadImpl(const char* name)
    : thread_(new base::Thread(name)) {
  thread_->Start();
}

void WebThreadImpl::postTask(Task* task) {
  thread_->message_loop()->PostTask(
      FROM_HERE, base::Bind(&blink::WebThread::Task::run, base::Owned(task)));
}

void WebThreadImpl::postDelayedTask(Task* task, long long delay_ms) {
  thread_->message_loop()->PostDelayedTask(
      FROM_HERE,
      base::Bind(&blink::WebThread::Task::run, base::Owned(task)),
      base::TimeDelta::FromMilliseconds(delay_ms));
}

void WebThreadImpl::enterRunLoop() {
  CHECK(isCurrentThread());
  CHECK(!thread_->message_loop()->is_running());  // We don't support nesting.
  thread_->message_loop()->Run();
}

void WebThreadImpl::exitRunLoop() {
  CHECK(isCurrentThread());
  CHECK(thread_->message_loop()->is_running());
  thread_->message_loop()->Quit();
}

bool WebThreadImpl::isCurrentThread() const {
  return thread_->thread_id() == base::PlatformThread::CurrentId();
}

WebThreadImpl::~WebThreadImpl() {
  thread_->Stop();
}

WebThreadImplForMessageLoop::WebThreadImplForMessageLoop(
    base::MessageLoopProxy* message_loop)
    : message_loop_(message_loop) {}

void WebThreadImplForMessageLoop::postTask(Task* task) {
  message_loop_->PostTask(
      FROM_HERE, base::Bind(&blink::WebThread::Task::run, base::Owned(task)));
}

void WebThreadImplForMessageLoop::postDelayedTask(Task* task,
                                                  long long delay_ms) {
  message_loop_->PostDelayedTask(
      FROM_HERE,
      base::Bind(&blink::WebThread::Task::run, base::Owned(task)),
      base::TimeDelta::FromMilliseconds(delay_ms));
}

void WebThreadImplForMessageLoop::enterRunLoop() {
  CHECK(isCurrentThread());
  // We don't support nesting.
  CHECK(!base::MessageLoop::current()->is_running());
  base::MessageLoop::current()->Run();
}

void WebThreadImplForMessageLoop::exitRunLoop() {
  CHECK(isCurrentThread());
  CHECK(base::MessageLoop::current()->is_running());
  base::MessageLoop::current()->Quit();
}

bool WebThreadImplForMessageLoop::isCurrentThread() const {
  return message_loop_->BelongsToCurrentThread();
}

WebThreadImplForMessageLoop::~WebThreadImplForMessageLoop() {}

}  // namespace content