blob: bd469c1fbe52270ba72ba878987c08066f0baee8 [file] [log] [blame]
// 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.
#include "content/child/worker_task_runner.h"
#include "base/callback.h"
#include "base/lazy_instance.h"
#include "base/location.h"
#include "base/logging.h"
#include "base/memory/scoped_ptr.h"
#include "base/observer_list.h"
#include "base/single_thread_task_runner.h"
#include "base/stl_util.h"
#include "base/thread_task_runner_handle.h"
namespace content {
namespace {
// A task-runner that refuses to run any tasks.
class DoNothingTaskRunner : public base::TaskRunner {
public:
DoNothingTaskRunner() {}
private:
~DoNothingTaskRunner() override {}
bool PostDelayedTask(const tracked_objects::Location& from_here,
const base::Closure& task,
base::TimeDelta delay) override {
return false;
}
bool RunsTasksOnCurrentThread() const override { return false; }
};
} // namespace
struct WorkerTaskRunner::ThreadLocalState {
ThreadLocalState() {}
base::ObserverList<WorkerTaskRunner::Observer> stop_observers_;
};
WorkerTaskRunner::WorkerTaskRunner()
: task_runner_for_dead_worker_(new DoNothingTaskRunner()) {
}
bool WorkerTaskRunner::PostTask(
int id, const base::Closure& closure) {
DCHECK(id > 0);
base::AutoLock locker(task_runner_map_lock_);
IDToTaskRunnerMap::iterator found = task_runner_map_.find(id);
if (found == task_runner_map_.end())
return false;
return found->second->PostTask(FROM_HERE, closure);
}
int WorkerTaskRunner::PostTaskToAllThreads(const base::Closure& closure) {
base::AutoLock locker(task_runner_map_lock_);
for (const auto& it : task_runner_map_)
it.second->PostTask(FROM_HERE, closure);
return static_cast<int>(task_runner_map_.size());
}
int WorkerTaskRunner::CurrentWorkerId() {
if (!current_tls_.Get())
return 0;
return base::PlatformThread::CurrentId();
}
WorkerTaskRunner* WorkerTaskRunner::Instance() {
static base::LazyInstance<WorkerTaskRunner>::Leaky
worker_task_runner = LAZY_INSTANCE_INITIALIZER;
return worker_task_runner.Pointer();
}
void WorkerTaskRunner::AddStopObserver(Observer* obs) {
DCHECK(CurrentWorkerId() > 0);
current_tls_.Get()->stop_observers_.AddObserver(obs);
}
void WorkerTaskRunner::RemoveStopObserver(Observer* obs) {
DCHECK(CurrentWorkerId() > 0);
current_tls_.Get()->stop_observers_.RemoveObserver(obs);
}
WorkerTaskRunner::~WorkerTaskRunner() {
}
void WorkerTaskRunner::OnWorkerRunLoopStarted() {
DCHECK(!current_tls_.Get());
DCHECK(!base::PlatformThread::CurrentRef().is_null());
current_tls_.Set(new ThreadLocalState());
int id = base::PlatformThread::CurrentId();
base::AutoLock locker_(task_runner_map_lock_);
task_runner_map_[id] = base::ThreadTaskRunnerHandle::Get().get();
CHECK(task_runner_map_[id]);
}
void WorkerTaskRunner::OnWorkerRunLoopStopped() {
DCHECK(current_tls_.Get());
FOR_EACH_OBSERVER(Observer, current_tls_.Get()->stop_observers_,
OnWorkerRunLoopStopped());
{
base::AutoLock locker(task_runner_map_lock_);
task_runner_map_.erase(CurrentWorkerId());
}
delete current_tls_.Get();
current_tls_.Set(NULL);
}
base::TaskRunner* WorkerTaskRunner::GetTaskRunnerFor(int worker_id) {
base::AutoLock locker(task_runner_map_lock_);
return ContainsKey(task_runner_map_, worker_id) ? task_runner_map_[worker_id]
: task_runner_for_dead_worker_.get();
}
} // namespace content