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// Copyright (c) 2012 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.
#ifndef REMOTING_BASE_PLUGIN_THREAD_TASK_RUNNER_H_
#define REMOTING_BASE_PLUGIN_THREAD_TASK_RUNNER_H_
#include <set>
#include "base/callback_forward.h"
#include "base/compiler_specific.h"
#include "base/pending_task.h"
#include "base/single_thread_task_runner.h"
#include "base/synchronization/lock.h"
#include "base/synchronization/waitable_event.h"
#include "base/threading/platform_thread.h"
#include "base/time/time.h"
namespace remoting {
// SingleThreadTaskRunner for plugin main threads.
class PluginThreadTaskRunner : public base::SingleThreadTaskRunner {
public:
class Delegate {
public:
virtual ~Delegate();
virtual bool RunOnPluginThread(
base::TimeDelta delay, void(function)(void*), void* data) = 0;
};
// Caller keeps ownership of delegate.
PluginThreadTaskRunner(Delegate* delegate);
// Detaches the PluginThreadTaskRunner from the underlying Delegate and
// processes posted tasks until Quit() is called. This is used during plugin
// shutdown, when the plugin environment has stopped accepting new tasks to
// run, to process cleanup tasks posted to the plugin thread.
// This method must be called on the plugin thread.
void DetachAndRunShutdownLoop();
// Makes DetachAndRunShutdownLoop() stop processing tasks and return control
// to the caller. Calling Quit() before DetachAndRunShutdownLoop() causes
// the latter to exit immediately when called, without processing any delayed
// shutdown tasks. This method can be called from any thread.
void Quit();
// base::SingleThreadTaskRunner interface.
virtual bool PostDelayedTask(
const tracked_objects::Location& from_here,
const base::Closure& task,
base::TimeDelta delay) OVERRIDE;
virtual bool PostNonNestableDelayedTask(
const tracked_objects::Location& from_here,
const base::Closure& task,
base::TimeDelta delay) OVERRIDE;
virtual bool RunsTasksOnCurrentThread() const OVERRIDE;
protected:
virtual ~PluginThreadTaskRunner();
private:
// Methods that can be called from any thread.
// Schedules RunTasks to be called on the plugin thread.
void PostRunTasks();
// Methods that are always called on the plugin thread.
// Schedules RunDelayedTasks() to be called on the plugin thread. |when|
// specifies the time when RunDelayedTasks() should be called.
void PostDelayedRunTasks(base::TimeTicks when);
// Processes the incoming task queue: runs all non delayed tasks and posts all
// delayed tasks to |delayed_queue_|.
void ProcessIncomingTasks();
// Called in response to PostDelayedRunTasks().
void RunDelayedTasks(base::TimeTicks when);
// Runs all tasks that are due.
void RunDueTasks(base::TimeTicks now);
// Called in response to PostRunTasks().
void RunTasks();
static void TaskSpringboard(void* data);
const base::PlatformThreadId plugin_thread_id_;
// Used by the shutdown loop to block the thread until there is a task ready
// to run.
base::WaitableEvent event_;
base::Lock lock_;
// The members below are protected by |lock_|.
// Pointer to the delegate that implements scheduling tasks via the plugin
// API.
Delegate* delegate_;
// Contains all posted tasks that haven't been sorted yet.
base::TaskQueue incoming_queue_;
// The next sequence number to use for delayed tasks.
int next_sequence_num_;
// True if Quit() has been called.
bool quit_received_;
// The members below are accessed only on the plugin thread.
// Contains delayed tasks, sorted by their 'delayed_run_time' property.
base::DelayedTaskQueue delayed_queue_;
// The list of timestamps when scheduled timers are expected to fire.
std::set<base::TimeTicks> scheduled_timers_;
// True if the shutdown task loop was been stopped.
bool stopped_;
DISALLOW_COPY_AND_ASSIGN(PluginThreadTaskRunner);
};
} // namespace remoting
#endif // REMOTING_BASE_PLUGIN_THREAD_TASK_RUNNER_H_