// Copyright 2011 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// Author: morlovich@google.com (Maksim Orlovich)
//
// Contains SchedulerThread, used to run the Scheduler dispatch loop for
// non-blocking servers.

#ifndef PAGESPEED_KERNEL_THREAD_SCHEDULER_THREAD_H_
#define PAGESPEED_KERNEL_THREAD_SCHEDULER_THREAD_H_

#include "pagespeed/kernel/base/basictypes.h"
#include "pagespeed/kernel/base/thread.h"
#include "pagespeed/kernel/base/thread_system.h"

namespace net_instaweb {

class Function;
class Scheduler;

// This class is a helper used to dispatch events on a scheduler in a thread
// in case where the server infrastructure is non-blocking and therefore does
// not provide a natural way to do it.
class SchedulerThread : public ThreadSystem::Thread {
 public:
  // Creates the thread. The user still needs to call Start() manually.
  SchedulerThread(ThreadSystem* thread_system, Scheduler* scheduler);

  // Returns a function that, when run, will properly synchronize with this
  // thread and shut it down cleanly, deleting the object as well.
  // It is suggested for use with RewriteDriverFactory::defer_cleanup(); as it
  // needs to be run after it's OK if scheduler timeouts no longer work.
  Function* MakeDeleter();

 protected:
  virtual void Run();

 private:
  class CleanupFunction;
  friend class CleanupFunction;

  virtual ~SchedulerThread();

  bool quit_;
  Scheduler* scheduler_;

  DISALLOW_COPY_AND_ASSIGN(SchedulerThread);
};

}  // namespace net_instaweb

#endif  // PAGESPEED_KERNEL_THREAD_SCHEDULER_THREAD_H_