scheduler_based_abstract_lock.h

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/*
 * 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.
 */


#ifndef PAGESPEED_KERNEL_THREAD_SCHEDULER_BASED_ABSTRACT_LOCK_H_
#define PAGESPEED_KERNEL_THREAD_SCHEDULER_BASED_ABSTRACT_LOCK_H_

#include "pagespeed/kernel/base/basictypes.h"
#include "pagespeed/kernel/base/named_lock_manager.h"

namespace net_instaweb {

class Function;
class Scheduler;

class SchedulerBasedAbstractLock : public NamedLock {
 public:
  virtual ~SchedulerBasedAbstractLock();

  virtual bool LockTimedWait(int64 wait_ms);
  virtual void LockTimedWait(int64 wait_ms, Function* callback);

  virtual bool LockTimedWaitStealOld(int64 wait_ms, int64 steal_ms);
  virtual void LockTimedWaitStealOld(
      int64 wait_ms, int64 steal_ms, Function* callback);

 protected:
  friend class SharedMemLockManagerTestBase;
  friend class FileSystemLockManagerTest;

  virtual bool TryLock() = 0;

  virtual bool TryLockStealOld(int64 steal_ms) = 0;

  virtual Scheduler* scheduler() const = 0;

 private:
  typedef bool (SchedulerBasedAbstractLock::*TryLockMethod)(int64 steal_ms);
  bool TryLockIgnoreSteal(int64 steal_ignored);
  bool BusySpin(TryLockMethod try_lock, int64 steal_ms);
  void PollAndCallback(TryLockMethod try_lock, int64 steal_ms,
                       int64 wait_ms, Function* callback);
};

}  

#endif