lib/cpp/src/concurrency/Monitor.h

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you 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 _THRIFT_CONCURRENCY_MONITOR_H_
#define _THRIFT_CONCURRENCY_MONITOR_H_ 1

#include "Exception.h"

namespace apache { namespace thrift { namespace concurrency {

/**
 * A monitor is a combination mutex and condition-event.  Waiting and
 * notifying condition events requires that the caller own the mutex.  Mutex
 * lock and unlock operations can be performed independently of condition
 * events.  This is more or less analogous to java.lang.Object multi-thread
 * operations
 *
 * Note that all methods are const.  Monitors implement logical constness, not
 * bit constness.  This allows const methods to call monitor methods without
 * needing to cast away constness or change to non-const signatures.
 *
 * @version $Id:$
 */
class Monitor {

 public:

  Monitor();

  virtual ~Monitor();

  virtual void lock() const;

  virtual void unlock() const;

  virtual void wait(int64_t timeout=0LL) const;

  virtual void notify() const;

  virtual void notifyAll() const;

 private:

  class Impl;

  Impl* impl_;
};

class Synchronized {
 public:

 Synchronized(const Monitor& value) :
   monitor_(value) {
   monitor_.lock();
  }

  ~Synchronized() {
    monitor_.unlock();
  }

 private:
  const Monitor& monitor_;
};


}}} // apache::thrift::concurrency

#endif // #ifndef _THRIFT_CONCURRENCY_MONITOR_H_