text: // 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.
  
  // bthread - A M:N threading library to make applications more concurrent.
  
  // Date: 2016/06/03 13:06:40
  
  #ifndef BTHREAD_COUNTDOWN_EVENT_H
  #define BTHREAD_COUNTDOWN_EVENT_H
  
  #include "bthread/bthread.h"
  
  namespace bthread {
  
  // A synchronization primitive to wait for multiple signallers.
  class CountdownEvent {
  public:
      CountdownEvent(int initial_count = 1);
      ~CountdownEvent();
  
      // Increase current counter by |v|
      void add_count(int v = 1);
  
      // Reset the counter to |v|
      void reset(int v = 1);
  
      // Decrease the counter by |sig|
      void signal(int sig = 1);
  
      // Block current thread until the counter reaches 0.
      // Returns 0 on success, error code otherwise.
      // This method never returns EINTR.
      int wait();
  
      // Block the current thread until the counter reaches 0 or duetime has expired
      // Returns 0 on success, error code otherwise. ETIMEDOUT is for timeout.
      // This method never returns EINTR.
      int timed_wait(const timespec& duetime);
  
  private:
      int *_butex;
      bool _wait_was_invoked;
  };
  
  }  // namespace bthread
  
  #endif  // BTHREAD_COUNTDOWN_EVENT_H
  