event.h

/*
 *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

#ifndef RTC_BASE_EVENT_H_
#define RTC_BASE_EVENT_H_

#include "rtc_base/constructor_magic.h"
#if defined(WEBRTC_WIN)
#include <windows.h>
#elif defined(WEBRTC_POSIX)
#define USE_SEMAPHORE 0
#if !USE_SEMAPHORE
#include <pthread.h>
#else // USE_SEMAPHORE
#include <semaphore.h>
#endif // USE_SEMAPHORE
#else // WEBRTC_WIN
#error "Must define either WEBRTC_WIN or WEBRTC_POSIX."
#endif // WEBRTC_WIN

namespace rtc {

class Event {
 public:
  static const int kForever = -1;

  Event(bool manual_reset, bool initially_signaled);
  ~Event();

  void Set();
  void Reset();

  // Waits for the event to become signaled, but logs a warning if it takes more
  // than `warn_after_ms` milliseconds, and gives up completely if it takes more
  // than `give_up_after_ms` milliseconds. (If `warn_after_ms >=
  // give_up_after_ms`, no warning will be logged.) Either or both may be
  // `kForever`, which means wait indefinitely.
  //
  // Returns true if the event was signaled, false if there was a timeout or
  // some other error.
  bool Wait(int give_up_after_ms, int warn_after_ms);

  // Waits with the given timeout and a reasonable default warning timeout.
  bool Wait(int give_up_after_ms) {
    return Wait(give_up_after_ms,
                give_up_after_ms == kForever ? 3000 : kForever);
  }

 private:
#if defined(WEBRTC_WIN)
  HANDLE event_handle_;
#elif defined(WEBRTC_POSIX)
#if !USE_SEMAPHORE
  pthread_mutex_t event_mutex_;
  pthread_cond_t event_cond_;
#else // USE_SEMAPHORE
  sem_t event_sem_;
#endif // USE_SEMAPHORE
  const bool is_manual_reset_;
  volatile bool event_status_;
#endif // WEBRTC_WIN

  RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(Event);
};

}  // namespace rtc

#endif  // RTC_BASE_EVENT_H_