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/*
* Copyright (c) 2011 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 SYSTEM_WRAPPERS_INCLUDE_EVENT_WRAPPER_H_
#define SYSTEM_WRAPPERS_INCLUDE_EVENT_WRAPPER_H_
namespace webrtc {
enum EventTypeWrapper {
kEventSignaled = 1,
kEventError = 2,
kEventTimeout = 3
};
#define WEBRTC_EVENT_INFINITE 0xffffffff
class EventTimerWrapper;
class EventWrapper {
public:
// Factory method. Constructor disabled.
static EventWrapper* Create();
virtual ~EventWrapper() {}
// Releases threads who are calling Wait() and has started waiting. Please
// note that a thread calling Wait() will not start waiting immediately.
// assumptions to the contrary is a very common source of issues in
// multithreaded programming.
// Set is sticky in the sense that it will release at least one thread
// either immediately or some time in the future.
virtual bool Set() = 0;
// Puts the calling thread into a wait state. The thread may be released
// by a Set() call depending on if other threads are waiting and if so on
// timing. The thread that was released will reset the event before leaving
// preventing more threads from being released. If multiple threads
// are waiting for the same Set(), only one (random) thread is guaranteed to
// be released. It is possible that multiple (random) threads are released
// Depending on timing.
//
// |max_time| is the maximum time to wait in milliseconds or
// WEBRTC_EVENT_INFINITE to wait infinitely.
virtual EventTypeWrapper Wait(unsigned long max_time) = 0;
};
class EventTimerWrapper : public EventWrapper {
public:
static EventTimerWrapper* Create();
// Starts a timer that will call a non-sticky version of Set() either once
// or periodically. If the timer is periodic it ensures that there is no
// drift over time relative to the system clock.
//
// |time| is in milliseconds.
virtual bool StartTimer(bool periodic, unsigned long time) = 0;
virtual bool StopTimer() = 0;
};
} // namespace webrtc
#endif // SYSTEM_WRAPPERS_INCLUDE_EVENT_WRAPPER_H_