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/*
* Copyright (c) 2013 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 WEBRTC_MODULES_AUDIO_DEVICE_ANDROID_LOW_LATENCY_EVENT_H_
#define WEBRTC_MODULES_AUDIO_DEVICE_ANDROID_LOW_LATENCY_EVENT_H_
#include <errno.h>
#include <limits.h>
#include <fcntl.h>
#include <stdio.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/types.h>
namespace webrtc {
// Implementation of event for single waiter, single signal threads. Event
// is sticky.
class LowLatencyEvent {
public:
LowLatencyEvent();
~LowLatencyEvent();
// Readies the event. Must be called before signaling or waiting for event.
// Returns true on success.
bool Start();
// Shuts down the event and releases threads calling WaitOnEvent. Once
// stopped SignalEvent and WaitOnEvent will have no effect. Start can be
// called to re-enable the event.
// Returns true on success.
bool Stop();
// Releases thread calling WaitOnEvent in a sticky fashion.
void SignalEvent(int event_id, int event_msg);
// Waits until SignalEvent or Stop is called.
void WaitOnEvent(int* event_id, int* event_msg);
private:
typedef int Handle;
static const Handle kInvalidHandle;
static const int kReadHandle;
static const int kWriteHandle;
// Closes the handle. Returns true on success.
static bool Close(Handle* handle);
// SignalEvent and WaitOnEvent are actually read/write to file descriptors.
// Write is signal.
void WriteFd(int message_id, int message);
// Read is wait.
void ReadFd(int* message_id, int* message);
Handle handles_[2];
};
} // namespace webrtc
#endif // WEBRTC_MODULES_AUDIO_DEVICE_ANDROID_LOW_LATENCY_EVENT_H_
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