dolphin/Source/Core/AudioCommon/AlsaSoundStream.h

// Copyright 2008 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.

#pragma once

#include <atomic>
#include <condition_variable>
#include <mutex>
#include <thread>

#if defined(HAVE_ALSA) && HAVE_ALSA
#include <alsa/asoundlib.h>
#endif

#include "AudioCommon/SoundStream.h"
#include "Common/CommonTypes.h"

class AlsaSound final : public SoundStream
{
#if defined(HAVE_ALSA) && HAVE_ALSA
public:
	AlsaSound();

	bool Start() override;
	void SoundLoop() override;
	void Stop() override;
	void Update() override;
	void Clear(bool) override;

	static bool isValid()
	{
		return true;
	}

private:
	// maximum number of frames the buffer can hold
	static constexpr size_t BUFFER_SIZE_MAX = 8192;

	// minimum number of frames to deliver in one transfer
	static constexpr u32 FRAME_COUNT_MIN = 256;

	// number of channels per frame
	static constexpr u32 CHANNEL_COUNT = 2;

	enum class ALSAThreadStatus
	{
		RUNNING,
		STOPPING,
		STOPPED,
	};

	bool AlsaInit();
	void AlsaShutdown();

	s16 mix_buffer[BUFFER_SIZE_MAX * CHANNEL_COUNT];
	std::thread thread;
	std::atomic<ALSAThreadStatus> m_thread_status;
	std::condition_variable cv;
	std::mutex cv_m;

	snd_pcm_t *handle;
	unsigned int frames_to_deliver;
#endif
};