Merge pull request #2387 from lioncash/atomic

AudioCommon: Remove usages of volatile variables.

Source/Core/AudioCommon/AOSoundStream.cpp

@@ -32,7 +32,7 @@ void AOSound::SoundLoop()
 
 	buf_size = format.bits/8 * format.channels * format.rate;
 
-	while (!threadData)
+	while (m_run_thread.load())
 	{
 		m_mixer->Mix(realtimeBuffer, numBytesToRender >> 2);
 
@@ -47,6 +47,7 @@ void AOSound::SoundLoop()
 
 bool AOSound::Start()
 {
+	m_run_thread.store(true);
 	memset(realtimeBuffer, 0, sizeof(realtimeBuffer));
 
 	thread = std::thread(&AOSound::SoundLoop, this);
@@ -60,7 +61,7 @@ void AOSound::Update()
 
 void AOSound::Stop()
 {
-	threadData = 1;
+	m_run_thread.store(false);
 	soundSyncEvent.Set();
 
 	{

Source/Core/AudioCommon/AOSoundStream.h

@@ -4,6 +4,7 @@
 
 #pragma once
 
+#include <atomic>
 #include <mutex>
 #include <thread>
 
@@ -19,6 +20,7 @@ class AOSound final : public SoundStream
 {
 #if defined(HAVE_AO) && HAVE_AO
 	std::thread thread;
+	std::atomic<bool> m_run_thread;
 	std::mutex soundCriticalSection;
 	Common::Event soundSyncEvent;
 

Source/Core/AudioCommon/AlsaSoundStream.cpp

@@ -10,7 +10,11 @@
 #define BUFFER_SIZE_MAX 8192
 #define BUFFER_SIZE_BYTES (BUFFER_SIZE_MAX*2*2)
 
-AlsaSound::AlsaSound(CMixer *mixer) : SoundStream(mixer), thread_data(0), handle(nullptr), frames_to_deliver(FRAME_COUNT_MIN)
+AlsaSound::AlsaSound(CMixer *mixer)
+	: SoundStream(mixer)
+	, m_thread_status(ALSAThreadStatus::STOPPED)
+	, handle(nullptr)
+	, frames_to_deliver(FRAME_COUNT_MIN)
 {
 	mix_buffer = new u8[BUFFER_SIZE_BYTES];
 }
@@ -22,14 +26,14 @@ AlsaSound::~AlsaSound()
 
 bool AlsaSound::Start()
 {
+	m_thread_status.store(ALSAThreadStatus::RUNNING);
 	thread = std::thread(&AlsaSound::SoundLoop, this);
-	thread_data = 0;
 	return true;
 }
 
 void AlsaSound::Stop()
 {
-	thread_data = 1;
+	m_thread_status.store(ALSAThreadStatus::STOPPING);
 	thread.join();
 }
 
@@ -42,11 +46,11 @@ void AlsaSound::Update()
 void AlsaSound::SoundLoop()
 {
 	if (!AlsaInit()) {
-		thread_data = 2;
+		m_thread_status.store(ALSAThreadStatus::STOPPED);
 		return;
 	}
 	Common::SetCurrentThreadName("Audio thread - alsa");
-	while (!thread_data)
+	while (m_thread_status.load() == ALSAThreadStatus::RUNNING)
 	{
 		m_mixer->Mix(reinterpret_cast<short *>(mix_buffer), frames_to_deliver);
 		int rc = m_muted ? 1337 : snd_pcm_writei(handle, mix_buffer, frames_to_deliver);
@@ -61,7 +65,7 @@ void AlsaSound::SoundLoop()
 		}
 	}
 	AlsaShutdown();
-	thread_data = 2;
+	m_thread_status.store(ALSAThreadStatus::STOPPED);
 }
 
 bool AlsaSound::AlsaInit()

Source/Core/AudioCommon/AlsaSoundStream.h

@@ -4,13 +4,15 @@
 
 #pragma once
 
+#include <atomic>
+#include <thread>
+
 #if defined(HAVE_ALSA) && HAVE_ALSA
 #include <alsa/asoundlib.h>
 #endif
 
 #include "AudioCommon/SoundStream.h"
 #include "Common/CommonTypes.h"
-#include "Common/Thread.h"
 
 class AlsaSound final : public SoundStream
 {
@@ -31,15 +33,19 @@ public:
 	virtual void Update() override;
 
 private:
+	enum class ALSAThreadStatus
+	{
+		RUNNING,
+		STOPPING,
+		STOPPED,
+	};
+
 	bool AlsaInit();
 	void AlsaShutdown();
 
 	u8 *mix_buffer;
 	std::thread thread;
-	// 0 = continue
+	std::atomic<ALSAThreadStatus> m_thread_status;
-	// 1 = shutdown
-	// 2 = done shutting down.
-	volatile int thread_data;
 
 	snd_pcm_t *handle;
 	int frames_to_deliver;

Source/Core/AudioCommon/Mixer.cpp

@@ -4,7 +4,6 @@
 
 #include "AudioCommon/AudioCommon.h"
 #include "AudioCommon/Mixer.h"
-#include "Common/Atomic.h"
 #include "Common/CPUDetect.h"
 #include "Common/MathUtil.h"
 #include "Core/ConfigManager.h"
@@ -31,8 +30,8 @@ unsigned int CMixer::MixerFifo::Mix(short* samples, unsigned int numSamples, boo
 	// so we will just ignore new written data while interpolating.
 	// Without this cache, the compiler wouldn't be allowed to optimize the
 	// interpolation loop.
-	u32 indexR = Common::AtomicLoad(m_indexR);
+	u32 indexR = m_indexR.load();
-	u32 indexW = Common::AtomicLoad(m_indexW);
+	u32 indexW = m_indexW.load();
 
 	float numLeft = (float)(((indexW - indexR) & INDEX_MASK) / 2);
 	m_numLeftI = (numLeft + m_numLeftI*(CONTROL_AVG-1)) / CONTROL_AVG;
@@ -53,8 +52,8 @@ unsigned int CMixer::MixerFifo::Mix(short* samples, unsigned int numSamples, boo
 
 	const u32 ratio = (u32)(65536.0f * aid_sample_rate / (float)m_mixer->m_sampleRate);
 
-	s32 lvolume = m_LVolume;
+	s32 lvolume = m_LVolume.load();
-	s32 rvolume = m_RVolume;
+	s32 rvolume = m_RVolume.load();
 
 	// TODO: consider a higher-quality resampling algorithm.
 	for (; currentSample < numSamples * 2 && ((indexW-indexR) & INDEX_MASK) > 2; currentSample += 2)
@@ -99,7 +98,7 @@ unsigned int CMixer::MixerFifo::Mix(short* samples, unsigned int numSamples, boo
 	}
 
 	// Flush cached variable
-	Common::AtomicStore(m_indexR, indexR);
+	m_indexR.store(indexR);
 
 	return numSamples;
 }
@@ -130,11 +129,11 @@ void CMixer::MixerFifo::PushSamples(const short *samples, unsigned int num_sampl
 	// Cache access in non-volatile variable
 	// indexR isn't allowed to cache in the audio throttling loop as it
 	// needs to get updates to not deadlock.
-	u32 indexW = Common::AtomicLoad(m_indexW);
+	u32 indexW = m_indexW.load();
 
 	// Check if we have enough free space
 	// indexW == m_indexR results in empty buffer, so indexR must always be smaller than indexW
-	if (num_samples * 2 + ((indexW - Common::AtomicLoad(m_indexR)) & INDEX_MASK) >= MAX_SAMPLES * 2)
+	if (num_samples * 2 + ((indexW - m_indexR.load()) & INDEX_MASK) >= MAX_SAMPLES * 2)
 		return;
 
 	// AyuanX: Actual re-sampling work has been moved to sound thread
@@ -151,9 +150,7 @@ void CMixer::MixerFifo::PushSamples(const short *samples, unsigned int num_sampl
 		memcpy(&m_buffer[indexW & INDEX_MASK], samples, num_samples * 4);
 	}
 
-	Common::AtomicAdd(m_indexW, num_samples * 2);
+	m_indexW.fetch_add(num_samples * 2);
-
-	return;
 }
 
 void CMixer::PushSamples(const short *samples, unsigned int num_samples)
@@ -215,6 +212,6 @@ void CMixer::MixerFifo::SetInputSampleRate(unsigned int rate)
 
 void CMixer::MixerFifo::SetVolume(unsigned int lvolume, unsigned int rvolume)
 {
-	m_LVolume = lvolume + (lvolume >> 7);
+	m_LVolume.store(lvolume + (lvolume >> 7));
-	m_RVolume = rvolume + (rvolume >> 7);
+	m_RVolume.store(rvolume + (rvolume >> 7));
 }

Source/Core/AudioCommon/Mixer.h

@@ -4,6 +4,7 @@
 
 #pragma once
 
+#include <atomic>
 #include <mutex>
 #include <string>
 
@@ -109,8 +110,8 @@ public:
 
 	std::mutex& MixerCritical() { return m_csMixing; }
 
-	float GetCurrentSpeed() const { return m_speed; }
+	float GetCurrentSpeed() const { return m_speed.load(); }
-	void UpdateSpeed(volatile float val) { m_speed = val; }
+	void UpdateSpeed(float val) { m_speed.store(val); }
 
 protected:
 	class MixerFifo {
@@ -135,11 +136,11 @@ protected:
 		CMixer *m_mixer;
 		unsigned m_input_sample_rate;
 		short m_buffer[MAX_SAMPLES * 2];
-		volatile u32 m_indexW;
+		std::atomic<u32> m_indexW;
-		volatile u32 m_indexR;
+		std::atomic<u32> m_indexR;
 		// Volume ranges from 0-256
-		volatile s32 m_LVolume;
+		std::atomic<s32> m_LVolume;
-		volatile s32 m_RVolume;
+		std::atomic<s32> m_RVolume;
 		float m_numLeftI;
 		u32 m_frac;
 	};
@@ -156,5 +157,5 @@ protected:
 
 	std::mutex m_csMixing;
 
-	volatile float m_speed; // Current rate of the emulation (1.0 = 100% speed)
+	std::atomic<float> m_speed; // Current rate of the emulation (1.0 = 100% speed)
 };

Source/Core/AudioCommon/OpenALStream.cpp

@@ -23,6 +23,7 @@ static soundtouch::SoundTouch soundTouch;
 //
 bool OpenALStream::Start()
 {
+	m_run_thread.store(true);
 	bool bReturn = false;
 
 	ALDeviceList pDeviceList;
@@ -72,7 +73,7 @@ bool OpenALStream::Start()
 
 void OpenALStream::Stop()
 {
-	threadData = 1;
+	m_run_thread.store(false);
 	// kick the thread if it's waiting
 	soundSyncEvent.Set();
 
@@ -183,7 +184,7 @@ void OpenALStream::SoundLoop()
 	soundTouch.setSetting(SETTING_SEEKWINDOW_MS, 28);
 	soundTouch.setSetting(SETTING_OVERLAP_MS, 12);
 
-	while (!threadData)
+	while (m_run_thread.load())
 	{
 		// num_samples_to_render in this update - depends on SystemTimers::AUDIO_DMA_PERIOD.
 		const u32 stereo_16_bit_size = 4;

Source/Core/AudioCommon/OpenALStream.h

@@ -4,6 +4,7 @@
 
 #pragma once
 
+#include <atomic>
 #include <thread>
 
 #include "AudioCommon/SoundStream.h"
@@ -72,6 +73,8 @@ public:
 
 private:
 	std::thread thread;
+	std::atomic<bool> m_run_thread;
+
 	Common::Event soundSyncEvent;
 
 	short realtimeBuffer[OAL_MAX_SAMPLES * STEREO_CHANNELS];

Source/Core/AudioCommon/SoundStream.h

@@ -11,17 +11,13 @@
 class SoundStream
 {
 protected:
-
 	CMixer* m_mixer;
-	// We set this to shut down the sound thread.
-	// 0=keep playing, 1=stop playing NOW.
-	volatile int threadData;
 	bool m_logAudio;
 	WaveFileWriter g_wave_writer;
 	bool m_muted;
 
 public:
-	SoundStream(CMixer* mixer) : m_mixer(mixer), threadData(0), m_logAudio(false), m_muted(false) {}
+	SoundStream(CMixer* mixer) : m_mixer(mixer), m_logAudio(false), m_muted(false) {}
 	virtual ~SoundStream() { delete m_mixer; }
 
 	static  bool isValid() { return false; }