- CModel3::StopThreads was rather gracelessly killing threads while they were waiting on their semaphores, which works okay Windows but not on Mac OS-X where it was preventing Supermodel from exiting properly. Hence, have instead altered StopThreads to signal to threads that they should exit and wait until until they have all done so. This is much better and is what I should have done the first time around had I not been so lazy :-)!

- Also fixed a small race condition in WakeSoundBoardThread.  Previously if it happened to be called just before the sound board thread had finished processing a frame's worth of audio but before it had got around to waiting on the sync condition variable then the wake notification would be lost.

Src/Model3/Model3.cpp

@@ -2169,6 +2169,10 @@ bool CModel3::StartThreads(void)
 	if (notifySync == NULL)
 		goto ThreadError;
 
+	// Reset thread flags
+	pauseThreads = false;
+	stopThreads = false;
+
 	// Create PPC main board thread, if multi-threading GPU
 	if (g_Config.gpuMultiThreaded)
 	{
@@ -2216,8 +2220,8 @@ bool CModel3::PauseThreads(void)
 	if (!notifyLock->Lock())
 		goto ThreadError;
 
-	// Wait for all threads to finish their processing
+	// Let threads know that they should pause and wait for all of them to do so
-	pausedThreads = true;
+	pauseThreads = true;
 	while (ppcBrdThreadRunning || sndBrdThreadRunning || drvBrdThreadRunning)
 	{
 		if (!notifySync->Wait(notifyLock))
@@ -2245,7 +2249,7 @@ bool CModel3::ResumeThreads(void)
 		goto ThreadError;
 
 	// Let all threads know that they can continue running
-	pausedThreads = false;
+	pauseThreads = false;
 
 	// Leave notify critical section
 	if (!notifyLock->Unlock())
@@ -2258,26 +2262,73 @@ ThreadError:
 	return false;
 }
 
-void CModel3::StopThreads(void)
+bool CModel3::StopThreads(void)
 {
 	if (!startedThreads)
-		return;
+		return true;
 
 	// If sound board thread is unsync'd then remove audio callback
 	if (!syncSndBrdThread)
 		SetAudioCallback(NULL, NULL);
 	
-	// Pause threads so that can safely delete thread objects
+	// Enter notify critical section
-	PauseThreads();
+	if (!notifyLock->Lock())
+		goto ThreadError;
+
+	// Let threads know that they should pause and wait for all of them to do so
+	pauseThreads = true;
+	while (ppcBrdThreadRunning || sndBrdThreadRunning || drvBrdThreadRunning)
+	{
+		if (!notifySync->Wait(notifyLock))
+			goto ThreadError;
+	}
+
+	// Now let threads know that they should exit
+	stopThreads = true;
+
+	// Leave notify critical section
+	if (!notifyLock->Unlock())
+		goto ThreadError;
 	
+	// Resume each thread in turn and wait for them to exit
+	if (ppcBrdThread != NULL)
+	{
+		if (ppcBrdThreadSync->Post())
+			ppcBrdThread->Wait();
+	}
+	if (sndBrdThread != NULL)
+	{
+		if (syncSndBrdThread)
+		{
+			if (sndBrdThreadSync->Post())
+				sndBrdThread->Wait();
+		}
+		else
+		{
+			if (WakeSoundBoardThread())
+				sndBrdThread->Wait();
+		}
+	}
+	if (drvBrdThread != NULL)
+	{
+		if (drvBrdThreadSync->Post())
+			drvBrdThread->Wait();
+	}
+
+	// Delete all thread and synchronization objects
 	DeleteThreadObjects();
 	startedThreads = false;
+	return true;
+
+ThreadError:
+	ErrorLog("Threading error in CModel3::StopThreads: %s\nSwitching back to single-threaded mode.\n", CThread::GetLastError());
+	g_Config.multiThreaded = false;
+	return false;
 }
 
 void CModel3::DeleteThreadObjects(void)
 {
-	// Delete (which in turn kills) PPC main board, sound board and drive board threads
+	// Delete PPC main board, sound board and drive board threads
-	// Note that can do so here safely because threads will always be waiting on their semaphores when this method is called
 	if (ppcBrdThread != NULL)
 	{
 		delete ppcBrdThread;
@@ -2347,40 +2398,37 @@ int CModel3::StartMainBoardThread(void *data)
 {
 	// Call method on CModel3 to run PPC main board thread
 	CModel3 *model3 = (CModel3*)data;
-	model3->RunMainBoardThread();
+	return model3->RunMainBoardThread();
-	return 0;
 }
 
 int CModel3::StartSoundBoardThread(void *data)
 {
 	// Call method on CModel3 to run sound board thread (unsync'd)
 	CModel3 *model3 = (CModel3*)data;
-	model3->RunSoundBoardThread();
+	return model3->RunSoundBoardThread();
-	return 0;
 }
 
 int CModel3::StartSoundBoardThreadSyncd(void *data)
 {
 	// Call method on CModel3 to run sound board thread (sync'd)
 	CModel3 *model3 = (CModel3*)data;
-	model3->RunSoundBoardThreadSyncd();
+	return model3->RunSoundBoardThreadSyncd();
-	return 0;
 }
 
 int CModel3::StartDriveBoardThread(void *data)
 {
 	// Call method on CModel3 to run drive board thread
 	CModel3 *model3 = (CModel3*)data;
-	model3->RunDriveBoardThread();
+	return model3->RunDriveBoardThread();
-	return 0;
 }
 
-void CModel3::RunMainBoardThread(void)
+int CModel3::RunMainBoardThread(void)
 {
 	for (;;)
 	{
 		bool wait = true;
-		while (wait)
+		bool exit = false;
+		while (wait && !exit)
 		{
 			// Wait on PPC main board thread semaphore
 			if (!ppcBrdThreadSync->Wait())
@@ -2390,8 +2438,10 @@ void CModel3::RunMainBoardThread(void)
 			if (!notifyLock->Lock())
 				goto ThreadError;
 
-			// Check threads not paused
+			// Check threads are not being stopped or paused
-			if (!pausedThreads)
+			if (stopThreads)
+				exit = true;
+			else if (!pauseThreads)
 			{
 				wait = false;
 				ppcBrdThreadRunning = true;
@@ -2401,6 +2451,8 @@ void CModel3::RunMainBoardThread(void)
 			if (!notifyLock->Unlock())
 				goto ThreadError;
 		}
+		if (exit)
+			return 0;
 
 		// Process a single frame for PPC main board
 		RunMainBoardFrame();
@@ -2423,6 +2475,7 @@ void CModel3::RunMainBoardThread(void)
 ThreadError:
 	ErrorLog("Threading error in RunMainBoardThread: %s\nSwitching back to single-threaded mode.\n", CThread::GetLastError());
 	g_Config.multiThreaded = false;
+	return 1;
 }
 
 void CModel3::AudioCallback(void *data)
@@ -2432,40 +2485,47 @@ void CModel3::AudioCallback(void *data)
 	model3->WakeSoundBoardThread();
 }
 
-void CModel3::WakeSoundBoardThread(void)
+bool CModel3::WakeSoundBoardThread(void)
 {
 	// Enter sound board notify critical section
 	if (!sndBrdNotifyLock->Lock())
 		goto ThreadError;
 
 	// Signal to sound board thread that it should start processing again
+	sndBrdWakeNotify = true;
 	if (!sndBrdNotifySync->Signal())
 		goto ThreadError;
 
 	// Exit sound board notify critical section
 	if (!sndBrdNotifyLock->Unlock())
 		goto ThreadError;
-	return;
+	return true;
 
 ThreadError:
 	ErrorLog("Threading error in WakeSoundBoardThread: %s\nSwitching back to single-threaded mode.\n", CThread::GetLastError());
 	g_Config.multiThreaded = false;
+	return false;
 }
 
-void CModel3::RunSoundBoardThread(void)
+int CModel3::RunSoundBoardThread(void)
 {
 	for (;;)
 	{
 		bool wait = true;
-		while (wait)
+		bool exit = false;
+		while (wait && !exit)
 		{
 			// Enter sound board notify critical section
 			if (!sndBrdNotifyLock->Lock())
 				goto ThreadError;
 
 			// Wait for notification from audio callback
-			if (!sndBrdNotifySync->Wait(sndBrdNotifyLock))
+			while (!sndBrdWakeNotify)
-				goto ThreadError;
+			{
+				if (!sndBrdNotifySync->Wait(sndBrdNotifyLock))
+					goto ThreadError;
+			}
+			sndBrdWakeNotify = false;
 
 			// Exit sound board notify critical section
 			if (!sndBrdNotifyLock->Unlock())
@@ -2475,8 +2535,10 @@ void CModel3::RunSoundBoardThread(void)
 			if (!notifyLock->Lock())
 				goto ThreadError;
 
-			// Check threads not paused
+			// Check threads are not being stopped or paused
-			if (!pausedThreads)
+			if (stopThreads)
+				exit = true;
+			else if (!pauseThreads)
 			{
 				wait = false;
 				sndBrdThreadRunning = true;
@@ -2486,8 +2548,10 @@ void CModel3::RunSoundBoardThread(void)
 			if (!notifyLock->Unlock())
 				goto ThreadError;
 		}
+		if (exit)
+			return 0;
 
-		// Keep processing frames until paused or audio buffer is full
+		// Keep processing frames until pausing or audio buffer is full
 		while (true)
 		{
 			// Enter main notify critical section
@@ -2495,7 +2559,7 @@ void CModel3::RunSoundBoardThread(void)
 			if (!notifyLock->Lock())
 				goto ThreadError;
 
-			paused = pausedThreads;
+			paused = pauseThreads;
 				
 			// Leave main notify critical section
 			if (!notifyLock->Unlock())
@@ -2524,14 +2588,16 @@ void CModel3::RunSoundBoardThread(void)
 ThreadError:
 	ErrorLog("Threading error in RunSoundBoardThread: %s\nSwitching back to single-threaded mode.\n", CThread::GetLastError());
 	g_Config.multiThreaded = false;
+	return 1;
 }
 
-void CModel3::RunSoundBoardThreadSyncd(void)
+int CModel3::RunSoundBoardThreadSyncd(void)
 {
 	for (;;)
 	{
 		bool wait = true;
-		while (wait)
+		bool exit = false;
+		while (wait && !exit)
 		{
 			// Wait on sound board thread semaphore
 			if (!sndBrdThreadSync->Wait())
@@ -2541,8 +2607,10 @@ void CModel3::RunSoundBoardThreadSyncd(void)
 			if (!notifyLock->Lock())
 				goto ThreadError;
 
-			// Check threads not paused
+			// Check threads are not being stopped or paused
-			if (!pausedThreads)
+			if (stopThreads)
+				exit = true;
+			else if (!pauseThreads)
 			{
 				wait = false;
 				sndBrdThreadRunning = true;
@@ -2552,6 +2620,8 @@ void CModel3::RunSoundBoardThreadSyncd(void)
 			if (!notifyLock->Unlock())
 				goto ThreadError;
 		}
+		if (exit)
+			return 0;
 
 		// Process a single frame for sound board
 		RunSoundBoardFrame();
@@ -2574,14 +2644,16 @@ void CModel3::RunSoundBoardThreadSyncd(void)
 ThreadError:
 	ErrorLog("Threading error in RunSoundBoardThreadSyncd: %s\nSwitching back to single-threaded mode.\n", CThread::GetLastError());
 	g_Config.multiThreaded = false;
+	return 1;
 }
 
-void CModel3::RunDriveBoardThread(void)
+int CModel3::RunDriveBoardThread(void)
 {
 	for (;;)
 	{
-		bool wait = true;
+		bool wait = true;	
-		while (wait)
+		bool exit = false;
+		while (wait && !exit)
 		{
 			// Wait on drive board thread semaphore
 			if (!drvBrdThreadSync->Wait())
@@ -2591,8 +2663,10 @@ void CModel3::RunDriveBoardThread(void)
 			if (!notifyLock->Lock())
 				goto ThreadError;
 
-			// Check threads not paused
+			// Check threads are not being stopped or paused
-			if (!pausedThreads)
+			if (stopThreads)
+				exit = true;
+			else if (!pauseThreads)
 			{
 				wait = false;
 				drvBrdThreadRunning = true;
@@ -2602,6 +2676,8 @@ void CModel3::RunDriveBoardThread(void)
 			if (!notifyLock->Unlock())
 				goto ThreadError;
 		}
+		if (exit)
+			return 0;
 
 		// Process a single frame for drive board
 		RunDriveBoardFrame();
@@ -2624,6 +2700,7 @@ void CModel3::RunDriveBoardThread(void)
 ThreadError:
 	ErrorLog("Threading error in RunDriveBoardThread: %s\nSwitching back to single-threaded mode.\n", CThread::GetLastError());
 	g_Config.multiThreaded = false;
+	return 1;
 }
 
 void CModel3::Reset(void)
@@ -3139,7 +3216,8 @@ CModel3::CModel3(void)
 	securityPtr = 0;
 	
 	startedThreads = false;
-	pausedThreads = false;
+	pauseThreads = false;
+	stopThreads = false;
 	ppcBrdThread = NULL;
 	sndBrdThread = NULL; 
 	drvBrdThread = NULL;

Src/Model3/Model3.h

@@ -361,7 +361,7 @@ private:
 	void    RunDriveBoardFrame(void);                  // Runs drive board for a frame
 
 	bool    StartThreads(void);                        // Starts all threads
-	void    StopThreads(void);                         // Stops all threads
+	bool    StopThreads(void);                         // Stops all threads
 	void    DeleteThreadObjects(void);                 // Deletes all threads and synchronization objects
 
 	static int StartMainBoardThread(void *data);       // Callback to start PPC main board thread
@@ -371,11 +371,11 @@ private:
 
 	static void AudioCallback(void *data);             // Audio buffer callback
 	
-	void    WakeSoundBoardThread(void);	               // Used by audio callback to wake sound board thread when not sync'd with PPC thread
+	bool    WakeSoundBoardThread(void);	               // Used by audio callback to wake sound board thread (when not sync'd with render thread)
-	void    RunMainBoardThread(void);                  // Runs PPC main board thread (sync'd in step with render thread)
+	int     RunMainBoardThread(void);                  // Runs PPC main board thread (sync'd in step with render thread)
-	void    RunSoundBoardThread(void);                 // Runs sound board thread (unsync'd with render thread, ie at full speed)
+	int     RunSoundBoardThread(void);                 // Runs sound board thread (not sync'd in step with render thread, ie running at full speed)
-	void    RunSoundBoardThreadSyncd(void);            // Runs sound board thread (sync'd in step with render thread)
+	int     RunSoundBoardThreadSyncd(void);            // Runs sound board thread (sync'd in step with render thread)
-	void    RunDriveBoardThread(void);                 // Runs drive board thread (sync'd in step with render thread)
+	int     RunDriveBoardThread(void);                 // Runs drive board thread (sync'd in step with render thread)
 	
 	// Game and hardware information
 	const struct GameInfo	*Game;
@@ -421,7 +421,8 @@ private:
 	// Multiple threading
 	bool        gpusReady;           // True if GPUs are ready to render
 	bool        startedThreads;      // True if threads have been created and started
-	bool        pausedThreads;       // True if threads are currently paused
+	bool        pauseThreads;        // True if threads should pause
+	bool        stopThreads;         // True if threads should stop
 	bool        syncSndBrdThread;    // True if sound board thread should be sync'd in step with render thread
 	CThread     *ppcBrdThread;       // PPC main board thread
 	CThread     *sndBrdThread;       // Sound board thread
@@ -430,6 +431,7 @@ private:
 	bool        ppcBrdThreadDone;    // Flag to indicate PPC main board thread has finished processing
 	bool        sndBrdThreadRunning; // Flag to indicate sound board thread is currently processing
 	bool        sndBrdThreadDone;    // Flag to indicate sound board thread has finished processing
+	bool        sndBrdWakeNotify;    // Flag to indicate that sound board thread has been woken by audio callback (when not sync'd with render thread)
 	bool        drvBrdThreadRunning; // Flag to indicate drive board thread is currently processing
 	bool        drvBrdThreadDone;    // Flag to indicate drive board thread has finished processing