Protect checking clock state with a mutex to prevent deadlock condition

git-svn-id: svn://svn.code.sf.net/p/sc2/code/trunk@550 8092fc87-c524-0410-9efc-e669fe64eaf9

sc2/ChangeLog

@@ -1,4 +1,5 @@
 Changes towards version 0.2:
+- Fixed a potential semaphore race when suspending clock -PhracturedBlue
 - Function name conflict fixes for Mac OSX -by peterb
 - Minor fixes for pc-fonts (Outfit screen, gradient color swap) -by Nic
 - DCQ is now accessed uniformly by routines in gfx_common.c

sc2/src/sc2code/clock.c

@@ -20,6 +20,8 @@
 
 #define IsLeapYear(yi) (!((yi) & 3) && (((yi) % 100) || ((yi) % 400)))
 
+static Mutex clock_mutex;
+
 int clock_task_func(void* data)
 {
 	BOOLEAN LastPilot;
@@ -170,7 +172,7 @@ InitGameClock (void)
 {
 	if (!InitQueue (&GLOBAL (GameClock.event_q), NUM_EVENTS, sizeof (EVENT)))
 		return (FALSE);
-
+	clock_mutex = CreateMutex ();
 	GLOBAL (GameClock.month_index) = 2;
 	GLOBAL (GameClock.day_index) = 17;
 	GLOBAL (GameClock.year_index) = START_YEAR; /* Feb 17, START_YEAR */
@@ -189,13 +191,13 @@ UninitGameClock (void)
 {
 	if (GLOBAL (GameClock.clock_task))
 	{
-		if (!GameClockRunning ())
-			ResumeGameClock ();
+		ResumeGameClock ();
 
 		ConcludeTask (GLOBAL (GameClock.clock_task));
 		
 		GLOBAL (GameClock.clock_task) = 0;
 	}
+	DestroyMutex (clock_mutex);
 
 	UninitQueue (&GLOBAL (GameClock.event_q));
 
@@ -205,21 +207,25 @@ UninitGameClock (void)
 void
 SuspendGameClock (void)
 {
+	LockMutex (clock_mutex);
 	if (GameClockRunning ())
 	{
 		SetSemaphore (GLOBAL (GameClock.clock_sem));
 		GLOBAL (GameClock.TimeCounter) = 0;
 	}
+	UnlockMutex (clock_mutex);
 }
 
 void
 ResumeGameClock (void)
 {
+	LockMutex (clock_mutex);
 	if (!GameClockRunning ())
 	{
 		GLOBAL (GameClock.TimeCounter) = GetTimeCounter ();
 		ClearSemaphore (GLOBAL (GameClock.clock_sem));
 	}
+	UnlockMutex (clock_mutex);
 }
 
 BOOLEAN

sc2/src/sc2code/confirm.c

@@ -30,11 +30,8 @@ INPUT_STATE
 ConfirmExit (void)
 {
 	INPUT_STATE InputState;
-	BOOLEAN ClockActive;
 
-	ClockActive = (BOOLEAN)(LOBYTE (GLOBAL (CurrentActivity)) != SUPER_MELEE
-			&& GameClockRunning ());
-	if (ClockActive)
+	if (LOBYTE (GLOBAL (CurrentActivity)) != SUPER_MELEE)
 		SuspendGameClock ();
 	else if (CommData.ConversationPhrases && PlayingTrack ())
 		PauseTrack ();
@@ -105,7 +102,7 @@ ConfirmExit (void)
 	}
 	ClearSemaphore (GraphicsSem);
 
-	if (ClockActive)
+	if (LOBYTE (GLOBAL (CurrentActivity)) != SUPER_MELEE)
 		ResumeGameClock ();
 	else if (CommData.ConversationPhrases && PlayingTrack ())
 		ResumeTrack ();

sc2/src/sc2code/hyper.c

@@ -362,8 +362,7 @@ BOOLEAN
 FreeHyperspace (void)
 {
 	ClearSemaphore (GraphicsSem);
-	if (GameClockRunning ())
-		SuspendGameClock ();
+	SuspendGameClock ();
 	SetSemaphore (GraphicsSem);
 
 	{

sc2/src/sc2code/starcon.c

@@ -902,8 +902,7 @@ extern COUNT _simple_count;
 
 sc = _simple_count;
 #endif //TESTING
-				if (GameClockRunning ())
-					SuspendGameClock ();
+				SuspendGameClock ();
 
 				if (!((GLOBAL (CurrentActivity) | NextActivity) & CHECK_LOAD))
 					ZeroVelocityComponents (

sc2/src/sc2code/utils.c

@@ -141,7 +141,6 @@ PauseGame (void)
 {
 	RECT r;
 	STAMP s;
-	BOOLEAN ClockActive;
 	CONTEXT OldContext;
 	FRAME F;
 	HOT_SPOT OldHot;
@@ -153,11 +152,7 @@ PauseGame (void)
 		
 	GLOBAL (CurrentActivity) |= CHECK_PAUSE;
 
-	ClockActive = (BOOLEAN)(
-			LOBYTE (GLOBAL (CurrentActivity)) != SUPER_MELEE
-			&& GameClockRunning ()
-			);
-	if (ClockActive)
+	if (LOBYTE (GLOBAL (CurrentActivity)) != SUPER_MELEE)
 		SuspendGameClock ();
 	else if (CommData.ConversationPhrases && PlayingTrack ())
 		PauseTrack ();
@@ -201,7 +196,7 @@ PauseGame (void)
 	FlushInput ();
 	ClearSemaphore (GraphicsSem);
 
-	if (ClockActive)
+	if (LOBYTE (GLOBAL (CurrentActivity)) != SUPER_MELEE)
 		ResumeGameClock ();
 	else if (CommData.ConversationPhrases && PlayingTrack ())
 		ResumeTrack ();