Fixed bug 2423 - timeBeginPeriod & timeEndPeriod mismatch

Coriiander

In src\timer\windows\SDL_systimer.c there is an error with regards to timeBeginPeriod and timeEndPeriod. These functions typically get called when no high resolution timer is available, and GetTickCount is not used.

According to MSDN (link: http://msdn.microsoft.com/en-us/library/windows/desktop/dd757624(v=vs.85).aspx), for every call to timeBeginPeriod a subsequent call to timeEndPeriod is required. While SDL is currently doing this, it fails to call timeEndPeriod when cleaning up/shutting down SDL. Please note that these functions affect things on a system level. Failing to call timeEndPeriod, disables applications for using WINMM-timers after usage&shutdown of SDL, as effectively they the mechanism is now broken.

Solution:
Ensure this code gets called when shutting down the timer subsystem:

#ifndef USE_GETTICKCOUNT
if (!hires_timer_available)
{
    timeSetPeriod(0);
}
#endif

src/SDL.c

@@ -38,7 +38,8 @@
 #if !SDL_TIMERS_DISABLED
 extern int SDL_TimerInit(void);
 extern void SDL_TimerQuit(void);
-extern void SDL_InitTicks(void);
+extern void SDL_TicksInit(void);
+extern void SDL_TicksQuit(void);
 #endif
 #if SDL_VIDEO_DRIVER_WINDOWS
 extern int SDL_HelperWindowCreate(void);
@@ -123,7 +124,7 @@ SDL_InitSubSystem(Uint32 flags)
 #endif
 
 #if !SDL_TIMERS_DISABLED
-    SDL_InitTicks();
+    SDL_TicksInit();
 #endif
 
     if ((flags & SDL_INIT_GAMECONTROLLER)) {
@@ -355,6 +356,10 @@ SDL_Quit(void)
 #endif
     SDL_QuitSubSystem(SDL_INIT_EVERYTHING);
 
+#if !SDL_TIMERS_DISABLED
+    SDL_TicksQuit();
+#endif
+
     SDL_ClearHints();
     SDL_AssertionsQuit();
     SDL_LogResetPriorities();

src/test/SDL_test_common.c

@@ -1542,6 +1542,7 @@ SDLTest_CommonQuit(SDLTest_CommonState * state)
         SDL_AudioQuit();
     }
     SDL_free(state);
+    SDL_Quit();
 }
 
 /* vi: set ts=4 sw=4 expandtab: */

src/timer/SDL_timer_c.h

@@ -26,7 +26,8 @@
 #define ROUND_RESOLUTION(X) \
     (((X+TIMER_RESOLUTION-1)/TIMER_RESOLUTION)*TIMER_RESOLUTION)
 
-extern void SDL_InitTicks(void);
+extern void SDL_TicksInit(void);
+extern void SDL_TicksQuit(void);
 extern int SDL_TimerInit(void);
 extern void SDL_TimerQuit(void);
 

src/timer/dummy/SDL_systimer.c

@@ -27,7 +27,7 @@
 static SDL_bool ticks_started = SDL_FALSE;
 
 void
-SDL_InitTicks(void)
+SDL_TicksInit(void)
 {
     if (ticks_started) {
         return;
@@ -35,11 +35,17 @@ SDL_InitTicks(void)
     ticks_started = SDL_TRUE;
 }
 
+void
+SDL_TicksQuit(void)
+{
+    ticks_started = SDL_FALSE;
+}
+
 Uint32
 SDL_GetTicks(void)
 {
     if (!ticks_started) {
-        SDL_InitTicks();
+        SDL_TicksInit();
     }
 
     SDL_Unsupported();

src/timer/haiku/SDL_systimer.c

@@ -30,7 +30,7 @@ static bigtime_t start;
 static SDL_bool ticks_started = SDL_FALSE;
 
 void
-SDL_InitTicks(void)
+SDL_TicksInit(void)
 {
     if (ticks_started) {
         return;
@@ -41,11 +41,17 @@ SDL_InitTicks(void)
     start = system_time();
 }
 
+void
+SDL_TicksQuit(void)
+{
+    ticks_started = SDL_FALSE;
+}
+
 Uint32
 SDL_GetTicks(void)
 {
     if (!ticks_started) {
-        SDL_InitTicks();
+        SDL_TicksInit();
     }
 
     return ((system_time() - start) / 1000);

src/timer/psp/SDL_systimer.c

@@ -31,7 +31,8 @@
 static struct timeval start;
 static SDL_bool ticks_started = SDL_FALSE;
 
-void SDL_InitTicks(void)
+void
+SDL_TicksInit(void)
 {
     if (ticks_started) {
         return;
@@ -41,10 +42,16 @@ void SDL_InitTicks(void)
     gettimeofday(&start, NULL);
 }
 
+void
+SDL_TicksQuit(void)
+{
+    ticks_started = SDL_FALSE;
+}
+
 Uint32 SDL_GetTicks(void)
 {
     if (!ticks_started) {
-        SDL_InitTicks();
+        SDL_TicksInit();
     }
 
     struct timeval now;

src/timer/unix/SDL_systimer.c

@@ -59,7 +59,7 @@ static struct timeval start_tv;
 static SDL_bool ticks_started = SDL_FALSE;
 
 void
-SDL_InitTicks(void)
+SDL_TicksInit(void)
 {
     if (ticks_started) {
         return;
@@ -83,12 +83,18 @@ SDL_InitTicks(void)
     }
 }
 
+void
+SDL_TicksQuit(void)
+{
+    ticks_started = SDL_FALSE;
+}
+
 Uint32
 SDL_GetTicks(void)
 {
     Uint32 ticks;
     if (!ticks_started) {
-        SDL_InitTicks();
+        SDL_TicksInit();
     }
 
     if (has_monotonic_time) {
@@ -117,7 +123,7 @@ SDL_GetPerformanceCounter(void)
 {
     Uint64 ticks;
     if (!ticks_started) {
-        SDL_InitTicks();
+        SDL_TicksInit();
     }
 
     if (has_monotonic_time) {
@@ -146,7 +152,7 @@ Uint64
 SDL_GetPerformanceFrequency(void)
 {
     if (!ticks_started) {
-        SDL_InitTicks();
+        SDL_TicksInit();
     }
 
     if (has_monotonic_time) {

src/timer/windows/SDL_systimer.c

@@ -40,7 +40,6 @@ static BOOL hires_timer_available;
 static LARGE_INTEGER hires_start_ticks;
 /* The number of ticks per second of the high-resolution performance counter */
 static LARGE_INTEGER hires_ticks_per_second;
-#endif
 
 static void
 timeSetPeriod(UINT uPeriod)
@@ -76,13 +75,15 @@ SDL_TimerResolutionChanged(void *userdata, const char *name, const char *oldValu
     }
 }
 
+#endif /* !USE_GETTICKCOUNT */
+
 void
-SDL_InitTicks(void)
+SDL_TicksInit(void)
 {
     if (ticks_started) {
         return;
     }
-    ticks_started = TRUE;
+    ticks_started = SDL_TRUE;
 
     /* Set first ticks value */
 #ifdef USE_GETTICKCOUNT
@@ -98,11 +99,26 @@ SDL_InitTicks(void)
         hires_timer_available = FALSE;
         timeSetPeriod(1);     /* use 1 ms timer precision */
         start = timeGetTime();
-    }
-#endif
 
         SDL_AddHintCallback(SDL_HINT_TIMER_RESOLUTION,
                             SDL_TimerResolutionChanged, NULL);
+    }
+#endif
+}
+
+void
+SDL_TicksQuit(void)
+{
+#ifndef USE_GETTICKCOUNT
+    if (!hires_timer_available) {
+        SDL_DelHintCallback(SDL_HINT_TIMER_RESOLUTION,
+                            SDL_TimerResolutionChanged, NULL);
+
+        timeSetPeriod(0);
+    }
+#endif
+
+    ticks_started = SDL_FALSE;
 }
 
 Uint32
@@ -114,7 +130,7 @@ SDL_GetTicks(void)
 #endif
 
     if (!ticks_started) {
-        SDL_InitTicks();
+        SDL_TicksInit();
     }
 
 #ifdef USE_GETTICKCOUNT

src/video/SDL_video.c

@@ -432,7 +432,7 @@ SDL_VideoInit(const char *driver_name)
     }
 
 #if !SDL_TIMERS_DISABLED
-    SDL_InitTicks();
+    SDL_TicksInit();
 #endif
 
     /* Start the event loop */