Skip to content
Permalink
Browse files

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
  • Loading branch information
slouken committed Mar 1, 2014
1 parent ab9345a commit e663b4eb76493b92e3218b1d4a55c4cadda8a5de
@@ -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();
@@ -1542,6 +1542,7 @@ SDLTest_CommonQuit(SDLTest_CommonState * state)
SDL_AudioQuit();
}
SDL_free(state);
SDL_Quit();
}

/* vi: set ts=4 sw=4 expandtab: */
@@ -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);

@@ -27,19 +27,25 @@
static SDL_bool ticks_started = SDL_FALSE;

void
SDL_InitTicks(void)
SDL_TicksInit(void)
{
if (ticks_started) {
return;
}
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();
@@ -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);
@@ -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;
@@ -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) {
@@ -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();

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

SDL_AddHintCallback(SDL_HINT_TIMER_RESOLUTION,
SDL_TimerResolutionChanged, NULL);
ticks_started = SDL_FALSE;
}

Uint32
@@ -114,7 +130,7 @@ SDL_GetTicks(void)
#endif

if (!ticks_started) {
SDL_InitTicks();
SDL_TicksInit();
}

#ifdef USE_GETTICKCOUNT
@@ -432,7 +432,7 @@ SDL_VideoInit(const char *driver_name)
}

#if !SDL_TIMERS_DISABLED
SDL_InitTicks();
SDL_TicksInit();
#endif

/* Start the event loop */

0 comments on commit e663b4e

Please sign in to comment.