SDL_DelayNS() will attempt to sleep exactly the requested amount of time

This provides a highly accurate sleep function for your application, although you are still subject to being switched out occasionally.

Fixes https://github.com/libsdl-org/SDL/issues/10210
This commit is contained in:
Sam Lantinga
2024-07-15 18:05:31 -07:00
parent 54366181c3
commit 033df70d4c
12 changed files with 62 additions and 11 deletions

View File

@@ -186,6 +186,34 @@ int main(int argc, char *argv[])
/* Wait for the results to be seen */
SDL_Delay(1 * 1000);
/* Check accuracy of precise delay */
{
Uint64 desired_delay = SDL_NS_PER_SECOND / 60;
Uint64 actual_delay;
Uint64 total_overslept = 0;
start = SDL_GetTicksNS();
SDL_DelayNS(1);
now = SDL_GetTicksNS();
actual_delay = (now - start);
SDL_Log("Minimum precise delay: %" SDL_PRIu64 " ns\n", actual_delay);
SDL_Log("Timing 100 frames at 60 FPS\n");
for (i = 0; i < 100; ++i) {
start = SDL_GetTicksNS();
SDL_DelayNS(desired_delay);
now = SDL_GetTicksNS();
actual_delay = (now - start);
if (actual_delay > desired_delay) {
total_overslept += (actual_delay - desired_delay);
}
}
SDL_Log("Overslept %.2f ms\n", (double)total_overslept / SDL_NS_PER_MS);
}
/* Wait for the results to be seen */
SDL_Delay(1 * 1000);
/* Test multiple timers */
SDL_Log("Testing multiple timers...\n");
t1 = SDL_AddTimer(100, callback, (void *)1);