Use CLOCK_MONOTONIC_RAW, if available, which is not subject to adjustment by NTP

This commit is contained in:
Sam Lantinga 2015-06-19 23:49:00 -07:00
parent f71fa2f402
commit 903df4afbd

View File

@ -48,6 +48,15 @@
#include <mach/mach_time.h> #include <mach/mach_time.h>
#endif #endif
/* Use CLOCK_MONOTONIC_RAW, if available, which is not subject to adjustment by NTP */
#if HAVE_CLOCK_GETTIME
#ifdef CLOCK_MONOTONIC_RAW
#define SDL_MONOTONIC_CLOCK CLOCK_MONOTONIC_RAW
#else
#define SDL_MONOTONIC_CLOCK CLOCK_MONOTONIC
#endif
#endif
/* The first ticks value of the application */ /* The first ticks value of the application */
#if HAVE_CLOCK_GETTIME #if HAVE_CLOCK_GETTIME
static struct timespec start_ts; static struct timespec start_ts;
@ -69,7 +78,7 @@ SDL_TicksInit(void)
/* Set first ticks value */ /* Set first ticks value */
#if HAVE_CLOCK_GETTIME #if HAVE_CLOCK_GETTIME
if (clock_gettime(CLOCK_MONOTONIC, &start_ts) == 0) { if (clock_gettime(SDL_MONOTONIC_CLOCK, &start_ts) == 0) {
has_monotonic_time = SDL_TRUE; has_monotonic_time = SDL_TRUE;
} else } else
#elif defined(__APPLE__) #elif defined(__APPLE__)
@ -101,7 +110,7 @@ SDL_GetTicks(void)
if (has_monotonic_time) { if (has_monotonic_time) {
#if HAVE_CLOCK_GETTIME #if HAVE_CLOCK_GETTIME
struct timespec now; struct timespec now;
clock_gettime(CLOCK_MONOTONIC, &now); clock_gettime(SDL_MONOTONIC_CLOCK, &now);
ticks = (now.tv_sec - start_ts.tv_sec) * 1000 + (now.tv_nsec - ticks = (now.tv_sec - start_ts.tv_sec) * 1000 + (now.tv_nsec -
start_ts.tv_nsec) / 1000000; start_ts.tv_nsec) / 1000000;
#elif defined(__APPLE__) #elif defined(__APPLE__)
@ -132,7 +141,7 @@ SDL_GetPerformanceCounter(void)
#if HAVE_CLOCK_GETTIME #if HAVE_CLOCK_GETTIME
struct timespec now; struct timespec now;
clock_gettime(CLOCK_MONOTONIC, &now); clock_gettime(SDL_MONOTONIC_CLOCK, &now);
ticks = now.tv_sec; ticks = now.tv_sec;
ticks *= 1000000000; ticks *= 1000000000;
ticks += now.tv_nsec; ticks += now.tv_nsec;