Atlas - SDL_systimer.c
Home / ext / SDL2 / src / timer / unix Lines: 1 | Size: 5810 bytes [Download] [Show on GitHub] [Search similar files] [Raw] [Raw (proxy)][FILE BEGIN]1/* 2 Simple DirectMedia Layer 3 Copyright (C) 1997-2018 Sam Lantinga <[email protected]> 4 5 This software is provided 'as-is', without any express or implied 6 warranty. In no event will the authors be held liable for any damages 7 arising from the use of this software. 8 9 Permission is granted to anyone to use this software for any purpose, 10 including commercial applications, and to alter it and redistribute it 11 freely, subject to the following restrictions: 12 13 1. The origin of this software must not be misrepresented; you must not 14 claim that you wrote the original software. If you use this software 15 in a product, an acknowledgment in the product documentation would be 16 appreciated but is not required. 17 2. Altered source versions must be plainly marked as such, and must not be 18 misrepresented as being the original software. 19 3. This notice may not be removed or altered from any source distribution. 20*/ 21#include "../../SDL_internal.h" 22 23#ifdef SDL_TIMER_UNIX 24 25#include <stdio.h> 26#include <sys/time.h> 27#include <unistd.h> 28#include <errno.h> 29 30#include "SDL_timer.h" 31#include "SDL_assert.h" 32#include "../SDL_timer_c.h" 33 34/* The clock_gettime provides monotonous time, so we should use it if 35 it's available. The clock_gettime function is behind ifdef 36 for __USE_POSIX199309 37 Tommi Kyntola ([email protected]) 27/09/2005 38*/ 39/* Reworked monotonic clock to not assume the current system has one 40 as not all linux kernels provide a monotonic clock (yeah recent ones 41 probably do) 42 Also added OS X Monotonic clock support 43 Based on work in https://github.com/ThomasHabets/monotonic_clock 44 */ 45#if HAVE_NANOSLEEP || HAVE_CLOCK_GETTIME 46#include <time.h> 47#endif 48#ifdef __APPLE__ 49#include <mach/mach_time.h> 50#endif 51 52/* Use CLOCK_MONOTONIC_RAW, if available, which is not subject to adjustment by NTP */ 53#if HAVE_CLOCK_GETTIME 54#ifdef CLOCK_MONOTONIC_RAW 55#define SDL_MONOTONIC_CLOCK CLOCK_MONOTONIC_RAW 56#else 57#define SDL_MONOTONIC_CLOCK CLOCK_MONOTONIC 58#endif 59#endif 60 61/* The first ticks value of the application */ 62#if HAVE_CLOCK_GETTIME 63static struct timespec start_ts; 64#elif defined(__APPLE__) 65static uint64_t start_mach; 66mach_timebase_info_data_t mach_base_info; 67#endif 68static SDL_bool has_monotonic_time = SDL_FALSE; 69static struct timeval start_tv; 70static SDL_bool ticks_started = SDL_FALSE; 71 72void 73SDL_TicksInit(void) 74{ 75 if (ticks_started) { 76 return; 77 } 78 ticks_started = SDL_TRUE; 79 80 /* Set first ticks value */ 81#if HAVE_CLOCK_GETTIME 82 if (clock_gettime(SDL_MONOTONIC_CLOCK, &start_ts) == 0) { 83 has_monotonic_time = SDL_TRUE; 84 } else 85#elif defined(__APPLE__) 86 kern_return_t ret = mach_timebase_info(&mach_base_info); 87 if (ret == 0) { 88 has_monotonic_time = SDL_TRUE; 89 start_mach = mach_absolute_time(); 90 } else 91#endif 92 { 93 gettimeofday(&start_tv, NULL); 94 } 95} 96 97void 98SDL_TicksQuit(void) 99{ 100 ticks_started = SDL_FALSE; 101} 102 103Uint32 104SDL_GetTicks(void) 105{ 106 Uint32 ticks; 107 if (!ticks_started) { 108 SDL_TicksInit(); 109 } 110 111 if (has_monotonic_time) { 112#if HAVE_CLOCK_GETTIME 113 struct timespec now; 114 clock_gettime(SDL_MONOTONIC_CLOCK, &now); 115 ticks = (now.tv_sec - start_ts.tv_sec) * 1000 + (now.tv_nsec - 116 start_ts.tv_nsec) / 1000000; 117#elif defined(__APPLE__) 118 uint64_t now = mach_absolute_time(); 119 ticks = (Uint32)((((now - start_mach) * mach_base_info.numer) / mach_base_info.denom) / 1000000); 120#else 121 SDL_assert(SDL_FALSE); 122 ticks = 0; 123#endif 124 } else { 125 struct timeval now; 126 127 gettimeofday(&now, NULL); 128 ticks = (Uint32)((now.tv_sec - start_tv.tv_sec) * 1000 + (now.tv_usec - start_tv.tv_usec) / 1000); 129 } 130 return (ticks); 131} 132 133Uint64 134SDL_GetPerformanceCounter(void) 135{ 136 Uint64 ticks; 137 if (!ticks_started) { 138 SDL_TicksInit(); 139 } 140 141 if (has_monotonic_time) { 142#if HAVE_CLOCK_GETTIME 143 struct timespec now; 144 145 clock_gettime(SDL_MONOTONIC_CLOCK, &now); 146 ticks = now.tv_sec; 147 ticks *= 1000000000; 148 ticks += now.tv_nsec; 149#elif defined(__APPLE__) 150 ticks = mach_absolute_time(); 151#else 152 SDL_assert(SDL_FALSE); 153 ticks = 0; 154#endif 155 } else { 156 struct timeval now; 157 158 gettimeofday(&now, NULL); 159 ticks = now.tv_sec; 160 ticks *= 1000000; 161 ticks += now.tv_usec; 162 } 163 return (ticks); 164} 165 166Uint64 167SDL_GetPerformanceFrequency(void) 168{ 169 if (!ticks_started) { 170 SDL_TicksInit(); 171 } 172 173 if (has_monotonic_time) { 174#if HAVE_CLOCK_GETTIME 175 return 1000000000; 176#elif defined(__APPLE__) 177 Uint64 freq = mach_base_info.denom; 178 freq *= 1000000000; 179 freq /= mach_base_info.numer; 180 return freq; 181#endif 182 } 183 184 return 1000000; 185} 186 187void 188SDL_Delay(Uint32 ms) 189{ 190 int was_error; 191 192#if HAVE_NANOSLEEP 193 struct timespec elapsed, tv; 194#else 195 struct timeval tv; 196 Uint32 then, now, elapsed; 197#endif 198 199 /* Set the timeout interval */ 200#if HAVE_NANOSLEEP 201 elapsed.tv_sec = ms / 1000; 202 elapsed.tv_nsec = (ms % 1000) * 1000000; 203#else 204 then = SDL_GetTicks(); 205#endif 206 do { 207 errno = 0; 208 209#if HAVE_NANOSLEEP 210 tv.tv_sec = elapsed.tv_sec; 211 tv.tv_nsec = elapsed.tv_nsec; 212 was_error = nanosleep(&tv, &elapsed); 213#else 214 /* Calculate the time interval left (in case of interrupt) */ 215 now = SDL_GetTicks(); 216 elapsed = (now - then); 217 then = now; 218 if (elapsed >= ms) { 219 break; 220 } 221 ms -= elapsed; 222 tv.tv_sec = ms / 1000; 223 tv.tv_usec = (ms % 1000) * 1000; 224 225 was_error = select(0, NULL, NULL, NULL, &tv); 226#endif /* HAVE_NANOSLEEP */ 227 } while (was_error && (errno == EINTR)); 228} 229 230#endif /* SDL_TIMER_UNIX */ 231 232/* vi: set ts=4 sw=4 expandtab: */ 233[FILE END](C) 2025 0x4248 (C) 2025 4248 Media and 4248 Systems, All part of 0x4248 See LICENCE files for more information. Not all files are by 0x4248 always check Licencing.