1 /* 2 * QEMU System Emulator 3 * 4 * Copyright (c) 2003-2008 Fabrice Bellard 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a copy 7 * of this software and associated documentation files (the "Software"), to deal 8 * in the Software without restriction, including without limitation the rights 9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 10 * copies of the Software, and to permit persons to whom the Software is 11 * furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice shall be included in 14 * all copies or substantial portions of the Software. 15 * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 22 * THE SOFTWARE. 23 */ 24 #include "qemu-timer.h" 25 26 /***********************************************************/ 27 /* real time host monotonic timer */ 28 29 #ifdef _WIN32 30 31 int64_t clock_freq; 32 33 static void __attribute__((constructor)) init_get_clock(void) 34 { 35 LARGE_INTEGER freq; 36 int ret; 37 ret = QueryPerformanceFrequency(&freq); 38 if (ret == 0) { 39 fprintf(stderr, "Could not calibrate ticks\n"); 40 exit(1); 41 } 42 clock_freq = freq.QuadPart; 43 } 44 45 #else 46 47 int use_rt_clock; 48 49 static void __attribute__((constructor)) init_get_clock(void) 50 { 51 use_rt_clock = 0; 52 #if defined(__linux__) || (defined(__FreeBSD__) && __FreeBSD_version >= 500000) \ 53 || defined(__DragonFly__) || defined(__FreeBSD_kernel__) \ 54 || defined(__OpenBSD__) 55 { 56 struct timespec ts; 57 if (clock_gettime(CLOCK_MONOTONIC, &ts) == 0) { 58 use_rt_clock = 1; 59 } 60 } 61 #endif 62 } 63 #endif 64
