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
init_get_clock(void)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
init_get_clock(void)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