qemu/qemu-timer-common.c

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/*
* QEMU System Emulator
*
* Copyright (c) 2003-2008 Fabrice Bellard
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "qemu-timer.h"
/***********************************************************/
/* real time host monotonic timer */
#ifdef _WIN32
int64_t clock_freq;
static void __attribute__((constructor)) init_get_clock(void)
{
LARGE_INTEGER freq;
int ret;
ret = QueryPerformanceFrequency(&freq);
if (ret == 0) {
fprintf(stderr, "Could not calibrate ticks\n");
exit(1);
}
clock_freq = freq.QuadPart;
}
#else
int use_rt_clock;
static void __attribute__((constructor)) init_get_clock(void)
{
use_rt_clock = 0;
#if defined(__linux__) || (defined(__FreeBSD__) && __FreeBSD_version >= 500000) \
|| defined(__DragonFly__) || defined(__FreeBSD_kernel__) \
|| defined(__OpenBSD__)
{
struct timespec ts;
if (clock_gettime(CLOCK_MONOTONIC, &ts) == 0) {
use_rt_clock = 1;
}
}
#endif
}
#endif