LXR qemu/util/qemu-timer-common.c

   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/osdep.h"
  25#include "qemu/timer.h"
  26
  27/***********************************************************/
  28/* real time host monotonic timer */
  29
  30#ifdef _WIN32
  31
  32int64_t clock_freq;
  33
  34static void __attribute__((constructor)) init_get_clock(void)
  35{
  36    LARGE_INTEGER freq;
  37    int ret;
  38    ret = QueryPerformanceFrequency(&freq);
  39    if (ret == 0) {
  40        fprintf(stderr, "Could not calibrate ticks\n");
  41        exit(1);
  42    }
  43    clock_freq = freq.QuadPart;
  44}
  45
  46#else
  47
  48int use_rt_clock;
  49
  50static void __attribute__((constructor)) init_get_clock(void)
  51{
  52    use_rt_clock = 0;
  53#ifdef CLOCK_MONOTONIC
  54    {
  55        struct timespec ts;
  56        if (clock_gettime(CLOCK_MONOTONIC, &ts) == 0) {
  57            use_rt_clock = 1;
  58        }
  59    }
  60#endif
  61}
  62#endif
  63