File:  [Qemu by Fabrice Bellard] / qemu / qemu-timer-common.c
Revision 1.1: download - view: text, annotated - select for diffs
Tue Apr 24 18:34:19 2018 UTC (3 years, 4 months ago) by root
CVS tags: MAIN, HEAD
Initial revision

    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

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