qemu

FORK: QEMU emulator
git clone https://git.neptards.moe/neptards/qemu.git
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qemu-timer-common.c (1930B)

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