src/videolib/videolib_clock.c

   1 /* coded by Ketmar // Vampire Avalon (psyc://ketmar.no-ip.org/~Ketmar)
   2  * Understanding is not required. Only obedience.
   3  *
   4  * This program is free software. It comes without any warranty, to
   5  * the extent permitted by applicable law. You can redistribute it
   6  * and/or modify it under the terms of the Do What The Fuck You Want
   7  * To Public License, Version 2, as published by Sam Hocevar. See
   8  * http://www.wtfpl.net/txt/copying/ for more details.
   9  */
  10 #include "videolib.h"
  11 #ifdef VIDEOLIB_ENABLE_CLOCK
  12
  13 #include <fcntl.h>
  14 #include <stdlib.h>
  15 #include <string.h>
  16 #include <time.h>
  17 #include <unistd.h>
  18
  19 #include <sys/stat.h>
  20 #include <sys/types.h>
  21
  22
  23 /******************************************************************************/
  24 static int k8clock_initialized = 0;
  25 static struct timespec clk;
  26
  27
  28 #ifndef CLOCK_MONOTONIC_RAW
  29 # define K8CLOCK_CLOCK_TYPE  CLOCK_MONOTONIC_RAW
  30 #else
  31 # define K8CLOCK_CLOCK_TYPE  CLOCK_MONOTONIC
  32 #endif
  33
  34
  35 __attribute__((constructor)) static void _k8clock_ctor (void) {
  36   struct timespec cres;
  37   k8clock_initialized = -1;
  38   if (clock_getres(K8CLOCK_CLOCK_TYPE, &cres) != 0) {
  39     //fprintf(stderr, "ERROR: can't get clock resolution!\n");
  40     return;
  41   }
  42   //fprintf(stderr, "CLOCK_MONOTONIC: %ld:%ld\n", cres.tv_sec, cres.tv_nsec);
  43   if (cres.tv_sec > 0 || cres.tv_nsec > (long)1000000*10 /*10 ms*/) {
  44     //fprintf(stderr, "ERROR: real-time clock resolution is too low!\n");
  45     return;
  46   }
  47   if (clock_gettime(K8CLOCK_CLOCK_TYPE, &clk) != 0) {
  48     //fprintf(stderr, "ERROR: real-time clock initialization failed!\n");
  49     return;
  50   }
  51   k8clock_initialized = 1;
  52 }
  53
  54
  55 Uint64 vl_clock_milli (void) {
  56   if (k8clock_initialized > 0) {
  57     struct timespec ts;
  58     if (clock_gettime(K8CLOCK_CLOCK_TYPE, &ts) != 0) {
  59       //fprintf(stderr, "ERROR: can't get real-time clock value!\n");
  60       return 0;
  61     }
  62     // ah, ignore nanoseconds in clk->stt here: we need only 'differential' time, and it can start with something weird
  63     return ((Uint64)(ts.tv_sec-clk.tv_sec))*1000+ts.tv_nsec/1000000+1;
  64   }
  65   return 0;
  66 }
  67
  68
  69 Uint64 vl_clock_micro (void) {
  70   if (k8clock_initialized > 0) {
  71     struct timespec ts;
  72     if (clock_gettime(K8CLOCK_CLOCK_TYPE, &ts) != 0) {
  73       //fprintf(stderr, "ERROR: can't get real-time clock value!\n");
  74       return 0;
  75     }
  76     // ah, ignore nanoseconds in clk->stt here: we need only 'differential' time, and it can start with something weird
  77     return ((Uint64)(ts.tv_sec-clk.tv_sec))*1000000+ts.tv_nsec/1000+1;
  78   }
  79   return 0;
  80 }
  81 #endif