lib/benchmark.c

   1 /*
   2  * Copyright (C) 2011 Free Software Foundation, Inc.
   3  *
   4  * This file is part of GnuTLS.
   5  *
   6  * GnuTLS is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation, either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * GnuTLS is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <stdio.h>
  21 #include <string.h>
  22 #include <signal.h>
  23 #include <sys/time.h>
  24 #include <time.h>
  25 #include <unistd.h>
  26 #include "benchmark.h"
  27
  28 int benchmark_must_finish = 0;
  29
  30 static void
  31 alarm_handler (int signo)
  32 {
  33   benchmark_must_finish = 1;
  34 }
  35
  36 int start_benchmark(struct benchmark_st * st)
  37 {
  38   int ret;
  39   struct itimerval timer;
  40
  41   memset(st, 0, sizeof(*st));
  42
  43   st->old_handler = signal (SIGPROF, alarm_handler);
  44
  45   ret = gettimeofday (&st->start, NULL);
  46   if (ret < 0) {
  47     perror("gettimeofday");
  48     return -1;
  49   }
  50
  51   benchmark_must_finish = 0;
  52
  53   memset(&timer, 0, sizeof(timer));
  54   timer.it_value.tv_sec = 0;
  55   timer.it_value.tv_usec = 100*1000;
  56
  57   ret = setitimer(ITIMER_PROF, &timer, NULL);
  58   if (ret < 0) {
  59     perror("setitimer");
  60     return -1;
  61   }
  62
  63   return 0;
  64 }
  65
  66 /* Returns -1 on error or 0 on success.
  67  * elapsed: the elapsed time in milliseconds
  68  */
  69 int stop_benchmark(struct benchmark_st * st, unsigned long * elapsed)
  70 {
  71   unsigned long msecs;
  72   struct timeval stop;
  73   int ret;
  74
  75   signal(SIGPROF, st->old_handler);
  76
  77   ret = gettimeofday (&stop, NULL);
  78   if (ret < 0)
  79     return -1;
  80
  81   msecs = (stop.tv_sec * 1000 + stop.tv_usec / 1000 -
  82           (st->start.tv_sec * 1000 + st->start.tv_usec / (1000)));
  83
  84   if (elapsed) *elapsed = msecs;
  85
  86   return 0;
  87 }
  88