tests/test_looplen.c

   1 /*
   2  * test_looplen.c
   3  *
   4  * Userspace RCU library - test program
   5  *
   6  * Copyright February 2009 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License along
  19  * with this program; if not, write to the Free Software Foundation, Inc.,
  20  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  21  */
  22
  23 #define _GNU_SOURCE
  24 #include <stdio.h>
  25 #include <pthread.h>
  26 #include <stdlib.h>
  27 #include <string.h>
  28 #include <sys/types.h>
  29 #include <sys/wait.h>
  30 #include <unistd.h>
  31 #include <stdio.h>
  32 #include <assert.h>
  33 #include <sys/syscall.h>
  34 #include <sched.h>
  35 #include <errno.h>
  36
  37 #include <urcu/arch.h>
  38
  39 #if defined(_syscall0)
  40 _syscall0(pid_t, gettid)
  41 #elif defined(__NR_gettid)
  42 static inline pid_t gettid(void)
  43 {
  44         return syscall(__NR_gettid);
  45 }
  46 #else
  47 #warning "use pid as tid"
  48 static inline pid_t gettid(void)
  49 {
  50         return getpid();
  51 }
  52 #endif
  53
  54 #ifndef DYNAMIC_LINK_TEST
  55 #define _LGPL_SOURCE
  56 #else
  57 #define debug_yield_read()
  58 #endif
  59 #include <urcu.h>
  60
  61 static inline void loop_sleep(unsigned long l)
  62 {
  63         while(l-- != 0)
  64                 cpu_relax();
  65 }
  66
  67 #define LOOPS 1048576
  68 #define TESTS 10
  69
  70 int main(int argc, char **argv)
  71 {
  72         unsigned long i;
  73         cycles_t time1, time2;
  74         cycles_t time_tot = 0;
  75         double cpl;
  76
  77         for (i = 0; i < TESTS; i++) {
  78                 time1 = get_cycles();
  79                 loop_sleep(LOOPS);
  80                 time2 = get_cycles();
  81                 time_tot += time2 - time1;
  82         }
  83         cpl = ((double)time_tot) / (double)TESTS / (double)LOOPS;
  84
  85         printf("CALIBRATION : %g cycles per loop\n", cpl);
  86         printf("time_tot = %llu, LOOPS = %d, TESTS = %d\n",
  87                time_tot, LOOPS, TESTS);
  88
  89         return 0;
  90 }