tests/lib/test_seqlock.c

   1 /*
   2  * basic test for seqlock
   3  *
   4  * Copyright (C) 2015  David Lamparter
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the Free
   8  * Software Foundation; either version 2 of the License, or (at your option)
   9  * any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  14  * more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along with
  17  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  18  * Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 #include <stdio.h>
  22 #include <stdint.h>
  23 #include <inttypes.h>
  24 #include <string.h>
  25 #include <unistd.h>
  26 #include <assert.h>
  27 #include <sys/uio.h>
  28
  29 #include "monotime.h"
  30 #include "seqlock.h"
  31
  32 static struct seqlock sqlo;
  33 static pthread_t thr1;
  34 static struct timeval start;
  35
  36 static void writestr(const char *str)
  37 {
  38         struct iovec iov[2];
  39         char buf[32];
  40         int64_t usec = monotime_since(&start, NULL);
  41
  42         snprintf(buf, sizeof(buf), "[%02"PRId64"] ", usec / 100000);
  43
  44         iov[0].iov_base = buf;
  45         iov[0].iov_len = strlen(buf);
  46         iov[1].iov_base = (char *)str;
  47         iov[1].iov_len = strlen(str);
  48         writev(1, iov, 2);
  49 }
  50
  51 static void *thr1func(void *arg)
  52 {
  53         assert(!seqlock_held(&sqlo));
  54         assert(seqlock_check(&sqlo, 1));
  55         seqlock_wait(&sqlo, 1);
  56         writestr("thr1 (unheld)\n");
  57
  58         sleep(2);
  59
  60         assert(seqlock_held(&sqlo));
  61         assert(seqlock_check(&sqlo, 1));
  62         seqlock_wait(&sqlo, 1);
  63         writestr("thr1 @1\n");
  64
  65         seqlock_wait(&sqlo, 3);
  66         writestr("thr1 @3\n");
  67
  68         seqlock_wait(&sqlo, 5);
  69         writestr("thr1 @5\n");
  70
  71         seqlock_wait(&sqlo, 7);
  72         writestr("thr1 @7\n");
  73
  74         seqlock_wait(&sqlo, 9);
  75         writestr("thr1 @9\n");
  76
  77         seqlock_wait(&sqlo, 11);
  78         writestr("thr1 @11\n");
  79         return NULL;
  80 }
  81
  82 int main(int argc, char **argv)
  83 {
  84         monotime(&start);
  85
  86         seqlock_init(&sqlo);
  87
  88         assert(!seqlock_held(&sqlo));
  89         seqlock_acquire_val(&sqlo, 1);
  90         assert(seqlock_held(&sqlo));
  91
  92         assert(seqlock_cur(&sqlo) == 1);
  93         assert(seqlock_bump(&sqlo) == 1);
  94         assert(seqlock_cur(&sqlo) == 3);
  95         assert(seqlock_bump(&sqlo) == 3);
  96         assert(seqlock_bump(&sqlo) == 5);
  97         assert(seqlock_bump(&sqlo) == 7);
  98         assert(seqlock_cur(&sqlo) == 9);
  99
 100         assert(seqlock_held(&sqlo));
 101         seqlock_release(&sqlo);
 102         assert(!seqlock_held(&sqlo));
 103
 104         pthread_create(&thr1, NULL, thr1func, NULL);
 105         sleep(1);
 106
 107         writestr("main @3\n");
 108         seqlock_acquire_val(&sqlo, 3);
 109         sleep(2);
 110
 111         writestr("main @5\n");
 112         seqlock_bump(&sqlo);
 113         sleep(1);
 114
 115         writestr("main @9\n");
 116         seqlock_acquire_val(&sqlo, 9);
 117         sleep(1);
 118
 119         writestr("main @release\n");
 120         seqlock_release(&sqlo);
 121         sleep(1);
 122 }