regress/sys/kern/select/select.c

   1 /*      $NetBSD: select.c,v 1.1 2008/03/21 12:27:12 yamt Exp $  */
   2
   3 /*-
   4  * Copyright (c)2008 YAMAMOTO Takashi,
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 #define FD_SETSIZE      65536
  30 #include <sys/select.h>
  31 #include <sys/atomic.h>
  32
  33 #include <errno.h>
  34 #include <fcntl.h>
  35 #include <pthread.h>
  36 #include <stdio.h>
  37 #include <stdlib.h>
  38 #include <string.h>
  39 #include <unistd.h>
  40
  41 #define NPIPE   128
  42 #define NTHREAD 64
  43 #define VERBOSE 0
  44
  45 #if !defined(RANDOM_MAX)
  46 #define RANDOM_MAX      ((1UL << 31) - 1)
  47 #endif
  48
  49 int fds[NPIPE][2];
  50
  51 unsigned count;
  52
  53 pthread_barrier_t barrier;
  54
  55 static void
  56 dowrite(void)
  57 {
  58         char buf[1];
  59         int fd;
  60         int i;
  61
  62         i = random() % NPIPE;
  63         fd = fds[i][1];
  64 #if VERBOSE
  65         printf("[%p] write %d\n", (void *)pthread_self(), fd);
  66 #endif
  67         if (write(fd, buf, sizeof(buf)) == -1) {
  68                 perror("write");
  69                 abort();
  70         }
  71 }
  72
  73 static void *
  74 f(void *dummy)
  75 {
  76
  77         pthread_barrier_wait(&barrier);
  78
  79         for (;;) {
  80                 struct timeval to;
  81                 fd_set oset;
  82                 fd_set set;
  83                 int maxfd = -1;
  84                 int nfd = 0;
  85                 int ret;
  86                 int fd;
  87                 int i;
  88
  89                 FD_ZERO(&set);
  90                 do {
  91                         for (i = 0; i < NPIPE; i++) {
  92                                 fd = fds[i][0];
  93                                 if (fd > FD_SETSIZE) {
  94                                         fprintf(stderr,
  95                                             "fd(%d) > FD_SETSIZE(%d)\n",
  96                                             fd, FD_SETSIZE);
  97                                         abort();
  98                                 }
  99                                 if (random() & 1) {
 100                                         FD_SET(fd, &set);
 101                                         if (fd > maxfd) {
 102                                                 maxfd = fd;
 103                                                 nfd++;
 104                                         }
 105                                 }
 106                         }
 107                 } while (nfd == 0);
 108                 memcpy(&oset, &set, sizeof(oset));
 109                 memset(&to, 0, sizeof(to));
 110                 to.tv_sec = random() % 10;
 111                 to.tv_usec = random() % 1000000;
 112 #if VERBOSE
 113                 printf("[%p] select start to=%lu\n", (void *)pthread_self(),
 114                     (unsigned long)to.tv_sec);
 115 #endif
 116                 ret = select(maxfd + 1, &set, NULL, NULL, &to);
 117 #if VERBOSE
 118                 printf("[%p] select done ret=%d\n",
 119                     (void *)pthread_self(), ret);
 120 #endif
 121                 if (ret == -1) {
 122                         perror("select");
 123                         abort();
 124                 }
 125                 if (ret > nfd) {
 126                         fprintf(stderr, "[%p] unexpected return value %d\n",
 127                             (void *)pthread_self(), ret);
 128                         abort();
 129                 }
 130                 nfd = 0;
 131                 for (fd = 0; fd <= maxfd; fd++) {
 132                         if (FD_ISSET(fd, &set)) {
 133                                 char buf[1];
 134
 135 #if VERBOSE
 136                                 printf("[%p] read %d\n",
 137                                     (void *)pthread_self(), fd);
 138 #endif
 139                                 if (!FD_ISSET(fd, &oset)) {
 140                                         fprintf(stderr, "[%p] unexpected\n",
 141                                             (void *)pthread_self());
 142                                         abort();
 143                                 }
 144                                 if (read(fd, buf, sizeof(buf)) == -1) {
 145                                         if (errno != EAGAIN) {
 146                                                 perror("read");
 147                                                 abort();
 148                                         }
 149                                 } else {
 150                                         dowrite();
 151                                         atomic_inc_uint(&count);
 152                                 }
 153                                 nfd++;
 154                         }
 155                 }
 156                 if (ret != nfd) {
 157                         fprintf(stderr, "[%p] ret(%d) != nfd(%d)\n",
 158                             (void *)pthread_self(), ret, nfd);
 159                         abort();
 160                 }
 161         }
 162 }
 163
 164 int
 165 main(int argc, char *argv[])
 166 {
 167         pthread_t pt[NTHREAD];
 168         int i;
 169         unsigned int secs;
 170
 171         secs = atoi(argv[1]);
 172
 173         for (i = 0; i < NPIPE; i++) {
 174                 if (pipe(fds[i])) {
 175                         perror("pipe");
 176                         abort();
 177                 }
 178                 if (fcntl(fds[i][0], F_SETFL, O_NONBLOCK) == -1) {
 179                         perror("fcntl");
 180                         abort();
 181                 }
 182         }
 183         pthread_barrier_init(&barrier, NULL, NTHREAD + 1);
 184         for (i = 0; i < NTHREAD; i++) {
 185                 int error = pthread_create(&pt[i], NULL, f, NULL);
 186                 if (error) {
 187                         errno = error;
 188                         perror("pthread_create");
 189                         abort();
 190                 }
 191         }
 192         pthread_barrier_wait(&barrier);
 193         dowrite();
 194         dowrite();
 195         dowrite();
 196         dowrite();
 197
 198         sleep(secs);
 199         printf("%u / %u = %lf\n", count, secs, (double)count / secs);
 200         exit(EXIT_SUCCESS);
 201 }