select.c revision 1.2.2.2
1 1.2.2.2 matt /* $NetBSD: select.c,v 1.2.2.2 2008/03/23 00:43:00 matt Exp $ */ 2 1.2.2.2 matt 3 1.2.2.2 matt /*- 4 1.2.2.2 matt * Copyright (c)2008 YAMAMOTO Takashi, 5 1.2.2.2 matt * All rights reserved. 6 1.2.2.2 matt * 7 1.2.2.2 matt * Redistribution and use in source and binary forms, with or without 8 1.2.2.2 matt * modification, are permitted provided that the following conditions 9 1.2.2.2 matt * are met: 10 1.2.2.2 matt * 1. Redistributions of source code must retain the above copyright 11 1.2.2.2 matt * notice, this list of conditions and the following disclaimer. 12 1.2.2.2 matt * 2. Redistributions in binary form must reproduce the above copyright 13 1.2.2.2 matt * notice, this list of conditions and the following disclaimer in the 14 1.2.2.2 matt * documentation and/or other materials provided with the distribution. 15 1.2.2.2 matt * 16 1.2.2.2 matt * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 1.2.2.2 matt * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 1.2.2.2 matt * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 1.2.2.2 matt * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 1.2.2.2 matt * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 1.2.2.2 matt * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 1.2.2.2 matt * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 1.2.2.2 matt * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 1.2.2.2 matt * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 1.2.2.2 matt * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 1.2.2.2 matt * SUCH DAMAGE. 27 1.2.2.2 matt */ 28 1.2.2.2 matt 29 1.2.2.2 matt #define FD_SETSIZE 65536 30 1.2.2.2 matt #include <sys/select.h> 31 1.2.2.2 matt #include <sys/atomic.h> 32 1.2.2.2 matt 33 1.2.2.2 matt #include <errno.h> 34 1.2.2.2 matt #include <fcntl.h> 35 1.2.2.2 matt #include <pthread.h> 36 1.2.2.2 matt #include <stdio.h> 37 1.2.2.2 matt #include <stdlib.h> 38 1.2.2.2 matt #include <string.h> 39 1.2.2.2 matt #include <unistd.h> 40 1.2.2.2 matt 41 1.2.2.2 matt #define NPIPE 128 42 1.2.2.2 matt #define NTHREAD 64 43 1.2.2.2 matt #define VERBOSE 0 44 1.2.2.2 matt 45 1.2.2.2 matt #if !defined(RANDOM_MAX) 46 1.2.2.2 matt #define RANDOM_MAX ((1UL << 31) - 1) 47 1.2.2.2 matt #endif 48 1.2.2.2 matt 49 1.2.2.2 matt int fds[NPIPE][2]; 50 1.2.2.2 matt 51 1.2.2.2 matt unsigned count; 52 1.2.2.2 matt 53 1.2.2.2 matt pthread_barrier_t barrier; 54 1.2.2.2 matt 55 1.2.2.2 matt static void 56 1.2.2.2 matt dowrite(void) 57 1.2.2.2 matt { 58 1.2.2.2 matt char buf[1]; 59 1.2.2.2 matt int fd; 60 1.2.2.2 matt int i; 61 1.2.2.2 matt 62 1.2.2.2 matt i = random() % NPIPE; 63 1.2.2.2 matt fd = fds[i][1]; 64 1.2.2.2 matt #if VERBOSE 65 1.2.2.2 matt printf("[%p] write %d\n", (void *)pthread_self(), fd); 66 1.2.2.2 matt #endif 67 1.2.2.2 matt if (write(fd, buf, sizeof(buf)) == -1) { 68 1.2.2.2 matt perror("write"); 69 1.2.2.2 matt abort(); 70 1.2.2.2 matt } 71 1.2.2.2 matt } 72 1.2.2.2 matt 73 1.2.2.2 matt static void * 74 1.2.2.2 matt f(void *dummy) 75 1.2.2.2 matt { 76 1.2.2.2 matt 77 1.2.2.2 matt pthread_barrier_wait(&barrier); 78 1.2.2.2 matt 79 1.2.2.2 matt for (;;) { 80 1.2.2.2 matt struct timeval to; 81 1.2.2.2 matt fd_set oset; 82 1.2.2.2 matt fd_set set; 83 1.2.2.2 matt int maxfd = -1; 84 1.2.2.2 matt int nfd = 0; 85 1.2.2.2 matt int ret; 86 1.2.2.2 matt int fd; 87 1.2.2.2 matt int i; 88 1.2.2.2 matt 89 1.2.2.2 matt FD_ZERO(&set); 90 1.2.2.2 matt do { 91 1.2.2.2 matt for (i = 0; i < NPIPE; i++) { 92 1.2.2.2 matt fd = fds[i][0]; 93 1.2.2.2 matt if (fd > FD_SETSIZE) { 94 1.2.2.2 matt fprintf(stderr, 95 1.2.2.2 matt "fd(%d) > FD_SETSIZE(%d)\n", 96 1.2.2.2 matt fd, FD_SETSIZE); 97 1.2.2.2 matt abort(); 98 1.2.2.2 matt } 99 1.2.2.2 matt if (random() & 1) { 100 1.2.2.2 matt FD_SET(fd, &set); 101 1.2.2.2 matt if (fd > maxfd) { 102 1.2.2.2 matt maxfd = fd; 103 1.2.2.2 matt nfd++; 104 1.2.2.2 matt } 105 1.2.2.2 matt } 106 1.2.2.2 matt } 107 1.2.2.2 matt } while (nfd == 0); 108 1.2.2.2 matt memcpy(&oset, &set, sizeof(oset)); 109 1.2.2.2 matt memset(&to, 0, sizeof(to)); 110 1.2.2.2 matt to.tv_sec = random() % 10; 111 1.2.2.2 matt to.tv_usec = random() % 1000000; 112 1.2.2.2 matt #if VERBOSE 113 1.2.2.2 matt printf("[%p] select start to=%lu\n", (void *)pthread_self(), 114 1.2.2.2 matt (unsigned long)to.tv_sec); 115 1.2.2.2 matt #endif 116 1.2.2.2 matt ret = select(maxfd + 1, &set, NULL, NULL, &to); 117 1.2.2.2 matt #if VERBOSE 118 1.2.2.2 matt printf("[%p] select done ret=%d\n", 119 1.2.2.2 matt (void *)pthread_self(), ret); 120 1.2.2.2 matt #endif 121 1.2.2.2 matt if (ret == -1) { 122 1.2.2.2 matt perror("select"); 123 1.2.2.2 matt abort(); 124 1.2.2.2 matt } 125 1.2.2.2 matt if (ret > nfd) { 126 1.2.2.2 matt fprintf(stderr, "[%p] unexpected return value %d\n", 127 1.2.2.2 matt (void *)pthread_self(), ret); 128 1.2.2.2 matt abort(); 129 1.2.2.2 matt } 130 1.2.2.2 matt nfd = 0; 131 1.2.2.2 matt for (fd = 0; fd <= maxfd; fd++) { 132 1.2.2.2 matt if (FD_ISSET(fd, &set)) { 133 1.2.2.2 matt char buf[1]; 134 1.2.2.2 matt 135 1.2.2.2 matt #if VERBOSE 136 1.2.2.2 matt printf("[%p] read %d\n", 137 1.2.2.2 matt (void *)pthread_self(), fd); 138 1.2.2.2 matt #endif 139 1.2.2.2 matt if (!FD_ISSET(fd, &oset)) { 140 1.2.2.2 matt fprintf(stderr, "[%p] unexpected\n", 141 1.2.2.2 matt (void *)pthread_self()); 142 1.2.2.2 matt abort(); 143 1.2.2.2 matt } 144 1.2.2.2 matt if (read(fd, buf, sizeof(buf)) == -1) { 145 1.2.2.2 matt if (errno != EAGAIN) { 146 1.2.2.2 matt perror("read"); 147 1.2.2.2 matt abort(); 148 1.2.2.2 matt } 149 1.2.2.2 matt } else { 150 1.2.2.2 matt dowrite(); 151 1.2.2.2 matt atomic_inc_uint(&count); 152 1.2.2.2 matt } 153 1.2.2.2 matt nfd++; 154 1.2.2.2 matt } 155 1.2.2.2 matt } 156 1.2.2.2 matt if (ret != nfd) { 157 1.2.2.2 matt fprintf(stderr, "[%p] ret(%d) != nfd(%d)\n", 158 1.2.2.2 matt (void *)pthread_self(), ret, nfd); 159 1.2.2.2 matt abort(); 160 1.2.2.2 matt } 161 1.2.2.2 matt } 162 1.2.2.2 matt } 163 1.2.2.2 matt 164 1.2.2.2 matt int 165 1.2.2.2 matt main(int argc, char *argv[]) 166 1.2.2.2 matt { 167 1.2.2.2 matt pthread_t pt[NTHREAD]; 168 1.2.2.2 matt int i; 169 1.2.2.2 matt unsigned int secs; 170 1.2.2.2 matt 171 1.2.2.2 matt secs = atoi(argv[1]); 172 1.2.2.2 matt 173 1.2.2.2 matt for (i = 0; i < NPIPE; i++) { 174 1.2.2.2 matt if (pipe(fds[i])) { 175 1.2.2.2 matt perror("pipe"); 176 1.2.2.2 matt abort(); 177 1.2.2.2 matt } 178 1.2.2.2 matt if (fcntl(fds[i][0], F_SETFL, O_NONBLOCK) == -1) { 179 1.2.2.2 matt perror("fcntl"); 180 1.2.2.2 matt abort(); 181 1.2.2.2 matt } 182 1.2.2.2 matt } 183 1.2.2.2 matt pthread_barrier_init(&barrier, NULL, NTHREAD + 1); 184 1.2.2.2 matt for (i = 0; i < NTHREAD; i++) { 185 1.2.2.2 matt int error = pthread_create(&pt[i], NULL, f, NULL); 186 1.2.2.2 matt if (error) { 187 1.2.2.2 matt errno = error; 188 1.2.2.2 matt perror("pthread_create"); 189 1.2.2.2 matt abort(); 190 1.2.2.2 matt } 191 1.2.2.2 matt } 192 1.2.2.2 matt pthread_barrier_wait(&barrier); 193 1.2.2.2 matt dowrite(); 194 1.2.2.2 matt dowrite(); 195 1.2.2.2 matt dowrite(); 196 1.2.2.2 matt dowrite(); 197 1.2.2.2 matt 198 1.2.2.2 matt sleep(secs); 199 1.2.2.2 matt printf("%u / %u = %lf\n", count, secs, (double)count / secs); 200 1.2.2.2 matt exit(EXIT_SUCCESS); 201 1.2.2.2 matt } 202
Indexes created Thu Oct 02 01:09:59 GMT 2025