1 /* 2 * Copyright (c) 2008 Bret S. Lambert <blambert@openbsd.org> 3 * 4 * Permission to use, copy, modify, and distribute this software for any 5 * purpose with or without fee is hereby granted, provided that the above 6 * copyright notice and this permission notice appear in all copies. 7 * 8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 15 */ 16 17 #include <err.h> 18 #include <errno.h> 19 #include <stdio.h> 20 #include <stdlib.h> 21 #include <string.h> 22 #include <unistd.h> 23 #include <pthread.h> 24 25 #define THREAD_COUNT 64 26 27 #define TEXT "barnacles" 28 #define TEXT_N "barnacles\n" 29 30 void run_threads(void (*)(void *), void *); 31 32 static pthread_rwlock_t start; 33 static void (*real_func)(void *); 34 35 static void * 36 thread(void *arg) 37 { 38 int r; 39 40 if ((r = pthread_rwlock_rdlock(&start))) 41 errc(1, r, "could not obtain lock in thread"); 42 real_func(arg); 43 if ((r = pthread_rwlock_unlock(&start))) 44 errc(1, r, "could not release lock in thread"); 45 return NULL; 46 } 47 48 void 49 run_threads(void (*func)(void *), void *arg) 50 { 51 pthread_t self, pthread[THREAD_COUNT]; 52 int i, r; 53 54 self = pthread_self(); 55 real_func = func; 56 if ((r = pthread_rwlock_init(&start, NULL))) 57 errc(1, r, "could not initialize lock"); 58 59 if ((r = pthread_rwlock_wrlock(&start))) /* block */ 60 errc(1, r, "could not lock lock"); 61 62 for (i = 0; i < THREAD_COUNT; i++) 63 if ((r = pthread_create(&pthread[i], NULL, thread, arg))) { 64 warnc(r, "could not create thread"); 65 pthread[i] = self; 66 } 67 68 69 if ((r = pthread_rwlock_unlock(&start))) /* unleash */ 70 errc(1, r, "could not release lock"); 71 72 sleep(1); 73 74 if ((r = pthread_rwlock_wrlock(&start))) /* sync */ 75 errx(1, "parent could not sync with children: %s", 76 strerror(r)); 77 78 for (i = 0; i < THREAD_COUNT; i++) 79 if (! pthread_equal(pthread[i], self) && 80 (r = pthread_join(pthread[i], NULL))) 81 warnc(r, "could not join thread"); 82 } 83 84