/* $OpenBSD: blocked_dup2.c,v 1.4 2012/02/20 17:06:11 kurt Exp $ */ /* * Copyright (c) 2006 Kurt Miller * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ /* * Test dup2() racing with other threads using the same file * descriptor, with some of them blocking on data that will never * arrive. */ #include #include #include #include #include #include #include #include "test.h" #define ITERATIONS 100 #define WAITING_THREADS 5 static void * deadlock_detector(void *arg) { sleep(15); PANIC("deadlock detected"); } static void * waiting_read(void *arg) { int fd = *(int *)arg; struct sockaddr remote_addr; char readBuf; int n, remote_addr_len = sizeof(struct sockaddr); n = recvfrom(fd, &readBuf, 1, 0, &remote_addr, &remote_addr_len); if (n == -1) return ((caddr_t)NULL + errno); else return (NULL); } int main(int argc, char *argv[]) { pthread_t waiting_threads[WAITING_THREADS]; pthread_t deadlock_thread; struct sockaddr_in addr; int fd, newfd, i, j; void *value_ptr; struct timespec rqtp; rqtp.tv_sec = 0; rqtp.tv_nsec = 1000000; bzero((char *) &addr, sizeof addr); addr.sin_family = AF_INET; addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK); addr.sin_port = htons(0); CHECKr(pthread_create(&deadlock_thread, NULL, deadlock_detector, NULL)); CHECKe(fd = socket(AF_INET, SOCK_DGRAM, 0)); CHECKr(bind(fd, (struct sockaddr *)&addr, sizeof(addr))); CHECKe(newfd = socket(AF_INET, SOCK_DGRAM, 0)); CHECKr(bind(newfd, (struct sockaddr *)&addr, sizeof(addr))); for (i = 0; i < ITERATIONS; i++) { for (j = 0; j < WAITING_THREADS; j++) CHECKr(pthread_create(&waiting_threads[j], NULL, waiting_read, (void *)&newfd)); nanosleep(&rqtp, NULL); CHECKe(dup2(fd, newfd)); for (j = 0; j < WAITING_THREADS; j++) { CHECKr(pthread_join(waiting_threads[j], &value_ptr)); ASSERT(value_ptr == (void *)EBADF); } } SUCCEED; }