1 /* $OpenBSD: blocked_dup2.c,v 1.3 2006/10/06 13:11:58 kurt Exp $ */ 2 /* 3 * Copyright (c) 2006 Kurt Miller <kurt@intricatesoftware.com> 4 * 5 * Permission to use, copy, modify, and distribute this software for any 6 * purpose with or without fee is hereby granted, provided that the above 7 * copyright notice and this permission notice appear in all copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18 /* 19 * Test dup2() racing with other threads using the same file 20 * descriptor, with some of them blocking on data that will never 21 * arrive. 22 */ 23 24 #include <pthread.h> 25 #include <unistd.h> 26 #include <fcntl.h> 27 #include <time.h> 28 #include <sys/types.h> 29 #include <sys/socket.h> 30 #include <netinet/in.h> 31 #include "test.h" 32 33 #define ITERATIONS 100 34 #define BUSY_THREADS 5 35 #define WAITING_THREADS 5 36 37 static void * 38 deadlock_detector(void *arg) 39 { 40 sleep(60); 41 PANIC("deadlock detected"); 42 } 43 44 static void * 45 waiting_read(void *arg) 46 { 47 int fd = *(int *)arg; 48 struct sockaddr remote_addr; 49 char readBuf; 50 int n, remote_addr_len = sizeof(struct sockaddr); 51 52 n = recvfrom(fd, &readBuf, 1, 0, &remote_addr, &remote_addr_len); 53 54 if (n == -1) 55 return ((caddr_t)NULL + errno); 56 else 57 return (NULL); 58 } 59 60 static void * 61 busy_thread(void *arg) 62 { 63 int fd = *(int *)arg; 64 65 /* loop until error */ 66 while(fcntl(fd, F_GETFD, NULL) != -1); 67 68 return ((caddr_t)NULL + errno); 69 } 70 71 int 72 main(int argc, char *argv[]) 73 { 74 pthread_t busy_threads[BUSY_THREADS]; 75 pthread_t waiting_threads[WAITING_THREADS]; 76 pthread_t deadlock_thread; 77 struct sockaddr_in addr; 78 int fd, newfd, i, j; 79 void *value_ptr; 80 struct timespec rqtp; 81 82 rqtp.tv_sec = 0; 83 rqtp.tv_nsec = 1000000; 84 85 bzero((char *) &addr, sizeof addr); 86 addr.sin_family = AF_INET; 87 addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK); 88 addr.sin_port = htons(0); 89 90 CHECKr(pthread_create(&deadlock_thread, NULL, 91 deadlock_detector, NULL)); 92 93 CHECKe(fd = socket(AF_INET, SOCK_DGRAM, 0)); 94 CHECKr(bind(fd, (struct sockaddr *)&addr, sizeof(addr))); 95 96 CHECKe(newfd = socket(AF_INET, SOCK_DGRAM, 0)); 97 CHECKr(bind(newfd, (struct sockaddr *)&addr, sizeof(addr))); 98 99 for (i = 0; i < ITERATIONS; i++) { 100 for (j = 0; j < BUSY_THREADS; j++) 101 CHECKr(pthread_create(&busy_threads[j], NULL, 102 busy_thread, (void *)&newfd)); 103 for (j = 0; j < WAITING_THREADS; j++) 104 CHECKr(pthread_create(&waiting_threads[j], NULL, 105 waiting_read, (void *)&newfd)); 106 nanosleep(&rqtp, NULL); 107 CHECKe(dup2(fd, newfd)); 108 for (j = 0; j < BUSY_THREADS; j++) { 109 CHECKr(pthread_join(busy_threads[j], &value_ptr)); 110 ASSERT(value_ptr == (void *)EBADF); 111 } 112 for (j = 0; j < WAITING_THREADS; j++) { 113 CHECKr(pthread_join(waiting_threads[j], &value_ptr)); 114 ASSERT(value_ptr == (void *)EBADF); 115 } 116 } 117 SUCCEED; 118 } 119