1 2 #include <sys/types.h> 3 #include <sys/select.h> 4 #include <sys/wait.h> 5 #include <err.h> 6 #include <fcntl.h> 7 #include <mqueue.h> 8 #include <signal.h> 9 #include <stdio.h> 10 #include <stdlib.h> 11 #include <unistd.h> 12 13 #define MQNAME "/mytstqueue3" 14 #define LOOPS 1000 15 #define PRIO 10 16 17 static void 18 sighandler(int sig __unused) 19 { 20 write(1, "timeout\n", 8); 21 _exit(1); 22 } 23 24 int 25 main(void) 26 { 27 fd_set set; 28 struct mq_attr attr; 29 int status; 30 mqd_t mq; 31 pid_t pid; 32 33 mq_unlink(MQNAME); 34 35 attr.mq_maxmsg = 5; 36 attr.mq_msgsize = 128; 37 mq = mq_open(MQNAME, O_CREAT | O_RDWR | O_EXCL, 0666, &attr); 38 if (mq == (mqd_t)-1) 39 err(1, "mq_open()"); 40 status = mq_getattr(mq, &attr); 41 if (status) 42 err(1, "mq_getattr()"); 43 44 pid = fork(); 45 if (pid == 0) { /* child */ 46 char *buf; 47 int j, i; 48 unsigned int prio; 49 50 mq_close(mq); 51 52 signal(SIGALRM, sighandler); 53 54 mq = mq_open(MQNAME, O_RDWR); 55 if (mq == (mqd_t)-1) 56 err(1, "child process: mq_open"); 57 buf = malloc(attr.mq_msgsize); 58 for (j = 0; j < LOOPS; ++j) { 59 FD_ZERO(&set); 60 FD_SET(mq_getfd_np(mq), &set); 61 alarm(3); 62 status = select(mq_getfd_np(mq) + 1, &set, NULL, 63 NULL, NULL); 64 if (status != 1) 65 err(1, "child process: select()"); 66 status = mq_receive(mq, buf, attr.mq_msgsize, &prio); 67 if (status == -1) 68 err(2, "child process: mq_receive"); 69 for (i = 0; i < attr.mq_msgsize; ++i) 70 if (buf[i] != i) 71 err(3, "message data corrupted"); 72 if (prio != PRIO) 73 err(4, "priority is incorrect: %d", prio); 74 } 75 alarm(0); 76 free(buf); 77 mq_close(mq); 78 return (0); 79 } else if (pid == -1) { 80 err(1, "fork()"); 81 } else { 82 char *buf; 83 int i, j; 84 85 signal(SIGALRM, sighandler); 86 buf = malloc(attr.mq_msgsize); 87 for (j = 0; j < LOOPS; ++j) { 88 for (i = 0; i < attr.mq_msgsize; ++i) { 89 buf[i] = i; 90 } 91 alarm(3); 92 FD_ZERO(&set); 93 FD_SET(mq_getfd_np(mq), &set); 94 status = select(mq_getfd_np(mq) + 1, NULL, &set, 95 NULL, NULL); 96 if (status != 1) 97 err(1, "select()"); 98 status = mq_send(mq, buf, attr.mq_msgsize, PRIO); 99 if (status) { 100 kill(pid, SIGKILL); 101 err(2, "mq_send()"); 102 } 103 } 104 alarm(3); 105 wait(&status); 106 alarm(0); 107 } 108 status = mq_close(mq); 109 if (status) 110 err(1, "mq_close"); 111 mq_unlink(MQNAME); 112 return (0); 113 } 114