1
2 #include <sys/types.h>
3 #include <sys/wait.h>
4 #include <err.h>
5 #include <fcntl.h>
6 #include <mqueue.h>
7 #include <signal.h>
8 #include <stdio.h>
9 #include <stdlib.h>
10 #include <unistd.h>
11
12 #define MQNAME "/mytstqueue2"
13 #define LOOPS 1000
14 #define PRIO 10
15
16 static void
alarmhandler(int sig __unused)17 alarmhandler(int sig __unused)
18 {
19 write(1, "timeout\n", 8);
20 _exit(1);
21 }
22
23 int
main(void)24 main(void)
25 {
26 struct mq_attr attr;
27 mqd_t mq;
28 int status;
29 pid_t pid;
30
31 mq_unlink(MQNAME);
32
33 attr.mq_maxmsg = 5;
34 attr.mq_msgsize = 128;
35 mq = mq_open(MQNAME, O_CREAT | O_RDWR | O_EXCL, 0666, &attr);
36 if (mq == (mqd_t)-1)
37 err(1, "mq_open");
38 status = mq_getattr(mq, &attr);
39 if (status)
40 err(1, "mq_getattr");
41 pid = fork();
42 if (pid == 0) { /* child */
43 char *buf;
44 int j, i;
45 unsigned int prio;
46
47 mq_close(mq);
48
49 signal(SIGALRM, alarmhandler);
50
51 mq = mq_open(MQNAME, O_RDWR);
52 if (mq == (mqd_t)-1)
53 err(1, "child: mq_open");
54 buf = malloc(attr.mq_msgsize);
55 for (j = 0; j < LOOPS; ++j) {
56 alarm(3);
57 status = mq_receive(mq, buf, attr.mq_msgsize, &prio);
58 if (status == -1)
59 err(2, "child: mq_receive");
60 for (i = 0; i < attr.mq_msgsize; ++i)
61 if (buf[i] != i)
62 err(3, "child: message data corrupted");
63 if (prio != PRIO)
64 err(4, "child: priority is incorrect: %d",
65 prio);
66 }
67 alarm(0);
68 free(buf);
69 mq_close(mq);
70 return (0);
71 } else if (pid == -1) {
72 err(1, "fork()");
73 } else {
74 char *buf;
75 int i, j;
76
77 signal(SIGALRM, alarmhandler);
78 buf = malloc(attr.mq_msgsize);
79 for (j = 0; j < LOOPS; ++j) {
80 for (i = 0; i < attr.mq_msgsize; ++i)
81 buf[i] = i;
82 alarm(3);
83 status = mq_send(mq, buf, attr.mq_msgsize, PRIO);
84 if (status)
85 err(1, "mq_send");
86 }
87 alarm(3);
88 wait(&status);
89 alarm(0);
90 }
91 status = mq_close(mq);
92 if (status)
93 err(1, "mq_close");
94 mq_unlink(MQNAME);
95 return (0);
96 }
97