sem.c revision e739ac0589b4fb43561f801c4faba8c1b89f8680 
1#define _GNU_SOURCE
2
3#include <config.h>
4#include <errno.h>
5#include <stdio.h>
6#include <stdlib.h>
7#include <sys/ipc.h>
8#include <sys/sem.h>
9#include <time.h>
10int main(int argc, char **argv)
11{
12   int semid;
13   struct sembuf sop;
14#ifdef HAVE_SEMTIMEDOP
15   struct timespec ts;
16#endif
17
18   if ((semid = semget(IPC_PRIVATE, 1, 0600)) < 0)
19   {
20      perror("semget");
21      exit(1);
22   }
23
24   sop.sem_num = 0;
25   sop.sem_op = 1;
26   sop.sem_flg = 0;
27
28   if (semop(semid, &sop, 1) < 0)
29   {
30      perror("semop");
31      semctl(semid, 0, IPC_RMID);
32      exit(1);
33   }
34
35   /* The next call to semtimedop causes the program to hang on
36      ppc32-linux (Yellow Dog 4.0).  I don't know why.  Hence the
37      extended ifdef. */
38#if defined(HAVE_SEMTIMEDOP) && !defined(__powerpc__)
39   sop.sem_num = 0;
40   sop.sem_op = 0;
41   sop.sem_flg = 0;
42
43   ts.tv_sec = 0;
44   ts.tv_nsec = 1000000;
45
46   if (semtimedop(semid, &sop, 1, &ts) < 0 && errno != EAGAIN)
47   {
48      perror("semtimedop");
49      semctl(semid, 0, IPC_RMID);
50      exit(1);
51   }
52#endif
53
54   sop.sem_num = 0;
55   sop.sem_op = -1;
56   sop.sem_flg = 0;
57
58   if (semop(semid, &sop, 1) < 0)
59   {
60      perror("semop");
61      semctl(semid, 0, IPC_RMID);
62      exit(1);
63   }
64
65#ifdef HAVE_SEMTIMEDOP
66   sop.sem_num = 0;
67   sop.sem_op = 0;
68   sop.sem_flg = 0;
69
70   ts.tv_sec = 0;
71   ts.tv_nsec = 1000;
72
73   if (semtimedop(semid, &sop, 1, &ts) < 0)
74   {
75      perror("semtimedop");
76      semctl(semid, 0, IPC_RMID);
77      exit(1);
78   }
79#endif
80
81   if (semctl(semid, 0, IPC_RMID) < 0)
82   {
83      perror("semctl(IPC_RMID)");
84      exit(1);
85   }
86
87   exit(0);
88}
89