src/functional/ipc_sem.c

   1 #ifndef _XOPEN_SOURCE
   2 #define _XOPEN_SOURCE 700
   3 #endif
   4 #include <errno.h>
   5 #include <stdlib.h>
   6 #include <string.h>
   7 #include <time.h>
   8 #include <sys/types.h>
   9 #include <sys/sem.h>
  10 #include <sys/wait.h>
  11 #include <unistd.h>
  12 #include "test.h"
  13
  14 static const char path[] = ".";
  15 static const int id = 's';
  16
  17 #define T(f) do{ \
  18         if ((f)+1 == 0) \
  19                 t_error("%s failed: %s\n", #f, strerror(errno)); \
  20 }while(0)
  21
  22 #define EQ(a,b,fmt) do{ \
  23         if ((a) != (b)) \
  24                 t_error("%s == %s failed: " fmt "\n", #a, #b, a, b); \
  25 }while(0)
  26
  27 static void inc()
  28 {
  29         time_t t;
  30         key_t k;
  31         int semid, semval, sempid, semncnt, semzcnt;
  32         struct semid_ds semid_ds;
  33         union semun {
  34                 int val;
  35                 struct semid_ds *buf;
  36                 unsigned short *array;
  37         } arg;
  38         struct sembuf sops;
  39
  40         T(t = time(0));
  41         T(k = ftok(path, id));
  42
  43         /* make sure we get a clean semaphore id */
  44         T(semid = semget(k, 1, IPC_CREAT|0666));
  45         T(semctl(semid, 0, IPC_RMID));
  46         T(semid = semget(k, 1, IPC_CREAT|IPC_EXCL|0666));
  47
  48         if (t_status)
  49                 exit(t_status);
  50
  51         /* check IPC_EXCL */
  52         errno = 0;
  53         if (semget(k, 1, IPC_CREAT|IPC_EXCL|0666) != -1 || errno != EEXIST)
  54                 t_error("semget(IPC_CREAT|IPC_EXCL) should have failed with EEXIST, got %s\n", strerror(errno));
  55
  56         /* check if msgget initilaized the msqid_ds structure correctly */
  57         arg.buf = &semid_ds;
  58         T(semctl(semid, 0, IPC_STAT, arg));
  59         EQ(semid_ds.sem_perm.cuid, geteuid(), "got %d, want %d");
  60         EQ(semid_ds.sem_perm.uid, geteuid(), "got %d, want %d");
  61         EQ(semid_ds.sem_perm.cgid, getegid(), "got %d, want %d");
  62         EQ(semid_ds.sem_perm.gid, getegid(), "got %d, want %d");
  63         EQ(semid_ds.sem_perm.mode & 0x1ff, 0666, "got %o, want %o");
  64         EQ(semid_ds.sem_nsems, 1, "got %d, want %d");
  65         EQ((long)semid_ds.sem_otime, 0, "got %ld, want %d");
  66         if (semid_ds.sem_ctime < t)
  67                 t_error("semid_ds.sem_ctime >= t failed: got %ld, want >= %ld\n", (long)semid_ds.sem_ctime, (long)t);
  68         if (semid_ds.sem_ctime > t+5)
  69                 t_error("semid_ds.sem_ctime <= t+5 failed: got %ld, want <= %ld\n", (long)semid_ds.sem_ctime, (long)t+5);
  70
  71         /* test sem_op > 0 */
  72         sops.sem_num = 0;
  73         sops.sem_op = 1;
  74         sops.sem_flg = 0;
  75         T(semop(semid, &sops, 1));
  76         T(semval = semctl(semid, 0, GETVAL));
  77         EQ(semval, 1, "got %d, want %d");
  78         T(sempid = semctl(semid, 0, GETPID));
  79         EQ(sempid, getpid(), "got %d, want %d");
  80         T(semncnt = semctl(semid, 0, GETNCNT));
  81         EQ(semncnt, 0, "got %d, want %d");
  82         T(semzcnt = semctl(semid, 0, GETZCNT));
  83         EQ(semzcnt, 0, "got %d, want %d");
  84 }
  85
  86 static void dec()
  87 {
  88         key_t k;
  89         int semid, semval;
  90         struct sembuf sops;
  91
  92         T(k = ftok(path, id));
  93         T(semid = semget(k, 0, 0));
  94
  95         /* test sem_op < 0 */
  96         sops.sem_num = 0;
  97         sops.sem_op = -1;
  98         sops.sem_flg = 0;
  99         T(semop(semid, &sops, 1));
 100         T(semval = semctl(semid, 0, GETVAL));
 101         EQ(semval, 0, "got %d, want %d");
 102
 103         /* cleanup */
 104         T(semctl(semid, 0, IPC_RMID));
 105 }
 106
 107 int main(void)
 108 {
 109         int p;
 110         int status;
 111
 112         inc();
 113         p = fork();
 114         if (p == -1)
 115                 t_error("fork failed: %s\n", strerror(errno));
 116         else if (p == 0)
 117                 dec();
 118         else {
 119                 T(waitpid(p, &status, 0));
 120                 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
 121                         t_error("child exit status: %d\n", status);
 122         }
 123         return t_status;
 124 }
 125