tests/fcntl_lock64.c

   1 /* test whether 64 bit fcntl locking really works on this system */
   2
   3 #if defined(HAVE_UNISTD_H)
   4 #include <unistd.h>
   5 #endif
   6
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9 #include <sys/types.h>
  10
  11 #ifdef HAVE_FCNTL_H
  12 #include <fcntl.h>
  13 #endif
  14
  15 #ifdef HAVE_SYS_FCNTL_H
  16 #include <sys/fcntl.h>
  17 #endif
  18
  19 #include <errno.h>
  20
  21 static int sys_waitpid(pid_t pid,int *status,int options)
  22 {
  23 #ifdef HAVE_WAITPID
  24   return waitpid(pid,status,options);
  25 #else /* USE_WAITPID */
  26   return wait4(pid, status, options, NULL);
  27 #endif /* USE_WAITPID */
  28 }
  29
  30 #define DATA "conftest.fcntl64"
  31
  32 /* lock a byte range in a open file */
  33 int main(int argc, char *argv[])
  34 {
  35         struct flock64 lock;
  36         int fd, ret, status=1;
  37         pid_t pid;
  38
  39         if (!(pid=fork())) {
  40                 sleep(2);
  41                 fd = open64(DATA, O_RDONLY);
  42
  43                 if (fd == -1) exit(1);
  44
  45                 lock.l_type = F_WRLCK;
  46                 lock.l_whence = SEEK_SET;
  47                 lock.l_start = 0;
  48                 lock.l_len = 4;
  49                 lock.l_pid = getpid();
  50
  51                 lock.l_type = F_WRLCK;
  52
  53                 /* check if a lock applies */
  54                 ret = fcntl(fd,F_GETLK64,&lock);
  55
  56                 if ((ret == -1) ||
  57                     (lock.l_type == F_UNLCK)) {
  58 /*            printf("No lock conflict\n"); */
  59                         exit(1);
  60                 } else {
  61 /*            printf("lock conflict\n"); */
  62                         exit(0);
  63                 }
  64         }
  65
  66         fd = open64(DATA, O_RDWR|O_CREAT|O_TRUNC, 0600);
  67
  68         lock.l_type = F_WRLCK;
  69         lock.l_whence = SEEK_SET;
  70 #if defined(COMPILER_SUPPORTS_LL)
  71         lock.l_start = 0x100000000LL;
  72 #else
  73         lock.l_start = 0x100000000;
  74 #endif
  75         lock.l_len = 4;
  76         lock.l_pid = getpid();
  77
  78         /* set a 4 byte write lock */
  79         fcntl(fd,F_SETLK64,&lock);
  80
  81         sys_waitpid(pid, &status, 0);
  82
  83 #if defined(WIFEXITED) && defined(WEXITSTATUS)
  84         if(WIFEXITED(status)) {
  85                 status = WEXITSTATUS(status);
  86         } else {
  87                 status = 1;
  88         }
  89 #else /* defined(WIFEXITED) && defined(WEXITSTATUS) */
  90         status = (status == 0) ? 0 : 1;
  91 #endif /* defined(WIFEXITED) && defined(WEXITSTATUS) */
  92
  93         unlink(DATA);
  94
  95         exit(status);
  96 }