src/functional/fcntl.c

   1 #include <stdio.h>
   2 #include <fcntl.h>
   3 #include <unistd.h>
   4 #include <errno.h>
   5 #include <string.h>
   6 #include <sys/wait.h>
   7 #include "test.h"
   8
   9 #define TEST(c, ...) ((c) ? 1 : (t_error(#c" failed: " __VA_ARGS__),0))
  10 #define TESTE(c) (errno=0, TEST(c, "errno = %s\n", strerror(errno)))
  11
  12 int main(void)
  13 {
  14         struct flock fl = {0};
  15         FILE *f;
  16         int fd;
  17         pid_t pid;
  18         int status;
  19
  20         if (!TESTE(f=tmpfile())) return t_status;
  21         fd = fileno(f);
  22
  23         fl.l_type = F_WRLCK;
  24         fl.l_whence = SEEK_SET;
  25         fl.l_start = 0;
  26         fl.l_len = 0;
  27         TESTE(fcntl(fd, F_SETLK, &fl)==0);
  28
  29         pid = fork();
  30         if (!pid) {
  31                 fl.l_type = F_RDLCK;
  32                 _exit(fcntl(fd, F_SETLK, &fl)==0 ||
  33                         (errno!=EAGAIN && errno!=EACCES));
  34         }
  35         while (waitpid(pid, &status, 0)<0 && errno==EINTR);
  36         TEST(status==0, "lock failed to work\n");
  37
  38         pid = fork();
  39         if (!pid) {
  40                 fl.l_type = F_WRLCK;
  41                 _exit(fcntl(fd, F_GETLK, &fl) || fl.l_pid != getppid());
  42         }
  43         while (waitpid(pid, &status, 0)<0 && errno==EINTR);
  44         TEST(status==0, "child failed to detect lock held by parent\n");
  45
  46         fclose(f);
  47
  48         return t_status;
  49 }