none/tests/syscall-restart2.c

   1 #include <stdio.h>
   2 #include <unistd.h>
   3 #include <signal.h>
   4 #include <errno.h>
   5 #include <sys/wait.h>
   6 #include <string.h>
   7
   8 /* Make sure that a blocking syscall restarts if hit by a signal,
   9    and SA_RESTART is set */
  10
  11 static void handler(int s)
  12 {
  13 }
  14
  15 int main()
  16 {
  17         int pid;
  18         int fds[2];
  19
  20         if (pipe(fds) == -1) {
  21                 perror("FAIL: pipe\n");
  22                 return 1;
  23         }
  24
  25         pid = fork();
  26
  27         if (pid == -1) {
  28                 perror("fork failed");
  29                 return 1;
  30         }
  31
  32         if (pid == 0) {
  33                 char ch = '?';
  34                 int ret;
  35                 struct sigaction sa;
  36
  37                 sa.sa_handler = handler;
  38                 sigfillset(&sa.sa_mask);
  39                 sa.sa_flags = SA_RESTART;
  40
  41                 sigaction(SIGUSR1, &sa, NULL);
  42
  43                 close(fds[1]);
  44                 ret = read(fds[0], &ch, 1);
  45
  46                 if (ret != 1 || ch != 'x')
  47                         fprintf(stderr, "FAIL: expected 1 byte, not %d/%s/%c\n",
  48                                 ret, strerror(errno), ch);
  49         } else {
  50                 signal(SIGPIPE, SIG_IGN);
  51
  52                 close(fds[0]);
  53                 sleep(1);
  54                 kill(pid, SIGUSR1);
  55                 sleep(1);
  56                 write(fds[1], "x", 1);
  57
  58                 waitpid(pid, NULL, 0);
  59         }
  60
  61         return 0;
  62 }