posix/test-vfork.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <unistd.h>
   4 #include <error.h>
   5 #include <errno.h>
   6 #include <sys/wait.h>
   7
   8 void __attribute_noinline__ noop (void);
   9
  10 #define NR      2       /* Exit code of the child.  */
  11
  12 int
  13 main (void)
  14 {
  15   pid_t pid;
  16   int status;
  17
  18   printf ("Before vfork\n");
  19   fflush (stdout);
  20   pid = vfork ();
  21   if (pid == 0)
  22     {
  23       /* This will clobber the return pc from vfork in the parent on
  24          machines where it is stored on the stack, if vfork wasn't
  25          implemented correctly, */
  26       noop ();
  27       _exit (NR);
  28     }
  29   else if (pid < 0)
  30     error (1, errno, "vfork");
  31   printf ("After vfork (parent)\n");
  32   if (waitpid (0, &status, 0) != pid
  33       || !WIFEXITED (status) || WEXITSTATUS (status) != NR)
  34     exit (1);
  35
  36   return 0;
  37 }
  38
  39 void
  40 noop (void)
  41 {
  42 }