#include <unistd.h> 
#include <stdlib.h> 
#include <stdio.h> 
#include <time.h> 
#include <signal.h> 
#include <errno.h> 
#include <sys/time.h> 
#include <sys/types.h>
#include <sys/wait.h>

//
// Purpose:	Test waitpid when process group sent SIGINT
// Usage:	test40 [xxx]
//	any arg indicates you want to ignore SIGINT
// Note:
// o Child sends SIGINT to its own process group which causes it to terminate
//   and interrupts the waitpid system call in the parent.  If you run like
//   this:
//	test40
//   the signal handler will be called (i.e., handler_called = 1).
//   If you run like this:
//	test40 xxx
//   the signal handler will NOT be called (i.e., handler_called = 0).
//

int	ignore_sigint = 0;
int	handler_called = 0;

pid_t	cpid;		// pid of children

void
print_mask (void) {
    sigset_t	sigset;
    int		errno_save;

    errno_save = errno;		/* just in case we get called by
				** a signal handler */
    if (sigprocmask (0, NULL, &sigset) < 0) {	// get signal sets
	printf ("sigprocmask() error\n");
	exit(1);
    }
    printf ("print_mask:\n");
// *** solaris only
//    printf ("Signal mask = <%x,%x,%x,%x>\n", sigset.__sigbits[0],
//                sigset.__sigbits[1], sigset.__sigbits[2],
//                sigset.__sigbits[3]);
    if (sigismember (&sigset, SIGINT))	printf ("  SIGINT");
    if (sigismember (&sigset, SIGQUIT))	printf ("  SIGQUIT");
    if (sigismember (&sigset, SIGUSR1))	printf ("  SIGUSR1");
    if (sigismember (&sigset, SIGALRM))	printf ("  SIGALRM");
    if (sigismember (&sigset, SIGCHLD))	printf ("  SIGCHLD");
    printf ("\n");
    errno = errno_save;
}

/*
** Signal mask in effect is action.sa_mask.  After returning,
** signal mask in effect will be oaction.sa_mask.
*/
static void
handle_sig (int signo) {
    handler_called = 1;
    return;
}

int
main(int argc, char *argv[]) {
  struct sigaction	action, oaction;

  if (argc > 1)	ignore_sigint = 1;

  sigemptyset (&action.sa_mask);	// no signals blocked
  action.sa_flags = 0;		// no special options
  if (!ignore_sigint)	action.sa_handler = handle_sig;	// signal handler is ...
  else			action.sa_handler = SIG_IGN;	// ignore SIGINT
  
  if (sigaction (SIGINT, &action, &oaction) < 0) {
    fprintf (stderr, "sigaction(SIGINT) error\n");
    return 1;
  }
  printf("procmask should be empty:\n");
  print_mask();
  printf ("\n");

  printf("parent pid = %d, pgrp = %d\n", getpid(), getpgrp());

  cpid = fork();
  if (cpid < 0) {
    fprintf(stderr, "*** bad 1st fork\n");
    exit(1);
  }
  if (cpid == 0) {	// child
    if (sigaction (SIGINT, &oaction, NULL) < 0) {	// restore default
      printf ("sigaction(SIGINT) error in child\n");
      return 1;
    }
    sleep(1);
    printf ("Child pid = %d, sending SIGINT = %d to pgrp = %d\n",
    					getpid(), SIGINT, getpgrp());
    printf ("Child exit code would be -3 if it got past kill, but it won't\n");
    kill(-getpgrp(), SIGINT);	// send SIGINT to process group
    exit(-3);
  } else {		// parent
    int	rc;
    int	status;
    int	pgrp = getpgrp();

    rc = waitpid(-pgrp, &status, 0);
    printf("++ Return from waitpid, rc = %d, handler_called = %d\n",
    						rc, handler_called);
    printf("++ Expect rc = -1 and handler_called = %d\n", 1-ignore_sigint);
    if (rc == -1) {
      fprintf(stderr, "++ waitpid returned %d when pgrp = %d\n", rc, pgrp);
      fprintf(stderr, "++ Expect rc = -1, pgrp = %d (Child terminates from SIGINT)\n",
      						getpgrp());
      fprintf(stderr, "errno = %d:  ", errno);
      perror("");
    } else {
      if (WIFEXITED(status)) {
	printf("pgrp = %d, cpid = %d, rc = %d, status = %d, WEXITSTATUS(status) = %d\n",
				pgrp, cpid, rc, status, WEXITSTATUS(status));
      } else if (WIFSIGNALED(status)) {
	printf("pgrp = %d, cpid = %d, rc = %d, status = %d, WTERMSIG(status) = %d\n",
				pgrp, cpid, rc, status, WTERMSIG(status));
      } else {
        printf("Neither WIFEXTED or WIFSIGNALED:\n");
	printf("pgrp = %d, cpid = %d, rc = %d, status = %d\n",
						pgrp, cpid, rc, status);
      }
    }
  }
  return 0;
}