/*
 * Copyright (c) 2002-2003, Intel Corporation. All rights reserved.
 * Created by:  Rusty.Lnch REMOVE-THIS AT intel DOT com
 * This file is licensed under the GPL license.  For the full content
 * of this license, see the COPYING file at the top level of this
 * source tree.

  Test assertion #9 by verifying that SIGCHLD signals are not sent when
  the parent has setup a SIGCHLD signal handler with the SA_NOCLDSTOP flag set
 * 12/18/02 - Adding in include of sys/time.h per
 *            rodrigc REMOVE-THIS AT attbi DOT com input that it needs
 *            to be included whenever the timeval struct is used.
 *
*/

 /*
  * adam.li@intel.com: 2004-05-26: select should block child
  */

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

#define NUMSTOPS 10

volatile int child_stopped = 0;

void handler(int signo, siginfo_t * info, void *context)
{
	if (info && info->si_code == CLD_STOPPED) {
		printf("Child has been stopped\n");
		child_stopped++;
	}
}

int main(void)
{
	pid_t pid;
	struct sigaction act;
	struct timeval tv;

	act.sa_sigaction = handler;
	act.sa_flags = SA_SIGINFO | SA_NOCLDSTOP;
	sigemptyset(&act.sa_mask);
	sigaction(SIGCHLD, &act, 0);

	if ((pid = fork()) == 0) {
		/* child */
		/* wait forever, or until we are
		   interrupted by a signal */
		select(0, NULL, NULL, NULL, NULL);
		return 0;
	} else {
		/* parent */
		int s;
		int i;

		for (i = 0; i < NUMSTOPS; i++) {
			printf("--> Sending SIGSTOP\n");
			kill(pid, SIGSTOP);

			/*
			   If we send a bunch of SIGSTOP/SIGCONT
			   signals one after the other then it is
			   perfectly OK for the OS to not send
			   the SIGSTOP/SIGCONT combination as an
			   optimization.

			   I can't think of any POSIX method to determine
			   if a process has been stopped, so I'm
			   going to punt with a one second sleep and
			   assume the child process gets put to sleep
			   within that time period.  This will be problem
			   when this test is run on a really stressed
			   system. (Although since we are sending multiple
			   SIGSTOP's then maybe in practice this will
			   cause any problems.)
			 */
			tv.tv_sec = 1;
			tv.tv_usec = 0;
			select(0, NULL, NULL, NULL, &tv);

			printf("--> Sending SIGCONT\n");
			kill(pid, SIGCONT);
		}

		kill(pid, SIGKILL);
		waitpid(pid, &s, 0);
	}

	if (child_stopped == 0) {
		printf("Test PASSED\n");
		return 0;
	}

	printf("Test FAILED\n");
	return -1;
}
