testcases/kernel/syscalls/waitpid/waitpid09.c

/*
 *
 *   Copyright (c) International Business Machines  Corp., 2001
 *
 *   This program is free software;  you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 *   the GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program;  if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

/*
 * NAME
 * 	waitpid09.c
 *
 * DESCRIPTION
 *	Check ability of parent to wait until child returns, and that the
 *	child's process id is returned through the waitpid. Check that
 *	waitpid returns immediately if no child is present.
 *	
 * ALGORITHM
 *	case 0:
 *		Parent forks a child and waits. Parent should do nothing
 *		further until child returns. The pid of the forked child
 *		should match the returned value from the waitpid.
 *
 *	case 1:
 *		Parent calls a waitpid with no children waiting. Waitpid
 *		should return a -1 since there are no children to wait for.
 *		
 * USAGE:  <for command-line>
 *      waitpid09 [-c n] [-e] [-i n] [-I x] [-P x] [-t]
 *      where,  -c n : Run n copies concurrently.
 *              -e   : Turn on errno logging.
 *              -i n : Execute test n times.
 *              -I x : Execute test for x seconds.
 *              -P x : Pause for x seconds between iterations.
 *              -t   : Turn on syscall timing.
 *		
 * History
 *	07/2001 John George
 *		-Ported 
 *      04/2002 wjhuie sigset cleanups
 *
 * Restrictions
 *	None
 */

#define _GNU_SOURCE 1
#include <sys/types.h>
#include <signal.h>
#include <errno.h>
#include <sys/wait.h>
#include <stdlib.h>

#include "test.h"
#include "usctest.h"

char *TCID = "waitpid09";
int TST_TOTAL = 1;
volatile int intintr;

/* 0 terminated list of expected errnos */
int exp_enos[] = {10,0};

extern int Tst_count;

void setup(void);
void cleanup(void);
void inthandlr();
void do_exit();
void setup_sigint();
#ifdef UCLINUX
void do_exit_uclinux();
#endif

int main(int argc, char **argv)
{
	int lc;				/* loop counter */
	char *msg;			/* message returned from parse_opts */

	int fail, pid, status, ret;

	/* parse standard options */
	if ((msg = parse_opts(argc, argv, (option_t *)NULL, NULL)) !=
	    (char *)NULL) {
		tst_brkm(TBROK, NULL, "OPTION PARSING ERROR - %s", msg);
		tst_exit();
		/*NOTREACHED*/
	}

#ifdef UCLINUX
	maybe_run_child(&do_exit_uclinux, "");
#endif

	setup();

	if ((pid = FORK_OR_VFORK()) < 0) {
		tst_brkm(TFAIL, cleanup, "Fork Failed");
		/*NOTREACHED*/
	} else if (pid == 0) {
		/*
		 * Child:
		 * Set up to catch SIGINT.  The kids will wait till a
		 * SIGINT has been received before they proceed.
		 */
		setup_sigint();

	/* check for looping state if -i option is given */
	for (lc = 0; TEST_LOOPING(lc); lc++) {
		/* reset Tst_count in case we are looping */
		Tst_count = 0;

		intintr = 0;

		fail = 0;
		if ((pid = FORK_OR_VFORK()) < 0) {
			tst_brkm(TFAIL, cleanup, "Fork failed.");
			/*NOTREACHED*/
		} else if (pid == 0) {		 /* child */
#ifdef UCLINUX
			if (self_exec(argv[0], "") < 0) {
				tst_brkm(TFAIL, cleanup, "self_exec failed");
				/*NOTREACHED*/
			}
#else
			do_exit();
#endif
		} else {			/* parent */	
		
			/*
			 *Check that waitpid with WNOHANG returns zero
			 */
			while (((ret = waitpid(pid, &status, WNOHANG))
					!= 0) || (errno == EINTR)) {
				if (ret == -1) {
					continue;
				}
				tst_resm(TFAIL, "return value for "
					"WNOHANG expected 0 got %d",
					ret);
				fail = 1;
			}
#ifdef UCLINUX
			/* Give the kids a chance to setup SIGINT again, since
			 * this is cleared by exec().
			 */
			sleep(3);
#endif

			/* send SIGINT to child to tell it to proceed */
			if (kill(pid, SIGINT) < 0) {
				tst_resm(TFAIL, "Kill of child failed, "
					 "errno = %d", errno);
				fail = 1;
			}

			while (((ret = waitpid(pid, &status, 0)) != -1)
					|| (errno == EINTR)) {
				if (ret == -1) {
					continue;
				}

				if (ret != pid) {
					tst_resm(TFAIL, "Expected %d "
						"got %d as proc id of "
						"child", pid, ret);
					fail = 1;
				}

				if (status != 0) {
					tst_resm(TFAIL, "status value "
						"got %d expected 0",
						status);
					fail = 1;
				}
			}
		}

		if ((pid = FORK_OR_VFORK()) < 0) {
			tst_brkm(TFAIL, cleanup, "Second fork failed.");
			/*NOTREACHED*/
		} else if (pid == 0) {		/* child */
			exit(0);
		} else {			/* parent */
			/* Give the child time to startup and exit */
			sleep(2);

			while (((ret = waitpid(pid, &status, WNOHANG))
					!= -1) || (errno == EINTR)) {
				if (ret == -1) {
					continue;
				}

				if (ret != pid) {
					tst_resm(TFAIL, "proc id %d "
						"and retval %d do not "
						"match", pid, ret);
					fail = 1;
				}
				
				if (status != 0) {
					tst_resm(TFAIL, "non zero "
						"status received %d",
						status);
					fail = 1;
				}
			}
		}
		if (fail) {
			tst_resm(TFAIL, "case 1 FAILED");
		} else {
			tst_resm(TPASS, "case 1 PASSED");
		}

		fail = 0;
		ret = waitpid(pid, &status, 0);

		if (ret != -1) {
			tst_resm(TFAIL, "Expected -1 got %d", ret);
			fail = 1;
		}
		TEST_ERROR_LOG(errno);
		if (errno != ECHILD) {
			tst_resm(TFAIL, "Expected ECHILD got %d",
					errno);
			fail = 1;
		}

		ret = waitpid(pid, &status, WNOHANG);
		if (ret != -1) {
			tst_resm(TFAIL, "WNOHANG: Expected -1 got %d",
					ret);
			fail = 1;
		}
		TEST_ERROR_LOG(errno);
		if (errno != ECHILD) {
			tst_resm(TFAIL, "WNOHANG: Expected ECHILD got "
				"%d", errno);
			fail = 1;
		}

		if (fail) {
			tst_resm(TFAIL, "case 2 FAILED");
		} else {
			tst_resm(TPASS, "case 2 PASSED");
		}

	}
	cleanup();
	/*NOTREACHED*/
	} else {	/* parent */
		/* wait for the child to return */
		waitpid(pid, &status, 0);
		if (WEXITSTATUS(status) != 0) {
			tst_brkm(TBROK, cleanup,  "child returned bad "
				"status");
			/*NOTREACHED*/
		}
	}

  return 0;

}

/*
 * setup_sigint()
 *	sets up a SIGINT handler
 */
void
setup_sigint(void)
{
	if ((sig_t)signal(SIGINT, inthandlr) == SIG_ERR) {
		tst_brkm(TFAIL, cleanup, "signal SIGINT failed, errno = %d",
			 errno);
		tst_exit();
		/*NOTREACHED*/
	}
}

/*
 * setup()
 *	performs all ONE TIME setup for this test
 */
void
setup(void)
{
	/* Set up the expected error numbers for -e option */
	TEST_EXP_ENOS(exp_enos);

	/* Pause if that option was specified
	 * TEST_PAUSE contains the code to fork the test with the -c option.
	 */
	TEST_PAUSE;
}

/*
 * cleanup()
 *	performs all ONE TIME cleanup for this test at
 *	completion or premature exit
 */
void
cleanup(void)
{
	/*
	 * print timing stats if that option was specified.
	 * print errno log if that option was specified.
	 */
	TEST_CLEANUP;

	/* exit with return code appropriate for results */
	tst_exit();
	/*NOTREACHED*/
}
void
inthandlr()
{
	intintr++;
}

void
wait_for_parent()
{
	int testvar;
	while (!intintr) {
		testvar = 0;
	}
}

void
do_exit()
{
	wait_for_parent();
	exit(0);
}

#ifdef UCLINUX
/*
 * do_exit_uclinux()
 *	Sets up SIGINT handler again, then calls do_exit
 */
void
do_exit_uclinux()
{
	setup_sigint();
	do_exit();
}
#endif