testcases/kernel/syscalls/fork/fork01.c

/*
 * Copyright (c) 2000 Silicon Graphics, Inc.  All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 *
 * Further, this software is distributed without any warranty that it is
 * free of the rightful claim of any third person regarding infringement
 * or the like.  Any license provided herein, whether implied or
 * otherwise, applies only to this software file.  Patent licenses, if
 * any, provided herein do not apply to combinations of this program with
 * other software, or any other product whatsoever.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
 * Mountain View, CA  94043, or:
 *
 * http://www.sgi.com
 *
 * For further information regarding this notice, see:
 *
 * http://oss.sgi.com/projects/GenInfo/NoticeExplan/
 *
 *
 *    OS Test - Silicon Graphics, Inc.
 *    TEST IDENTIFIER	: fork01
 *    EXECUTED BY	: anyone
 *    TEST TITLE	: Basic test for fork(2)
 *    PARENT DOCUMENT	: frktds02
 *    TEST CASE TOTAL	: 2
 *    WALL CLOCK TIME	: 1
 *    CPU TYPES		: ALL
 *    AUTHOR		: Kathy Olmsted
 *    CO-PILOT		: Steve Shaw
 *    DATE STARTED	: 06/17/92
 *    INITIAL RELEASE	: UNICOS 7.0
 *    TEST CASES
 *	1.) fork returns without error
 *	2.) fork returns the pid of the child
 *    INPUT SPECIFICATIONS
 *	The standard options for system call tests are accepted.
 *	(See the parse_opts(3) man page).
 *    OUTPUT SPECIFICATIONS
 *    DURATION
 *	Terminates - with frequency and infinite modes.
 *    SIGNALS
 *	Uses SIGUSR1 to pause before test if option set.
 *	(See the parse_opts(3) man page).
 *    RESOURCES
 *	None
 *    ENVIRONMENTAL NEEDS
 *      No run-time environmental needs.
 *    SPECIAL PROCEDURAL REQUIREMENTS
 *	None
 *    INTERCASE DEPENDENCIES
 *	None
 *    DETAILED DESCRIPTION
 *	Setup:
 *	Setup signal handling.
 *	  Pause for SIGUSR1 if option specified.
 *	Test:
 *	 Loop if the proper options are given.
 *        fork()
 *	  Check return code, if system call failed (return=-1)
 *		Log the errno and Issue a FAIL message.
 *	  Otherwise, Issue a PASS message.
 *        CHILD:
 *           determine PID
 *           write to PID to a file and close the file
 *           exit
 *        PARENT:
 *           wait for child to exit
 *           read child PID from file
 *           compare child PID to fork() return code and report
 *           results
 *
 *	  Cleanup:
 *           Print errno log and/or timing stats if options given
 */

#include <errno.h>
#include <string.h>
#include <signal.h>
#include <fcntl.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/wait.h>
#include "test.h"

#define	KIDEXIT	42
static void setup();
static void cleanup();

#define LINE_SZ	20
#define FILENAME "childpid"

char *TCID = "fork01";
int TST_TOTAL = 2;

/*
 * child_pid - the child side of the test
 *             determine the PID and write to a file
 */
static void child_pid(void)
{

	int fildes;
	char tmp_line[LINE_SZ];

	fildes = creat(FILENAME, 0700);
	sprintf(tmp_line, "%d\n", getpid());
	write(fildes, tmp_line, LINE_SZ);
	close(fildes);

}

/*
 * parent_pid - the parent side of the test
 *              read the value determined by the child
 *              compare and report results
 */
static void parent_pid(void)
{

	int fildes;
	char tmp_line[LINE_SZ];
	pid_t child_id;

	fildes = open(FILENAME, O_RDWR);
	if (fildes == -1) {
		tst_brkm(TBROK, cleanup,
			 "parent open failed. errno: %d (%s)\n",
			 errno, strerror(errno));
	} else {
		if (read(fildes, tmp_line, LINE_SZ) == 0) {
			tst_brkm(TBROK, cleanup,
				 "fork(): parent failed to read PID from file errno: %d (%s)",
				 errno, strerror(errno));
		} else {
			child_id = atoi(tmp_line);
			if (TEST_RETURN != child_id) {
				tst_resm(TFAIL,
					 "child reported a pid of %d. parent received %ld from fork()",
					 child_id, TEST_RETURN);
			} else {
				tst_resm(TPASS,
					 "child pid and fork() return agree: %d",
					 child_id);
			}
		}
		close(fildes);
	}
}

int main(int ac, char **av)
{
	int lc;
	const char *msg;
	int fails;
	int kid_status, wait_status;

	msg = parse_opts(ac, av, NULL, NULL);
	if (msg != NULL)
		tst_brkm(TBROK, NULL, "OPTION PARSING ERROR - %s", msg);

	setup();

	for (lc = 0; TEST_LOOPING(lc); lc++) {
		tst_count = 0;
		fails = 0;

		TEST(fork());
		if (TEST_RETURN == -1) {
			tst_resm(TFAIL, "fork() Failed, errno=%d : %s",
				 TEST_ERRNO, strerror(TEST_ERRNO));
			tst_resm(TBROK, "unable to continue");
		}
		if (TEST_RETURN == 0) {
			/* child */
			child_pid();
			exit(KIDEXIT);
		} else {
			/* parent */
			tst_resm(TPASS, "fork() returned %ld",
				 TEST_RETURN);
			/* wait for the child to complete */
			wait_status = waitpid(TEST_RETURN, &kid_status, 0);

			if (wait_status == TEST_RETURN) {
				if (kid_status != KIDEXIT << 8) {
					tst_resm(TBROK,
						 "incorrect child status returned on wait(): %d",
						 kid_status);
					fails++;
				}
			} else {
				tst_resm(TBROK,
					 "wait() for child status failed with %d errno: %d : %s",
					 wait_status, errno,
					 strerror(errno));
				fails++;
			}
			if (fails == 0) {
				/* verification tests */
				parent_pid();
			}
		}		/* TEST_RETURN */
	}

	cleanup();
	tst_exit();
}

static void setup(void)
{

	tst_sig(FORK, DEF_HANDLER, cleanup);

	TEST_PAUSE;

	tst_tmpdir();
}

static void cleanup(void)
{

	tst_rmdir();

}