fork01.c

cygwin, 著名的在win32下模拟unix操作系统的东东

/*
 * 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., 59
 * Temple Place - Suite 330, Boston MA 02111-1307, 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/
 *
 */
/* $Id: fork01.c,v 1.2 2000/09/06 14:21:53 duda Exp $ */
/**********************************************************
 * 
 *    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"
#include "usctest.h"

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

#define LINE_SZ	20		/* size of the line written/read to the file */
#define FILENAME	"childpid"



char *TCID="fork01"; 		/* Test program identifier.    */
int TST_TOTAL=2;    		/* Total number of test cases. */
extern int Tst_count;		/* Test Case counter for tst_* routines */

/***************************************************************
 * child_pid - the child side of the test
 *        determine the PID and write to a file
 ***************************************************************/
void child_pid()
{
  
  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
 ***************************************************************/
void parent_pid()
{
  
  int fildes;
  char tmp_line[LINE_SZ];
  pid_t child_id;
		
  if ((fildes = open(FILENAME,O_RDWR)) == -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 %d from fork()",
		 child_id,TEST_RETURN);
      } else {
	tst_resm(TPASS,"child pid and fork() return agree: %d",child_id);
      }
    }
    close(fildes);
  }
}

/***************************************************************
 * main() - performs tests
 *	
 ***************************************************************/

int
main(int ac, char **av)
{
    int lc;		/* loop counter */
    const char *msg;		/* message returned from parse_opts */
    int fails;
    int kid_status, wait_status; 
    
    /***************************************************************
     * parse standard options
     ***************************************************************/
    if ( (msg=parse_opts(ac, av, (option_t *) NULL, NULL)) != (char *) NULL )
	tst_brkm(TBROK, cleanup, "OPTION PARSING ERROR - %s", msg);

    /***************************************************************
     * perform global setup for test
     ***************************************************************/
    setup();

    /* set the expected errnos... */
    /***************************************************************
     * check looping state if -c option given
     ***************************************************************/
    for (lc=0; TEST_LOOPING(lc); lc++) {

      /* reset Tst_count in case we are looping. */
      Tst_count=0;
      fails = 0;
      
      /* 
       * Call fork(2)
       */
      TEST(fork());
      
      /* check return code */
      if ( TEST_RETURN == -1 ) {
	TEST_ERROR_LOG(TEST_ERRNO);
	if ( STD_FUNCTIONAL_TEST ) {
	  tst_resm(TFAIL, "fork() Failed, errno=%d : %s",
		   TEST_ERRNO, strerror(TEST_ERRNO));
	  tst_resm(TBROK,"unable to continue");
	}
      } 
      if (TEST_RETURN == 0) {
	/* child */
	if ( STD_FUNCTIONAL_TEST ) {
	  child_pid();
	}
	exit(KIDEXIT);
      } else {
	/* parent */
	if ( STD_FUNCTIONAL_TEST ) {
	  tst_resm(TPASS, "fork() returned %d", TEST_RETURN);
	}
	/* wait for the child to complete */
	wait_status = wait(&kid_status);
	if ( STD_FUNCTIONAL_TEST ) {
	  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();
	  }
	}	 	  /* STD_FUNCTIONAL_TEST */
      }  /* TEST_RETURN */
    }	/* End for TEST_LOOPING */
    
    /***************************************************************
     * cleanup and exit
     ***************************************************************/
    cleanup();

    return 0;
}	/* End main */

/***************************************************************
 * setup() - performs all ONE TIME setup for this test.
 ***************************************************************/
void 
  setup()
{
  /* capture signals */
  tst_sig(FORK, DEF_HANDLER, cleanup);
  
  tst_tmpdir();

  /* Pause if that option was specified */
  TEST_PAUSE;
}	/* End setup() */


/***************************************************************
 * cleanup() - performs all ONE TIME cleanup for this test at
 *		completion or premature exit.
 ***************************************************************/
void 
  cleanup()
{
  /*
   * 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_rmdir();
  tst_exit();
}	/* End cleanup() */