joey.c

/*--------------------------------------------------------------------------*
 *----									
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 *----		joey.c							
----*
 *----									
----*
 *----	    This program implements the joey processes, which try to 	
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 *----	leave the mall.							
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 *----									
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 *----	----	----	----	----	----	----	----	----	
----*
 *----									
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 *----	Version 1.0		2016 April 11		Joseph Phillips	
----*
 *----									
----*
 
*--------------------------------------------------------------------------*/

//
//		Header inclusion:
//
#include	"kangarooHeaders.h"


//
//		Definition of global vars:
//

//  PURPOSE:  To tell if the mama is still looking for joeys.
int		shouldStillRun		= 1;

//  PURPOSE:  To tell which joey this joey is.
int		joeyIndex;

//  PURPOSE:  To tell the process id of the mall process.
pid_t		mallPid;

//  PURPOSE:  To hold what the next turn will be.
int		nextTurn;

//  PURPOSE:  To initialize most globals given the 'argc' command line
//	arguments pointed to by 'argv[]'.  No return value.
void		initializeMostGlobals	(int		argc,
                                     char*		argv[]
                                     )
{
    //  I.  Application validity check:
    if  (argc < MIN_JOEY_CMD_LINE_PARAMS)
    {
        fprintf(stderr,"Usage: %s <index> <mallPid> <randSeed>\n",JOEY_PROG_NAME);
        exit(EXIT_FAILURE);
    }
    
    //  II.  Initialize globals:
    //  II.A.  Initialize 'joeyIndex':
    joeyIndex	= strtol(argv[JOEYS_INDEX_CMD_LINE_INDEX],NULL,10);  // <-- REPLACE with code that gets integer from 'argv[JOEYS_INDEX_CMD_LINE_INDEX]'
    
    //  II.B.  Initialize 'mallPid':
    mallPid	= strtol(argv[JOEYS_MALL_PID_CMD_LINE_INDEX],NULL,10); 
// <-- REPLACE with code that gets integer from 'argv[JOEYS_MALL_PID_CMD_LINE_INDEX]'
    
    //  II.C.  Initialize random number generator:
    int	seed	= strtol(argv[JOEYS_RAND_SEED_CMD_LINE_INDEX],NULL,10);  
// <-- REPLACE with code that gets integer from 'argv[JOEYS_RAND_SEED_CMD_LINE_INDEX]'
    
    srand(seed);
    
    //  III.  Finished:
}


//  PURPOSE:  To handle 'CORRECT_TURN_SIGNAL'.  Ignores 'sig'.  No return value.
void		correctTurnSignalHandler	(int		sig
                                         )
{
    //  I.  Application validity check:
    
    //  II.
    nextTurn = ((rand() % 2) == 1) ? LEFT_TURN_SIGNAL : RIGHT_TURN_SIGNAL;
    printf("Joey # %d: Yay!  On to the next turn; I'll guess %s.\n",
           joeyIndex,
           (nextTurn == LEFT_TURN_SIGNAL) ? "left" : "right"
           );
    fflush(stdout);
    // YOUR CODE HERE to send 'nextTurn' to 'mallPid'
    
     kill(mallPid, nextTurn);
    
    //  III.  Finished:
}


//  PURPOSE:  To handle 'WRONG_TURN_SIGNAL'.  Ignores 'sig'.  No return value.
void		wrongTurnSignalHandler		(int	      sig
                                         )
{
    //  I.  Application validity check:
    
    //  II.
    nextTurn = (nextTurn == LEFT_TURN_SIGNAL)
    ? RIGHT_TURN_SIGNAL: LEFT_TURN_SIGNAL;
    printf("Joey # %d: Oops!  Let us try the other direction: %s.\n",
           joeyIndex,
           (nextTurn == LEFT_TURN_SIGNAL) ? "left" : "right");
    fflush(stdout);
    // YOUR CODE HERE to send 'nextTurn' to 'mallPid'
    kill(mallPid,nextTurn);
    
    //  III.  Finished:
}


//  PURPOSE:  To note that the program may now finish (after receiving
//	'SIGINT').  Ignores 'sig'.   No return value.
void		sigIntHandler			(int		sig
                                     )
{
    
    printf("Joey # %d: Yay!  I'm safely in mommy's pouch!\n",joeyIndex);
    fflush(stdout);
    shouldStillRun	= 0;
}


//  PURPOSE:  To install 'correctTurnSignalHandler()' as the signal handler for
//	'CORRECT_TURN_SIGNAL' and 'wrongTurnSignalHandler()' as the handler for
//	'WRONG_TURN_SIGNAL'.  No parameters.  No return value.
void		installTurnHandlers		()
{
    //  I.  Application validity check:
    
    //  II.  Install the handler:
    //  YOUR CODE HERE
    struct sigaction	act;
    
    memset(&act,'\0',sizeof(struct sigaction));
    act.sa_handler = correctTurnSignalHandler;
    act.sa_flags	 = SA_NOCLDSTOP | SA_RESTART;
    sigaction(CORRECT_TURN_SIGNAL,&act,NULL);
    
    struct sigaction	actt;
    
    memset(&act,'\0',sizeof(struct sigaction));
    actt.sa_handler = wrongTurnSignalHandler;
    actt.sa_flags	 = SA_NOCLDSTOP | SA_RESTART;
    sigaction(WRONG_TURN_SIGNAL,&actt,NULL);

    
    
    //  III.  Finished:
}


//  PURPOSE:  To install 'sigIntHandler()' as the handler for 'SIGINT'.  No
//	parameters.  No return value.
void		installSigIntHandler		()
{
    //  I.  Application validity check:
    
    //  II.  Install handler:
    //  II.A.  Set up struct to specify the new action.
    //  YOUR CODE HERE
    struct sigaction	act;
    
    memset(&act,'\0',sizeof(struct sigaction));
    act.sa_handler = sigIntHandler;
    act.sa_flags	 = SA_NOCLDSTOP | SA_RESTART;
    sigaction(SIGINT,&act,NULL);

    
    //  III.  Finished:
}


int	main			(int		argc,
                     char*		argv[])
{
    //  I.  Application validity check (done by 'initializeMostGlobals()'):
    
    //  II.  Try to leave mall:
    //  II.A.  Initialize globals:
    initializeMostGlobals(argc,argv);
    installTurnHandlers();
    installSigIntHandler();
    
    //  II.B.  Try to leave mall:
    nextTurn = ((rand() % 2) == 1) ? LEFT_TURN_SIGNAL : RIGHT_TURN_SIGNAL;
    printf("Joey # %d: Which direction?  Decisions, Decisions!  I'll guess %s.\n",
           joeyIndex,
           (nextTurn == LEFT_TURN_SIGNAL) ? "left" : "right");
    fflush(stdout);
    // YOUR CODE HERE to send 'nextTurn' to 'mallPid'
     kill(mallPid,nextTurn);
    while  (shouldStillRun)
        sleep(1);
    
    //  III.  Finished:
    return(EXIT_SUCCESS);
}