// buffer.cpp -- add any necessary code to implement producer/consumer

// includes 

#include "vxWorks.h"
#include "stdio.h"
#include "stdlib.h"
#include "semLib.h"
#include "taskLib.h"

#define STACK_SIZE	20000
#define BUFFER_SIZE     10

// use these to initialize the counting semaphores
#define INITIAL_SPACES   BUFFER_SIZE
#define INITIAL_ITEMS    0

// use for cleanup and stopping of program
#define ALL_STOP 1
#define ALL_GO   2
#define PROD_STOP 3
#define CONS_STOP 4

// buffer
int buffer[BUFFER_SIZE];

// used to control circular buffer
int in = 0;			
int out = 0;

// task ids
int tidProducer;
int tidConsumer;

volatile UINT8 runState = ALL_STOP;	/* controls shutdown */
	
// use these ids to create counting semaphores
SEM_ID itemsSemId;	
SEM_ID spacesSemId;

// use to create binary semaphore to provide mutual exclusion for printf
SEM_ID printSemId;

void produce (void);
void consume (void);
void progStop (void);
STATUS progStart (void);

/*************************************************************************
*
* progStart - start the program.
*
* Create various semaphores and spawn various tasks, while doing
* incredibly little error checking.
*
* RETURNS: OK
*/

STATUS progStart (void) {

	// setup counting semaphores

	// setup binary semaphore
    
	// get started

	runState = ALL_GO;

	tidConsumer = taskSpawn ("consumer", 200, 0, STACK_SIZE,
	        (FUNCPTR) consume2,0,0,0,0,0,0,0,0,0,0);

	tidProducer = taskSpawn ("producer", 200, 0, STACK_SIZE,
 	       (FUNCPTR) produce2,0,0,0,0,0,0,0,0,0,0);

	return (OK);
}


void consume(void) {

	while (runState != CONS_STOP) {

		// delay task for random amount of time
		taskDelay((rand() % 100) + 1);

		// add code for consumer

	}

	runState = ALL_STOP;		
}


void produce(void) {

	while (runState != PROD_STOP) {

		// delay for random amount of time
		taskDelay((rand() % 100) + 1);

		// add code for producer
	}

	// stop conumser
	runState = CONS_STOP;
	semFlush(itemsSemId);
}


/*************************************************************************
*
* progStop - stops the program 
*
* Call this routine to end it all.
*/

void progStop (void)    {
    runState = PROD_STOP;
    semFlush(spacesSemId);

    // Wait for everyone to finish up
    while (runState != ALL_STOP)
	taskDelay (1);
    
    // clean up
    semDelete (spacesSemId);
    semDelete (itemsSemId);
    semDelete (printSemId);
    
    printf ("BYE!TSCHUESS!ADIEU!\n");
}