Prodcon.cpp

#include "mbed.h"

DigitalOut errorLed(LED3);
DigitalOut produceLed(LED1);
DigitalOut consumeLed(LED2);

Thread prodThread;
Thread consThread;

//Again Moving this to a Libary is left as an exersise
class TheStack{
    private: 
        int maxSize;
        int itemCount;
        int data[5];

    public:
        TheStack(){
	  maxSize = 5;
            itemCount = 0;
        }

        int addItem(int item)
        /* Add an Item to the stack,  
        Returns:
             0 if Successful
             -1 On Error
        */
        {
            if (itemCount < maxSize){
                data[itemCount] = item;
                itemCount +=1;
                return 0;
            }
            else{
                errorLed = 1;
                return -1;
            }
        }

        int removeItem()
        /* Remove an Item from the Stack
        Return -1 on error
        */
        {
            if (itemCount < 0){
                errorLed = 1;
                return -1;
            }
            else{
                itemCount -= 1;
                int tmp = data[itemCount];
                return tmp;
            }
        }

        int numItems(){
            return itemCount;
        }
};

//Function to simulate busywait Data processing
//Accepts a time in MS
void fakeWait(int time){
    Timer t;
    t.start();
    while (t.read_ms() < time){
            //Simulate Processing
        }
    t.stop();
}


//Global Stack
TheStack myStack;


/* Function to produce items.  You will need to make this safe*/
void produce(){
    int counter = 0; //For the Item we are producing
    while(1){
        produceLed = !produceLed;
        int data = counter;
        fakeWait(200); //Fake Procesing
        counter +=1;
        printf("Produced %d\n", data);
        myStack.addItem(data);
        //And ask the theread to sleep
        wait(0.5);
    }
}

/* Function to Consume Items.  This also needs to be safe */
void consume(){
    int value;
    while(1){
        consumeLed = !consumeLed;
        value = myStack.removeItem();
        printf("--> Consumed %d\n", value);
        fakeWait(200);
        wait(0.5);
    }
}

int main(){
    errorLed = 0;
    prodThread.start(produce);
    consThread.start(consume);

    while(1){
        printf("Tick %d in Stack\n", myStack.numItems());
        wait(5);
    }
}