proconsumer.c

//Implementation of producer-consumer problem//
//Alin Babu.7,R5//
//File name : proconsumer.c//
#include<stdio.h>
#include<semaphore.h>
#include<pthread.h>
#include<stdlib.h>
#define buffersize 10
pthread_mutex_t mutex;      //Intiallize declaration//
pthread_t tidP[20],tidC[20]; //Thread declaration for producer and consumer//
sem_t full,empty;    //Semapore declaration//
int counter;
int buffer[buffersize];   //Buffer declaration//
void initialize()     //Funstion to initiallizw mutex and semaphore//
{
        pthread_mutex_init(&mutex,NULL);
        sem_init(&full,1,0);
        sem_init(&empty,1,buffersize);
        counter=0;
}
void write(int item) //Function to write into the buffer//
{
        buffer[counter++]=item;
}
int read()    //Function to read from buffer//
{
        return(buffer[--counter]);
}
void * producer (void * param)  //Function for producer thread to wait and write item to buffer//
{
        int waittime,item,i;
        item=rand()%5;
        waittime=rand()%5;
        sem_wait(&empty);
        pthread_mutex_lock(&mutex);
        printf("\nProducer has produced item: %d\n",item);
        write(item);
        pthread_mutex_unlock(&mutex);
        sem_post(&full);
}
void * consumer (void * param) //Function for consumer thread to wait and read item to buffer//
{
        int waittime,item;
        waittime=rand()%5;
        sem_wait(&full);
        pthread_mutex_lock(&mutex);
        item=read();
        printf("\nConsumer has consumed item: %d\n",item);
        pthread_mutex_unlock(&mutex);
        sem_post(&empty);
}
int main()
{
        int n1,n2,i;
        initialize();
        printf("\nEnter the no of producers:");
        scanf("%d",&n1);
        printf("\nEnter the no of consumers:");
        scanf("%d",&n2);
        for(i=0;i<n1;i++)
        pthread_create(&tidP[i],NULL,producer,NULL);
        for(i=0;i<n2;i++)
        pthread_create(&tidC[i],NULL,consumer,NULL);
        for(i=0;i<n1;i++)
        pthread_join(tidP[i],NULL);
        for(i=0;i<n2;i++)
        pthread_join(tidC[i],NULL);
        //sleep(5);
        exit(0);
}