Producer Consumer Problem using Semaphore (Operating Systems)

Producer Consumer Problem using Semaphore (Operating Systems)

04:47

#include<stdlib.h>

#include <stdio.h>

#include <stdint.h>

#include <unistd.h>

#include <pthread.h>

#include <semaphore.h>

typedef int buffer_item;

#define BUFFER_SIZE 5

sem_t mutex;

sem_t empty;

sem_t full;

buffer_item buffer_data[BUFFER_SIZE];

int no_of_elements=0;

int insert_item(buffer_item obj){

   if(no_of_elements<BUFFER_SIZE){

      buffer_data[no_of_elements++]=obj;

      return 0;

   }

   else

      return -1;  

}

int remove_item(buffer_item *obj){

  
   if(no_of_elements==0)

      return -1;

   else{

      *obj=buffer_data[--no_of_elements];

      return 0;

   } 

}

void *Producer(void *param){

    

   buffer_item obj;

   int i,id,time;

   id=param;

   while(1){

      sem_wait(&empty);

      sem_wait(&mutex);

      time=(rand()%3)+2;

      sleep(time);

      obj=rand()%10+1;

      if(insert_item(obj))

         printf("PRODUCER#%d: Report Error Condition\n",id);

      else

         printf("PRODUCER#%d: Item=%d has successfully been produced\n",id,obj);

      sem_post(&mutex);

      sem_post(&full);

   }

}

void *Consumer(void *param){

   buffer_item obj;

   int i,id,time;

   id=param;

   while(1){

      sem_wait(&full);

      sem_wait(&mutex);

      time=(rand()%3)+2;

      sleep(time);

      if(remove_item(&obj))

         printf("CONSUMER#%d: Report Error Condition\n",id);

      else

         printf("CONSUMER#%d: Item=%d has successfully been consumed\n",id,obj);

     

      sem_post(&mutex);

      sem_post(&empty);

   }

}

int main(int argc,char *argv[]){

   sem_init(&mutex, 2, 1);

   sem_init(&empty, 2, 5);

   sem_init(&full, 2, 0);

   int i,temp,sleep_time,no_of_prod_threads,no_of_cons_threads;

  

   sleep_time=atoi(argv[1]);

   no_of_prod_threads=atoi(argv[2]);

   no_of_cons_threads=atoi(argv[3]);

     

   pthread_t threadID;

   pthread_attr_t attributes;

   pthread_attr_init (&attributes);

   for(i=0;i<no_of_prod_threads;i++)

      pthread_create(&threadID,&attributes,Producer,i+1);

     

   for(i=0;i<no_of_cons_threads;i++)

      pthread_create(&threadID,&attributes,Consumer,i+1);

     

   sleep(sleep_time);

   exit(0);

   return 0;

}