Producer Consumer Problem Using Semaphores

Codings:

 Producer.c

#include<stdio.h>

#include<sys/shm.h>

#include<sys/sem.h>

#include<sys/ipc.h>

#include<sys/types.h>

#include<stdlib.h>

main()

{

int *data,shmid,semid,pid,i;

shmid=shmget(1234,1,0666|IPC_CREAT);

semid=semget(1234,1,0666|IPC_CREAT);

data=(int*)shmat(shmid,0,0);

for(i=1;i<=5;i++)

{

printf("\n Producer entering critical stage\n");

struct sembuf *sbuf=(struct sembuf*)malloc(sizeof(struct sembuf));

sbuf->sem_num=0;

sbuf->sem_op=1;

sbuf->sem_flg=0;

printf("\n Enter The Data To Be Produced\n");

scanf("%d",data);

printf("\nProducer exiting the critical region\n");

semop(semid,sbuf,1);

}

}

Consumer.c

#include<stdio.h>

#include<sys/shm.h>

#include<sys/sem.h>

#include<sys/types.h>

#include<stdlib.h>

main()

{

int *data,shmid,semid,pid,i,d1,val=0;

shmid=shmget(1234,1,0666|IPC_CREAT);

semid=semget(1234,1,0666|IPC_CREAT);

data=(int*)shmat(shmid,0,0);

for(i=1;i<=5;i++)

{

struct sembuf *sbuf=(struct sembuf*)malloc(sizeof(struct sembuf));

sbuf->sem_num=0;

sbuf->sem_op=1;

sbuf->sem_flg=0;

printf("\n Consumer Waiting \n");

semop(semid,sbuf,1);

printf("\nConsumer Entering The Critical Region\n");

printf("\n Enter The Consumer Values\n");

scanf("%d",&d1);

*data=*data+val;

if(d1<=*data)

{

val=*data-d1;

printf("\n Data Consumed  %d  ",d1);

printf("\n Remaining data  %d  ",val);

}

else

{

printf("\n Consumer value exceeds producer values\n");

printf("\n Consumer Exiting the Critical Region\n");

}

}

semctl(semid,IPC_RMID,0);

shmdt(data);

shmctl(shmid,IPC_RMID,0);

}

Ouptut:

 [telnet50@linux ~]$ cc producer.c

 [telnet50@linux ~]$ ./a.out

 Producer entering critical stage

 Enter The Data To Be Produced

10

Producer exiting the critical region

 Producer entering critical stage

 Enter The Data To Be Produced

2

Producer exiting the critical region

 Producer entering critical stage

 Enter The Data To Be Produced

4

Producer exiting the critical region

 Producer entering critical stage

 Enter The Data To Be Produced

0

Producer exiting the critical region

 Producer entering critical stage

 Enter The Data To Be Produced

1

Producer exiting the critical region

 [telnet50@linux ~]$ cc consumer.c

[telnet50@linux ~]$ ./a.out

 Consumer Waiting

Consumer Entering The Critical Region

 Enter The Consumer Values

5

 Data Consumed  5

 Remaining data  5

 Consumer Waiting

Consumer Entering The Critical Region

 Enter The Consumer Values

5

 Data Consumed  5

 Remaining data  2

 Consumer Waiting

Consumer Entering The Critical Region

 Enter The Consumer Values

3

 Data Consumed  3

 Remaining data  3

 Consumer Waiting

Consumer Entering The Critical Region

 Enter The Consumer Values

3

 Data Consumed  3

 Remaining data  0

 Consumer Waiting

Consumer Entering The Critical Region

 Enter The Consumer Values

1

 Data Consumed  1

 Remaining data  0