08.practical.work.pthread.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <pthread.h>
#define BUFFER_SIZE 10

typedef struct {
  char type; // 0=fried chicken, 1=French fries
  int amount; // pieces or weight
  char unit; // 0=piece, 1=gram
} item;

item buffer[BUFFER_SIZE];
int first = 0;
int last = 0;

void produce(item *i) {
  while ((first + 1) % BUFFER_SIZE == last) {
    // do nothing -- no free buffer item
  }
  memcpy(&buffer[first], i, sizeof(item));
  first = (first + 1) % BUFFER_SIZE;
}

item *consume() {
  item *i = malloc(sizeof(item));
  while (first == last) {
    // do nothing -- nothing to consume
  }
  memcpy(i, &buffer[last], sizeof(item));
  last = (last + 1) % BUFFER_SIZE;
  return i;
}

item* initItem(char type, int amount, char unit){
  item* i = malloc(sizeof(item));
  i->type = type;
  i->amount = amount;
  i->unit = unit;
  return i;
}

void *producer(void *para) {
	item fc={'1',0,'1'}, Ff1={'1',3,'0'}, Ff2={'1',3,'1'};
	produce(&fc);
	produce(&Ff1);
	produce(&Ff2);
}

void display(item* i) {
	printf("Type: %c Amount(s): %d Unit: %c\n",i->type,i->amount,i->unit);
} 

void *consumer(void *para) {
	display(consume());
    display(consume());
}

int main() {
	    pthread_t tid1,tid2;
	    pthread_create(&tid1, NULL, producer, NULL);
        pthread_create(&tid2, NULL, consumer, NULL);

        printf("After produce: First: %d Last %d \n", first, last);
        consume();
        printf("After consume: First: %d Last %d \n", first, last);
		
        pthread_join(tid1, NULL);
	    pthread_join(tid2, NULL);
 return 0;
}