music-brainz-go/pthread/example2.c

#include "example2.h"

void *produce(void *buf)
{
	buffer *buff;
	buff = (buffer *) buf;
	printf("\nproducer started");

	for (int i = 0; i < 20; i++) {
		sem_wait(&buff->full);
		pthread_mutex_lock(&buff->mutex);

		buff->data[buff->pos] = 0;
		buff->pos = buff->pos + 1;
		printf("\nproduced");

		sem_post(&buff->empty);
		pthread_mutex_unlock(&buff->mutex);

		sleep(1);
	}

	pthread_exit(0);
}

void *consume(void *buf)
{

	buffer *buff;
	buff = (buffer *) buf;
	printf("\nconsumer started");
	for (int i = 0; i < 20; i++) {
		sem_wait(&buff->empty);
		pthread_mutex_lock(&buff->mutex);

		buff->pos = buff->pos - 1;
		printf("\ngot value %d", buff->data[buff->pos]);

		printf("\nconsumed");

		sem_post(&buff->full);

		pthread_mutex_unlock(&buff->mutex);
		sleep(2);
	}
	pthread_exit(0);
}

void init_buffer(buffer * buf)
{

	sem_init(&buf->empty, 0, 0);
	sem_init(&buf->full, 0, BUFFER_SIZE);
	pthread_mutex_init(&buf->mutex, NULL);
	buf->pos = 0;

	for (int i = 0; i < BUFFER_SIZE; i++) {
		buf->data[i] = -1;
	}
}