生产者消费者问题

#include <pthread.h>
#include <semaphore.h>
#include <unistd.h>
#include <stdio.h>

#define N 5

pthread_mutex_t mutex;
sem_t empty;
sem_t full;

void *producer() {
  while (1) {
    sem_wait(&empty);
    pthread_mutex_lock(&mutex);
    printf("producer put item into buffer ...\n");
    pthread_mutex_unlock(&mutex);
    sem_post(&full);
  }
}

void *consumer() {
  while (1) {
    sem_wait(&full);
    pthread_mutex_lock(&mutex);
    printf("consumer get item from buffer ...\n");
    pthread_mutex_unlock(&mutex);
    sem_post(&empty);
  }
}

int main() {
  pthread_t p, c;

  pthread_mutex_init(&mutex, NULL);
  sem_init(&empty, 0, N);
  sem_init(&full, 0, 0);

  pthread_create(&p, NULL, producer, NULL);
  pthread_create(&c, NULL, consumer, NULL);

  pthread_join(p, NULL);
  pthread_join(c, NULL);

  return 0;
}