linux 线程 信号量队列

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

#define QUEUE_SIZE 10

int queue[QUEUE_SIZE];
int front = 0, rear = 0;
sem_t empty, full;
pthread_mutex_t mutex;

void* producer(void* arg) {
    for (int i = 0; i < 20; ++i) {
        sem_wait(&empty);
        pthread_mutex_lock(&mutex);
        queue[rear] = i;
        rear = (rear + 1) % QUEUE_SIZE;
        printf("Produced: %d\n", i);
        pthread_mutex_unlock(&mutex);
        sem_post(&full);
    }
    return NULL;
}

void* consumer(void* arg) {
    for (int i = 0; i < 20; ++i) {
        sem_wait(&full);
        pthread_mutex_lock(&mutex);
        int item = queue[front];
        front = (front + 1) % QUEUE_SIZE;
        printf("Consumed: %d\n", item);
        pthread_mutex_unlock(&mutex);
        sem_post(&empty);
    }
    return NULL;
}

int main() {
    pthread_t prod_thread, cons_thread;
    sem_init(&empty, 0, QUEUE_SIZE);
    sem_init(&full, 0, 0);
    pthread_mutex_init(&mutex, NULL);

    pthread_create(&prod_thread, NULL, producer, NULL);
    pthread_create(&cons_thread, NULL, consumer, NULL);

    pthread_join(prod_thread, NULL);
    pthread_join(cons_thread, NULL);

    sem_destroy(&empty);
    sem_destroy(&full);
    pthread_mutex_destroy(&mutex);

    return 0;
}