生产者和消费者进程的同步与互斥 代码c++

关于生产者和消费者进程的同步与互斥的代码实现，以下是一个简单的示例：

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

#define BUFFER_SIZE 10
int buffer[BUFFER_SIZE];
int count = 0;
int in = 0, out = 0;

pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
pthread_cond_t cond_full = PTHREAD_COND_INITIALIZER;
pthread_cond_t cond_empty = PTHREAD_COND_INITIALIZER;

void *producer(void *arg){
    int tid = *(int*)arg;
    for (int i = 0; i < 100; i++){
        pthread_mutex_lock(&mutex);
        while (count == BUFFER_SIZE){  // 缓冲区已满，等待消费者消费
            pthread_cond_wait(&cond_full, &mutex);
        }
        buffer[in] = rand() % 100;
        printf("生产者%d生产了%d\n", tid, buffer[in]);
        in = (in + 1) % BUFFER_SIZE;
        count++;

        pthread_cond_signal(&cond_empty);  // 通知消费者可以消费了
        pthread_mutex_unlock(&mutex);
    }
    return NULL;
}

void *consumer(void *arg){
    int tid = *(int*)arg;
    for (int i = 0; i < 100; i++){
        pthread_mutex_lock(&mutex);
        while (count == 0){  // 缓冲区为空，等待生产者生产
            pthread_cond_wait(&cond_empty, &mutex);
        }
        int data = buffer[out];
        printf("消费者%d消费了%d\n", tid, data);
        out = (out + 1) % BUFFER_SIZE;
        count--;

        pthread_cond_signal(&cond_full);  // 通知生产者可以生产了
        pthread_mutex_unlock(&mutex);
    }
    return NULL;
}

int main(){
    pthread_t p1, p2, c1, c2;
    int id1 = 1, id2 = 2;

    pthread_create(&p1, NULL, producer, &id1);
    pthread_create(&p2, NULL, producer, &id2);
    pthread_create(&c1, NULL, consumer, &id1);
    pthread_create(&c2, NULL, consumer, &id2);

    pthread_join(p1, NULL);
    pthread_join(p2, NULL);
    pthread_join(c1, NULL);
    pthread_join(c2, NULL);

    return 0;
}

在这个示例中，使用了互斥锁 `mutex` 和条件变量 `cond_full`、`cond_empty` 实现了生产者和消费者的同步与互斥。当生产者需要生产时，若缓冲区已满，则进入等待状态，等待消费者消费；当消费者需要消费时，若缓冲区为空，则进入等待状态，等待生产者生产。生产者和消费者之间通过条件变量进行通知，以达到同步与互斥的效果。