c 消费者生产者V2

Posted 2021-03-11 luckygxf

增加了buffsize，生产者生产过多，wait

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

#define PRODUCER_SIZE 1
#define CONSUMER_SIZE 1

int products = 0;
int buffsize = 5;

pthread_mutex_t mutex;
pthread_cond_t empty_cond;
pthread_cond_t full_cond;

void produce();
void consume();


int main() {
    pthread_t producer;
    pthread_t consumer;

    pthread_mutex_init(&mutex, NULL);
    pthread_cond_init(&empty_cond, NULL);
    pthread_cond_init(&full_cond, NULL);

    pthread_create(&producer, NULL, produce, NULL);
    pthread_create(&consumer, NULL, consume, NULL);

    pthread_join(producer, NULL);
    pthread_join(consumer, NULL);

    return 0;
}

void produce(){
//    sleep(2);
    printf("start produce
");
    while (1) {
        pthread_mutex_lock(&mutex);
        while (products >= 10) {
            printf("buff full, producer start wait
");
            pthread_cond_wait(&full_cond, &mutex);
            printf("producer wakeup
");
        }
        products++;
        printf("produce:%d start wake consum
", products);
        pthread_mutex_unlock(&mutex);
        pthread_cond_signal(&empty_cond);
        sleep(1);
    }
}

void consume() {
    printf("start consum
");
    while (1) {
        pthread_mutex_lock(&mutex);
        while (products <= buffsize) {
            printf("consum start wait cond
");
            pthread_cond_wait(&empty_cond, &mutex);
            printf("consum wake up
");
        }
        if (products > 0) {
            printf("consum:%d
", products);
            products --;
        }
        pthread_cond_signal(&full_cond);
        pthread_mutex_unlock(&mutex);
        sleep(3);
    }
}