linux 条件变量

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

#define BUFFER_SIZE 10

int buffer[BUFFER_SIZE];
int count = 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) {
    for (int i = 0; i < 20; ++i) {
        pthread_mutex_lock(&mutex);
        while (count == BUFFER_SIZE) {
            pthread_cond_wait(&cond_full, &mutex);
        }
        buffer[count++] = i;
        printf("Produced: %d\n", i);
        pthread_cond_signal(&cond_empty);
        pthread_mutex_unlock(&mutex);
    }
    return NULL;
}

void* consumer(void* arg) {
    for (int i = 0; i < 20; ++i) {
        pthread_mutex_lock(&mutex);
        while (count == 0) {
            pthread_cond_wait(&cond_empty, &mutex);
        }
        int item = buffer[--count];
        printf("Consumed: %d\n", item);
        pthread_cond_signal(&cond_full);
        pthread_mutex_unlock(&mutex);
    }
    return NULL;
}

int main() {
    pthread_t producer_thread, consumer_thread;

    pthread_create(&producer_thread, NULL, producer, NULL);
    pthread_create(&consumer_thread, NULL, consumer, NULL);

    pthread_join(producer_thread, NULL);
    pthread_join(consumer_thread, NULL);

    return 0;
}

while (condition_not_met) {
    pthread_cond_wait(&cond, &mutex);
}