在C++中，如何让一个pthread在另一个线程等待信号量时继续运行？

#include <pthread.h>

pthread_mutex_t mutex;
pthread_cond_t cond;
bool signal_received = false;

void* thread_func(void* arg) {
    // 等待信号量
    pthread_mutex_lock(&mutex);
    while (!signal_received) {
        pthread_cond_wait(&cond, &mutex);
    }
    pthread_mutex_unlock(&mutex);

    // 继续运行
    // TODO: 在这里添加需要执行的代码

    return NULL;
}

int main() {
    pthread_t thread;
    pthread_mutex_init(&mutex, NULL);
    pthread_cond_init(&cond, NULL);

    // 创建线程
    pthread_create(&thread, NULL, thread_func, NULL);

    // 发送信号
    pthread_mutex_lock(&mutex);
    signal_received = true;
    pthread_cond_signal(&cond);
    pthread_mutex_unlock(&mutex);

    // 等待线程结束
    pthread_join(thread, NULL);

    pthread_mutex_destroy(&mutex);
    pthread_cond_destroy(&cond);

    return 0;
}