如何在循环中使用std::condition_variable

std::mutex mtx;
std::condition_variable cv;

std::unique_lock<std::mutex> lock(mtx);

while (!condition) {
    cv.wait(lock);
}

cv.notify_one();  // 唤醒一个等待线程
// 或
cv.notify_all();  // 唤醒所有等待线程

#include <iostream>
#include <thread>
#include <mutex>
#include <condition_variable>

std::mutex mtx;
std::condition_variable cv;
bool condition = false;

void worker() {
    std::this_thread::sleep_for(std::chrono::seconds(1));  // 模拟耗时操作
    {
        std::lock_guard<std::mutex> lock(mtx);
        condition = true;
    }
    cv.notify_one();  // 唤醒等待线程
}

int main() {
    std::thread t(worker);

    {
        std::unique_lock<std::mutex> lock(mtx);
        while (!condition) {
            cv.wait(lock);
        }
    }

    std::cout << "Condition is satisfied." << std::endl;

    t.join();
    return 0;
}