How do I use condition variables in C++?

How do I use condition variables in C++?

Condition variables in C++ are used for synchronizing threads. They allow threads to wait until a particular condition is met.

Can you show me a simple example of using condition variables?

Sure! Here's a basic example:

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

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

void worker() {
    std::unique_lock<std::mutex> lock(mtx);
    cv.wait(lock, [] { return ready; });
    std::cout << "Worker thread is running!" << std::endl;
}

int main() {
    std::thread t(worker);
    std::this_thread::sleep_for(std::chrono::seconds(1));
    {
        std::lock_guard<std::mutex> lock(mtx);
        ready = true;
    }
    cv.notify_one();
    t.join();
    return 0;
}

What does the cv.wait function do in that example?

The cv.wait function makes the current thread wait until it is notified and the condition (in this case, ready being true) is met.

Are there any potential issues I should be aware of when using condition variables?

Yes, potential issues include deadlocks if not managed properly, and spurious wakeups, which means a thread may wake up without being notified.