What is a condition variable in C++?

Can you explain what a condition variable is in C++?

Sure! A condition variable in C++ is a synchronization primitive that allows threads to wait until a particular condition occurs.

How do I use a condition variable in my code?

You typically use it with a mutex. You lock the mutex, check the condition, and if it's not met, you call wait() on the condition variable.

What happens when I call wait()?

When you call wait(), the mutex is released, and the thread goes to sleep until another thread signals the condition variable.

Can you give me a simple code example?

Certainly! Here's a basic example:

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

void worker() {
    std::unique_lock<std::mutex> lock(m);
    while (!ready) cv.wait(lock);
    // Do work after being notified
}

void go() {
    std::lock_guard<std::mutex> lock(m);
    ready = true;
    cv.notify_all();
}