How do I use condition variables effectively in multithreading?

How do I use condition variables effectively in multithreading?

Condition variables are synchronization primitives that allow threads to wait for certain conditions to be true. They are used in conjunction with mutexes to avoid race conditions.

Can you give me an example of how to implement a condition variable?

Sure! Here's a simple example in C++:

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

void worker() {
    std::unique_lock<std::mutex> lock(mtx);
    while (!ready) {
        cv.wait(lock);
    }
    // Do work after condition is met
}

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

What are some common pitfalls when using condition variables?

Common pitfalls include forgetting to lock the mutex before waiting, not using a loop to check the condition, and failing to notify waiting threads.

How can I debug issues related to condition variables?

You can use logging to track when threads are waiting and notifying, and tools like thread sanitizers can help identify race conditions.