What is a mutex in programming?

What is a mutex in programming?

A mutex, or mutual exclusion, is a synchronization primitive used to prevent multiple threads from accessing a shared resource simultaneously.

Why do I need to use a mutex?

You need a mutex to avoid race conditions, which can lead to inconsistent data or application crashes when multiple threads modify shared resources.

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

Sure! In C++, you can use the std::mutex class. Here's a simple example:

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

std::mutex mtx;

void print(int id) {
    mtx.lock();
    std::cout << "Thread " << id << " is running." << std::endl;
    mtx.unlock();
}

int main() {
    std::thread t1(print, 1);
    std::thread t2(print, 2);
    t1.join();
    t2.join();
    return 0;
}

What happens if I forget to unlock a mutex?

If you forget to unlock a mutex, it can lead to deadlocks, where other threads are unable to acquire the mutex and get stuck waiting indefinitely.