What is mutex locking in C++?

What is mutex locking in C++?

Mutex locking is a synchronization mechanism used to control access to a shared resource in concurrent programming.

Why do I need to use mutexes?

You need to use mutexes to prevent data races and ensure that only one thread can access a resource at a time.

Can you show me a simple example of using a mutex in C++?

Sure! Here's a basic example:

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

std::mutex mtx;

void printThreadId(int id) {
    mtx.lock();  // Lock the mutex
    std::cout << "Thread ID: " << id << '\n';
    mtx.unlock();  // Unlock the mutex
}

int main() {
    std::thread threads[5];
    for (int i = 0; i < 5; ++i) {
        threads[i] = std::thread(printThreadId, i);
    }
    for (auto& th : threads) {
        th.join();
    }
    return 0;
}

What happens if I forget to unlock the mutex?

If you forget to unlock the mutex, it can lead to deadlocks, where other threads are unable to access the locked resource, causing your program to hang.