What is a mutex in C++14 and how do I use it?

What is a mutex in C++14 and how do I use it?

A mutex, or mutual exclusion, is a synchronization primitive used to protect shared data from being accessed by multiple threads simultaneously in C++14. You can use the std::mutex class to create a mutex.

Can you show me a simple example of using a mutex?

Sure! Here's a basic example:

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

std::mutex mtx;

void printNumbers(int id) {
    mtx.lock(); // Lock the mutex
    for (int i = 0; i < 5; ++i) {
        std::cout << "Thread " << id << ": " << i << '\n';
    }
    mtx.unlock(); // Unlock the mutex
}

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

What happens if I forget to unlock the mutex?

If you forget to unlock the mutex, it can lead to a deadlock situation where other threads are unable to acquire the lock and will be stuck waiting indefinitely. It's crucial to always unlock the mutex after you're done with the critical section.

Are there any alternatives to using a mutex?

Yes, alternatives include using std::lock_guard or std::unique_lock, which automatically manage the locking and unlocking of the mutex, reducing the risk of forgetting to unlock it.