What is a mutex and how is it implemented in different programming languages?

What is a mutex and how is it used in programming?

A mutex, or mutual exclusion, is a synchronization primitive used to prevent concurrent access to a shared resource.

Can you show me how to implement a mutex in Python?

Sure! In Python, you can use the threading module. Here's a simple example:

import threading

mutex = threading.Lock()

# Function to be executed by threads
def thread_function():
    with mutex:
        # Critical section of code
        print('Thread is accessing the shared resource')

How about in Java?

In Java, you can use the synchronized keyword or ReentrantLock. Here's an example using synchronized:

public class MutexExample {
    public synchronized void accessResource() {
        // Critical section
        System.out.println("Thread is accessing the shared resource");
    }
}

What about C++?

In C++, you can use std::mutex from the <mutex> header. Here's a simple example:

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

std::mutex mtx;

void threadFunction() {
    mtx.lock();
    // Critical section
    std::cout << "Thread is accessing the shared resource" << std::endl;
    mtx.unlock();
}