What is a pthread mutex and how do I use it?

What is a pthread mutex and how do I use it?

A pthread mutex is a synchronization primitive used in multithreading to protect shared data from concurrent access.

Can you show me a simple example of how to implement a pthread mutex?

Sure! Here's a basic example:

#include <pthread.h>
#include <stdio.h>

pthread_mutex_t lock;

void* thread_function(void* arg) {
    pthread_mutex_lock(&lock);
    // Critical section
    printf("Thread %d is in the critical section.\n", *(int*)arg);
    pthread_mutex_unlock(&lock);
    return NULL;
}

int main() {
    pthread_t threads[2];
    int thread_args[2] = {1, 2};
    pthread_mutex_init(&lock, NULL);

    for (int i = 0; i < 2; i++) {
        pthread_create(&threads[i], NULL, thread_function, &thread_args[i]);
    }

    for (int i = 0; i < 2; i++) {
        pthread_join(threads[i], NULL);
    }

    pthread_mutex_destroy(&lock);
    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 access the critical section, causing your program to hang.