How do I use semaphores in coding?

What are semaphores in programming?

Semaphores are synchronization tools used to control access to shared resources in concurrent programming.

How do I implement a semaphore in C?

You can use the semaphore.h library in C. First, include it, then initialize a semaphore using sem_init().

Can you show me a simple example?

Sure! Here's a basic example:

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

sem_t semaphore;

void* threadFunction(void* arg) {
    sem_wait(&semaphore);
    // Critical section
    printf("Thread %d is in the critical section.\n", *(int*)arg);
    sem_post(&semaphore);
    return NULL;
}

int main() {
    pthread_t threads[5];
    sem_init(&semaphore, 0, 1);
    int threadArgs[5];
    for (int i = 0; i < 5; i++) {
        threadArgs[i] = i;
        pthread_create(&threads[i], NULL, threadFunction, &threadArgs[i]);
    }
    for (int i = 0; i < 5; i++) {
        pthread_join(threads[i], NULL);
    }
    sem_destroy(&semaphore);
    return 0;
}

What happens if I forget to destroy the semaphore?

If you forget to destroy the semaphore, it can lead to resource leaks, which may exhaust system resources over time.