How do I create a thread using the pthreads library?

How do I create a thread using the pthreads library?

To create a thread using the pthreads library in C, you can use the pthread_create function. Here's a basic example:

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

void* threadFunction(void* arg) {
    printf("Thread is running!\n");
    return NULL;
}

int main() {
    pthread_t thread;
    pthread_create(&thread, NULL, threadFunction, NULL);
    pthread_join(thread, NULL);
    return 0;
}

This code creates a thread that runs threadFunction.

What parameters do I need to pass to pthread_create?

The pthread_create function takes four parameters:

1. A pointer to pthread_t (the thread identifier).
2. Thread attributes (or NULL for default).
3. The function to execute in the thread.
4. An argument to pass to the thread function (or NULL if not needed).

How do I handle thread synchronization?

To handle thread synchronization, you can use mutexes provided by the pthreads library. You can create a mutex using pthread_mutex_init, lock it with pthread_mutex_lock, and unlock it with pthread_mutex_unlock. This ensures that only one thread accesses a shared resource at a time.

Can you give an example of using mutexes?

Sure! Here's a simple example of using a mutex:

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

pthread_mutex_t lock;
int sharedResource = 0;

void* threadFunction(void* arg) {
    pthread_mutex_lock(&lock);
    sharedResource++;
    printf("Resource value: %d\n", sharedResource);
    pthread_mutex_unlock(&lock);
    return NULL;
}

int main() {
    pthread_t threads[5];
    pthread_mutex_init(&lock, NULL);
    for (int i = 0; i < 5; i++) {
        pthread_create(&threads[i], NULL, threadFunction, NULL);
    }
    for (int i = 0; i < 5; i++) {
        pthread_join(threads[i], NULL);
    }
    pthread_mutex_destroy(&lock);
    return 0;
}

This code safely increments a shared resource using a mutex.