Spawn N threads, join all

Challenge

Implement int run_n_threads(int n) that spawns n threads (each one just immediately returns), joins them all in order, and returns n on success. Return -1 if any pthread_create or pthread_join fails.

Why this matters

Real programs spawn a pool of threads, not one. Practice the spawn-loop + join-loop pattern.

Starter code

#include <pthread.h>
int run_n_threads(int n) {
    /* TODO */
    return -1;
}

Background lessons

• pthread_create() and pthread_join()

Up next

• Pass an integer to each thread (by value)