starvation.c

Download • View Raw

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

pthread_mutex_t mutex_counter = PTHREAD_MUTEX_INITIALIZER;
int counter = 0;

void *thread_func(void *arg) {
    int unlocked = 0;
    while (counter < 1000000) {
        if ((int) arg == 0) {
            sleep(1);
        }

        pthread_mutex_lock(&mutex_counter);
        counter++;
        unlocked++;
        pthread_mutex_unlock(&mutex_counter);
    }
    printf("I am thread %d and got access %d times!\n", (int) arg, unlocked);
    return 0;
}

int main(int argc, char* argv[]) {
    long thread;
    pthread_t* thread_handles;
    int num_threads = 10;

    thread_handles = malloc(num_threads * sizeof(pthread_t));

    for (thread = 0; thread < num_threads; thread++) {
        pthread_create(&thread_handles[thread], NULL, thread_func, (void*) thread);
    }

    for (thread = 0; thread < num_threads; thread++) {
        pthread_join(thread_handles[thread], NULL);
    }

    return 0;
}