task3.c

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

#define THREAD_COUNT 1000
#define THREAD_ITERATION 10000

#ifdef COMPLILE_TASK3A
int x = 0;
#else
#include <stdatomic.h>
_Atomic int x = 0;
#endif

void *increment(void *arg) {
    for (int i = 0; i < THREAD_ITERATION; ++i) {
        x++;
    }
    return NULL;
}

int main(void) {
    int ret[THREAD_COUNT];
    pthread_t thread[THREAD_COUNT];

    // create 1000 Threads
    for (int i = 0; i < THREAD_COUNT; i++) {
        ret[i] = pthread_create(&thread[i], NULL, increment, NULL);
        if (ret[i] != 0) {
            fprintf(stderr, "ERROR %d: Cant create thread\n", ret[i]);
            return EXIT_FAILURE;
        }
    }

    // Wait for finish
    for (int i = 0; i < THREAD_COUNT; i++) {
        ret[i] = pthread_join(thread[i], NULL);
        if (ret[i] != 0) {
            fprintf(stderr, "ERROR %d: Cant join thread\n", ret[i]);
            return EXIT_FAILURE;
        }
    }

    printf("Result: %d\n", x);

    return EXIT_SUCCESS;
}