operating issues qustions - threads, processes etc. for the above code:

Question

int S1 = 0;
int S2 = 0;
int x = 0;
int run = 1;
void Producer(void) {
    while(run) {
    while (S1 == S2);
    x++;
    __sync_synchronize();
    S1 = S2;
    __sync_synchronize();
    }
}

void Consumer(void) {
    while(run) {
    while (S1 != S2);
    x--;
    __sync_synchronize();
    S1 = !S2;
    __sync_synchronize();
    }
}

void* Worker(void *func) {
    long func_id = (long)func & 0x1;
    printf("%s %d\n",__func__, (int)func_id);
    switch (func_id) {
    case 0:
    Producer();
    break;
    case 1:
    Consumer();
    break;
    }
    return NULL;
}

int main(int argc, char *argv[]) {
     pthread_t t[argc];
     pthread_attr_t at;
     cpu_set_t cpuset;
     int threads;
     int i;
    #define MAX_PROCESSORS 4 // Minimal processors is 2.
     threads = argc > 1 ? (( atoi(argv[1]) < 4) ? atoi(argv[1]): MAX_PROCESSORS ) : 1;
    
     
     for (i = 0;i < threads; i++){ 
        CPU_ZERO(&cpuset);
        CPU_SET(i, &cpuset);
        pthread_attr_init(&at);
        
        (&at, sizeof(cpuset), &cpuset);
        if (pthread_create(&t[i], &at , Worker, (void *) (long)i) ) {
        perror("pthread create 1 error\n"); }
     }
     
     do {
        sleep(1);
     } while(x < 0);
     
    run = 0;
    void *val;
    for(i = 0; i < threads; i++)
    pthread_join(t[i], &val);
    printf("x=%d\n", x);
}

The questions: In ex1.c (6.1), which of the following properties achieved:

(1) Mutual exclusion but not progress

(2) Progress but not mutual exclusion

(3) Neither mutual exclusion nor progress

(4) Both mutual exclusion and progress

Please explain?

1.2

To which arguments (in 6.1) is correct and which does not:

(1) always exits. when threads = 2 or threads <= 0

(2) always hangs. threads = 1 or thread > 2

Any help would be much appreeciated