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

typedef struct { pthread_mutex_t m; } tick_arg;
void *tick(void *arg) {
    pthread_mutex_t m = ((tick_arg *)arg)->m;
    pthread_mutex_lock(&m);
    printf("tick │ %04ld │\n", time(NULL)%1000);
    sleep(1);
    pthread_mutex_unlock(&m);
    return NULL;
}

typedef struct { pthread_mutex_t *m; } tock_arg;
void *tock(void *arg) {
    pthread_mutex_t *m = ((tock_arg *)arg)->m;
    pthread_mutex_lock(m);
    printf("tock │ %04ld │\n", time(NULL)%1000);
    sleep(1);
    pthread_mutex_unlock(m);
    return NULL;
}

int main(int argc, const char *argv[]) {
    pthread_mutex_t tick_lock, tock_lock;
    pthread_mutex_init(&tick_lock, NULL);
    pthread_mutex_init(&tock_lock, NULL);

    int n = argc > 1 ? atoi(argv[1]) : 5;
    pthread_t *id = (pthread_t *)calloc(n, sizeof(pthread_t));
    tick_arg *tick_args = (tick_arg *)calloc(n, sizeof(tick_arg));
    tock_arg *tock_args = (tock_arg *)calloc(n, sizeof(tock_arg));

    puts("     ┌──────┐");
    for(size_t i=0; i<n; i+=1)
        tick_args[i].m = tick_lock;
    for(size_t i=0; i<n; i+=1)
        pthread_create(id+i, NULL, tick, tick_args+i);
    for(size_t i=0; i<n; i+=1)
        pthread_join(id[i], NULL);
    puts("     └──────┘");

    puts("     ┌──────┐");
    for(size_t i=0; i<n; i+=1)
        tock_args[i].m = &tock_lock;
    for(size_t i=0; i<n; i+=1)
        pthread_create(id+i, NULL, tock, tock_args+i);
    for(size_t i=0; i<n; i+=1)
        pthread_join(id[i], NULL);
    puts("     └──────┘");

    pthread_mutex_destroy(&tick_lock);
    pthread_mutex_destroy(&tock_lock);

    free(id);
    free(tick_args);
    free(tock_args);
}