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

pthread_mutex_t mutex1 = PTHREAD_MUTEX_INITIALIZER;
pthread_mutex_t mutex2 = PTHREAD_MUTEX_INITIALIZER;
pthread_mutex_t mutex3 = PTHREAD_MUTEX_INITIALIZER;


void* process_fun(void* arg) {
  int id = *(int*)arg;
  bool success = false;
  pthread_mutex_t* mutexs[3];
  if (id == 0) { // Gives deadlock sometimes
    mutexs[0] = &mutex1;
    mutexs[1] = &mutex2;
    mutexs[2] = &mutex3;
  } else if (id == 1) {
    mutexs[0] = &mutex2;
    mutexs[1] = &mutex1;
    mutexs[2] = &mutex3;
  } else if (id == 2) {
    mutexs[0] = &mutex1;
    mutexs[1] = &mutex2;
    mutexs[2] = &mutex3;
  }

  while (!success) {
    bool csucc = true;
    for (int i=0; i < 3; i++) {
      if (pthread_mutex_trylock(mutexs[i]) != 0) {
        for (int j=0; j < i; j++) {
          pthread_mutex_unlock(mutexs[i]);
        }
        csucc = false;
        break;
      }
    }
    success = csucc;
  }
  printf("I have access\n");
  pthread_mutex_unlock(mutexs[0]);
  pthread_mutex_unlock(mutexs[1]);
  pthread_mutex_unlock(mutexs[2]);

  return NULL;
}

int main() {
  pthread_t tid[3];
  int args[3];

  for (int i=0; i < 3; i++) {
    args[i] = i;
    pthread_create(&(tid[i]), NULL, &process_fun, &(args[i]));
  }

  for (int i=0; i < 3; i++) {
    pthread_join(tid[i], NULL);
  }
}