#include <pthread.h>
#pragma once

typedef struct queue_node {
   int value;
   struct queue_node* next;
} queue_node_t;

typedef struct queue {
   queue_node_t* root;
   pthread_mutex_t *mx_push, *mx_pop, *mx_valid_root; /* critical funcs are per-instance */
   pthread_cond_t  *valid_root;
} queue_t;

void queue_init(queue_t* queue);
void queue_clear(queue_t* queue);

void queue_add(queue_t* queue, int value);
int queue_pop(queue_t* queue);