Ring, consumer/producer problem

ring..c

#include <stdio.h>
#include "ring.h"


void ring_init(Ring* r, int size) {
  r->data = malloc(sizeof(int)*size);
  r->capacity = size;
  r->actualSize = 0;
  r->write_cursor = 0;
  r->read_cursor = 0;
  pthread_mutex_init(&r->lock, NULL);
  pthread_cond_init(&r->cond_no_more_empty, NULL);
}

int ring_push(Ring* r, int i) {
  pthread_mutex_lock(&r->lock);
  if (r->read_cursor==r->write_cursor && r->actualSize != 0) {
    pthread_mutex_unlock(&r->lock);
    return -2;
  }
  r->data[r->write_cursor] = i;
  r->actualSize++;
  r->write_cursor++;
  if (r->write_cursor >= r->capacity) r->write_cursor = 0;
  pthread_cond_signal(&r->cond_no_more_empty); // reveille le while (r->actualSize==0)
  pthread_mutex_unlock(&r->lock);
  return 1;
}

void ring_destroy(Ring* r) {
  free(r->data);
  free(r);
}

int ring_pop(Ring* r) {
  pthread_mutex_lock(&r->lock);
  while (r->actualSize==0) {
    pthread_cond_wait(&r->cond_no_more_empty, &r->lock);
  }
  int number;
  number = r->data[r->read_cursor];
  r->actualSize--;
  r->read_cursor++;
  if (r->read_cursor >= r->capacity) r->read_cursor = 0;
  pthread_mutex_unlock(&r->lock);
  return number;
}

ring.h

#ifndef RING_H
#define RING_H

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

typedef struct {
  int* data;
  int actualSize;
  int capacity;
  int write_cursor;
  int read_cursor;
  pthread_mutex_t lock;
  pthread_cond_t cond_no_more_empty;
} Ring;

void ring_init(Ring* r, int size);
int ring_push(Ring* r, int i);
void ring_destroy(Ring* r);
int ring_pop(Ring* r);

#endif