queue.c

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

struct queue {
    int size;
    int head;
    int tail;
    int count;
    void **buffer;
    pthread_mutex_t mutex;
    pthread_cond_t not_full;
    pthread_cond_t not_empty;
};

queue_t *queue_new(int size) {
    queue_t *q = malloc(sizeof(queue_t));
    q->size = size;
    q->buffer = malloc(sizeof(void *) * size);
    q->head = q->tail = q->count = 0;
    pthread_mutex_init(&q->mutex, NULL);
    pthread_cond_init(&q->not_full, NULL);
    pthread_cond_init(&q->not_empty, NULL);
    return q;
}

void queue_delete(queue_t **q) {
    if (*q) {
        pthread_mutex_destroy(&(*q)->mutex);
        pthread_cond_destroy(&(*q)->not_full);
        pthread_cond_destroy(&(*q)->not_empty);
        free((*q)->buffer);
        free(*q);
        *q = NULL;
    }
}

bool queue_push(queue_t *q, void *elem) {
    pthread_mutex_lock(&q->mutex);
    while (q->count == q->size) pthread_cond_wait(&q->not_full, &q->mutex);
    q->buffer[q->tail] = elem;
    q->tail = (q->tail + 1) % q->size;
    q->count++;
    pthread_cond_signal(&q->not_empty);
    pthread_mutex_unlock(&q->mutex);
    return true;
}

bool queue_pop(queue_t *q, void **elem) {
    pthread_mutex_lock(&q->mutex);
    while (q->count == 0) pthread_cond_wait(&q->not_empty, &q->mutex);
    *elem = q->buffer[q->head];
    q->head = (q->head + 1) % q->size;
    q->count--;
    pthread_cond_signal(&q->not_full);
    pthread_mutex_unlock(&q->mutex);
    return true;
}