pcewing · June 18, 2020 01:19 · Jun 18, 2020
diff --git a/main.c b/main.c
@@ -0,0 +1,38 @@
+#include "queue.h"
+#include <stdio.h>
+
+#define UNUSED(x) ((void)(x))
+
+void string_print_callback(void *item) {
+    const char *str = item;
+    printf("%s", str);
+}
+
+void int_print_callback(void *item) {
+    int *i = item;
+    printf("%i", *i);
+}
+
+int main(int argc, char *argv[]) {
+    UNUSED(argc);
+    UNUSED(argv);
+
+    int a = 1;
+    int b = 2;
+    int c = 3;
+    struct queue_t *queue = queue_new(sizeof(int));
+    queue_enqueue(queue, &a);
+    queue_enqueue(queue, &b);
+    queue_enqueue(queue, &c);
+    queue_print(queue, int_print_callback);
+
+    int d;
+    for (int i = 0; i < 4; ++i) {
+        if (queue_dequeue(queue, &d))
+            printf("Dequeued: %i\n", d);
+        else
+            printf("Nothing to dequeue\n");
+    }
+
+    return 0;
+}
diff --git a/meson.build b/meson.build
@@ -0,0 +1,11 @@
+project('queue', 'c')
+
+executable(
+    'queue_test',
+    [
+        'main.c',
+        'queue.c',
+    ],
+    dependencies : [
+        dependency('threads'),
+    ])
diff --git a/queue.c b/queue.c
@@ -0,0 +1,120 @@
+#include "queue.h"
+#include <pthread.h>
+#include <stdio.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+
+struct queue_node_t {
+    void *data;
+    struct queue_node_t *next;
+};
+
+struct queue_t {
+    struct queue_node_t *head;
+    struct queue_node_t *tail;
+    size_t item_size;
+    size_t size;
+
+    pthread_mutex_t lock;
+};
+
+struct queue_node_t *queue_node_new(size_t item_size, void *item) {
+    struct queue_node_t *queue_node = malloc(sizeof(struct queue_node_t));
+    if (!queue_node)
+        return NULL;
+
+    memset(queue_node, 0, sizeof(struct queue_node_t));
+
+    queue_node->data = malloc(item_size);
+    if (!queue_node->data) {
+        free(queue_node);
+        return NULL;
+    }
+
+    memcpy(queue_node->data, item, item_size);
+
+    return queue_node;
+}
+
+void queue_node_free(struct queue_node_t *queue_node) {
+    free(queue_node);
+}
+
+struct queue_t *queue_new(size_t item_size) {
+    struct queue_t *queue = malloc(sizeof(struct queue_t));
+    memset(queue, 0, sizeof(struct queue_t));
+
+    if (queue) {
+        queue->item_size = item_size;
+        pthread_mutex_init(&queue->lock, NULL);
+    }
+
+    return queue;
+}
+
+void queue_free(struct queue_t *queue) {
+    pthread_mutex_destroy(&queue->lock);
+    free(queue);
+}
+
+bool queue_enqueue(struct queue_t *queue, void *item) {
+    bool result = true;
+
+    pthread_mutex_lock(&queue->lock);
+
+    struct queue_node_t *new_node = queue_node_new(queue->item_size, item);
+    if (new_node) {
+        if (queue->size == 0)
+            queue->head = queue->tail = new_node;
+        else
+            queue->tail = queue->tail->next = new_node;
+        ++queue->size;
+    } else {
+        result = false;
+    }
+
+    pthread_mutex_unlock(&queue->lock);
+
+    return result;
+}
+
+bool queue_dequeue(struct queue_t *queue, void *item) {
+    bool result = true;
+
+    pthread_mutex_lock(&queue->lock);
+
+    if (queue->size == 0) {
+        result = false;
+    } else {
+        memcpy(item, queue->head->data, queue->item_size);
+        struct queue_node_t *temp = queue->head;
+        queue->head = queue->head->next;
+        queue_node_free(temp);
+        --queue->size;
+    }
+
+    pthread_mutex_unlock(&queue->lock);
+
+    return result;
+}
+
+void queue_print(struct queue_t *queue, print_callback p) {
+    pthread_mutex_lock(&queue->lock);
+
+    printf("[ ");
+    struct queue_node_t *itr = queue->head;
+    while (itr) {
+        p(itr->data);
+
+        if (itr->next)
+            printf(", ");
+
+        itr = itr->next;
+    }
+    printf(" ]\n");
+
+    pthread_mutex_unlock(&queue->lock);
+}
diff --git a/queue.h b/queue.h
@@ -0,0 +1,15 @@
+#pragma once
+
+#include <stdbool.h>
+#include <stddef.h>
+
+struct queue_t;
+
+struct queue_t *queue_new(size_t item_size);
+void queue_free(struct queue_t *queue);
+bool queue_enqueue(struct queue_t *queue, void *item);
+bool queue_dequeue(struct queue_t *queue, void *item);
+
+// For debugging purposes
+typedef void(*print_callback)(void *item);
+void queue_print(struct queue_t *queue, print_callback p);
No results found