First Commit

2026-06-10 16:58:35 +02:00
commit 1e5eeb704f
42 changed files with 4037 additions and 0 deletions
@@ -0,0 +1,134 @@
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <threads.h>
+
+#include "queue.h"
+
+Queue *queue_create(int capacity, void (*destroyer)(void *item)) {
+  Queue *queue = (Queue *)malloc(sizeof(Queue));
+  if (queue == NULL) {
+    perror("FATAL ERROR: Could not allocate memory for queue structure");
+    exit(EXIT_FAILURE);
+  }
+
+  queue->items = malloc(capacity * sizeof(void *));
+  if (queue->items == NULL) {
+    perror("FATAL ERROR: Could not allocate memory for queue items");
+    free(queue);
+    exit(EXIT_FAILURE);
+  }
+
+  for (int i = 0; i < capacity; ++i) {
+    queue->items[i] = NULL;
+  }
+
+  queue->capacity = capacity;
+  queue->front = 0;
+  queue->rear = 0;
+  queue->size = 0;
+  queue->item_destroyer = destroyer;
+
+  return queue;
+}
+
+void queue_destroy(Queue *queue) {
+  if (queue == NULL)
+    return;
+
+  if (queue->item_destroyer != NULL) {
+    for (int i = 0; i < queue->size; ++i) {
+      int index = (queue->front + i) % queue->capacity;
+      queue->item_destroyer(queue->items[index]);
+    }
+  }
+  free(queue->items);
+  free(queue);
+}
+
+bool queue_is_empty(Queue *queue) {
+  if (queue == NULL)
+    return true;
+  return queue->size == 0;
+}
+
+bool queue_is_full(Queue *queue) {
+  if (queue == NULL)
+    return false;
+  return queue->size == queue->capacity;
+}
+
+void queue_double_capacity(Queue *queue) {
+  if (queue == NULL)
+    return;
+  unsigned int new_capacity = queue->capacity * 2;
+  if (new_capacity <= 1)
+    new_capacity = 100;
+  void **new_items = malloc(new_capacity * sizeof(void *));
+  if (new_items == NULL) {
+    perror("FATAL ERROR: Could not allocate memory for doubling capacity of "
+           "queue.");
+    exit(EXIT_FAILURE);
+  }
+  for (int i = 0; i < queue->size; i++)
+    new_items[i] = queue->items[(i + queue->front) % queue->capacity];
+  free(queue->items);
+  queue->items = new_items;
+  queue->front = 0;
+  queue->rear = queue->size;
+  queue->capacity = new_capacity;
+}
+
+void queue_enqueue(Queue *queue, void *item) {
+  if (queue == NULL || item == NULL) {
+    perror("ERROR: Cannot enqueue with a null queue or item.\n");
+    exit(EXIT_FAILURE);
+  }
+  if (queue_is_full(queue))
+    queue_double_capacity(queue);
+  queue->items[queue->rear] = item;
+  queue->rear = (queue->rear + 1) % queue->capacity;
+  queue->size++;
+}
+
+void queue_enqueue_multithreaded(Queue *queue, void *item, mtx_t *mutex,
+                                 cnd_t *condition_not_empty,
+                                 cnd_t *condition_not_full) {
+  mtx_lock(mutex);
+  while (queue_is_full(queue))
+    cnd_wait(condition_not_full, mutex);
+  queue_enqueue(queue, item);
+  cnd_signal(condition_not_empty);
+  mtx_unlock(mutex);
+}
+
+void *queue_dequeue(Queue *queue) {
+  if (queue == NULL || queue_is_empty(queue)) {
+    perror("ERROR: Could not dequeue from null or empty queue.");
+    return NULL;
+  }
+
+  void *item = queue->items[queue->front];
+  queue->items[queue->front] = NULL;
+  queue->front = (queue->front + 1) % queue->capacity;
+  queue->size--;
+  return item;
+}
+
+void *queue_dequeue_multithreaded(Queue *queue, mtx_t *mutex,
+                                  cnd_t *condition_not_empty,
+                                  cnd_t *condition_not_full,
+                                  bool *other_thread_done) {
+  mtx_lock(mutex);
+  while (queue_is_empty(queue) && !*other_thread_done)
+    cnd_wait(condition_not_empty, mutex);
+  if (queue_is_empty(queue) && *other_thread_done) {
+    mtx_unlock(mutex);
+    return NULL;
+  }
+  void *item = queue_dequeue(queue);
+  cnd_signal(condition_not_full);
+  mtx_unlock(mutex);
+  return item;
+}