main.c

@@ -52,6 +52,21 @@ struct block* find_first(size_t s)
 	return current;
 }
 
+struct block* fragment_block(struct block* in, size_t s)
+{
+	size_t totalSize = BLOCK_SIZE + s;
+	struct block* b = (struct block*)((char*)(in + 1) + (in->size - totalSize));
+	b->size = s;
+	b->prev = in;
+	b->next = in->next;
+	b->free = 0;
+
+	in->size -= totalSize;
+	in->next = b;
+
+	return b;
+}
+
 /// Will find or allocate a memory block.
 /// @param [in] size The size of the memory block to request.
 /// @returns The requested memory on the heap.
@@ -66,13 +81,9 @@ void* malloc(size_t size)
 	{
 		b = find_first(alignedSize);
 		if (!b)
-		{
 			b = extend_heap(alignedSize);
-		}
+		else if (b->size > BLOCK_SIZE + alignedSize)
-		/*
+			b = fragment_block(b, alignedSize);
-		else
-		 	Fragment here if possible.
-		*/
 	}
 	else
 	{
@@ -95,6 +106,9 @@ void free(void* ptr)
 		return;
 
 	struct block* b = (struct block*)ptr - 1;
+	if (b->free)
+		return;
+
 	b->free = 1;
 
 	while (b->prev && b->prev->free)
@@ -124,5 +138,7 @@ int main()
 	free(a);
 	free(b);
 
+	int* c = (int*)malloc(sizeof(int));
+
 	return 0;
 }