Game Development
Heap allocation
Learn the cost of heap allocation and how to avoid it.
Heap allocation
The heap is the dynamic memory region where objects are stored. Every object created with the new keyword sits on the heap, and this operation is called a heap allocation. A heap allocation costs more than putting a value on the stack.
GameObject kasa = new GameObject("Kasa"); // heap allocation
Large or frequent allocations increase memory pressure.
Avoiding allocations
The first way to avoid allocation cost is to reuse objects. Producing an object once and keeping it is much cheaper than creating a new one every frame. Unnecessary temporary objects should also be reduced.
private Nesne nesne; // produced once
void Start()
{
nesne = new Nesne();
}
This way the allocation count drops and the GC runs less often.
Exercise Compute the allocation cost
In a class named HeapTakip, define an integer field named tahsisMaliyeti with the value 10 and an integer field named toplamMaliyet with the value 0. In the Start method set toplamMaliyet to three times tahsisMaliyeti and print the text "Toplam maliyet: " joined with toplamMaliyet using Debug.Log.
Show example solution
using UnityEngine;
public class HeapTakip : MonoBehaviour
{
int tahsisMaliyeti = 10;
int toplamMaliyet = 0;
void Start()
{
toplamMaliyet = tahsisMaliyeti * 3;
Debug.Log("Toplam maliyet: " + toplamMaliyet);
}
}
Test yourself
-
Which of the following causes a heap allocation?
GameObject kasa = new GameObject("Kasa");
- Printing text with Debug.Log
- Creating a new object with new
- Assigning a constant value to a variable
- Calling a method
Show answer
Creating a new object with new — The new keyword reserves a new object on the heap; the other operations alone do not allocate.
-
Create the new object with new
GameObject kasa = ____ GameObject("Kasa");
Show answer
GameObject kasa = new GameObject("Kasa");
-
Heap allocation terms
- Heap
- Dynamic memory storing objects
- new anahtarı
- Performs a heap allocation
- Tahsis maliyeti
- The memory cost of a new object
- Yeniden kullanma
- The technique that reduces allocations
Next lesson: Struct vs class
