Pooling with ObjectPool<T> in .NET

Object pooling is a design pattern that helps manage object reuse to reduce memory allocations and improve performance. The ObjectPool<T> class in .NET provides a way to efficiently reuse objects.

Why Use ObjectPool<T>?

• Reduces the overhead of frequent object creation and garbage collection.
• Improves performance by reusing objects.
• Useful for managing expensive resources like database connections, HTTP clients, or large objects.

Using ObjectPool<T> in .NET

The Microsoft.Extensions.ObjectPool package provides the ObjectPool<T> class for managing reusable objects.

1. Installing the Required Package

Install-Package Microsoft.Extensions.ObjectPool

2. Creating a Custom Object Pool

Define a factory to create objects when needed.

using Microsoft.Extensions.ObjectPool;

public class MyObject
{
    public int Id { get; set; }
}

public class MyObjectPoolPolicy : PooledObjectPolicy
{
    public override MyObject Create() => new MyObject();
    
    public override bool Return(MyObject obj)
    {
        obj.Id = 0; // Reset object state before reuse
        return true;
    }
}

3. Using the Object Pool

Once the pool is created, objects can be obtained and returned efficiently.

var pool = new DefaultObjectPool(new MyObjectPoolPolicy());

// Get an object from the pool
MyObject obj = pool.Get();
obj.Id = 42;

// Return the object to the pool for reuse
pool.Return(obj);

Advanced Usage

You can use object pooling for performance-sensitive scenarios like.

• Caching objects in web applications.
• Reusing large byte arrays to reduce memory allocations.
• Managing database connections efficiently.

Conclusion

Using ObjectPool<T> in .NET helps improve application performance by reusing objects and reducing memory allocations. It is a useful tool for optimizing resource management in high-performance applications.