The Object Pool Pattern

The Object Pool Pattern


The Object Pool Pattern is a valuable tool for managing and reusing objects efficiently in C#.

It aims to optimise resource utilisation by maintaining a pool of reusable objects, reducing the overhead associated with frequent object creation and disposal.

Understanding the Object Pool Pattern

The Object Pool Pattern revolves around a centralised pool that holds pre-allocated objects of a specific type.

When a new object of that type is needed, it is retrieved from the pool, avoiding the cost of object creation.

After the object is used, it is returned to the pool, making it available for reuse.

Benefits of the Object Pool Pattern

The Object Pool Pattern offers several advantages, including:

  • Resource Optimisation: It reduces the overhead of object creation and disposal, improving resource utilisation.
  • Improved Performance: It can improve application performance by minimising garbage collection overhead.
  • Reduced Memory Usage: It can reduce memory usage by minimising the creation of unnecessary objects.
  • Thread-Safety: It can be implemented in a thread-safe manner, ensuring concurrent access to pooled objects.
  • Flexibility in Object Lifetime: It allows for flexible object lifetime management, ranging from pooled objects to short-lived objects.

Applications of the Object Pool Pattern

The Object Pool Pattern finds applications in various scenarios, including:

  • Connection Management: It can be used to manage database connections, reducing the number of open database connections.
  • Resource-Intensive Tasks: It can be used to manage resources like network connections or graphics resources, improving performance and reducing resource contention.
  • Memory-Constrained Environments: It can be used to manage memory-intensive objects in memory-constrained environments.
  • High-Concurrency Scenarios: It can be used to improve concurrency and responsiveness in high-concurrency scenarios.

Implementing the Object Pool Pattern in C#

To illustrate the implementation of the Object Pool Pattern in C#, consider a simplified scenario of managing database connections:

Database Connection Interface

public interface IDatabaseConnection
    void ExecuteQuery(string query);

Concrete Database Connection

public class MySqlConnection : IDatabaseConnection
    public void ExecuteQuery(string query)
        // Connect to the database and execute the query
        Console.WriteLine("Executing query: " + query);

Object Pool

public class ConnectionPool
    private static Dictionary<int, MySqlConnection> connections = new Dictionary<int, MySqlConnection>();

    public MySqlConnection GetConnection()
        // Get a free connection from the pool
        int connectionId = GetFreeConnectionId();
        MySqlConnection connection = connections[connectionId];

        // Return the connection to the pool
        return connection;

    public void ReturnConnection(MySqlConnection connection)
        // Add the connection to the pool
        int connectionId = connectionIds.Count;
        connections[connectionId] = connection;

Using the Object Pool

ConnectionPool connectionPool = new ConnectionPool();

// Get a connection from the pool
MySqlConnection connection = connectionPool.GetConnection();

// Use the connection to execute a query
connection.ExecuteQuery("SELECT * FROM customers");

// Return the connection to the pool

This example demonstrates a basic implementation of the Object Pool Pattern for managing database connections.


The Object Pool Pattern is a valuable tool for optimising resource utilisation and improving performance in C# applications.

By leveraging object pools, developers can minimise the overhead associated with object creation and disposal, enhancing their applications’ overall efficiency and responsiveness.

Developers can effectively manage resources and optimise application performance by understanding the principles of the Object Pool Pattern and its various applications.


Hi, my name is Stephen Finchett. I have been a software engineer for over 30 years and worked on complex, business critical, multi-user systems for all of my career. For the last 15 years, I have been concentrating on web based solutions using the Microsoft Stack including ASP.Net, C#, TypeScript, SQL Server and running everything at scale within Kubernetes.