Wiaoj.ObjectPool 0.0.1-alpha.69

Wiaoj.ObjectPool

A high-performance, thread-safe, and unified asynchronous/synchronous object pooling library for .NET.

Wiaoj.ObjectPool extends the capabilities of Microsoft.Extensions.ObjectPool by providing a unified API surface for both sync and async pools. It introduces true asynchronous support, blocking/bounded pools, factory pattern integration, and zero-allocation leasing. It is designed for high-throughput applications where garbage collection pressure must be minimized and resource management is critical.

🚀 Key Features

• ⚡ True Async Support: Native IAsyncObjectPool<T> with ValueTask support. Handles asynchronous creation (CreateAsync) and cleanup (TryResetAsync).
• 🤝 Unified API: Provides a consistent, clean API surface for both Microsoft's standard synchronous pools and our custom asynchronous pools. No need to switch contexts!
• 🏭 Factory Integration: Seamlessly integrates with IAsyncFactory<T> for complex object creation logic using Dependency Injection.
• 🛡️ Hybrid Operation Modes:
  • FIFO (Elastic): Lock-free, extremely fast. Creates new objects instantly if the pool is empty.
  • Bounded (Blocking): Uses SemaphoreSlim. Waits asynchronously if the pool limit is reached. Ideal for resource throttling (e.g., DB connections).
• 🧠 Smart Lifecycle Management: Supports IResettable (Sync) and IAsyncResettable (Async) interfaces for self-managing objects.
• 📦 True Zero-Allocation Leasing: Uses a value-type struct (PooledObject<T>) to manage the lease lifecycle, ensuring 0 heap allocations during Get/Return cycles.

📥 Installation

Install via NuGet Package Manager:

dotnet add package Wiaoj.ObjectPool

⚡ Quick Start (Synchronous)

For simple CPU-bound objects like StringBuilder or List<T>, use the standard synchronous pool. Our library wraps it cleanly.

1. Register in DI

using Wiaoj.ObjectPool.Extensions;

var builder = WebApplication.CreateBuilder(args);

// Simple registration (uses new T())
builder.Services.AddObjectPool<StringBuilder>();

// Or with custom factory and reset logic via Lambdas
builder.Services.AddObjectPool<List<int>>(
    factory: () => new List<int>(),
    resetter: list => { list.Clear(); return true; }
);

2. Inject and Use

public class StringService(IObjectPool<StringBuilder> pool)
{
    public string BuildMessage()
    {
        // 'using' ensures the object is automatically returned to the pool
        using PooledObject<StringBuilder> lease = pool.Lease();
        
        StringBuilder sb = lease.Item;
        sb.Append("Hello High Performance!");
        
        return sb.ToString();
    }
}

🔥 Advanced Usage (Asynchronous)

This is where Wiaoj.ObjectPool shines. Ideal for database connections, network streams, or any resource where creation/reset is costly and requires I/O.

1. Register Async Pool

builder.Services.AddAsyncPool<MyDbConnection>(
    factory: async ct => await MyDbConnection.CreateAsync(ct),
    resetter: async conn => await conn.ResetStateAsync(),
    options => 
    {
        // Wait asynchronously if 50 connections are already in use.
        options.MaximumRetained = 50;
        options.AccessMode = PoolAccessMode.Bounded; 
    }
);

2. Inject and Use

public class DataService(IAsyncObjectPool<MyDbConnection> dbPool)
{
    public async Task ProcessDataAsync()
    {
        // Leases a connection asynchronously. 
        // If pool is 'Bounded' and full, this line awaits until a slot opens.
        // Supports 'await using' for async disposal.
        await using var lease = await dbPool.LeaseAsync();
        
        var connection = lease.Item;
        await connection.ExecuteQueryAsync("SELECT * FROM Users");
    }
}

🧠 Defining Pool Logic: Strategies

Wiaoj.ObjectPool offers flexibility in how you define object creation and cleanup.

1. The "OOP" Way (IResettable) - Recommended

Best for objects that know how to clean themselves. No external logic required in Program.cs.

Step 1: Implement IResettable (Sync) or IAsyncResettable (Async).

public class SocketClient : IAsyncResettable
{
    public async ValueTask<bool> TryResetAsync()
    {
        await SendResetCommandAsync(); // Async cleanup!
        return true;
    }
}

Step 2: Register

// No factory or resetter needed! 
builder.Services.AddAsyncResettablePool<SocketClient>(); 

2. The "Factory" Way (IAsyncFactory)

Best when object creation is complex and already handled by an IAsyncFactory<T> implementation in your DI container.

// 1. You already have a factory registered
builder.Services.AddSingleton<IAsyncFactory<MyService>, MyServiceFactory>();

// 2. Register the pool (It automatically resolves the factory!)
builder.Services.AddAsyncFactoryPool<MyService>(
    resetter: async svc => { /* Custom reset logic */ return true; }
);

⚙️ Configuration Modes

You can control the pool's behavior via ObjectPoolOptions.AccessMode:

⚠️ Best Practices: Zero-Allocation Leasing

To achieve 0 heap allocations during the Lease operation, PooledObject<T> is designed as a struct (Value Type).

Important Rule: Do NOT copy the leased struct or pass it by value to other methods. Doing so could result in double-disposal. Always use it tightly within a using or await using block.

Correct:

await using var lease = await pool.LeaseAsync();
var client = lease.Item;

Incorrect:

var lease1 = pool.Lease();
var lease2 = lease1; // ❌ DO NOT DO THIS! (Copies the struct)

📄 License

This project is licensed under the MIT License.