Class ScyllaGenericObjectPool<T>

High-performance object pool for any type T. Stores available instances in an array-backed free-list (LIFO). Unsynchronized by default; use AsSynchronized(object) to obtain a synchronized wrapper.

Inheritance
object
ScyllaGenericObjectPool<T>
Implements
Inherited Members
Namespace: Scylla.Core.Structures
Assembly: ScyllaCore.dll
Syntax
public sealed class ScyllaGenericObjectPool<T> : IScyllaCollection<T>, IScyllaCollection
Type Parameters
Name Description
T

Pooled type
Remarks
// Direct construction
var pool = new ScyllaGenericObjectPool<MyClass>(createFunc: () => new MyClass(), maxSize: 100, capacity: 32);
// Using fluent builder for complex configuration
var pool = ScyllaGenericObjectPool<MyClass>.CreateBuilder()
.WithCapacity(64)
.WithMaxSize(200)
.WithCreateFunc(() => new MyClass())
.OnGet(obj => obj.Reset())
.OnRelease(obj => obj.Cleanup())
.CollectionCheck()
.Synchronized()
.Build();

Constructors

ScyllaGenericObjectPool(Func<T>, Action<T>, Action<T>, Action<T>, bool, bool, bool, int, int)

Creates a new object pool backed by a free-list of available instances.

Declaration
public ScyllaGenericObjectPool(Func<T> createFunc = null, Action<T> onGet = null, Action<T> onRelease = null, Action<T> onDestroy = null, bool collectionCheck = false, bool allowCreate = true, bool disposeOnDestroy = false, int maxSize = 2147483647, int capacity = 4)
Parameters
Type Name Description
Func<T> createFunc

Optional creation function used when the pool is empty and allowCreate is true. If null and allowCreate is true, the pool will create instances using CreateInstance<T>() (requires a public parameterless constructor for reference types).
Action<T> onGet

Optional callback invoked after an instance is retrieved from the pool
Action<T> onRelease

Optional callback invoked before an instance is stored back into the pool
Action<T> onDestroy

Optional callback invoked before an instance is destroyed/forgotten
bool collectionCheck

If true, Release(T) checks whether the instance is already in the pool (O(n)). Useful for debugging; disable for maximum performance.
bool allowCreate

If true, Get() creates a new instance when the pool is empty. If false, TryGet(out T) returns false when empty.
bool disposeOnDestroy

If true, when an instance is destroyed/forgotten, and it implements IDisposable, Dispose() will be called.
int maxSize

Maximum number of available instances to keep in the pool. When exceeded, released instances are destroyed/forgotten (and not stored).
int capacity

Initial free-list capacity (rounded up to at least 1)

Properties

AllowCreate

True if the pool creates new instances when empty.

Declaration
public bool AllowCreate { get; }
Property Value
Type Description
bool

Capabilities

Feature/capability flags supported by this pool instance.

Declaration
public ScyllaCollectionCapabilities Capabilities { get; }
Property Value
Type Description
ScyllaCollectionCapabilities

Capacity

Current free-list capacity (number of available slots that can be stored without resizing).

Declaration
public int Capacity { get; }
Property Value
Type Description
int

Count

Number of available instances currently stored in the pool. This maps to Count.

Declaration
public int Count { get; }
Property Value
Type Description
int

CountAll

Total number of instances created by this pool and not subsequently destroyed via Clear(bool).

Declaration
public int CountAll { get; }
Property Value
Type Description
int

DisposeOnDestroy

True if instances implementing IDisposable are disposed when destroyed/forgotten.

Declaration
public bool DisposeOnDestroy { get; }
Property Value
Type Description
bool

IsEmpty

True if the pool has no available instances.

Declaration
public bool IsEmpty { get; }
Property Value
Type Description
bool

MaxSize

Maximum number of available instances that can be stored before releases begin destroying/forgetting instances.

Declaration
public int MaxSize { get; }
Property Value
Type Description
int

SyncRoot

Synchronization root for externally coordinating operations. This pool is unsynchronized by default.

Declaration
public object SyncRoot { get; }
Property Value
Type Description
object

ThreadSafety

Thread-safety guarantees provided by this pool instance.

Declaration
public ScyllaCollectionThreadSafety ThreadSafety { get; }
Property Value
Type Description
ScyllaCollectionThreadSafety

Methods

AsSynchronized(object)

Creates and returns a thread-safe synchronized wrapper around this pool.

Declaration
public ScyllaGenericObjectPool<T>.SynchronizedScyllaGenericObjectPool AsSynchronized(object syncRoot = null)
Parameters
Type Name Description
object syncRoot

Optional external lock object to use for synchronization. If null, the wrapper creates and owns a private lock.
Returns
Type Description
ScyllaGenericObjectPool<T>.SynchronizedScyllaGenericObjectPool

A thread-safe wrapper that synchronizes all operations

Clear()

Removes all available instances from the pool and destroys/disposes them.

Declaration
public void Clear()

Clear(bool)

Removes all available instances from the pool. If destroy is true, also destroys/disposes them based on configuration.

Declaration
public void Clear(bool destroy)
Parameters
Type Name Description
bool destroy

If true, destroys/disposes available instances; if false, just forgets them

Contains(T, IEqualityComparer<T>)

Determines whether the pool currently contains the specified available instance (O(n)).

Declaration
public bool Contains(T instance, IEqualityComparer<T> comparer = null)
Parameters
Type Name Description
T instance

Instance to locate
IEqualityComparer<T> comparer

Optional comparer. For reference types, if null, reference identity is used. For value types, if null, Default is used.
Returns
Type Description
bool

True if found among available instances, false otherwise

CopyTo(Span<T>)

Copies available instances from the pool into the provided span (top-to-bottom / LIFO order).

Declaration
public int CopyTo(Span<T> destination)
Parameters
Type Name Description
Span<T> destination

The span to copy instances into
Returns
Type Description
int

The number of instances copied

CopyTo(T[], int)

Copies available instances from the pool into the provided array starting at the specified index (top-to-bottom / LIFO order).

Declaration
public int CopyTo(T[] destination, int destinationIndex)
Parameters
Type Name Description
T[] destination

The array to copy instances into
int destinationIndex

The zero-based index in the destination array at which copying begins
Returns
Type Description
int

The number of instances copied

CreateBuilder()

Creates a new fluent builder for configuring and constructing a ScyllaGenericObjectPool instance. The builder provides a discoverable API for setting capacity, max size, creation function, callbacks, and synchronized wrappers.

Declaration
public static ScyllaGenericObjectPool<T>.Builder CreateBuilder()
Returns
Type Description
ScyllaGenericObjectPool<T>.Builder

A new builder instance for configuring ScyllaGenericObjectPool construction
Remarks
var pool = ScyllaGenericObjectPool<MyClass>.CreateBuilder()
.WithCapacity(64)
.WithMaxSize(200)
.WithCreateFunc(() => new MyClass())
.Build();

Get()

Retrieves an instance from the pool. If the pool is empty and AllowCreate is true, a new instance is created.

Declaration
public T Get()
Returns
Type Description
T

An instance
Exceptions
Type Condition
InvalidOperationException

Thrown when the pool is empty and AllowCreate is false

GetEnumerator()

Returns an enumerator that iterates through available instances in the pool (top-to-bottom / LIFO order). The enumerator is a value type, enabling allocation-free enumeration when using the concrete type.

Declaration
public ScyllaGenericObjectPool<T>.Enumerator GetEnumerator()
Returns
Type Description
ScyllaGenericObjectPool<T>.Enumerator

A value-type ScyllaGenericObjectPool<T>.Enumerator positioned before the first available instance. The count is snapshotted at construction time; pool mutations during enumeration are not reflected.

Prewarm(int)

Pre-creates and stores up to the specified number of available instances.

Declaration
public int Prewarm(int count)
Parameters
Type Name Description
int count

Number of instances to create and store
Returns
Type Description
int

The number of instances actually created and stored

Release(T)

Returns an instance back to the pool. If the pool is at MaxSize, the instance is destroyed/forgotten instead of being stored.

Declaration
public bool Release(T instance)
Parameters
Type Name Description
T instance

The instance to return to the pool
Returns
Type Description
bool

True if stored in the pool; false if destroyed/forgotten due to capacity constraints
Exceptions
Type Condition
InvalidOperationException

Thrown when instance is already in the pool and collection checking is enabled

TryAdd(T)

Attempts to add an instance to the pool (equivalent to Release(T)).

Declaration
public bool TryAdd(T item)
Parameters
Type Name Description
T item

The instance to add
Returns
Type Description
bool

True if stored; false if destroyed/forgotten due to capacity constraints

TryGet(out T)

Attempts to retrieve an instance from the pool. If the pool is empty and AllowCreate is true, a new instance is created.

Declaration
public bool TryGet(out T instance)
Parameters
Type Name Description
T instance

When this method returns, contains the retrieved instance if successful, or default if not
Returns
Type Description
bool

True if an instance was retrieved or created; false if the pool is empty and AllowCreate is false

TryPeek(out T)

Attempts to peek at the next available instance without removing it.

Declaration
public bool TryPeek(out T item)
Parameters
Type Name Description
T item

When this method returns, contains the next available instance if available, or default if empty
Returns
Type Description
bool

True if an available instance was present; false otherwise

TryRemove(out T)

Attempts to remove an instance from the pool (equivalent to TryGet(out T)).

Declaration
public bool TryRemove(out T item)
Parameters
Type Name Description
T item

When this method returns, contains the retrieved instance if successful, or default if not
Returns
Type Description
bool

True if an instance was retrieved or created; false if the pool is empty and AllowCreate is false

Implements

Extension Methods