Class ManualResetValueTaskSource<T>

Namespace

CryptoHives.Foundation.Threading.Pools

Assembly

CryptoHives.Foundation.Threading.dll

An abstract implementation of IValueTaskSource<TResult>.

public abstract class ManualResetValueTaskSource<T> : IValueTaskSource<T>, IValueTaskSource, IResettable

Type Parameters

T

Inheritance

object

ManualResetValueTaskSource<T>

Implements

IValueTaskSource<T>

IValueTaskSource

IResettable

Derived

LocalManualResetValueTaskSource<T>

PooledManualResetValueTaskSource<T>

Inherited Members

object.ToString()

object.Equals(object)

object.Equals(object, object)

object.ReferenceEquals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

Remarks

This class is a sealed implementation of IValueTaskSource<TResult> and provides methods to manage the lifecycle of a task-like operation. It allows resetting and signaling the completion of the operation, and supports querying the status and retrieving the result. In addition, an implementation can set the owner instance to return the instance to the pool when it is no longer needed. This class is designed for direct use with CryptoHives.Foundation.Threading.Pools.WaiterQueue<T> to store the derived waiters allocation free. The IResettable interface is implemented to allow resetting the state of the instance for reuse by an implementation of an ObjectPool that uses the DefaultObjectPool<T> implementation.

Properties

CancellationToken

Gets the CancellationToken associated with the current operation.

public abstract CancellationToken CancellationToken { get; set; }

Property Value

CancellationToken

Remarks

This token may be cancelled during long-running operations.

CancellationTokenRegistration

Gets the CancellationTokenRegistration associated with the current operation.

public abstract CancellationTokenRegistration CancellationTokenRegistration { get; set; }

Property Value

CancellationTokenRegistration

Remarks

Use this token to unregister from cancellation requests.

Owner

Gets or sets the owner associated with this instance.

public abstract object? Owner { get; }

Property Value

object

RunContinuationsAsynchronously

Gets or sets whether to force continuations to run asynchronously.

public abstract bool RunContinuationsAsynchronously { get; set; }

Property Value

bool

Remarks

Continuations may run asynchronously if this is false, but they'll never run synchronously if this is true.

TimeoutTimer

Gets or sets the TimeoutTimer used to enforce a timeout on the wait operation.

public abstract ITimer? TimeoutTimer { get; set; }

Property Value

ITimer

Remarks

Set to a non-null value when the waiter is created with a timeout. The timer is disposed and cleared by TryReset() when the waiter is recycled.

Assign this after leaving the owner's lock, not inside it. Creating a timer takes the runtime's process-global timer queue lock and allocates, which is the one cost in those critical sections that the library cannot bound - and the primitives' spin lock is tuned on the premise that everything it guards is a few pointer writes.

This is safe for the same reason CancellationTokenRegistration is already assigned outside the lock. A waiter is recycled only by TryReset(), which runs from GetResult(short), which is reachable only through the ValueTask the enqueueing method has not returned yet. So between releasing the lock and returning that ValueTask, the waiter is owned exclusively by the enqueueing thread: another thread may SetResult(T) it, but cannot reset it, so Version is stable and the timer cannot be disposed underneath the assignment.

A waiter completed inside that window still gets a timer, which fires and finds either a version mismatch or a waiter no longer in the queue, and does nothing - the stale-callback case CryptoHives.Foundation.Threading.Pools.TimeoutState<T> already exists to handle.

Version

Gets the version number of the current instance.

public abstract short Version { get; }

Property Value

short

Methods

GetResult(short)

Gets the result of the IValueTaskSource<TResult>.

public abstract T GetResult(short token)

Parameters

token short

Opaque value that was provided to the ValueTask's constructor.

Returns

T

GetStatus(short)

Gets the status of the current operation.

public abstract ValueTaskSourceStatus GetStatus(short token)

Parameters

token short

Opaque value that was provided to the ValueTask's constructor.

Returns

ValueTaskSourceStatus

OnCompleted(Action<object?>, object?, short, ValueTaskSourceOnCompletedFlags)

Schedules the continuation action for this IValueTaskSource<TResult>.

public abstract void OnCompleted(Action<object?> continuation, object? state, short token, ValueTaskSourceOnCompletedFlags flags)

Parameters

continuation Action<object>

The continuation to invoke when the operation has completed.

state object

The state object to pass to continuation when it's invoked.

token short

Opaque value that was provided to the ValueTask's constructor.

flags ValueTaskSourceOnCompletedFlags

The flags describing the behavior of the continuation.

SetChainResult(T)

Signals the completion of an operation, setting the result to T for a chain of operations.

public abstract void SetChainResult(T result)

Parameters

result T

Remarks

This method is typically used to indicate that a chain of asynchronous operations has completed successfully.

SetException(Exception)

Sets the specified exception to be associated with the current operation.

public abstract void SetException(Exception ex)

Parameters

ex Exception

SetResult(T)

Signals the completion of an operation, setting the result to T.

public abstract void SetResult(T result)

Parameters

result T

Remarks

This method is typically used to indicate that an asynchronous operation has completed successfully.

TryReset()

Reset the object to a neutral state, semantically similar to when the object was first constructed.

public abstract bool TryReset()

Returns

bool

true if the object was able to reset itself, otherwise false.

Remarks

In general, this method is not expected to be thread-safe.