TransformBlock<TInput,TOutput>.ISourceBlock<TOutput>.ReserveMessage(DataflowMessageHeader, ITargetBlock<TOutput>) TransformBlock<TInput,TOutput>.ISourceBlock<TOutput>.ReserveMessage(DataflowMessageHeader, ITargetBlock<TOutput>) TransformBlock<TInput,TOutput>.ISourceBlock<TOutput>.ReserveMessage(DataflowMessageHeader, ITargetBlock<TOutput>) Method

Definition

Called by a linked ITargetBlock<TInput> to reserve a previously offered DataflowMessageHeader by this ISourceBlock<TOutput>.

 virtual bool System.Threading.Tasks.Dataflow.ISourceBlock<TOutput>.ReserveMessage(System::Threading::Tasks::Dataflow::DataflowMessageHeader messageHeader, System::Threading::Tasks::Dataflow::ITargetBlock<TOutput> ^ target) = System::Threading::Tasks::Dataflow::ISourceBlock<TOutput>::ReserveMessage;
bool ISourceBlock<TOutput>.ReserveMessage (System.Threading.Tasks.Dataflow.DataflowMessageHeader messageHeader, System.Threading.Tasks.Dataflow.ITargetBlock<TOutput> target);
Function ReserveMessage (messageHeader As DataflowMessageHeader, target As ITargetBlock(Of TOutput)) As Boolean Implements ISourceBlock(Of TOutput).ReserveMessage

Parameters

target
ITargetBlock<TOutput>

The ITargetBlock<TInput> reserving the message.

Returns

true if the message was successfully reserved; otherwise, false.

Implements

Exceptions

The messageHeader is not valid.

Remarks

Only ITargetBlock<TInput> instances linked to this ISourceBlock<TOutput> instance may use ReserveMessage, and it must only be used to reserve DataflowMessageHeader instances previously offered by this source to the target.

If true is returned, the ITargetBlock<TInput> must subsequently call either ConsumeMessage or ReleaseReservation for this message. Failure to do so may result in the source being unable to propagate any further messages to this or other targets.

ReserveMessage must not be called while the target is holding any internal locks. Doing so will violate the lock hierarchy necessary to avoid deadlocks in a dataflow network.

Applies to