JoinBlock<T1,T2>.ISourceBlock<Tuple<T1,T2>>.ReserveMessage Method

Definition

Namespace:

System.Threading.Tasks.Dataflow

Assembly:

System.Threading.Tasks.Dataflow.dll

Source:

JoinBlock.cs

Reserves the right to pass the ownership of the message identified by the DataflowMessageHeader from this ISourceBlock<TOutput> to the ITargetBlock<TInput>.

C#

bool ISourceBlock<Tuple<T1,T2>>.ReserveMessage(System.Threading.Tasks.Dataflow.DataflowMessageHeader messageHeader, System.Threading.Tasks.Dataflow.ITargetBlock<Tuple<T1,T2>> target);

Parameters

messageHeader

DataflowMessageHeader

The DataflowMessageHeader of the message that is to be reserved.

target

ITargetBlock<Tuple<T1,T2>>

The ITargetBlock<TInput> for which the message is to be reserved.

Returns

Boolean

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

Implements

ReserveMessage(DataflowMessageHeader, ITargetBlock<TOutput>)

Exceptions

ArgumentException

The messageHeader is not valid.

ArgumentNullException

The target is null (Nothing in Visual Basic).

Remarks

The ITargetBlock<TInput> for which the message is to be reserved need not be linked from this ISourceBlock<TOutput> instance. Moreover, this ISourceBlock<TOutput> instance may have never offered the message directly to the ITargetBlock<TInput>.

If true is returned, you must subsequently call either ConsumeMessage or ReleaseReservation for this message with the same DataflowMessageHeader and ITargetBlock<TInput>. If you don't, the source may be unable to propagate any further messages to any target.

Don't call ReserveMessage 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