multitype_join Class
A multitype_join
messaging block is a multi-source, single-target messaging block that combines together messages of different types from each of its sources and offers a tuple of the combined messages to its targets.
Syntax
template<
typename T,
join_type _Jtype = non_greedy
>
class multitype_join: public ISource<typename _Unwrap<T>::type>;
Parameters
T
The tuple
payload type of the messages joined and propagated by the block.
_Jtype
The kind of join
block this is, either greedy
or non_greedy
Members
Public Typedefs
Name | Description |
---|---|
type |
A type alias for T . |
Public Constructors
Name | Description |
---|---|
multitype_join | Overloaded. Constructs a multitype_join messaging block. |
~multitype_join Destructor | Destroys the multitype_join messaging block. |
Public Methods
Name | Description |
---|---|
accept | Accepts a message that was offered by this multitype_join block, transferring ownership to the caller. |
acquire_ref | Acquires a reference count on this multitype_join messaging block, to prevent deletion. |
consume | Consumes a message previously offered by the multitype_join messaging block and successfully reserved by the target, transferring ownership to the caller. |
link_target | Links a target block to this multitype_join messaging block. |
release | Releases a previous successful message reservation. |
release_ref | Releases a reference count on this multiple_join messaging block. |
reserve | Reserves a message previously offered by this multitype_join messaging block. |
unlink_target | Unlinks a target block from this multitype_join messaging block. |
unlink_targets | Unlinks all targets from this multitype_join messaging block. (Overrides ISource::unlink_targets.) |
Remarks
For more information, see Asynchronous Message Blocks.
Inheritance Hierarchy
multitype_join
Requirements
Header: agents.h
Namespace: concurrency
accept
Accepts a message that was offered by this multitype_join
block, transferring ownership to the caller.
virtual message<_Destination_type>* accept(
runtime_object_identity _MsgId,
_Inout_ ITarget<_Destination_type>* _PTarget);
Parameters
_MsgId
The runtime_object_identity
of the offered message
object.
_PTarget
A pointer to the target block that is calling the accept
method.
Return Value
A pointer to the message that the caller now has ownership of.
acquire_ref
Acquires a reference count on this multitype_join
messaging block, to prevent deletion.
virtual void acquire_ref(_Inout_ ITarget<_Destination_type>* _PTarget);
Parameters
_PTarget
A pointer to the target block that is calling this method.
Remarks
This method is called by an ITarget
object that is being linked to this source during the link_target
method.
consume
Consumes a message previously offered by the multitype_join
messaging block and successfully reserved by the target, transferring ownership to the caller.
virtual message<_Destination_type>* consume(
runtime_object_identity _MsgId,
_Inout_ ITarget<_Destination_type>* _PTarget);
Parameters
_MsgId
The runtime_object_identity
of the reserved message
object.
_PTarget
A pointer to the target block that is calling the consume
method.
Return Value
A pointer to the message
object that the caller now has ownership of.
Remarks
The consume
method is similar to accept
, but must always be preceded by a call to reserve
that returned true
.
link_target
Links a target block to this multitype_join
messaging block.
virtual void link_target(_Inout_ ITarget<_Destination_type>* _PTarget);
Parameters
_PTarget
A pointer to an ITarget
block to link to this multitype_join
messaging block.
multitype_join
Constructs a multitype_join
messaging block.
explicit multitype_join(
T _Tuple);
multitype_join(
Scheduler& _PScheduler,
T _Tuple);
multitype_join(
ScheduleGroup& _PScheduleGroup,
T _Tuple);
multitype_join(
multitype_join&& _Join);
Parameters
_Tuple
A tuple
of sources for this multitype_join
messaging block.
_PScheduler
The Scheduler
object within which the propagation task for the multitype_join
messaging block is scheduled.
_PScheduleGroup
The ScheduleGroup
object within which the propagation task for the multitype_join
messaging block is scheduled. The Scheduler
object used is implied by the schedule group.
_Join
A multitype_join
messaging block to copy from. Note that the original object is orphaned, making this a move constructor.
Remarks
The runtime uses the default scheduler if you do not specify the _PScheduler
or _PScheduleGroup
parameters.
Move construction is not performed under a lock, which means that it is up to the user to make sure that there are no light-weight tasks in flight at the time of moving. Otherwise, numerous races can occur, leading to exceptions or inconsistent state.
~multitype_join
Destroys the multitype_join
messaging block.
~multitype_join();
release
Releases a previous successful message reservation.
virtual void release(
runtime_object_identity _MsgId,
_Inout_ ITarget<_Destination_type>* _PTarget);
Parameters
_MsgId
The runtime_object_identity
of the message
object being released.
_PTarget
A pointer to the target block that is calling the release
method.
release_ref
Releases a reference count on this multiple_join
messaging block.
virtual void release_ref(_Inout_ ITarget<_Destination_type>* _PTarget);
Parameters
_PTarget
A pointer to the target block that is calling this method.
Remarks
This method is called by an ITarget
object that is being unlinked from this source. The source block is allowed to release any resources reserved for the target block.
reserve
Reserves a message previously offered by this multitype_join
messaging block.
virtual bool reserve(
runtime_object_identity _MsgId,
_Inout_ ITarget<_Destination_type>* _PTarget);
Parameters
_MsgId
The runtime_object_identity
of the message
object being reserved.
_PTarget
A pointer to the target block that is calling the reserve
method.
Return Value
true
if the message was successfully reserved, false
otherwise. Reservations can fail for many reasons, including: the message was already reserved or accepted by another target, the source could deny reservations, and so forth.
Remarks
After you call reserve
, if it succeeds, you must call either consume
or release
in order to take or give up possession of the message, respectively.
unlink_target
Unlinks a target block from this multitype_join
messaging block.
virtual void unlink_target(_Inout_ ITarget<_Destination_type>* _PTarget);
Parameters
_PTarget
A pointer to an ITarget
block to unlink from this multitype_join
messaging block.
unlink_targets
Unlinks all targets from this multitype_join
messaging block.
virtual void unlink_targets();