Asynchronously passes a message from an ISource block to this transformer messaging block. It is invoked by the propagate method, when called by a source block.
virtual message_status propagate_message( _Inout_ message<_Input> * _PMessage, _Inout_ ISource<_Input> * _PSource );
A pointer to the message object.
A pointer to the source block offering the message.
A message_status indication of what the target decided to do with the message.