TT_HANDLER

This type of addressing is "point-to-point" delivery -- the message is passed directly to the receiver. You cannot monitor point-to-point messages because registered patterns are never checked.  

No matching required. 

TT_PROCEDURE

Scans list of static signatures (sig) that have same operation (op) and collects lists of observers and potential handlers. 

If the sig has no arguments and no contexts 

If sig prototype (number, type and mode of args) have different values 

If the sig contexts are a subset of the contexts in the message 

Saves information for any static observers that require queuing. 

Scans through dynamic patterns and adds to lists of observers and potential handlers. To form the lists, ttsession first uses the patterns with operations, then the patterns without operations. 

Checks reliability, states, class, address, handler, handler ptype, scope, object, otype, sender, sender_ptype, args, contexts. 

Delivers to observers first (because a handler can change state). 

Delivers to handler with best match -- if more than one handler equally "best" matches, the handler is arbitrarily chosen. 

=> Match 

=> No Match 

=> Match 

TT_OBJECT & TT_OTYPE

Checks whether the otype argument is filled in 

If sig has a different otype 

If sig has no otype & scope is different 

Otherwise, matches in the same manner as for TT_PROCEDURE matching.

=> No Match 

=> No Match