T-Kernel Specification (1.B0.02)

144 CHAPTER 4. T-KERNEL/OS FUNCTIONS
tk ref por
Reference Port Status
[C Language Interface]
ER ercd = tk_ref_por ( ID porid, T_RPOR *pk_rpor ) ;
[Parameters]
ID porid Rendezvous port ID
T RPOR* pk rpor Start address of packet for returning status information
[Return Parameters]
ER ercd Error code
pk rpor detail:
VP exinf Extended information
ID wtsk Waiting task information
ID atsk Accept task information
INT maxcmsz Maximum call message size (in bytes)
INT maxrmsz Maximum reply message size (in bytes)
(Other implementation-dependent parameters may be added beyond this point.)
[Error Codes]
E OK
E ID
E NOEXS
E PAR
Normal completion
Invalid ID number (porid is invalid or cannot be used)
Object does not exist (the rendezvous port designated in porid does not exist)
Parameter error (the return parameter packet address cannot be used)
[Description]
References the status of the rendezvous port designated in porid, passing in return parameters information
about the accepting task (atsk), information about a task waiting on a rendezvous call (wtsk),
maximum message sizes (maxcmsz, maxrmsz), and extended information (exinf).
wtsk indicates the ID of a task in WAIT state on rendezvous call at the rendezvous port. If there is no
task waiting on rendezvous call, wtsk = 0 is returned. atsk indicates the ID of a task in WAIT state
on rendezvous acceptance at the rendezvous port. If there is no task waiting for rendezvous acceptance,
atsk = 0 is returned. If there are multiple tasks waiting on rendezvous call or acceptance at this
rendezvous port, the ID of the task at the head of the call queue and accept queue is returned.
If the designated rendezvous port does not exist, error code E NOEXS is returned.
Copyright c○ 2002, 2003 by T-Engine Forum
T-Kernel 1.B0.02