T-Kernel Specification (1.B0.02)

4.5. EXTENDED SYNCHRONIZATION AND COMMUNICATION FUNCTIONS 115
tk ref mtx
Refer Mutex Status
[C Language Interface]
ER ercd = tk_ref_mtx ( ID mtxid, T_RMTX *pk_rmtx ) ;
[Parameters]
ID mtxid Mutex ID
T RMTX* pk rmtx Address of packet for returning status information
[Return Parameters]
ER ercd Error code
pk rmtx detail:
VP exinf Extended information
ID htsk ID of task locking the mutex
ID wtsk ID of tasks waiting to lock the mutex
(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 (mtxid is invalid or cannot be used)
Object does not exist (the mutex designated in mtxid does not exist)
Parameter error (the return parameter packet address cannot be used)
[Description]
References the status of the mutex designated in mtxid, passing in the return parameters the task
currently locking the mutex (htsk), tasks waiting to lock the mutex (wtsk), and extended information
(exinf).
htsk returns the ID of the task locking the mutex. If no task is locking it, htsk = 0 is returned.
wtsk indicates the ID of a task waiting to lock the mutex. If there are multiple waiting tasks, the ID of
the task at the head of the queue is returned. If no tasks are waiting, wtsk = 0 is returned.
If the designated mutex does not exist, error code E NOEXS is returned.
Copyright c○ 2002, 2003 by T-Engine Forum
T-Kernel 1.B0.02