T-Kernel Specification (1.B0.02)

4.5. EXTENDED SYNCHRONIZATION AND COMMUNICATION FUNCTIONS 109
tk cre mtx
Create Mutex
[C Language Interface]
ID mtxid = tk_cre_mtx ( T_CMTX *pk_cmtx ) ;
[Parameters]
T CMTX* pk cmtx Information about the mutex to be created
pk cmtx detail:
VP exinf Extended information
ATR mtxatr Mutex attributes
PRI ceilpri Mutex ceiling priority
(Other implementation-dependent parameters may be added beyond this point.)
[Return Parameters]
ID mtxid Mutex ID
or Error Code
[Error Codes]
E OK
E NOMEM
E LIMIT
E RSATR
E PAR
Normal completion
Insufficient memory (memory for control block cannot be allocated)
Number of mutexes exceeds the system limit
Reserved attribute (mtxatr is invalid or cannot be used)
Parameter error (pk cmtx or ceilpri is invalid)
[Description]
Creates a mutex, assigning to it a mutex ID.
exinf can be used freely by the user to set miscellaneous information about the created mutex. The
information set in this parameter can be referenced by tk ref mtx. If a larger area is needed for
indicating user information, or if the information may need to be changed after the mutex is created,
this can be done by allocating separate memory for this purpose and putting the memory packet address
in exinf. The OS pays no attention to the contents of exinf.
mtxatr indicates system attributes in its low bits and implementation-dependent information in the
high bits. Designation in the system attributes part of mtxatr is as follows.
mtxatr:= (TA_TFIFO || TA_TPRI || TA_INHERIT || TA_CEILING)| [TA_NODISWAI]
Copyright c○ 2002, 2003 by T-Engine Forum
T-Kernel 1.B0.02