These functions are fully supported in this release:
ER sig_sem
(ID semid);ER wai_sem
(ID semid);ER preq_sem
(ID semid);ER twai_sem
(ID semid, TMO tmout);ER ref_sem
(T_RSEM *pk_rsem , ID semid);ER set_flg
(ID flgid, UINT setptn);ER clr_flg
(ID flgid, UINT clrptn);ER wai_flg
(UINT *p_flgptn, ID flgid , UINT waiptn , UINT wfmode);ER pol_flg
(UINT *p_flgptn, ID flgid , UINT waiptn , UINT wfmode);ER twai_flg
(UINT *p_flgptn, ID flgid , UINT waiptn , UINT wfmode, TMO tmout);ER ref_flg
(T_RFLG *pk_rflg, ID flgid);ER snd_msg
(ID mbxid, T_MSG *pk_msg);ER rcv_msg
(T_MSG **ppk_msg, ID mbxid);ER prcv_msg
(T_MSG **ppk_msg, ID mbxid);ER trcv_msg
(T_MSG **ppk_msg, ID mbxid , TMO tmout);ER ref_mbx
(T_RMBX *pk_rmbx, ID mbxid);The following functions are supported in this release (with some restrictions) if enabled with the appropriate configuration option for the object type (for example CYGPKG_UITRON_SEMAS_CREATE_DELETE) (see the section called Component: Support create and delete in Chapter 18):
ER cre_sem
(ID semid, T_CSEM *pk_csem);ER del_sem
(ID semid);ER cre_flg
(ID flgid, T_CFLG *pk_cflg);ER del_flg
(ID flgid);ER cre_mbx
(ID mbxid, T_CMBX *pk_cmbx);ER del_mbx
(ID mbxid);In general the queueing order when waiting on a synchronization object depends on the underlying kernel configuration. The multi-level queue scheduler is required for strict µITRON conformance and it queues tasks in FIFO order, so requests to create an object with priority queueing of tasks (pk_cxxx->xxxatr = TA_TPRI) are rejected with E_RSATR. Additional undefined bits in the attributes fields must be zero.
In general, extended information (pk_cxxx->exinf) is ignored.
For semaphores, the initial semaphore count (pk_csem->isemcnt) is supported; the new semaphore"s count is set. The maximum count is not supported, and is not in fact defined in type pk_csem.
For flags, multiple tasks are allowed to wait. Because single task waiting is a subset of this, the W bit (TA_WMUL) of the flag attributes is ignored; all other bits must be zero. The initial flag value is supported.
For mailboxes, the buffer count is defined statically by kernel configuration option CYGNUM_KERNEL_SYNCH_MBOX_QUEUE_SIZE (see the section called Component: Synchronization primitives in Chapter 17); therefore the buffer count field is not supported and is not in fact defined in type pk_cmbx. Queueing of messages is FIFO ordered only, so TA_MPRI (in pk_cmbx->mbxatr) is not supported.
The following conditions are only checked for, and only return errors if CYGSEM_UITRON_BAD_PARAMS_RETURN_ERRORS is enabled:
invalid object id; less than 1 or greater than CYGNUM_UITRON_TASKS/SEMAS/MBOXES as appropriate returns E_ID
dispatching is enabled in any call which can sleep, or E_CTX
tmout must be positive, otherwise E_PAR
pk_cxxx pointers in cre_xxx() must be valid pointer, or E_PAR
return value pointers in ref_xxx() is a valid pointer, or E_PAR
flag wait pattern must be non-zero, and mode must be valid, or E_PAR
return value pointer in flag wait calls is a valid pointer, or E_PAR
The following conditions are checked for, and can return error codes, regardless of the setting of CYGSEM_UITRON_BAD_PARAMS_RETURN_ERRORS:
When create and delete functions cre_xxx() and del_xxx() are supported, all calls which use a valid object ID number check that the object exists. If not, E_NOEXS is returned; see the section called Component: Support create and delete in Chapter 18.
In create functions cre_xxx(), when supported, if the object already exists, then E_OBJ
In any call which can sleep, such as twai_sem(): return codes E_TMOUT, E_RLWAI, E_DLT or of course E_OK are returned depending on the reason for terminating the sleep
In polling functions such as preq_sem()return codes E_TMOUT or E_OK are returned depending on the state of the synchronization object
In creation functions, the attributes must be compatible with the selected underlying kernel configuration: in cre_sem() pk_csem->sematr must be equal to TA_TFIFO else E_RSATR.
In cre_flg() pk_cflg->flgatr must be either TA_WMUL or TA_WSGL else E_RSATR.
In cre_mbx() pk_cmbx->mbxatr must be TA_TFIFO + TA_MFIFO else E_RSATR.