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, 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 15), with some restrictions:
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 14); 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, or non-existent object, returns E_ID or E_NOEXS
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