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):
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; 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 pointers, or E_PAR
return value pointer in ref_xxx() is 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.
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.