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><A
NAME="COMPAT-UITRON-SYNC-AND-COMM-FUNCTIONS">Synchronization and Communication Functions</H1
><P
>These functions are fully supported in this release: </P
><TABLE
BORDER="5"
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><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>ER <TT
CLASS="FUNCTION"
>sig_sem</TT
>(
ID <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>semid</I
></SPAN
> )</PRE
></TD
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><TABLE
BORDER="5"
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><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>ER <TT
CLASS="FUNCTION"
>wai_sem</TT
>(
ID <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>semid</I
></SPAN
> )</PRE
></TD
></TR
></TABLE
><TABLE
BORDER="5"
BGCOLOR="#E0E0F0"
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><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>ER <TT
CLASS="FUNCTION"
>preq_sem</TT
>(
ID <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>semid</I
></SPAN
> )</PRE
></TD
></TR
></TABLE
><TABLE
BORDER="5"
BGCOLOR="#E0E0F0"
WIDTH="70%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>ER <TT
CLASS="FUNCTION"
>twai_sem</TT
>(
ID <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>semid,</I
></SPAN
> TMO <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>tmout</I
></SPAN
> )</PRE
></TD
></TR
></TABLE
><TABLE
BORDER="5"
BGCOLOR="#E0E0F0"
WIDTH="70%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>ER <TT
CLASS="FUNCTION"
>ref_sem</TT
>(
T_RSEM *<SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>pk_rsem ,</I
></SPAN
> ID <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>semid</I
></SPAN
> )</PRE
></TD
></TR
></TABLE
><TABLE
BORDER="5"
BGCOLOR="#E0E0F0"
WIDTH="70%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>ER <TT
CLASS="FUNCTION"
>set_flg</TT
>(
ID <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>flgid,</I
></SPAN
> UINT <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>setptn</I
></SPAN
> )</PRE
></TD
></TR
></TABLE
><TABLE
BORDER="5"
BGCOLOR="#E0E0F0"
WIDTH="70%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>ER <TT
CLASS="FUNCTION"
>clr_flg</TT
>(
ID <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>flgid,</I
></SPAN
> UINT <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>clrptn</I
></SPAN
> )</PRE
></TD
></TR
></TABLE
><TABLE
BORDER="5"
BGCOLOR="#E0E0F0"
WIDTH="70%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>ER <TT
CLASS="FUNCTION"
>wai_flg</TT
>(
UINT *<SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>p_flgptn,</I
></SPAN
> ID <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>flgid ,</I
></SPAN
>
UINT <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>waiptn ,</I
></SPAN
> UINT <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>wfmode</I
></SPAN
> )</PRE
></TD
></TR
></TABLE
><TABLE
BORDER="5"
BGCOLOR="#E0E0F0"
WIDTH="70%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>ER <TT
CLASS="FUNCTION"
>pol_flg</TT
>(
UINT *<SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>p_flgptn,</I
></SPAN
> ID <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>flgid ,</I
></SPAN
>
UINT <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>waiptn ,</I
></SPAN
> UINT <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>wfmode</I
></SPAN
> )</PRE
></TD
></TR
></TABLE
><TABLE
BORDER="5"
BGCOLOR="#E0E0F0"
WIDTH="70%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>ER <TT
CLASS="FUNCTION"
>twai_flg</TT
>(
UINT *<SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>p_flgptn</I
></SPAN
> ID <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>flgid ,</I
></SPAN
>
UINT <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>waiptn ,</I
></SPAN
> UINT <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>wfmode,</I
></SPAN
> TMO <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>tmout</I
></SPAN
> )</PRE
></TD
></TR
></TABLE
><TABLE
BORDER="5"
BGCOLOR="#E0E0F0"
WIDTH="70%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>ER <TT
CLASS="FUNCTION"
>ref_flg</TT
>(
T_RFLG *<SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>pk_rflg,</I
></SPAN
> ID <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>flgid</I
></SPAN
> )</PRE
></TD
></TR
></TABLE
><TABLE
BORDER="5"
BGCOLOR="#E0E0F0"
WIDTH="70%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>ER <TT
CLASS="FUNCTION"
>snd_msg</TT
>(
ID <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>mbxid,</I
></SPAN
> T_MSG <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>*pk_msg</I
></SPAN
> )</PRE
></TD
></TR
></TABLE
><TABLE
BORDER="5"
BGCOLOR="#E0E0F0"
WIDTH="70%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>ER <TT
CLASS="FUNCTION"
>rcv_msg</TT
>(
T_MSG **<SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>ppk_msg,</I
></SPAN
> ID <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>mbxid</I
></SPAN
> )</PRE
></TD
></TR
></TABLE
><TABLE
BORDER="5"
BGCOLOR="#E0E0F0"
WIDTH="70%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>ER <TT
CLASS="FUNCTION"
>prcv_msg</TT
>(
T_MSG **<SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>ppk_msg,</I
></SPAN
> ID <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>mbxid</I
></SPAN
> )</PRE
></TD
></TR
></TABLE
><TABLE
BORDER="5"
BGCOLOR="#E0E0F0"
WIDTH="70%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>ER <TT
CLASS="FUNCTION"
>trcv_msg</TT
>(
T_MSG **<SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>ppk_msg,</I
></SPAN
> ID <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>mbxid ,</I
></SPAN
> TMO <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>tmout</I
></SPAN
> )</PRE
></TD
></TR
></TABLE
><TABLE
BORDER="5"
BGCOLOR="#E0E0F0"
WIDTH="70%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>ER <TT
CLASS="FUNCTION"
>ref_mbx</TT
>(
T_RMBX *<SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>pk_rmbx,</I
></SPAN
> ID <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>mbxid</I
></SPAN
> )</PRE
></TD
></TR
></TABLE
><P
>The following functions are supported in this release (with
some restrictions) if enabled with the appropriate configuration
option for the object type (for example
<TT
CLASS="LITERAL"
>CYGPKG_UITRON_SEMAS_CREATE_DELETE</TT
>):</P
><TABLE
BORDER="5"
BGCOLOR="#E0E0F0"
WIDTH="70%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>ER <TT
CLASS="FUNCTION"
>cre_sem</TT
>(
ID <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>semid,</I
></SPAN
> T_CSEM *<SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>pk_csem</I
></SPAN
> )</PRE
></TD
></TR
></TABLE
><TABLE
BORDER="5"
BGCOLOR="#E0E0F0"
WIDTH="70%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>ER <TT
CLASS="FUNCTION"
>del_sem</TT
>(
ID <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>semid</I
></SPAN
> )</PRE
></TD
></TR
></TABLE
><TABLE
BORDER="5"
BGCOLOR="#E0E0F0"
WIDTH="70%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>ER <TT
CLASS="FUNCTION"
>cre_flg</TT
>(
ID <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>flgid,</I
></SPAN
> T_CFLG *<SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>pk_cflg</I
></SPAN
> )</PRE
></TD
></TR
></TABLE
><TABLE
BORDER="5"
BGCOLOR="#E0E0F0"
WIDTH="70%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>ER <TT
CLASS="FUNCTION"
>del_flg</TT
>(
ID <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>flgid</I
></SPAN
> )</PRE
></TD
></TR
></TABLE
><TABLE
BORDER="5"
BGCOLOR="#E0E0F0"
WIDTH="70%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>ER <TT
CLASS="FUNCTION"
>cre_mbx</TT
>(
ID <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>mbxid,</I
></SPAN
> T_CMBX *<SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>pk_cmbx</I
></SPAN
> )</PRE
></TD
></TR
></TABLE
><TABLE
BORDER="5"
BGCOLOR="#E0E0F0"
WIDTH="70%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>ER <TT
CLASS="FUNCTION"
>del_mbx</TT
>(
ID <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>mbxid</I
></SPAN
> )</PRE
></TD
></TR
></TABLE
><P
>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 (<TT
CLASS="LITERAL"
>pk_cxxx->xxxatr = TA_TPRI</TT
>)
are rejected with E_RSATR. Additional undefined bits in
the attributes fields must be zero. </P
><P
>In general, extended information (pk_cxxx->exinf)
is ignored. </P
><P
>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. </P
><P
>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. </P
><P
>For mailboxes, the buffer count is defined statically by kernel
configuration option
<TT
CLASS="LITERAL"
>CYGNUM_KERNEL_SYNCH_MBOX_QUEUE_SIZE</TT
>;
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. </P
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN13716">Error checking</H2
><P
>The following conditions are only checked for, and only return
errors if
<TT
CLASS="LITERAL"
>CYGSEM_UITRON_BAD_PARAMS_RETURN_ERRORS</TT
>
is enabled:</P
><P
></P
><UL
><LI
><P
>invalid object id; less than 1 or greater than
<TT
CLASS="LITERAL"
>CYGNUM_UITRON_TASKS/SEMAS/MBOXES</TT
>
as appropriate returns E_ID</P
></LI
><LI
><P
>dispatching is enabled in any call which can sleep, or
E_CTX</P
></LI
><LI
><P
>tmout must be positive, otherwise E_PAR</P
></LI
><LI
><P
>pk_cxxx pointers in
<TT
CLASS="FUNCTION"
>cre_xxx()</TT
>
must be valid pointers, or E_PAR</P
></LI
><LI
><P
>return value pointer in
<TT
CLASS="FUNCTION"
>ref_xxx()</TT
>
is valid pointer, or E_PAR</P
></LI
><LI
><P
>flag wait pattern must be non-zero, and mode must be valid,
or E_PAR</P
></LI
><LI
><P
>return value pointer in flag wait calls is a valid pointer,
or E_PAR</P
></LI
></UL
><P
>The following conditions are checked for, and can return error
codes, regardless of the setting of
<TT
CLASS="LITERAL"
>CYGSEM_UITRON_BAD_PARAMS_RETURN_ERRORS</TT
>
:</P
><P
></P
><UL
><LI
><P
>When create and delete functions
<TT
CLASS="FUNCTION"
>cre_xxx()</TT
>
and
<TT
CLASS="FUNCTION"
>del_xxx()</TT
>
are supported, all calls which use a valid object ID number check
that the object exists. If not, E_NOEXS is returned.</P
></LI
><LI
><P
>In create functions
<TT
CLASS="FUNCTION"
>cre_xxx()</TT
>
, when supported, if the object already exists, then E_OBJ</P
></LI
><LI
><P
>In any call which can sleep, such as
<TT
CLASS="FUNCTION"
>twai_sem()</TT
>
: return codes E_TMOUT, E_RLWAI, E_DLT
or of course E_OK are returned depending on the reason
for terminating the sleep</P
></LI
><LI
><P
>In polling functions such as
<TT
CLASS="FUNCTION"
>preq_sem()</TT
>
return codes E_TMOUT or E_OK are returned depending
on the state of the synchronization object</P
></LI
><LI
><P
>In creation functions, the attributes must be compatible
with the selected underlying kernel configuration: in
<TT
CLASS="FUNCTION"
>cre_sem()</TT
>
<TT
CLASS="LITERAL"
>pk_csem->sematr</TT
>
must be equal to
<TT
CLASS="LITERAL"
>TA_TFIFO</TT
>
else E_RSATR.</P
></LI
><LI
><P
>In
<TT
CLASS="FUNCTION"
>cre_flg()</TT
>
<TT
CLASS="LITERAL"
>pk_cflg->flgatr</TT
>
must be either
<TT
CLASS="VARNAME"
>TA_WMUL</TT
>
or
<TT
CLASS="VARNAME"
>TA_WSGL</TT
>
else <TT
CLASS="VARNAME"
>E_RSATR</TT
>.</P
></LI
><LI
><P
>In
<TT
CLASS="FUNCTION"
>cre_mbx()</TT
>
<TT
CLASS="LITERAL"
>pk_cmbx->mbxatr</TT
>
must be
<TT
CLASS="LITERAL"
>TA_TFIFO + TA_MFIFO</TT
>
else E_RSATR.</P
></LI
></UL
></DIV
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