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+<HTML
+><HEAD
+><TITLE
+>Task Management Functions</TITLE
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+TITLE="eCos Reference Manual"
+HREF="ecos-ref.html"><LINK
+REL="UP"
+TITLE="µITRON API"
+HREF="compat-uitron-microitron-api.html"><LINK
+REL="PREVIOUS"
+TITLE="µITRON and eCos"
+HREF="compat-uitron-over-ecos.html"><LINK
+REL="NEXT"
+TITLE="Task-Dependent Synchronization Functions"
+HREF="compat-uitron-task-dependent-synch-functions.html"></HEAD
+><BODY
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+WIDTH="100%"
+BORDER="0"
+CELLPADDING="0"
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+><TR
+><TH
+COLSPAN="3"
+ALIGN="center"
+>eCos Reference Manual</TH
+></TR
+><TR
+><TD
+WIDTH="10%"
+ALIGN="left"
+VALIGN="bottom"
+><A
+HREF="compat-uitron-over-ecos.html"
+ACCESSKEY="P"
+>Prev</A
+></TD
+><TD
+WIDTH="80%"
+ALIGN="center"
+VALIGN="bottom"
+>Chapter 32. µITRON API</TD
+><TD
+WIDTH="10%"
+ALIGN="right"
+VALIGN="bottom"
+><A
+HREF="compat-uitron-task-dependent-synch-functions.html"
+ACCESSKEY="N"
+>Next</A
+></TD
+></TR
+></TABLE
+><HR
+ALIGN="LEFT"
+WIDTH="100%"></DIV
+><DIV
+CLASS="SECT1"
+><H1
+CLASS="SECT1"
+><A
+NAME="COMPAT-UITRON-TASK-MANAGEMENT-FUNCTIONS">Task Management Functions</H1
+><P
+>The following functions are fully supported in this release: </P
+><TABLE
+BORDER="5"
+BGCOLOR="#E0E0F0"
+WIDTH="70%"
+><TR
+><TD
+><PRE
+CLASS="PROGRAMLISTING"
+>ER <TT
+CLASS="FUNCTION"
+>sta_tsk</TT
+>(
+ ID <SPAN
+CLASS="emphasis"
+><I
+CLASS="EMPHASIS"
+>tskid,</I
+></SPAN
+>
+ INT <SPAN
+CLASS="emphasis"
+><I
+CLASS="EMPHASIS"
+>stacd</I
+></SPAN
+> )</PRE
+></TD
+></TR
+></TABLE
+><TABLE
+BORDER="5"
+BGCOLOR="#E0E0F0"
+WIDTH="70%"
+><TR
+><TD
+><PRE
+CLASS="PROGRAMLISTING"
+>void <TT
+CLASS="FUNCTION"
+>ext_tsk</TT
+>( void )</PRE
+></TD
+></TR
+></TABLE
+><TABLE
+BORDER="5"
+BGCOLOR="#E0E0F0"
+WIDTH="70%"
+><TR
+><TD
+><PRE
+CLASS="PROGRAMLISTING"
+>void <TT
+CLASS="FUNCTION"
+>exd_tsk</TT
+>( void )</PRE
+></TD
+></TR
+></TABLE
+><TABLE
+BORDER="5"
+BGCOLOR="#E0E0F0"
+WIDTH="70%"
+><TR
+><TD
+><PRE
+CLASS="PROGRAMLISTING"
+>ER <TT
+CLASS="FUNCTION"
+>dis_dsp</TT
+>( void )</PRE
+></TD
+></TR
+></TABLE
+><TABLE
+BORDER="5"
+BGCOLOR="#E0E0F0"
+WIDTH="70%"
+><TR
+><TD
+><PRE
+CLASS="PROGRAMLISTING"
+>ER <TT
+CLASS="FUNCTION"
+>ena_dsp</TT
+>( void )</PRE
+></TD
+></TR
+></TABLE
+><TABLE
+BORDER="5"
+BGCOLOR="#E0E0F0"
+WIDTH="70%"
+><TR
+><TD
+><PRE
+CLASS="PROGRAMLISTING"
+>ER <TT
+CLASS="FUNCTION"
+>chg_pri</TT
+>(
+ ID <SPAN
+CLASS="emphasis"
+><I
+CLASS="EMPHASIS"
+>tskid,</I
+></SPAN
+>
+ PRI <SPAN
+CLASS="emphasis"
+><I
+CLASS="EMPHASIS"
+>tskpri</I
+></SPAN
+> )</PRE
+></TD
+></TR
+></TABLE
+><TABLE
+BORDER="5"
+BGCOLOR="#E0E0F0"
+WIDTH="70%"
+><TR
+><TD
+><PRE
+CLASS="PROGRAMLISTING"
+>ER <TT
+CLASS="FUNCTION"
+>rot_rdq</TT
+>(
+ PRI <SPAN
+CLASS="emphasis"
+><I
+CLASS="EMPHASIS"
+>tskpri</I
+></SPAN
+> )</PRE
+></TD
+></TR
+></TABLE
+><TABLE
+BORDER="5"
+BGCOLOR="#E0E0F0"
+WIDTH="70%"
+><TR
+><TD
+><PRE
+CLASS="PROGRAMLISTING"
+>ER <TT
+CLASS="FUNCTION"
+>get_tid</TT
+>(
+ ID *<SPAN
+CLASS="emphasis"
+><I
+CLASS="EMPHASIS"
+>p_tskid</I
+></SPAN
+> )</PRE
+></TD
+></TR
+></TABLE
+><TABLE
+BORDER="5"
+BGCOLOR="#E0E0F0"
+WIDTH="70%"
+><TR
+><TD
+><PRE
+CLASS="PROGRAMLISTING"
+>ER <TT
+CLASS="FUNCTION"
+>ref_tsk</TT
+>(
+ T_RTSK *<SPAN
+CLASS="emphasis"
+><I
+CLASS="EMPHASIS"
+>pk_rtsk,</I
+></SPAN
+>
+ ID <SPAN
+CLASS="emphasis"
+><I
+CLASS="EMPHASIS"
+>tskid</I
+></SPAN
+> )</PRE
+></TD
+></TR
+></TABLE
+><TABLE
+BORDER="5"
+BGCOLOR="#E0E0F0"
+WIDTH="70%"
+><TR
+><TD
+><PRE
+CLASS="PROGRAMLISTING"
+>ER <TT
+CLASS="FUNCTION"
+>ter_tsk</TT
+>(
+ ID <SPAN
+CLASS="emphasis"
+><I
+CLASS="EMPHASIS"
+>tskid</I
+></SPAN
+> )</PRE
+></TD
+></TR
+></TABLE
+><TABLE
+BORDER="5"
+BGCOLOR="#E0E0F0"
+WIDTH="70%"
+><TR
+><TD
+><PRE
+CLASS="PROGRAMLISTING"
+>ER <TT
+CLASS="FUNCTION"
+>rel_wai</TT
+>(
+ ID <SPAN
+CLASS="emphasis"
+><I
+CLASS="EMPHASIS"
+>tskid</I
+></SPAN
+> )</PRE
+></TD
+></TR
+></TABLE
+><P
+>The following two functions are supported in this release,
+when enabled with the configuration option
+<TT
+CLASS="LITERAL"
+>CYGPKG_UITRON_TASKS_CREATE_DELETE</TT
+>
+with some restrictions:</P
+><TABLE
+BORDER="5"
+BGCOLOR="#E0E0F0"
+WIDTH="70%"
+><TR
+><TD
+><PRE
+CLASS="PROGRAMLISTING"
+>ER <TT
+CLASS="FUNCTION"
+>cre_tsk</TT
+>(
+ ID <SPAN
+CLASS="emphasis"
+><I
+CLASS="EMPHASIS"
+>tskid,</I
+></SPAN
+>
+ T_CTSK *<SPAN
+CLASS="emphasis"
+><I
+CLASS="EMPHASIS"
+>pk_ctsk</I
+></SPAN
+> )</PRE
+></TD
+></TR
+></TABLE
+><TABLE
+BORDER="5"
+BGCOLOR="#E0E0F0"
+WIDTH="70%"
+><TR
+><TD
+><PRE
+CLASS="PROGRAMLISTING"
+>ER <TT
+CLASS="FUNCTION"
+>del_tsk</TT
+>(
+ ID <SPAN
+CLASS="emphasis"
+><I
+CLASS="EMPHASIS"
+>tskid</I
+></SPAN
+> )</PRE
+></TD
+></TR
+></TABLE
+><P
+>These functions are restricted as follows:</P
+><P
+>Because of the static initialization facilities provided for
+system objects, a task is allocated stack space statically in the
+configuration. So while tasks can be created and deleted, the same
+stack space is used for that task (task ID number) each time. Thus
+the stack size (pk_ctsk->stksz) requested in <TT
+CLASS="FUNCTION"
+>cre_tsk()</TT
+> is
+checked for being less than that which was statically allocated,
+and otherwise ignored. This ensures that the new task will have
+enough stack to run. For this reason <TT
+CLASS="FUNCTION"
+>del_tsk()</TT
+> does
+not in any sense free the memory that was in use for the task's
+stack. </P
+><P
+>The task attributes (pk_ctsk->tskatr) are
+ignored; current versions of <SPAN
+CLASS="emphasis"
+><I
+CLASS="EMPHASIS"
+>eCos</I
+></SPAN
+> do not need
+to know whether a task is written in assembler or C/C++ so
+long as the procedure call standard appropriate to the CPU is followed.</P
+><P
+>Extended information (pk_ctsk->exinf) is
+ ignored.</P
+><DIV
+CLASS="SECT2"
+><H2
+CLASS="SECT2"
+><A
+NAME="AEN13490">Error checking</H2
+><P
+>For all these calls, an invalid task id (tskid) (less than
+1 or greater than the number of configured tasks) only returns E_ID
+when bad params return errors (
+<TT
+CLASS="LITERAL"
+>CYGSEM_UITRON_BAD_PARAMS_RETURN_ERRORS</TT
+>
+is enabled, see above).</P
+><P
+>Similarly, 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
+>pk_crtk in
+<TT
+CLASS="FUNCTION"
+>cre_tsk()</TT
+>
+ is a valid pointer, otherwise return E_PAR</P
+></LI
+><LI
+><P
+><TT
+CLASS="FUNCTION"
+>ter_tsk()</TT
+>
+ or
+<TT
+CLASS="FUNCTION"
+>rel_wai()</TT
+>
+ on the calling task returns E_OBJ</P
+></LI
+><LI
+><P
+>the CPU is not locked already in
+<TT
+CLASS="FUNCTION"
+>dis_dsp()</TT
+>
+ and
+<TT
+CLASS="FUNCTION"
+>ena_dsp()</TT
+>
+; returns E_CTX</P
+></LI
+><LI
+><P
+>priority level in
+<TT
+CLASS="FUNCTION"
+>chg_pri()</TT
+>
+ and
+<TT
+CLASS="FUNCTION"
+>rot_rdq()</TT
+>
+ is checked for validity, E_PAR</P
+></LI
+><LI
+><P
+>return value pointer in
+<TT
+CLASS="FUNCTION"
+>get_tid()</TT
+>
+ and
+<TT
+CLASS="FUNCTION"
+>ref_tsk()</TT
+>
+ is a valid pointer, or E_PAR</P
+></LI
+></UL
+><P
+>The following conditions are checked for, and return
+ error codes if appropriate, 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_tsk()</TT
+>
+ and
+<TT
+CLASS="FUNCTION"
+>del_tsk()</TT
+>
+ are supported, all calls which use a valid task ID number check
+that the task exists; if not, E_NOEXS is returned</P
+></LI
+><LI
+><P
+>When supported,
+<TT
+CLASS="FUNCTION"
+>cre_tsk()</TT
+>
+: the task must not already exist; otherwise E_OBJ</P
+></LI
+><LI
+><P
+>When supported,
+<TT
+CLASS="FUNCTION"
+>cre_tsk()</TT
+>
+: the requested stack size must not be larger than that statically
+configured for the task; see the configuration options
+“Static initializers”, and “Default stack size”.
+Else E_NOMEM</P
+></LI
+><LI
+><P
+>When supported,
+<TT
+CLASS="FUNCTION"
+>del_tsk()</TT
+>
+: the underlying
+<SPAN
+CLASS="emphasis"
+><I
+CLASS="EMPHASIS"
+>eCos</I
+></SPAN
+>
+ thread must not be running - this would imply either a bug or some
+program bypassing the
+µITRON compatibility layer and manipulating the thread directly.
+E_OBJ</P
+></LI
+><LI
+><P
+><TT
+CLASS="FUNCTION"
+>sta_tsk()</TT
+>
+: the task must be dormant, else E_OBJ</P
+></LI
+><LI
+><P
+><TT
+CLASS="FUNCTION"
+>ter_tsk()</TT
+>
+: the task must not be dormant, else E_OBJ</P
+></LI
+><LI
+><P
+><TT
+CLASS="FUNCTION"
+>chg_pri()</TT
+>
+: the task must not be dormant, else E_OBJ</P
+></LI
+><LI
+><P
+><TT
+CLASS="FUNCTION"
+>rel_wai()</TT
+>
+: the task must be in
+<TT
+CLASS="VARNAME"
+>WAIT</TT
+> or <TT
+CLASS="VARNAME"
+>WAIT-SUSPEND</TT
+>
+ state, else E_OBJ</P
+></LI
+></UL
+></DIV
+></DIV
+><DIV
+CLASS="NAVFOOTER"
+><HR
+ALIGN="LEFT"
+WIDTH="100%"><TABLE
+SUMMARY="Footer navigation table"
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+VALIGN="top"
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+HREF="compat-uitron-over-ecos.html"
+ACCESSKEY="P"
+>Prev</A
+></TD
+><TD
+WIDTH="34%"
+ALIGN="center"
+VALIGN="top"
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+ACCESSKEY="H"
+>Home</A
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+><TD
+WIDTH="33%"
+ALIGN="right"
+VALIGN="top"
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+WIDTH="33%"
+ALIGN="left"
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+CLASS="emphasis"
+><I
+CLASS="EMPHASIS"
+>eCos</I
+></SPAN
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+WIDTH="34%"
+ALIGN="center"
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+>Task-Dependent Synchronization Functions</TD
+></TR
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+>
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