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7<TITLE>OS_GetIrqStackStatus</TITLE>
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11<H1 align="left">OS_GetIrqStackStatus <IMG src="../../image/NTR.gif" align="middle"><IMG src="../../image/TWL.gif" align="middle"></H1>
12<H2>Syntax</H2>
13<DL>
14  <DD>
15  <PRE><CODE>#include &lt;nitro/os.h&gt;</CODE></PRE>
16  <PRE><CODE>OSStackStatus OS_GetIrqStackStatus( void );
17 </CODE></PRE>
18</DL>
19<H2>Arguments</H2>
20<P>None.</P>
21<H2>Return Values</H2>
22<P><code>OS_STACK_OVERFLOW</code> &mdash; The magic number at the bottom of the stack is rewritten.<br /><code>OS_STACK_UNDERFLOW</code> &mdash; The magic number at the top of the stack is rewritten.<br /><code>OS_STACK_ABOUT_TO_OVERFLOW</code> &mdash; The warning level magic number set by the user is rewritten.</P>
23<P>When none of the previous cases apply, returns <code>OS_STACK_NO_ERROR</code> (defined as <code>0</code>).</P>
24<H2>Description</H2>
25<P>Checks the stack used for IRQ mode for stack leaks and checks stack status.</P>
26<P>This function checks a magic number that is preset in the top and bottom (in addition, a warning level if set by the user) of the stack, to see whether it is overwritten (if that portion is ever used).</P>
27<P>If the magic number at the bottom of the stack is overwritten, it returns <code>OS_STACK_OVERFLOW</code>.<br />If the magic number at the top of the stack is overwritten, it returns <code>OS_STACK_UNDERFLOW</code>.<br />If the magic number at the warning level set by the user in the stack is overwritten, it returns <code>OS_STACK_ABOUT_TO_OVERFLOW</code>.</P>
28<P>The stack is checked in this order so that <code>OS_STACK_OVERFLOW</code> is returned when both the top and bottom of the stack are overwritten.   </P>
29<P>If none of these condition are met (none of the magic numbers have been overwritten), <CODE>OS_STACK_NO_ERROR</CODE> is returned. <CODE>OS_STACK_NO_ERROR</CODE> is defined as 0, so whether an error has occurred can be determined by whether the value is 0 or non-zero.</P>
30
31<H2>See Also</H2>
32<P><CODE><A href="OS_SetIrqStackWarningOffset.html">OS_SetIrqStackWarningOffset</A>, <A href="OS_CheckIrqStack.html">OS_CheckIrqStack</A><BR></CODE></P>
33<H2>Revision History</H2>
34<P>2005/07/15 Initial version.</P>
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