visus
/
toolchain-gcc-arm-embedded

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<!-- Created by GNU Texinfo 6.5, http://www.gnu.org/software/texinfo/ -->
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Reentrancy (LIBM)</title>

<meta name="description" content="Reentrancy (LIBM)">
<meta name="keywords" content="Reentrancy (LIBM)">
<meta name="resource-type" content="document">
<meta name="distribution" content="global">
<meta name="Generator" content="makeinfo">
<link href="index.html#Top" rel="start" title="Top">
<link href="Document-Index.html#Document-Index" rel="index" title="Document Index">
<link href="Document-Index.html#SEC_Contents" rel="contents" title="Table of Contents">
<link href="index.html#Top" rel="up" title="Top">
<link href="Long-Double-Functions.html#Long-Double-Functions" rel="next" title="Long Double Functions">
<link href="feupdateenv.html#feupdateenv" rel="prev" title="feupdateenv">
<style type="text/css">
<!--
a.summary-letter {text-decoration: none}
blockquote.indentedblock {margin-right: 0em}
blockquote.smallindentedblock {margin-right: 0em; font-size: smaller}
blockquote.smallquotation {font-size: smaller}
div.display {margin-left: 3.2em}
div.example {margin-left: 3.2em}
div.lisp {margin-left: 3.2em}
div.smalldisplay {margin-left: 3.2em}
div.smallexample {margin-left: 3.2em}
div.smalllisp {margin-left: 3.2em}
kbd {font-style: oblique}
pre.display {font-family: inherit}
pre.format {font-family: inherit}
pre.menu-comment {font-family: serif}
pre.menu-preformatted {font-family: serif}
pre.smalldisplay {font-family: inherit; font-size: smaller}
pre.smallexample {font-size: smaller}
pre.smallformat {font-family: inherit; font-size: smaller}
pre.smalllisp {font-size: smaller}
span.nolinebreak {white-space: nowrap}
span.roman {font-family: initial; font-weight: normal}
span.sansserif {font-family: sans-serif; font-weight: normal}
ul.no-bullet {list-style: none}
-->
</style>


</head>

<body lang="en">
<a name="Reentrancy"></a>
<div class="header">
<p>
Next: <a href="Long-Double-Functions.html#Long-Double-Functions" accesskey="n" rel="next">Long Double Functions</a>, Previous: <a href="Fenv.html#Fenv" accesskey="p" rel="prev">Fenv</a>, Up: <a href="index.html#Top" accesskey="u" rel="up">Top</a> &nbsp; [<a href="Document-Index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Document-Index.html#Document-Index" title="Index" rel="index">Index</a>]</p>
</div>
<hr>
<a name="Reentrancy-Properties-of-libm"></a>
<h2 class="chapter">4 Reentrancy Properties of <code>libm</code></h2>

<a name="index-reentrancy"></a>
<a name="index-matherr-and-reentrancy"></a>
<p>When a libm function detects an exceptional case, <code>errno</code> may be
set.
</p>

<p><code>errno</code> is a macro which expands to the per-thread error value.
This makes it thread safe, and therefore reentrant.
</p>


</body>
</html>