<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> <title>Thread Safety</title> <link rel="stylesheet" href="../../../../../../../doc/src/boostbook.css" type="text/css"> <meta name="generator" content="DocBook XSL Stylesheets V1.74.0"> <link rel="home" href="../../index.html" title="Math Toolkit"> <link rel="up" href="../main_overview.html" title="Overview"> <link rel="prev" href="pol_overview.html" title="Configuration and Policies"> <link rel="next" href="perf_over.html" title="Performance"> </head> <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> <table cellpadding="2" width="100%"><tr> <td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../../boost.png"></td> <td align="center"><a href="../../../../../../../index.html">Home</a></td> <td align="center"><a href="../../../../../../../libs/libraries.htm">Libraries</a></td> <td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> <td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> <td align="center"><a href="../../../../../../../more/index.htm">More</a></td> </tr></table> <hr> <div class="spirit-nav"> <a accesskey="p" href="pol_overview.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../main_overview.html"><img src="../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="perf_over.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a> </div> <div class="section" lang="en"> <div class="titlepage"><div><div><h3 class="title"> <a name="math_toolkit.main_overview.threads"></a><a class="link" href="threads.html" title="Thread Safety"> Thread Safety</a> </h3></div></div></div> <p> The library is fully thread safe and re-entrant provided the function and class templates in the library are instantiated with built-in floating point types: i.e. the types <code class="computeroutput"><span class="keyword">float</span></code>, <code class="computeroutput"><span class="keyword">double</span></code> and <code class="computeroutput"><span class="keyword">long</span> <span class="keyword">double</span></code>. </p> <p> However, the library <span class="bold"><strong>is not thread safe</strong></span> when used with user-defined (i.e. class type) numeric types. </p> <p> The reason for the latter limitation is the need to initialise symbolic constants using constructs such as: </p> <pre class="programlisting"><span class="keyword">static</span> <span class="keyword">const</span> <span class="identifier">T</span> <span class="identifier">coefficient_array</span> <span class="special">=</span> <span class="special">{</span> <span class="special">...</span> <span class="identifier">list</span> <span class="identifier">of</span> <span class="identifier">values</span> <span class="special">...</span> <span class="special">};</span> </pre> <p> Which is always thread safe when T is a built-in floating point type, but not when T is a user defined type: as in this case there is a need for T's constructors to be run, leading to potential race conditions. </p> <p> This limitation may be addressed in a future release. </p> </div> <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> <td align="left"></td> <td align="right"><div class="copyright-footer">Copyright © 2006 , 2007, 2008, 2009 John Maddock, Paul A. Bristow, Hubert Holin, Xiaogang Zhang, Bruno Lalande, Johan Råde, Gautam Sewani and Thijs van den Berg<p> Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) </p> </div></td> </tr></table> <hr> <div class="spirit-nav"> <a accesskey="p" href="pol_overview.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../main_overview.html"><img src="../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="perf_over.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a> </div> </body> </html>