1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>Thread Safety</title> 5<link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css"> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="../../index.html" title="Boost.Regex 5.1.4"> 8<link rel="up" href="../background.html" title="Background Information"> 9<link rel="prev" href="locale.html" title="Localization"> 10<link rel="next" href="examples.html" title="Test and Example Programs"> 11</head> 12<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 13<table cellpadding="2" width="100%"><tr> 14<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td> 15<td align="center"><a href="../../../../../../index.html">Home</a></td> 16<td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td> 17<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> 18<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 19<td align="center"><a href="../../../../../../more/index.htm">More</a></td> 20</tr></table> 21<hr> 22<div class="spirit-nav"> 23<a accesskey="p" href="locale.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../background.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="examples.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h3 class="title"> 27<a name="boost_regex.background.thread_safety"></a><a class="link" href="thread_safety.html" title="Thread Safety">Thread Safety</a> 28</h3></div></div></div> 29<p> 30 The Boost.Regex library is thread safe when Boost is: you can verify that 31 Boost is in thread safe mode by checking to see if <code class="computeroutput"><span class="identifier">BOOST_HAS_THREADS</span></code> 32 is defined: this macro is set automatically by the config system when threading 33 support is turned on in your compiler. 34 </p> 35<p> 36 Class <a class="link" href="../ref/basic_regex.html" title="basic_regex"><code class="computeroutput"><span class="identifier">basic_regex</span></code></a> 37 and its typedefs regex and wregex are thread safe, in that compiled regular 38 expressions can safely be shared between threads. The matching algorithms 39 <a class="link" href="../ref/regex_match.html" title="regex_match"><code class="computeroutput"><span class="identifier">regex_match</span></code></a>, 40 <a class="link" href="../ref/regex_search.html" title="regex_search"><code class="computeroutput"><span class="identifier">regex_search</span></code></a>, 41 and <a class="link" href="../ref/regex_replace.html" title="regex_replace"><code class="computeroutput"><span class="identifier">regex_replace</span></code></a> 42 are all re-entrant and thread safe. Class <a class="link" href="../ref/match_results.html" title="match_results"><code class="computeroutput"><span class="identifier">match_results</span></code></a> is now thread safe, 43 in that the results of a match can be safely copied from one thread to another 44 (for example one thread may find matches and push <a class="link" href="../ref/match_results.html" title="match_results"><code class="computeroutput"><span class="identifier">match_results</span></code></a> instances onto a queue, 45 while another thread pops them off the other end), otherwise use a separate 46 instance of <a class="link" href="../ref/match_results.html" title="match_results"><code class="computeroutput"><span class="identifier">match_results</span></code></a> 47 per thread. 48 </p> 49<p> 50 The <a class="link" href="../ref/posix.html" title="POSIX Compatible C API's">POSIX API functions</a> are 51 all re-entrant and thread safe, regular expressions compiled with regcomp 52 can also be shared between threads. 53 </p> 54<p> 55 The <a class="link" href="../ref/deprecated/old_regex.html" title="High Level Class RegEx (Deprecated)">class RegEx</a> 56 is only thread safe if each thread gets its own RegEx instance (apartment 57 threading) - this is a consequence of RegEx handling both compiling and matching 58 regular expressions. 59 </p> 60<p> 61 Finally note that changing the global locale invalidates all compiled regular 62 expressions, therefore calling <code class="computeroutput"><span class="identifier">set_locale</span></code> 63 from one thread while another uses regular expressions will produce unpredictable 64 results. 65 </p> 66<p> 67 There is also a requirement that there is only one thread executing prior 68 to the start of main(). 69 </p> 70</div> 71<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 72<td align="left"></td> 73<td align="right"><div class="copyright-footer">Copyright © 1998-2013 John Maddock<p> 74 Distributed under the Boost Software License, Version 1.0. (See accompanying 75 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>) 76 </p> 77</div></td> 78</tr></table> 79<hr> 80<div class="spirit-nav"> 81<a accesskey="p" href="locale.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../background.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="examples.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> 82</div> 83</body> 84</html> 85
