From 77771ee209768a8c9a78cd47c135bf4c48030629 Mon Sep 17 00:00:00 2001
From: John Maddock <john@johnmaddock.co.uk>
Date: Fri, 1 Oct 2010 08:03:51 +0000
Subject: [PATCH] Use call_once in test code to avoid race condition which may
 otherwise occur.

[SVN r65702]
---
 test/regress/test.hpp | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/test/regress/test.hpp b/test/regress/test.hpp
index 02a08ef1..e93ac5ec 100644
--- a/test/regress/test.hpp
+++ b/test/regress/test.hpp
@@ -36,6 +36,9 @@
 #include "test_icu.hpp"
 #include "test_locale.hpp"
 
+#ifdef TEST_THREADS
+#include <boost/thread/once.hpp>
+#endif
 
 //
 // define test entry proc, this forwards on to the appropriate
@@ -62,6 +65,16 @@ void test(const wchar_t&, const test_regex_search_tag&);
 void test(const wchar_t&, const test_invalid_regex_tag&);
 #endif
 
+template <class Regex>
+struct call_once_func
+{
+   Regex* pregex;
+   void operator()()const
+   {
+      return test_empty(*pregex);
+   }
+};
+
 template <class charT, class tagT>
 void do_test(const charT& c, const tagT& tag)
 {
@@ -73,12 +86,18 @@ void do_test(const charT& c, const tagT& tag)
    test_info<charT>::set_typename(typeid(boost::basic_regex<charT, boost::cpp_regex_traits<charT> >).name());
 #endif
    boost::basic_regex<charT, boost::cpp_regex_traits<charT> > e1;
+#ifndef TEST_THREADS
    static bool done_empty_test = false;
    if(done_empty_test == false)
    {
       test_empty(e1);
       done_empty_test = true;
    }
+#else
+   boost::once_flag f = BOOST_ONCE_INIT;
+   call_once_func<boost::basic_regex<charT, boost::cpp_regex_traits<charT> > > proc = { &e1 };
+   boost::call_once(f, proc);
+#endif
    if(test_locale::cpp_locale_state() == test_locale::test_with_locale)
       e1.imbue(test_locale::cpp_locale());
    if(test_locale::cpp_locale_state() != test_locale::no_test)