--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/imgtools/imglib/boostlibrary/boost/thread/barrier.hpp	Mon May 10 19:54:49 2010 +0100
@@ -0,0 +1,63 @@
+// Copyright (C) 2002-2003
+// David Moore, William E. Kempf
+// Copyright (C) 2007-8 Anthony Williams
+//
+//  Distributed under the Boost Software License, Version 1.0. (See accompanying 
+//  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_BARRIER_JDM030602_HPP
+#define BOOST_BARRIER_JDM030602_HPP
+
+#include <boost/thread/detail/config.hpp>
+
+#include <boost/thread/mutex.hpp>
+#include <boost/thread/condition_variable.hpp>
+#include <string>
+#include <stdexcept>
+
+#include <boost/config/abi_prefix.hpp>
+
+namespace boost
+{
+
+    class barrier
+    {
+    public:
+        barrier(unsigned int count)
+            : m_threshold(count), m_count(count), m_generation(0)
+        {
+            if (count == 0)
+                throw std::invalid_argument("count cannot be zero.");
+        }
+    
+        bool wait()
+        {
+            boost::mutex::scoped_lock lock(m_mutex);
+            unsigned int gen = m_generation;
+        
+            if (--m_count == 0)
+            {
+                m_generation++;
+                m_count = m_threshold;
+                m_cond.notify_all();
+                return true;
+            }
+
+            while (gen == m_generation)
+                m_cond.wait(lock);
+            return false;
+        }
+
+    private:
+        mutex m_mutex;
+        condition_variable m_cond;
+        unsigned int m_threshold;
+        unsigned int m_count;
+        unsigned int m_generation;
+    };
+
+}   // namespace boost
+
+#include <boost/config/abi_suffix.hpp>
+
+#endif