--- thread.hpp.orig	2009-04-21 10:08:59.000000000 -0400
+++ thread.hpp	2009-04-21 10:18:08.000000000 -0400
@@ -530,17 +530,32 @@
             }
         }
         
         void join_all()
         {
-            boost::lock_guard<mutex> guard(m);
-            
-            for(std::list<thread*>::iterator it=threads.begin(),end=threads.end();
-                it!=end;
-                ++it)
+            std::list<thread*> joined;
+            for(;;)
             {
-                (*it)->join();
+                thread* t; // thread to join while mutex not held
+                {
+                    boost::lock_guard<mutex> guard(m);
+
+                    for(std::list<thread*>::iterator it=threads.begin(),end=threads.end();;++it)
+                    {
+                        if(it=end)
+                        {
+                            return;
+                        }
+                        std::list<thread*>::iterator const j=std::find(joined.begin(),joined.end(),*it);
+                        if(j==joined.end())
+                        {
+                            t = *it;
+                            break;
+                        }
+                    }
+                }
+                t->join();
             }
         }
         
         void interrupt_all()
         {