bug in identifying current thread fixed

src/thread.hpp

@@ -55,6 +55,15 @@ namespace zmq
         //  Waits for thread termination.
         void stop ();
 
+#ifdef ZMQ_HAVE_WINDOWS
+        typedef DWORD id_t;
+#else
+        typedef pthread_t id_t;
+#endif
+
+        static id_t id ();
+        static bool equal (id_t id1_, id_t id2_);
+        
     private:
 
 #ifdef ZMQ_HAVE_WINDOWS