-extern void dbg_hit_on(bool b);
-extern void dbg_hit_on_c(bool c, bool b);
-extern void dbg_before();
-extern void dbg_after();
-extern void dbg_mean_of(int v);
-extern void dbg_print_hit_rate();
-extern void dbg_print_mean();
-extern void dbg_print_hit_rate(std::ofstream& logFile);
-extern void dbg_print_mean(std::ofstream& logFile);
+
+enum SyncCout { io_lock, io_unlock };
+std::ostream& operator<<(std::ostream&, SyncCout);
+
+#define sync_cout std::cout << io_lock
+#define sync_endl std::endl << io_unlock