-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