Index: libcfa/src/concurrency/select.cfa
===================================================================
--- libcfa/src/concurrency/select.cfa	(revision 3d9831beab011c6d472dffc1449b55c58e50d167)
+++ libcfa/src/concurrency/select.cfa	(revision e1358c0ea59c560c010e5261b3e1fe2ac3ad8a2c)
@@ -10,7 +10,7 @@
 // Author           : Colby Alexander Parsons
 // Created On       : Thu Apr 21 19:46:50 2023
-// Last Modified By :
-// Last Modified On :
-// Update Count     :
+// Last Modified By : Kyoung Seo
+// Last Modified On : Wed Mar 19 12:00:00 2025
+// Update Count     : 1
 //
 
@@ -51,9 +51,2 @@
 bool on_selected( select_timeout_node & this, select_node & node ) { return true; }
 
-// Gateway routine to wait on duration
-select_timeout_node timeout( Duration duration ) {
-	select_timeout_node node{ duration, timeout_handler_select_cast };
-    return node;
-}
-select_timeout_node sleep( Duration duration ) { return timeout( duration ); }
-
Index: libcfa/src/concurrency/select.hfa
===================================================================
--- libcfa/src/concurrency/select.hfa	(revision 3d9831beab011c6d472dffc1449b55c58e50d167)
+++ libcfa/src/concurrency/select.hfa	(revision e1358c0ea59c560c010e5261b3e1fe2ac3ad8a2c)
@@ -10,7 +10,7 @@
 // Author           : Colby Alexander Parsons
 // Created On       : Thu Jan 21 19:46:50 2023
-// Last Modified By :
-// Last Modified On :
-// Update Count     :
+// Last Modified By : Kyoung Seo
+// Last Modified On : Wed Mar 19 12:00:00 2025
+// Update Count     : 1
 //
 
@@ -214,6 +214,4 @@
 select_timeout_node __CFA_select_get_type( select_timeout_node this );
 
-// Gateway routines to waituntil on duration
-select_timeout_node timeout( Duration duration );
-select_timeout_node sleep( Duration duration );
-
+// Timer macro for waituntil
+#define _timeout(D) (select_timeout_node) { D, timeout_handler_select_cast }