slightly faster path for port-commit-peeked with always-evt

svn: r2794

src/mzscheme/src/port.c

@@ -1928,6 +1928,11 @@ int scheme_peeked_read_via_get(Scheme_Input_Port *ip,
       /* No other thread is trying to commit. This one is hereby
 	 elected "main" if multiple threads try to commit. */
 
+      if (SAME_TYPE(t, scheme_always_evt_type)) {
+	/* Fast path: always-evt is ready */
+	return complete_peeked_read_via_get(ip, size);
+      }
+
       /* This sema makes other threads wait before reading: */
       sema = scheme_make_sema(0);
       ip->input_lock = sema;