(scm_current_time, scm_gettimeofday): Add a comment about

setzone/restorezone protection for DOS.

diff --git a/libguile/stime.c b/libguile/stime.c
index e792eba..6bf2122 100644 (file)
--- a/libguile/stime.c
+++ b/libguile/stime.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1995,1996,1997,1998,1999,2000,2001, 2003 Free Software Foundation, Inc.
+/* Copyright (C) 1995,1996,1997,1998,1999,2000,2001, 2003, 2004 Free Software Foundation, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -180,6 +180,13 @@ SCM_DEFINE (scm_get_internal_run_time, "get-internal-run-time", 0, 0, 0,
 }
 #undef FUNC_NAME
 
+/* For reference, note that current-time and gettimeofday both should be
+   protected against setzone/restorezone changes in another thread, since on
+   DOS the system time is normally kept as local time, which means TZ
+   affects the return from current-time and gettimeofday.  Not sure if DJGPP
+   etc actually has concurrent multi-threading, but it seems prudent not to
+   make assumptions about this.  */
+
 SCM_DEFINE (scm_current_time, "current-time", 0, 0, 0,
            (void),
            "Return the number of seconds since 1970-01-01 00:00:00 UTC,\n"