--- a/src/event-stream.c	Thu May 31 12:03:39 2001 +0000
+++ b/src/event-stream.c	Thu May 31 12:45:41 2001 +0000
@@ -924,12 +924,28 @@
 /*                            timeouts                                */
 /**********************************************************************/
 
-/**** Low-level timeout functions. ****
+/* NOTE: "Low-level" or "interval" timeouts are one-shot timeouts that
+   measure single intervals.  "High-level timeouts" or "wakeups" are
+   the objects generated by `add-timeout' or `add-async-timout' --
+   they can fire repeatedly (and in fact can have a different initial
+   time and resignal time).  Given the nature of both setitimer() and
+   select() -- i.e. all we get is a single one-shot timer -- we have
+   to decompose all high-level timeouts into a series of intervals or
+   low-level timeouts.
+
+   Low-level timeouts are of two varieties: synchronous and asynchronous.
+   The former are handled at the window-system level, the latter in
+   signal.c.
+*/
+
+/**** Low-level timeout helper functions. ****
 
    These functions maintain a sorted list of one-shot timeouts (where
-   the timeouts are in absolute time).  They are intended for use by
-   functions that need to convert a list of absolute timeouts into a
-   series of intervals to wait for. */
+   the timeouts are in absolute time so we never lose any time as a
+   result of the delay between noting an interval and firing the next
+   one).  They are intended for use by functions that need to convert
+   a list of absolute timeouts into a series of intervals to wait
+   for. */
 
 /* We ensure that 0 is never a valid ID, so that a value of 0 can be
    used to indicate an absence of a timer. */
@@ -954,6 +970,8 @@
 
   tm = Blocktype_alloc (the_low_level_timeout_blocktype);
   tm->next = NULL;
+  /* Don't just use ++low_level_timeout_id_tick, for the (admittedly
+     rare) case in which numbers wrap around. */
   if (low_level_timeout_id_tick == 0)
     low_level_timeout_id_tick++;
   tm->id = low_level_timeout_id_tick++;
@@ -1047,8 +1065,10 @@
 }
 
 
-/**** High-level timeout functions. ****/
-
+/**** High-level timeout functions. **** */
+
+/* We ensure that 0 is never a valid ID, so that a value of 0 can be
+   used to indicate an absence of a timer. */
 static int timeout_id_tick;
 
 static Lisp_Object pending_timeout_list, pending_async_timeout_list;
@@ -1098,6 +1118,10 @@
   EMACS_TIME current_time;
   EMACS_TIME interval;
 
+  /* Don't just use ++timeout_id_tick, for the (admittedly rare) case
+     in which numbers wrap around. */
+  if (timeout_id_tick == 0)
+    timeout_id_tick++;
   timeout->id = timeout_id_tick++;
   timeout->resignal_msecs = vanilliseconds;
   timeout->function = function;
@@ -1111,9 +1135,9 @@
   if (async_p)
     {
       timeout->interval_id =
-	event_stream_add_async_timeout (timeout->next_signal_time);
-      pending_async_timeout_list = noseeum_cons (op,
-						 pending_async_timeout_list);
+	signal_add_async_interval_timeout (timeout->next_signal_time);
+      pending_async_timeout_list =
+	noseeum_cons (op, pending_async_timeout_list);
     }
   else
     {
@@ -1138,7 +1162,7 @@
    NOTE: The returned FUNCTION and OBJECT are *not* GC-protected at all.
 */
 
-static int
+int
 event_stream_resignal_wakeup (int interval_id, int async_p,
 			      Lisp_Object *function, Lisp_Object *object)
 {
@@ -1197,7 +1221,7 @@
 
       if (async_p)
         timeout->interval_id =
-	  event_stream_add_async_timeout (timeout->next_signal_time);
+	  signal_add_async_interval_timeout (timeout->next_signal_time);
       else
         timeout->interval_id =
 	  event_stream_add_timeout (timeout->next_signal_time);
@@ -1241,7 +1265,7 @@
       *timeout_list =
 	delq_no_quit_and_free_cons (op, *timeout_list);
       if (async_p)
-	event_stream_remove_async_timeout (timeout->interval_id);
+	signal_remove_async_interval_timeout (timeout->interval_id);
       else
 	event_stream_remove_timeout (timeout->interval_id);
       free_managed_lcrecord (Vtimeout_free_list, op);
@@ -1277,50 +1301,6 @@
 }
 
 
-/**** Asynch. timeout functions (see also signal.c) ****/
-
-#if !defined (SIGIO) && !defined (DONT_POLL_FOR_QUIT)
-extern int poll_for_quit_id;
-#endif
-
-#if defined(HAVE_UNIX_PROCESSES) && !defined(SIGCHLD)
-extern int poll_for_sigchld_id;
-#endif
-
-void
-event_stream_deal_with_async_timeout (int interval_id)
-{
-  /* This function can GC */
-  Lisp_Object humpty, dumpty;
-#if ((!defined (SIGIO) && !defined (DONT_POLL_FOR_QUIT)) \
-     || defined(HAVE_UNIX_PROCESSES) && !defined(SIGCHLD))
-  int id =
-#endif
-    event_stream_resignal_wakeup (interval_id, 1, &humpty, &dumpty);
-
-#if !defined (SIGIO) && !defined (DONT_POLL_FOR_QUIT)
-  if (id == poll_for_quit_id)
-    {
-      quit_check_signal_happened = 1;
-      quit_check_signal_tick_count++;
-      return;
-    }
-#endif
-
-#if defined(HAVE_UNIX_PROCESSES) && !defined(SIGCHLD)
-  if (id == poll_for_sigchld_id)
-    {
-      kick_status_notify ();
-      return;
-    }
-#endif
-
-  /* call1 GC-protects its arguments */
-  call1_trapping_errors ("Error in asynchronous timeout callback",
-			 humpty, dumpty);
-}
-
-
 /**** Lisp-level timeout functions. ****/
 
 static unsigned long