From 2e0e0a86b435e78d100bcba597d2639263ebdc8a Mon Sep 17 00:00:00 2001
From: Robby Findler <robby@racket-lang.org>
Date: Mon, 24 Nov 2003 17:55:29 +0000
Subject: [PATCH] ..

original commit: 0f2e555ddb2fe756a3f2925eb6d2616cb1c10511
---
 collects/framework/framework.ss           |  4 ++--
 collects/framework/private/preferences.ss | 19 +++++--------------
 2 files changed, 7 insertions(+), 16 deletions(-)

diff --git a/collects/framework/framework.ss b/collects/framework/framework.ss
index c1c311c0..fea324ad 100644
--- a/collects/framework/framework.ss
+++ b/collects/framework/framework.ss
@@ -147,7 +147,7 @@
     "preference in that file is used instead of \\var{value}."
     ""
     "Once"
-    "@flink preferences:start-writing-thread "
+    "@flink preferences:start-writing-timer "
     "has been called, no more default preferences may be registered.")
    (preferences:set-un/marshall
     (symbol? (any? . -> . printable?) (printable? . -> . any?) . -> . void?)
@@ -188,7 +188,7 @@
     ()
     "\\rawscm{(preferences:restore-defaults)} restores the users's configuration to the"
     "default preferences.")
-   (preferences:start-writing-thread
+   (preferences:start-writing-timer
     (-> void?)
     ()
     "Starts a thread that periodically flushes the preferences"
diff --git a/collects/framework/private/preferences.ss b/collects/framework/private/preferences.ss
index e3bbbc92..3d435a46 100644
--- a/collects/framework/private/preferences.ss
+++ b/collects/framework/private/preferences.ss
@@ -61,20 +61,11 @@
         (hash-table-put! changed p #t))
       
       ;; periodically checks to see if changes need to be written out.
-      (define (start-writing-thread)
+      (define (start-writing-timer)
         (set! no-more-defaults? #t)
-        (thread 
-         (lambda ()
-           (let loop ()
-             (sleep 5)
-             (let ([s (make-semaphore 0)])
-               (queue-callback
-                (lambda ()
-                  (maybe-flush-changes)
-                  (semaphore-post s))
-                #f)
-               (semaphore-wait s))
-             (loop))))
+        (new timer%
+             [notify-callback (lambda () (maybe-flush-changes))]
+             [interval (* 5 1000)])
         (void))
       
       (define last-time-read #f)
@@ -235,7 +226,7 @@
       ;; set-default : (sym TST (TST -> boolean) -> void
       (define (set-default p default-value checker)
         (when no-more-defaults?
-          (error 'set-default "tried to register the pref ~e too late; preferences:start-writing-thread has already been called" p))
+          (error 'set-default "tried to register the pref ~e too late; preferences:start-writing-timer has already been called" p))
         (let ([default-okay? (checker default-value)])
           (unless default-okay?
             (error 'set-default "~s: checker (~s) returns ~s for ~s, expected #t~n"