changeset 5632:f7aad97a8066

7196533: TimeZone.getDefault() slow due to synchronization bottleneck Reviewed-by: okutsu
author coffeys
date Tue, 15 Jan 2013 10:37:49 +0000
parents 7aa5b507e745
children c9fb7c0e371f
files src/share/classes/java/util/TimeZone.java
diffstat 1 files changed, 18 insertions(+), 16 deletions(-) [+]
line wrap: on
line diff
--- a/src/share/classes/java/util/TimeZone.java	Tue Jul 17 11:28:16 2012 +0800
+++ b/src/share/classes/java/util/TimeZone.java	Tue Jan 15 10:37:49 2013 +0000
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1996, 2012, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1996, 2013, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -162,16 +162,6 @@
     private static final int ONE_HOUR   = 60*ONE_MINUTE;
     private static final int ONE_DAY    = 24*ONE_HOUR;
 
-    /*
-     * Provides access implementation-private methods without using reflection
-     *
-     * Note that javaAWTAccess may be null if sun.awt.AppContext class hasn't
-     * been loaded. If so, it implies that AWTSecurityManager is not our
-     * SecurityManager and we can use a local static variable.
-     * This works around a build time issue.
-     */
-    private static JavaAWTAccess javaAWTAccess;
-
     // Proclaim serialization compatibility with JDK 1.1
     static final long serialVersionUID = 3581463369166924961L;
 
@@ -729,9 +719,15 @@
      * Returns the default TimeZone in an AppContext if any AppContext
      * has ever used. null is returned if any AppContext hasn't been
      * used or if the AppContext doesn't have the default TimeZone.
+     *
+     * Note that javaAWTAccess may be null if sun.awt.AppContext class hasn't
+     * been loaded. If so, it implies that AWTSecurityManager is not our
+     * SecurityManager and we can use a local static variable.
+     * This works around a build time issue.
      */
-    private synchronized static TimeZone getDefaultInAppContext() {
-        javaAWTAccess = SharedSecrets.getJavaAWTAccess();
+    private static TimeZone getDefaultInAppContext() {
+        // JavaAWTAccess provides access implementation-private methods without using reflection.
+        JavaAWTAccess javaAWTAccess = SharedSecrets.getJavaAWTAccess();
         if (javaAWTAccess == null) {
             return mainAppContextDefault;
         } else {
@@ -753,9 +749,15 @@
      * tz. null is handled special: do nothing if any AppContext
      * hasn't been used, remove the default TimeZone in the
      * AppContext otherwise.
+     *
+     * Note that javaAWTAccess may be null if sun.awt.AppContext class hasn't
+     * been loaded. If so, it implies that AWTSecurityManager is not our
+     * SecurityManager and we can use a local static variable.
+     * This works around a build time issue.
      */
-    private synchronized static void setDefaultInAppContext(TimeZone tz) {
-        javaAWTAccess = SharedSecrets.getJavaAWTAccess();
+    private static void setDefaultInAppContext(TimeZone tz) {
+        // JavaAWTAccess provides access implementation-private methods without using reflection.
+        JavaAWTAccess javaAWTAccess = SharedSecrets.getJavaAWTAccess();
         if (javaAWTAccess == null) {
             mainAppContextDefault = tz;
         } else {
@@ -820,7 +822,7 @@
     private static final int    GMT_ID_LENGTH = 3;
 
     // a static TimeZone we can reference if no AppContext is in place
-    private static TimeZone mainAppContextDefault;
+    private static volatile TimeZone mainAppContextDefault;
 
     /**
      * Parses a custom time zone identifier and returns a corresponding zone.