8048983: Enhance thread contexts in JAXP

Reviewed-by: chegar, lancea, dfuchs, hawtin

jaxp/src/java.xml/share/classes/com/sun/org/apache/xml/internal/utils/SafeThread.java

@@ -0,0 +1,94 @@
+/*
+ * Copyright (c) 2015, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package com.sun.org.apache.xml.internal.utils;
+
+import sun.misc.Unsafe;
+
+/**
+ * This is a combination of ThreadControllerWrapper's inner class SafeThread
+ * that was introduced as a fix for CR 6607339
+ * and sun.misc.ManagedLocalsThread, a thread that has it's thread locals, and
+ * inheritable thread locals erased on construction. Except the run method,
+ * it is identical to sun.misc.ManagedLocalsThread.
+ */
+public class SafeThread extends Thread {
+
+    private static final Unsafe UNSAFE;
+    private static final long THREAD_LOCALS;
+    private static final long INHERITABLE_THREAD_LOCALS;
+
+    private volatile boolean ran = false;
+
+    public SafeThread(Runnable target) {
+        super(target);
+        eraseThreadLocals();
+    }
+
+    public SafeThread(Runnable target, String name) {
+        super(target, name);
+        eraseThreadLocals();
+    }
+
+    public SafeThread(ThreadGroup group, Runnable target, String name) {
+        super(group, target, name);
+        eraseThreadLocals();
+    }
+
+    public final void run() {
+        if (Thread.currentThread() != this) {
+            throw new IllegalStateException("The run() method in a"
+                    + " SafeThread cannot be called from another thread.");
+        }
+        synchronized (this) {
+            if (!ran) {
+                ran = true;
+            } else {
+                throw new IllegalStateException("The run() method in a"
+                        + " SafeThread cannot be called more than once.");
+            }
+        }
+        super.run();
+    }
+
+    /**
+     * Drops all thread locals (and inherited thread locals).
+     */
+    public final void eraseThreadLocals() {
+        UNSAFE.putObject(this, THREAD_LOCALS, null);
+        UNSAFE.putObject(this, INHERITABLE_THREAD_LOCALS, null);
+    }
+
+    static {
+        UNSAFE = Unsafe.getUnsafe();
+        Class<?> t = Thread.class;
+        try {
+            THREAD_LOCALS = UNSAFE.objectFieldOffset(t.getDeclaredField("threadLocals"));
+            INHERITABLE_THREAD_LOCALS = UNSAFE.objectFieldOffset(t.getDeclaredField("inheritableThreadLocals"));
+        } catch (Exception e) {
+            throw new Error(e);
+        }
+    }
+
+}

jaxp/src/java.xml/share/classes/com/sun/org/apache/xml/internal/utils/ThreadControllerWrapper.java

@@ -3,11 +3,12 @@
  * DO NOT REMOVE OR ALTER!
  */
 /*
- * Copyright 1999-2004 The Apache Software Foundation.
+ * Licensed to the Apache Software Foundation (ASF) under one or more
- *
+ * contributor license agreements.  See the NOTICE file distributed with
- * Licensed under the Apache License, Version 2.0 (the "License");
+ * this work for additional information regarding copyright ownership.
- * you may not use this file except in compliance with the License.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
- * You may obtain a copy of the License at
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
@@ -17,110 +18,73 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-/*
- * $Id: ThreadControllerWrapper.java,v 1.2.4.1 2005/09/15 08:15:59 suresh_emailid Exp $
- */
 package com.sun.org.apache.xml.internal.utils;
 
 /**
- * A utility class that wraps the ThreadController, which is used
+ * A utility class that wraps the ThreadController, which is used by
- * by IncrementalSAXSource for the incremental building of DTM.
+ * IncrementalSAXSource for the incremental building of DTM.
  */
-public class ThreadControllerWrapper
+public class ThreadControllerWrapper {
-{
-
-  /** The ThreadController pool   */
-  private static ThreadController m_tpool = new ThreadController();
-
-  public static Thread runThread(Runnable runnable, int priority)
-  {
-    return m_tpool.run(runnable, priority);
-  }
-
-  public static void waitThread(Thread worker, Runnable task)
-    throws InterruptedException
-  {
-    m_tpool.waitThread(worker, task);
-  }
-
-  /**
-   * Thread controller utility class for incremental SAX source. Must
-   * be overriden with a derived class to support thread pooling.
-   *
-   * All thread-related stuff is in this class.
-   */
-  public static class ThreadController
-  {
 
     /**
-     * This class was introduced as a fix for CR 6607339.
+     * The ThreadController pool
      */
-    final class SafeThread extends Thread {
+    private static ThreadController m_tpool = new ThreadController();
-         private volatile boolean ran = false;
 
-         public SafeThread(Runnable target) {
+    public static Thread runThread(Runnable runnable, int priority) {
-             super(target);
+        return m_tpool.run(runnable, priority);
-         }
+    }
 
-         public final void run() {
+    public static void waitThread(Thread worker, Runnable task)
-             if (Thread.currentThread() != this) {
+            throws InterruptedException {
-                 throw new IllegalStateException("The run() method in a"
+        m_tpool.waitThread(worker, task);
-                     + " SafeThread cannot be called from another thread.");
-             }
-             synchronized (this) {
-                if (!ran) {
-                    ran = true;
-                }
-                else {
-                 throw new IllegalStateException("The run() method in a"
-                     + " SafeThread cannot be called more than once.");
-                 }
-             }
-             super.run();
-         }
     }
 
     /**
-     * Will get a thread from the pool, execute the task
+     * Thread controller utility class for incremental SAX source. Must be
-     *  and return the thread to the pool.
+     * overridden with a derived class to support thread pooling.
      *
-     *  The return value is used only to wait for completion
+     * All thread-related stuff is in this class.
-     *
-     *
-     * NEEDSDOC @param task
-     * @param priority if >0 the task will run with the given priority
-     *  ( doesn't seem to be used in xalan, since it's allways the default )
-     * @return  The thread that is running the task, can be used
-     *          to wait for completion
      */
-    public Thread run(Runnable task, int priority)
+    public static class ThreadController {
-    {
 
-      Thread t = new SafeThread(task);
+        /**
+         * Will get a thread from the pool, execute the task and return the
+         * thread to the pool.
+         *
+         * The return value is used only to wait for completion
+         *
+         *
+         * @param task the Runnable
+         *
+         * @param priority if >0 the task will run with the given priority (
+         * doesn't seem to be used in xalan, since it's always the default )
+         * @return The thread that is running the task, can be used to wait for
+         * completion
+         */
+        public Thread run(Runnable task, int priority) {
 
-      t.start();
+            Thread t = new SafeThread(task);
+            t.start();
 
-      //       if( priority > 0 )
+            //if( priority > 0 )
-      //      t.setPriority( priority );
+            //    t.setPriority( priority );
-      return t;
+            return t;
+        }
+
+        /**
+         * Wait until the task is completed on the worker thread.
+         *
+         * @param worker worker thread
+         * @param task the Runnable
+         *
+         * @throws InterruptedException
+         */
+        public void waitThread(Thread worker, Runnable task)
+                throws InterruptedException {
+
+            // This should wait until the transformThread is considered not alive.
+            worker.join();
+        }
     }
-
-    /**
-     *  Wait until the task is completed on the worker
-     *  thread.
-     *
-     * NEEDSDOC @param worker
-     * NEEDSDOC @param task
-     *
-     * @throws InterruptedException
-     */
-    public void waitThread(Thread worker, Runnable task)
-            throws InterruptedException
-    {
-
-      // This should wait until the transformThread is considered not alive.
-      worker.join();
-    }
-  }
-
 }