feat(jdk8): move files to new folder to avoid resources compiled.

jdkSrc/jdk8/java/util/concurrent/ForkJoinWorkerThread.java

@@ -0,0 +1,287 @@
+/*
+ * 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.
+ */
+
+/*
+ * This file is available under and governed by the GNU General Public
+ * License version 2 only, as published by the Free Software Foundation.
+ * However, the following notice accompanied the original version of this
+ * file:
+ *
+ * Written by Doug Lea with assistance from members of JCP JSR-166
+ * Expert Group and released to the public domain, as explained at
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+package java.util.concurrent;
+
+import java.security.AccessControlContext;
+import java.security.ProtectionDomain;
+
+/**
+ * A thread managed by a {@link ForkJoinPool}, which executes
+ * {@link ForkJoinTask}s.
+ * This class is subclassable solely for the sake of adding
+ * functionality -- there are no overridable methods dealing with
+ * scheduling or execution.  However, you can override initialization
+ * and termination methods surrounding the main task processing loop.
+ * If you do create such a subclass, you will also need to supply a
+ * custom {@link ForkJoinPool.ForkJoinWorkerThreadFactory} to
+ * {@linkplain ForkJoinPool#ForkJoinPool use it} in a {@code ForkJoinPool}.
+ *
+ * @since 1.7
+ * @author Doug Lea
+ */
+public class ForkJoinWorkerThread extends Thread {
+    /*
+     * ForkJoinWorkerThreads are managed by ForkJoinPools and perform
+     * ForkJoinTasks. For explanation, see the internal documentation
+     * of class ForkJoinPool.
+     *
+     * This class just maintains links to its pool and WorkQueue.  The
+     * pool field is set immediately upon construction, but the
+     * workQueue field is not set until a call to registerWorker
+     * completes. This leads to a visibility race, that is tolerated
+     * by requiring that the workQueue field is only accessed by the
+     * owning thread.
+     *
+     * Support for (non-public) subclass InnocuousForkJoinWorkerThread
+     * requires that we break quite a lot of encapsulation (via Unsafe)
+     * both here and in the subclass to access and set Thread fields.
+     */
+
+    final ForkJoinPool pool;                // the pool this thread works in
+    final ForkJoinPool.WorkQueue workQueue; // work-stealing mechanics
+
+    /** An AccessControlContext supporting no privileges */
+    private static final AccessControlContext INNOCUOUS_ACC =
+        new AccessControlContext(
+            new ProtectionDomain[] { new ProtectionDomain(null, null) });
+
+    /**
+     * Creates a ForkJoinWorkerThread operating in the given pool.
+     *
+     * @param pool the pool this thread works in
+     * @throws NullPointerException if pool is null
+     */
+    protected ForkJoinWorkerThread(ForkJoinPool pool) {
+        // Use a placeholder until a useful name can be set in registerWorker
+        super("aForkJoinWorkerThread");
+        this.pool = pool;
+        this.workQueue = pool.registerWorker(this);
+    }
+
+    /**
+     * Version for use by the default pool.  This is a separate constructor to
+     * avoid affecting the protected constructor.
+     */
+    ForkJoinWorkerThread(ForkJoinPool pool, boolean innocuous) {
+        super("aForkJoinWorkerThread");
+        if (innocuous) {
+            U.putOrderedObject(this, INHERITEDACCESSCONTROLCONTEXT, INNOCUOUS_ACC);
+        }
+        this.pool = pool;
+        this.workQueue = pool.registerWorker(this);
+    }
+
+    /**
+     * Version for InnocuousForkJoinWorkerThread
+     */
+    ForkJoinWorkerThread(ForkJoinPool pool, ThreadGroup threadGroup,
+                         AccessControlContext acc) {
+        super(threadGroup, null, "aForkJoinWorkerThread");
+        U.putOrderedObject(this, INHERITEDACCESSCONTROLCONTEXT, acc);
+        eraseThreadLocals(); // clear before registering
+        this.pool = pool;
+        this.workQueue = pool.registerWorker(this);
+    }
+
+    /**
+     * Returns the pool hosting this thread.
+     *
+     * @return the pool
+     */
+    public ForkJoinPool getPool() {
+        return pool;
+    }
+
+    /**
+     * Returns the unique index number of this thread in its pool.
+     * The returned value ranges from zero to the maximum number of
+     * threads (minus one) that may exist in the pool, and does not
+     * change during the lifetime of the thread.  This method may be
+     * useful for applications that track status or collect results
+     * per-worker-thread rather than per-task.
+     *
+     * @return the index number
+     */
+    public int getPoolIndex() {
+        return workQueue.getPoolIndex();
+    }
+
+    /**
+     * Initializes internal state after construction but before
+     * processing any tasks. If you override this method, you must
+     * invoke {@code super.onStart()} at the beginning of the method.
+     * Initialization requires care: Most fields must have legal
+     * default values, to ensure that attempted accesses from other
+     * threads work correctly even before this thread starts
+     * processing tasks.
+     */
+    protected void onStart() {
+    }
+
+    /**
+     * Performs cleanup associated with termination of this worker
+     * thread.  If you override this method, you must invoke
+     * {@code super.onTermination} at the end of the overridden method.
+     *
+     * @param exception the exception causing this thread to abort due
+     * to an unrecoverable error, or {@code null} if completed normally
+     */
+    protected void onTermination(Throwable exception) {
+    }
+
+    /**
+     * This method is required to be public, but should never be
+     * called explicitly. It performs the main run loop to execute
+     * {@link ForkJoinTask}s.
+     */
+    public void run() {
+        if (workQueue.array == null) { // only run once
+            Throwable exception = null;
+            try {
+                onStart();
+                pool.runWorker(workQueue);
+            } catch (Throwable ex) {
+                exception = ex;
+            } finally {
+                try {
+                    onTermination(exception);
+                } catch (Throwable ex) {
+                    if (exception == null)
+                        exception = ex;
+                } finally {
+                    pool.deregisterWorker(this, exception);
+                }
+            }
+        }
+    }
+
+    /**
+     * Erases ThreadLocals by nulling out Thread maps.
+     */
+    final void eraseThreadLocals() {
+        U.putObject(this, THREADLOCALS, null);
+        U.putObject(this, INHERITABLETHREADLOCALS, null);
+    }
+
+    /**
+     * Non-public hook method for InnocuousForkJoinWorkerThread
+     */
+    void afterTopLevelExec() {
+    }
+
+    // Set up to allow setting thread fields in constructor
+    private static final sun.misc.Unsafe U;
+    private static final long THREADLOCALS;
+    private static final long INHERITABLETHREADLOCALS;
+    private static final long INHERITEDACCESSCONTROLCONTEXT;
+    static {
+        try {
+            U = sun.misc.Unsafe.getUnsafe();
+            Class<?> tk = Thread.class;
+            THREADLOCALS = U.objectFieldOffset
+                (tk.getDeclaredField("threadLocals"));
+            INHERITABLETHREADLOCALS = U.objectFieldOffset
+                (tk.getDeclaredField("inheritableThreadLocals"));
+            INHERITEDACCESSCONTROLCONTEXT = U.objectFieldOffset
+                (tk.getDeclaredField("inheritedAccessControlContext"));
+
+        } catch (Exception e) {
+            throw new Error(e);
+        }
+    }
+
+    /**
+     * A worker thread that has no permissions, is not a member of any
+     * user-defined ThreadGroup, and erases all ThreadLocals after
+     * running each top-level task.
+     */
+    static final class InnocuousForkJoinWorkerThread extends ForkJoinWorkerThread {
+        /** The ThreadGroup for all InnocuousForkJoinWorkerThreads */
+        private static final ThreadGroup innocuousThreadGroup =
+            createThreadGroup();
+
+        InnocuousForkJoinWorkerThread(ForkJoinPool pool) {
+            super(pool, innocuousThreadGroup, INNOCUOUS_ACC);
+        }
+
+        @Override // to erase ThreadLocals
+        void afterTopLevelExec() {
+            eraseThreadLocals();
+        }
+
+        @Override // to always report system loader
+        public ClassLoader getContextClassLoader() {
+            return ClassLoader.getSystemClassLoader();
+        }
+
+        @Override // to silently fail
+        public void setUncaughtExceptionHandler(UncaughtExceptionHandler x) { }
+
+        @Override // paranoically
+        public void setContextClassLoader(ClassLoader cl) {
+            throw new SecurityException("setContextClassLoader");
+        }
+
+        /**
+         * Returns a new group with the system ThreadGroup (the
+         * topmost, parent-less group) as parent.  Uses Unsafe to
+         * traverse Thread.group and ThreadGroup.parent fields.
+         */
+        private static ThreadGroup createThreadGroup() {
+            try {
+                sun.misc.Unsafe u = sun.misc.Unsafe.getUnsafe();
+                Class<?> tk = Thread.class;
+                Class<?> gk = ThreadGroup.class;
+                long tg = u.objectFieldOffset(tk.getDeclaredField("group"));
+                long gp = u.objectFieldOffset(gk.getDeclaredField("parent"));
+                ThreadGroup group = (ThreadGroup)
+                    u.getObject(Thread.currentThread(), tg);
+                while (group != null) {
+                    ThreadGroup parent = (ThreadGroup)u.getObject(group, gp);
+                    if (parent == null)
+                        return new ThreadGroup(group,
+                                               "InnocuousForkJoinWorkerThreadGroup");
+                    group = parent;
+                }
+            } catch (Exception e) {
+                throw new Error(e);
+            }
+            // fall through if null as cannot-happen safeguard
+            throw new Error("Cannot create ThreadGroup");
+        }
+    }
+
+}