/*
 * Copyright (c) 2007, 2008, 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 sun.java2d.d3d;

import sun.java2d.ScreenUpdateManager;
import sun.java2d.pipe.RenderBuffer;
import sun.java2d.pipe.RenderQueue;
import static sun.java2d.pipe.BufferedOpCodes.*;

D3D-specific implementation of RenderQueue.
/**
 * D3D-specific implementation of RenderQueue.
 */
public class D3DRenderQueue extends RenderQueue {

    private static D3DRenderQueue theInstance;
    private static Thread rqThread;

    private D3DRenderQueue() {
    }

    
Returns the single D3DRenderQueue instance.  If it has not yet been
initialized, this method will first construct the single instance
before returning it.
/**
     * Returns the single D3DRenderQueue instance.  If it has not yet been
     * initialized, this method will first construct the single instance
     * before returning it.
     */
    public static synchronized D3DRenderQueue getInstance() {
        if (theInstance == null) {
            theInstance = new D3DRenderQueue();
            // no need to lock, noone has reference to this instance yet
            theInstance.flushAndInvokeNow(new Runnable() {
                public void run() {
                    rqThread = Thread.currentThread();
                }
            });
        }
        return theInstance;
    }

    
Flushes the single D3DRenderQueue instance synchronously.  If an
D3DRenderQueue has not yet been instantiated, this method is a no-op.
This method is useful in the case of Toolkit.sync(), in which we want
to flush the D3D pipeline, but only if the D3D pipeline is currently
enabled.  Since this class has few external dependencies, callers need
not be concerned that calling this method will trigger initialization
of the D3D pipeline and related classes.
/**
     * Flushes the single D3DRenderQueue instance synchronously.  If an
     * D3DRenderQueue has not yet been instantiated, this method is a no-op.
     * This method is useful in the case of Toolkit.sync(), in which we want
     * to flush the D3D pipeline, but only if the D3D pipeline is currently
     * enabled.  Since this class has few external dependencies, callers need
     * not be concerned that calling this method will trigger initialization
     * of the D3D pipeline and related classes.
     */
    public static void sync() {
        if (theInstance != null) {
            // need to make sure any/all screen surfaces are presented prior
            // to completing the sync operation
            D3DScreenUpdateManager mgr =
                (D3DScreenUpdateManager)ScreenUpdateManager.getInstance();
            mgr.runUpdateNow();

            theInstance.lock();
            try {
                theInstance.ensureCapacity(4);
                theInstance.getBuffer().putInt(SYNC);
                theInstance.flushNow();
            } finally {
                theInstance.unlock();
            }
        }
    }

    
Attempt to restore the devices if they're in the lost state.
(used when a full-screen window is activated/deactivated)
/**
     * Attempt to restore the devices if they're in the lost state.
     * (used when a full-screen window is activated/deactivated)
     */
    public static void restoreDevices() {
        D3DRenderQueue rq = getInstance();
        rq.lock();
        try {
            rq.ensureCapacity(4);
            rq.getBuffer().putInt(RESTORE_DEVICES);
            rq.flushNow();
        } finally {
            rq.unlock();
        }
    }

    
Returns:
true if current thread is the render queue thread,
false otherwise/**
     * @return true if current thread is the render queue thread,
     * false otherwise
     */
    public static boolean isRenderQueueThread() {
        return (Thread.currentThread() == rqThread);
    }

    
Disposes the native memory associated with the given native
graphics config info pointer on the single queue flushing thread.
/**
     * Disposes the native memory associated with the given native
     * graphics config info pointer on the single queue flushing thread.
     */
    public static void disposeGraphicsConfig(long pConfigInfo) {
        D3DRenderQueue rq = getInstance();
        rq.lock();
        try {

            RenderBuffer buf = rq.getBuffer();
            rq.ensureCapacityAndAlignment(12, 4);
            buf.putInt(DISPOSE_CONFIG);
            buf.putLong(pConfigInfo);

            // this call is expected to complete synchronously, so flush now
            rq.flushNow();
        } finally {
            rq.unlock();
        }
    }

    public void flushNow() {
        // assert lock.isHeldByCurrentThread();
        flushBuffer(null);
    }

    public void flushAndInvokeNow(Runnable r) {
        // assert lock.isHeldByCurrentThread();
        flushBuffer(r);
    }

    private native void flushBuffer(long buf, int limit, Runnable task);

    private void flushBuffer(Runnable task) {
        // assert lock.isHeldByCurrentThread();
        int limit = buf.position();
        if (limit > 0 || task != null) {
            // process the queue
            flushBuffer(buf.getAddress(), limit, task);
        }
        // reset the buffer position
        buf.clear();
        // clear the set of references, since we no longer need them
        refSet.clear();
    }
}