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OGLRenderQueue
/*
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
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* 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
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*/
package sun.java2d.opengl;
import sun.misc.ThreadGroupUtils;
import sun.java2d.pipe.RenderBuffer;
import sun.java2d.pipe.RenderQueue;
import static sun.java2d.pipe.BufferedOpCodes.*;
import java.security.AccessController;
import java.security.PrivilegedAction;
OGL-specific implementation of RenderQueue. This class provides a
single (daemon) thread that is responsible for periodically flushing
the queue, thus ensuring that only one thread communicates with the native
OpenGL libraries for the entire process.
/**
* OGL-specific implementation of RenderQueue. This class provides a
* single (daemon) thread that is responsible for periodically flushing
* the queue, thus ensuring that only one thread communicates with the native
* OpenGL libraries for the entire process.
*/
public class OGLRenderQueue extends RenderQueue {
private static OGLRenderQueue theInstance;
private final QueueFlusher flusher;
private OGLRenderQueue() {
/*
* The thread must be a member of a thread group
* which will not get GCed before VM exit.
*/
flusher = AccessController.doPrivileged((PrivilegedAction<QueueFlusher>) () -> {
return new QueueFlusher(ThreadGroupUtils.getRootThreadGroup());
});
}
Returns the single OGLRenderQueue instance. If it has not yet been
initialized, this method will first construct the single instance
before returning it.
/**
* Returns the single OGLRenderQueue instance. If it has not yet been
* initialized, this method will first construct the single instance
* before returning it.
*/
public static synchronized OGLRenderQueue getInstance() {
if (theInstance == null) {
theInstance = new OGLRenderQueue();
}
return theInstance;
}
Flushes the single OGLRenderQueue instance synchronously. If an
OGLRenderQueue 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 OGL pipeline, but only if the OGL 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 OGL pipeline and related classes.
/**
* Flushes the single OGLRenderQueue instance synchronously. If an
* OGLRenderQueue 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 OGL pipeline, but only if the OGL 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 OGL pipeline and related classes.
*/
public static void sync() {
if (theInstance != null) {
theInstance.lock();
try {
theInstance.ensureCapacity(4);
theInstance.getBuffer().putInt(SYNC);
theInstance.flushNow();
} finally {
theInstance.unlock();
}
}
}
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) {
OGLRenderQueue rq = getInstance();
rq.lock();
try {
// make sure we make the context associated with the given
// GraphicsConfig current before disposing the native resources
OGLContext.setScratchSurface(pConfigInfo);
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();
}
}
Returns true if the current thread is the OGL QueueFlusher thread.
/**
* Returns true if the current thread is the OGL QueueFlusher thread.
*/
public static boolean isQueueFlusherThread() {
return (Thread.currentThread() == getInstance().flusher);
}
public void flushNow() {
// assert lock.isHeldByCurrentThread();
try {
flusher.flushNow();
} catch (Exception e) {
System.err.println("exception in flushNow:");
e.printStackTrace();
}
}
public void flushAndInvokeNow(Runnable r) {
// assert lock.isHeldByCurrentThread();
try {
flusher.flushAndInvokeNow(r);
} catch (Exception e) {
System.err.println("exception in flushAndInvokeNow:");
e.printStackTrace();
}
}
private native void flushBuffer(long buf, int limit);
private void flushBuffer() {
// assert lock.isHeldByCurrentThread();
int limit = buf.position();
if (limit > 0) {
// process the queue
flushBuffer(buf.getAddress(), limit);
}
// reset the buffer position
buf.clear();
// clear the set of references, since we no longer need them
refSet.clear();
}
private class QueueFlusher extends Thread {
private boolean needsFlush;
private Runnable task;
private Error error;
public QueueFlusher(ThreadGroup threadGroup) {
super(threadGroup, "Java2D Queue Flusher");
setDaemon(true);
setPriority(Thread.MAX_PRIORITY);
start();
}
public synchronized void flushNow() {
// wake up the flusher
needsFlush = true;
notify();
// wait for flush to complete
while (needsFlush) {
try {
wait();
} catch (InterruptedException e) {
}
}
// re-throw any error that may have occurred during the flush
if (error != null) {
throw error;
}
}
public synchronized void flushAndInvokeNow(Runnable task) {
this.task = task;
flushNow();
}
public synchronized void run() {
boolean timedOut = false;
while (true) {
while (!needsFlush) {
try {
timedOut = false;
/*
* Wait until we're woken up with a flushNow() call,
* or the timeout period elapses (so that we can
* flush the queue periodically).
*/
wait(100);
/*
* We will automatically flush the queue if the
* following conditions apply:
* - the wait() timed out
* - we can lock the queue (without blocking)
* - there is something in the queue to flush
* Otherwise, just continue (we'll flush eventually).
*/
if (!needsFlush && (timedOut = tryLock())) {
if (buf.position() > 0) {
needsFlush = true;
} else {
unlock();
}
}
} catch (InterruptedException e) {
}
}
try {
// reset the throwable state
error = null;
// flush the buffer now
flushBuffer();
// if there's a task, invoke that now as well
if (task != null) {
task.run();
}
} catch (Error e) {
error = e;
} catch (Exception x) {
System.err.println("exception in QueueFlusher:");
x.printStackTrace();
} finally {
if (timedOut) {
unlock();
}
task = null;
// allow the waiting thread to continue
needsFlush = false;
notify();
}
}
}
}
}