[OpenJDK 2D-Dev] RFR: 7018932 : Drawing very large coordinates with a dashed Stroke can cause Java to hang [v3]

[Laurent Bourgès]

On Sun, 10 Jan 2021 11:16:51 GMT, Laurent Bourgès <lbourges at openjdk.org> wrote:

>> test/jdk/sun/java2d/marlin/DrawingTest7018932.java line 42:
>> 
>>> 40:  * @run main DrawingTest7018932
>>> 41:  */
>>> 42: public class DrawingTest7018932 extends JPanel {
>> 
>> This will work only in the headful environment, I suggest something like this:
>> /*
>>  * Copyright (c) 2021, 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.
>>  *
>>  * 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.
>>  */
>> 
>> import java.awt.BasicStroke;
>> import java.awt.Graphics2D;
>> import java.awt.RenderingHints;
>> import java.awt.Stroke;
>> import java.awt.geom.Line2D;
>> import java.awt.image.BufferedImage;
>> 
>> import static java.awt.image.BufferedImage.TYPE_INT_ARGB_PRE;
>> 
>> /*
>>  * @test
>>  * @bug 7018932
>>  * @summary fix LoopPipe.getStrokedSpans() performance (clipping enabled by Marlin renderer)
>>  */
>> public final class StrokedLinePerf {
>> 
>>     public static void main(String[] args) {
>>         BufferedImage bi = new BufferedImage(400, 400, TYPE_INT_ARGB_PRE);
>>         test(bi, true);
>>         test(bi, false);
>>     }
>> 
>>     private static void test(BufferedImage bi, boolean useAA) {
>>         Graphics2D g2d = bi.createGraphics();
>>         long start = System.nanoTime();
>> 
>>         if (useAA) {
>>             g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
>>                     RenderingHints.VALUE_ANTIALIAS_ON);
>>         } else {
>>             g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
>>                     RenderingHints.VALUE_ANTIALIAS_OFF);
>>         }
>> 
>>         Stroke stroke = new BasicStroke(2.0f, 1, 0, 1.0f, new float[]{0.0f, 4.0f}, 0.0f);
>>         g2d.setStroke(stroke);
>> 
>>         //Large values to trigger crash / infinite loop.
>>         g2d.draw(new Line2D.Double(4.0, 1.794369841E9, 567.0, -2.147483648E9));
>> 
>>         System.out.println("Test duration= " + (1e-6 * (System.nanoTime() - start)) + " ms.");
>>         g2d.dispose();
>>     }
>> }
>
> Interesting, but BufferedImage rendering may use another java2d pipeline... so I will check if LoopPipe.getStrokedSpans() is used by your test code.

Moreover the bug was detected on both gdi & xrender native pipelines...

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PR: https://git.openjdk.java.net/jdk/pull/2013