On Tue, 21 Oct 2025 20:50:17 GMT, Phil Race <[email protected]> wrote:
>> I meant, is it possible to get this surfaceData before invalidation on one
>> thread, start rendering to it, and then call delegate.dispose() on another
>> thread? Don't we need some kind of synchronization or is it already somehow
>> implemented?
>
> delegate.dispose just replaces the reference in the graphics with a
> NullSurfaceData.
> There's no synchronization needed.
multi-threaded version of the `PrintJobAfterEndTest` always crashed for me even
with a patch:
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.JobAttributes;
import java.awt.JobAttributes.DialogType;
import java.awt.PageAttributes;
import java.awt.PrintJob;
import java.awt.Toolkit;
import java.util.concurrent.CountDownLatch;
public final class MTPrintJobAfterEndTest {
public static void main(String[] args) throws InterruptedException {
JobAttributes jobAttributes = new JobAttributes();
jobAttributes.setDialog(DialogType.NONE);
PageAttributes pageAttributes = new PageAttributes();
Frame f = new Frame();
Toolkit toolkit = f.getToolkit();
for (int i = 0; i < 1000; i++) {
PrintJob job = toolkit.getPrintJob(f, "Crash Test",jobAttributes,
pageAttributes);
if (job != null) {
Graphics g = job.getGraphics();
CountDownLatch latch = new CountDownLatch(1);
Thread endThread = new Thread(() -> {
try {
latch.await();
job.end();
} catch (Throwable ignore) {}
});
Thread drawThread = new Thread(() -> {
try {
latch.await();
g.drawLine(0, 100, 200, 100);
} catch (Throwable ignore) {}
});
endThread.start();
drawThread.start();
latch.countDown();
endThread.join();
drawThread.join();
}
}
}
}
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PR Review Comment: https://git.openjdk.org/jdk/pull/27905#discussion_r2449772224
