<div dir="ltr"><div>Could you please elaborate why the implementation of <a href="https://github.com/openjdk/jdk/blob/8ec6b8de3bb3d7aeebdcb45d761b18cce3bab75e/src/java.desktop/unix/classes/sun/awt/X11/XTextAreaPeer.java#L258" target="_blank">sun.awt.X11.XTextAreaPeer#repaintText</a> is <i>correct</i>?<br></div><div><br></div><div>Also let me add more context to the question:</div><div>With one of the X11 regression tests on our infrastructure, we're struggling with a deadlock when the test invokes the public AWT's API method <i>java.awt.TextComponent#setText</i> <u>outside of EDT</u> while EDT is dispatching an input event. Sometimes, it leads to the situation when EDT obtains the AWT tree lock and is trying to lock the instance of <i>java.awt.TextComponent</i> while the call of <i>java.awt.TextComponent#setText</i> (which is on a different thread), in opposite, locks self and is trying to obtain the AWT tree lock. Here is a classical deadlock.</div><div><br></div><div>Before this discussion, I was strongly convinced that AWT guarantees thread-safety in the sense that it's safe to invoke any of its (not Swing's) public UI operations on any thread. However I can't find any proof (or refutation) about this in the AWT documentation now. Is it wrong?</div><div><br></div><div>If there's such a guarantee, let's take a look at the case described above again:</div><div>* The test seems correctly written, although it invokes <i>java.awt.TextComponent#setText</i> outside of EDT.</div><div>* But it internally leads to a call of <a href="https://github.com/openjdk/jdk/blob/8ec6b8de3bb3d7aeebdcb45d761b18cce3bab75e/src/java.desktop/unix/classes/sun/awt/X11/XTextAreaPeer.java#L258" target="_blank">sun.awt.X11.XTextAreaPeer#repaintText</a> which, in this case, calls Swing API outside of EDT, which is definitely incorrect. Thus we must fix the implementation of XTextAreaPeer#repaintText, not the test, right?</div><div><br></div><div><b>Summarizing all the questions:</b></div><div>* Does AWT (still) guarantee thread-safety? The question is about AWT only, excluding Swing.</div><div>* If it does, the implementation of <a href="https://github.com/openjdk/jdk/blob/8ec6b8de3bb3d7aeebdcb45d761b18cce3bab75e/src/java.desktop/unix/classes/sun/awt/X11/XTextAreaPeer.java#L258" target="_blank">sun.awt.X11.XTextAreaPeer#repaintText</a> doesn't take this into account, so it must be fixed, mustn't it?</div><div><br></div><div>Thanks in advance!</div><div><br></div><div><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr">Best regards,<div>Nikita Provotorov</div></div></div></div><br></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, Nov 17, 2023 at 7:42 PM Philip Race <<a href="mailto:philip.race@oracle.com">philip.race@oracle.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><u></u>
<div>
No, the code that calls setText() is where it starts.<br>
<br>
-phil.<br>
<br>
<div>On 11/17/23 2:51 AM, Nikita Provotorov
wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">
<div>Thanks for the response!</div>
<div>However I'd like to clarify: is it correct to say that the
current implementation of <a href="https://github.com/openjdk/jdk/blob/8ec6b8de3bb3d7aeebdcb45d761b18cce3bab75e/src/java.desktop/unix/classes/sun/awt/X11/XTextAreaPeer.java#L258" target="_blank">sun.awt.X11.XTextAreaPeer#repaintText</a> is
wrong because it doesn't make sure if <i>javax.swing.JComponent#paintImmediately</i>
is called on EDT only<span> </span>(e.g.
via<span> </span><i>SwingUtilities#invokeLater</i>)?</div>
<br clear="all">
<div>
<div dir="ltr" class="gmail_signature">
<div dir="ltr">Best regards,
<div>Nikita Provotorov</div>
</div>
</div>
</div>
<br>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Thu, Nov 16, 2023 at
9:30 PM Philip Race <<a href="mailto:philip.race@oracle.com" target="_blank">philip.race@oracle.com</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex">
<div> Because (like in this case), an AWT component might
actually be implemented using Swing,<br>
the recommendation is to treat AWT components like Swing,
and update them only on the EDT.<br>
<br>
-phil.<br>
<br>
<div>On 11/15/23 4:01 PM, Nikita Provotorov wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">
<div>Hello!<br>
</div>
<div>I've discovered that on X11 platforms a call
of java.awt.TextComponent#setText can lead to a call
of javax.swing.JComponent#paintImmediately(java.awt.Rectangle)
on the same thread.</div>
<div>Since java.awt.TextComponent#setText is allowed to
be called on any thread (because it's AWT, not Swing),
JComponent#paintImmediately may be called outside of
EDT. Is this a valid behavior?</div>
<div><br>
</div>
<div>The following stacktrace shows how exactly this can
happen:</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex">at
javax.swing.JComponent.paintImmediately<br>
at sun.awt.X11.XTextAreaPeer$AWTTextArea.repaintNow<br>
at sun.awt.X11.XTextAreaPeer.repaintText<br>
at sun.awt.X11.XTextAreaPeer.setText<br>
at java.awt.TextComponent.setText</blockquote>
<br clear="all">
<div>
<div dir="ltr" class="gmail_signature">
<div dir="ltr">Best regards,
<div>Nikita Provotorov</div>
</div>
</div>
</div>
</div>
</blockquote>
<br>
</div>
</blockquote>
</div>
</blockquote>
<br>
</div>
</blockquote></div>