<Swing Dev> 7189299 DefaultButtonModel instance keeps stale listeners of JButton in case of multiple SwingUtilities.updateComponentTreeUI() calls
Frank Ding
dingxmin at linux.vnet.ibm.com
Thu Dec 6 08:39:43 UTC 2012
Hi Alexandr,
I did several attempts but still have hang issues somewhere. It
seems the new approach of caching gui components created each time is
not practical because of the threading restriction already imposed on
HTMLDocument.
Can we make compromise by turning to previous solution (v7 in
particular) and generalize it to other gui components (which means there
would be JCheckBoxWrapper, JRadioButtonWrapper, JPasswordFieldWrapper,
JTextFieldWrapper, JListWrapper, JComboBoxWrapper, and JButtonWrapper).
Or shall we fix JButton only because it causes obvious exception visible
to client? I am short of ideas...
http://cr.openjdk.java.net/~dingxmin/7189299/webrev.07/
Best regards,
Frank
On 12/5/2012 2:12 PM, Frank Ding wrote:
> Hi Alexandr,
> I observed the same issue in my environment as well. My proposed
> patch would cause severe regression issues. I am looking into the
> locking issue.
>
> Thanks,
> Frank
>
> On 12/3/2012 6:53 PM, Alexander Scherbatiy wrote:
>>
>>
>> Could you check the following sample with your latest fix? It just
>> hangs on my side.
>>
>> - put the sample.html and the response.html files on a server
>> - update path to the html files in the LoadingWebPageToJEditorPane
>> class
>>
>> ------------- sample.html ------------
>> <form name="input" action="response.html" method="get">
>> Username: <input type="text" name="user">
>> <input type="submit" value="Submit">
>> </form>
>> ------------- response.html ------------
>> <html>
>> <body>
>> Hello World!
>> </body>
>> </html>
>> ------------- LoadingWebPageToJEditorPane.html ------------
>> import java.net.URL;
>> import javax.swing.JEditorPane;
>> import javax.swing.JFrame;
>> import javax.swing.JScrollPane;
>> import javax.swing.SwingUtilities;
>>
>> public class LoadingWebPageToJEditorPane {
>>
>> private static final String HTML_PATH =
>> "http://serever/path/sample.html";
>>
>> public static void main(String[] a) throws Exception {
>>
>> SwingUtilities.invokeAndWait(new Runnable() {
>>
>> @Override
>> public void run() {
>> try {
>>
>> JFrame frame = new JFrame();
>> frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
>>
>> JEditorPane editorPane = new JEditorPane();
>> editorPane.setPage(new URL(HTML_PATH));
>>
>> frame.add(new JScrollPane(editorPane));
>> frame.setSize(300, 200);
>> frame.setVisible(true);
>> SwingUtilities.updateComponentTreeUI(editorPane);
>> } catch (Exception ex) {
>> throw new RuntimeException(ex);
>> }
>> }
>> });
>> }
>> }
>> ---------------------------------------
>>
>> Thanks,
>> Alexandr.
>>
>>
>> On 11/28/2012 10:29 AM, Frank Ding wrote:
>>> Hi Alexandr,
>>> I created a new patch v8 @
>>> http://cr.openjdk.java.net/~dingxmin/7189299/webrev.08/. It uses
>>> the newly proposed approach mentioned in my last email. Could you
>>> please help to review it again?
>>>
>>> The patch, of course, passed jtreg test bug7189299.java in the
>>> patch. What's more, I did additional tests for JComboBox,
>>> JTextField and JList in my IDE by comparing listener numbers
>>> observed during debugging with/without my patch. The listener
>>> numbers were doubled without the fix. This proves that v8 patch
>>> works for all components. I think I can write those additional
>>> tests as jtreg tests after the patch passes review.
>>>
>>> One notable change is that I had to restrict the scope of holding
>>> a write lock in DefaultStyledDocument because otherwise, we cannot
>>> store the new component created in FormView.createComponent(). The
>>> stack trace is pasted below for reference.
>>>
>>> Exception in thread "main" java.lang.reflect.InvocationTargetException
>>> at java.awt.EventQueue.invokeAndWait(EventQueue.java:1270)
>>> at
>>> javax.swing.SwingUtilities.invokeAndWait(SwingUtilities.java:1350)
>>> at bug7189299.main(bug7189299.java:116)
>>> Caused by: java.lang.IllegalStateException: Attempt to mutate in
>>> notification
>>> at
>>> javax.swing.text.AbstractDocument.writeLock(AbstractDocument.java:1357)
>>> at
>>> javax.swing.text.html.HTMLDocument.obtainLock(HTMLDocument.java:1708)
>>> at
>>> javax.swing.text.html.FormView.createComponent(FormView.java:211)
>>> ......(omitted)......
>>> at
>>> javax.swing.plaf.basic.BasicTextUI$RootView.insertUpdate(BasicTextUI.java:1602)
>>> at
>>> javax.swing.plaf.basic.BasicTextUI$UpdateHandler.insertUpdate(BasicTextUI.java:1861)
>>> at
>>> javax.swing.text.AbstractDocument.fireInsertUpdate(AbstractDocument.java:201)
>>>
>>> at
>>> javax.swing.text.DefaultStyledDocument.create(DefaultStyledDocument.java:155)
>>> <------ FormView.createComponent is triggered by this call which
>>> has already held the lock
>>> at javax.swing.text.html.HTMLDocument.create(HTMLDocument.java:469)
>>> ......(omitted)......
>>>
>>> This change did violate what is documented in
>>> AbstractDocument.writeLock that "This situation violates the bean
>>> event model where order of delivery is not guaranteed and all
>>> listeners should be notified before further mutations are allowed.
>>> " However, without the change of shrinking lock scope, the
>>> component cannot be saved once it is created in
>>> FormView.createComponent(). I found it is even harder to save it
>>> later in code but perhaps there does exist a more appropriate place
>>> to do this. If you have any better suggestion, I am glad to know.
>>>
>>> Also I searched references to 'StyleConstants.ComponentAttribute'
>>> as you asked. The result is listed below. Note that the command
>>> 'grep' is invoked under openjdk 8 top directory.
>>> $ grep -R 'ComponentAttribute' .
>>> ./jdk/src/share/classes/javax/swing/text/StyleConstants.java: public
>>> static final Object ComponentAttribute = new
>>> CharacterConstants("component");
>>> ./jdk/src/share/classes/javax/swing/text/StyleConstants.java: return
>>> (Component) a.getAttribute(ComponentAttribute);
>>> ./jdk/src/share/classes/javax/swing/text/StyleConstants.java:
>>> a.addAttribute(ComponentAttribute, c);
>>> ./jdk/src/share/classes/javax/swing/text/StyleConstants.java:
>>> Background, ComponentAttribute, IconAttribute,
>>> ./jdk/src/share/classes/javax/swing/text/StyledEditorKit.java:
>>> set.removeAttribute(StyleConstants.ComponentAttribute);
>>> Binary file ./jdk/test/sun/tools/jhat/jmap.bin matches
>>>
>>> So ComponentAttribute is not referenced by other classes except
>>> StyledEditorKit. StyleConstants exposes ComponentAttribute in
>>> getComponent() and setComponent() methods. References to
>>> StyleConstants.getComponent and StyleConstants.setComponent are
>>> further searched in repo.
>>>
>>> $ grep -R 'StyleConstants.getComponent' .
>>> ./jdk/src/share/classes/javax/swing/text/ComponentView.java: * the
>>> element (by calling StyleConstants.getComponent). A
>>> ./jdk/src/share/classes/javax/swing/text/ComponentView.java:
>>> Component comp = StyleConstants.getComponent(attr);
>>>
>>> $ grep -R 'StyleConstants.setComponent' .
>>> ./jdk/src/share/classes/javax/swing/JTextPane.java:
>>> StyleConstants.setComponent(inputAttributes, c);
>>>
>>> From the facts above, I think we are sufficiently confident to use
>>> ComponentAttribute.
>>>
>>> Please let me know if you have any comments and I can do more
>>> regression tests and provide more jtreg test cases as next step.
>>>
>>> Thanks and regards,
>>> Frank
>>>
>>> On 11/15/2012 5:18 PM, Alexander Scherbatiy wrote:
>>>> On 11/14/2012 10:22 AM, Frank Ding wrote:
>>>>> Hi Alexandr,
>>>>> After a couple of hours investigating the possibility of fixing
>>>>> JComboBox.setModel(null) and JTextComponent.setComponent(null), I
>>>>> found that
>>>>> 1. In JComboBox.setModel, the new model, null in this case, is
>>>>> eventually passed to BasicComboPopup.propertyChange where
>>>>> JList.setModel is called. JList.setModel rejects the null model
>>>>> because of its api restriction. Below I listed the offending call
>>>>> stacks in my IDE. This makes sense as the associated drop down
>>>>> JList needs new model. However, it makes fixing
>>>>> JComboBox.setModel(null) hard or impossible.
>>>>> Exception in thread "main" java.lang.IllegalArgumentException:
>>>>> model must be non null
>>>>> at javax.swing.JList.setModel(JList.java:1674)
>>>>> at
>>>>> javax.swing.plaf.basic.BasicComboPopup$Handler.propertyChange(BasicComboPopup.java:939)
>>>>> at
>>>>> java.beans.PropertyChangeSupport.fire(PropertyChangeSupport.java:335)
>>>>> at
>>>>> java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:327)
>>>>> at
>>>>> java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:263)
>>>>> at java.awt.Component.firePropertyChange(Component.java:8413)
>>>>> at javax.swing.JComboBox.setModel(JComboBox.java:322)
>>>>>
>>>>> 2. JTextComponent.setComponent(null) can be fixed but code change
>>>>> in BasicTextUI is also required.
>>>>>
>>>>> Since setting null model to JComboBox, JList and JTextComponent is
>>>>> impossible or dangerous, just as you mentioned, we could set a non
>>>>> null new model to these UI components just for the purpose of
>>>>> having the side effect of removing listeners from old model. Are
>>>>> you ok with this approach?
>>>> Yes. Please, try this and run the html swing automated tests
>>>> from the test/javax/swing/text/html diroctory to check possible
>>>> regressions.
>>>>
>>>> Thanks,
>>>> Alexandr.
>>>>
>>>>> By the way, I will investigate your another question "Could you
>>>>> also check that the StyleConstants.ComponentAttribute property
>>>>> value can't be rewritten by the JDK code or by public methods."
>>>>> and reply soon.
>>>>>
>>>>> Best regards,
>>>>> Frank
>>>>>
>>>>> On 11/13/2012 7:49 PM, Alexander Scherbatiy wrote:
>>>>>> On 11/13/2012 11:53 AM, Frank Ding wrote:
>>>>>>> Hi Alexandr,
>>>>>>> As for your comment "Could you create an issue that a
>>>>>>> JComboBox.setModel(null) call throws NPE? You could fix it
>>>>>>> before the 7189299 issue. ", I created a bug with internal
>>>>>>> review ID of 2381499 on JComboBox.setModel(null). But test
>>>>>>> shows that JPasswordField.setDocument(null),
>>>>>>> JTextField.setDocument(null), JList.setModel(null) and
>>>>>>> JTextArea.setDocument(null) all throw NPE. Particularly,
>>>>>>> JList.setModel(null) has null check and throws
>>>>>>> IllegalArgumentException("model" must be non null"). Shall I
>>>>>>> include those components as well?
>>>>>>
>>>>>> There is the javadoc for the JList setModel() method: Throws
>>>>>> IllegalArgumentException - if model is null. So it is
>>>>>> undesirable to change the public API.
>>>>>> However, it is possible to set a new empty model for the
>>>>>> JList. The list listeners should be removed from the old model in
>>>>>> this case.
>>>>>>
>>>>>> You could have only 2 issues: one for components that allow
>>>>>> to set a null model but throws NPE (like JComboBox) and another
>>>>>> for components that does not allow to set null model but they do
>>>>>> not remove listeners from the old model in case if a new model is
>>>>>> set.
>>>>>>
>>>>>> Thanks,
>>>>>> Alexandr.
>>>>>>
>>>>>>> Thanks for your guidance in advance.
>>>>>>>
>>>>>>> Best regards,
>>>>>>> Frank
>>>>>>>
>>>>>>> On 11/8/2012 10:55 PM, Alexander Scherbatiy wrote:
>>>>>>>> On 11/7/2012 10:56 AM, Frank Ding wrote:
>>>>>>>>> Hi Alexandr,
>>>>>>>>> Unfortunately, all the JComponents involved in
>>>>>>>>> FormView.createComponent() have bugs!
>>>>>>>>> I have done tests for all other swing components, i.e.
>>>>>>>>> JCheckBox, JRadioButton, JPasswordField, JTextField, JList,
>>>>>>>>> JComboBox and JTextField. Sadder news is that if we fix all
>>>>>>>>> components in the same way as I did for JButton, we need to
>>>>>>>>> subclass them all, resulting in JCheckBoxWrapper,
>>>>>>>>> JRadioButtonWrapper, JPasswordFieldWrapper, JTextFieldWrapper,
>>>>>>>>> JListWrapper, JComboBoxWrapper, JTextFieldWrapper plus
>>>>>>>>> JButtonWrapper! This approach becomes unacceptable when all
>>>>>>>>> swing components are affected.
>>>>>>>>> Shall we fix it in other way illustrated below?
>>>>>>>>> 1. Whenever a swing component is created, it is kept in
>>>>>>>>> AttributeSet, as what is now for model.
>>>>>>>>> 2. In FormView.createComponent(), the old swing component can
>>>>>>>>> be retrieved via
>>>>>>>>> attr.getAttribute(StyleConstants.ComponentAttribute). Note
>>>>>>>>> that ComponentAttribute is newly added.
>>>>>>>> This way should be carefully investigated that it does
>>>>>>>> not introduce new memory leaks.
>>>>>>>> Could you also check that the
>>>>>>>> StyleConstants.ComponentAttribute property value can't be
>>>>>>>> rewritten by the JDK code or by public methods.
>>>>>>>>
>>>>>>>>> 3. Before setting shared model to a newly initialized swing
>>>>>>>>> component, call oldComp.setModel(null), delegating
>>>>>>>>> deregistration to setModel method.
>>>>>>>>> 4. Seems some setModel such as AbstractButton.setModel() can
>>>>>>>>> function well when the param, new model, is null while
>>>>>>>>> JComboBox.setModel() will throw NPE in case of null param.
>>>>>>>> Could you create an issue that a JComboBox.setModel(null)
>>>>>>>> call throws NPE? You could fix it before the 7189299 issue.
>>>>>>>>
>>>>>>>> Thanks,
>>>>>>>> Alexandr.
>>>>>>>>
>>>>>>>>> 5. Add null check code in those problematic setModel or
>>>>>>>>> setDocument methods.
>>>>>>>>>
>>>>>>>>> Any idea is appreciated. Thanks.
>>>>>>>>>
>>>>>>>>> Best regards,
>>>>>>>>> Frank
>>>>>>>>>
>>>>>>>>> On 11/6/2012 9:26 PM, Alexander Scherbatiy wrote:
>>>>>>>>>> On 11/5/2012 11:20 AM, Frank Ding wrote:
>>>>>>>>>>> Hi Alexander,
>>>>>>>>>>> Based on your comments last time, I refined my patch of v6
>>>>>>>>>>> and offered v7 @
>>>>>>>>>>> http://cr.openjdk.java.net/~dingxmin/7189299/webrev.07/
>>>>>>>>>>
>>>>>>>>>> This version of the fix looks good for me.
>>>>>>>>>> It seems that it is the only good way to check that a
>>>>>>>>>> button model contains AbstarctButton.Handler listener.
>>>>>>>>>>
>>>>>>>>>> Could you also check that others models used in the
>>>>>>>>>> createComponent() method do not have such memory leaks (even
>>>>>>>>>> the NPE is not thrown)?
>>>>>>>>>>
>>>>>>>>>>> 4. Could you add the check that the action listener is
>>>>>>>>>>> invoked only once after a component tree updating and the
>>>>>>>>>>> action does the same that it does before a component tree
>>>>>>>>>>> updating?
>>>>>>>>>>> Answer: I am afraid I could not make it in the auto test
>>>>>>>>>>> (bug7189299.java) but I can achieve it to some degree in
>>>>>>>>>>> manual test FormSubmit, the one you illustrated below.
>>>>>>>>>>> My idea of checking it in FormSubmit.java is subclassing
>>>>>>>>>>> JEditorPane and overriding 'public EditorKit getEditorKit()'
>>>>>>>>>>> where stack traces can be examined in the overridden method
>>>>>>>>>>> to make sure FormView.submitData occurs only once. This
>>>>>>>>>>> approach works because FormView.submitData() calls
>>>>>>>>>>> JEditorPane.getEditorKit but is tricky. However, it's the
>>>>>>>>>>> only way I can think of without any additional framework
>>>>>>>>>>> support. If you are in favor of adding the check in
>>>>>>>>>>> FormSubmit.java, I am willing to do that.
>>>>>>>>>>
>>>>>>>>>> At least a separated manual test can be added that asks
>>>>>>>>>> a user to put a response.html file to a server and according
>>>>>>>>>> to the server url checks that JTeditor pane show the response
>>>>>>>>>> text after a button pressing.
>>>>>>>>>>
>>>>>>>>>> html = new JEditorPane("text/html",
>>>>>>>>>> "<html><body><form action=\"" + userURL + "\">"
>>>>>>>>>> + "<input type=submit name=submit
>>>>>>>>>> value=\"submit\"/>"
>>>>>>>>>> + "</form></body></html>");
>>>>>>>>>>
>>>>>>>>>> response.html:
>>>>>>>>>> <html> <body> Hello World! </body> </html>
>>>>>>>>>>
>>>>>>>>>> Thanks,
>>>>>>>>>> Alexandr.
>>>>>>>>>>
>>>>>>>>>>> Thanks again for all your comments and your support. Once
>>>>>>>>>>> again, if you have any further concern or comment, please
>>>>>>>>>>> don't hesitate to let me know.
>>>>>>>>>>>
>>>>>>>>>>> Best regards,
>>>>>>>>>>> Frank
>>>>>>>>>>>
>>>>>
>>>>
>>>
>>
>
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