[OpenJDK 2D-Dev] RFR: 8221741 ClassCastException happen when fontconfig.properties was used

Phil Race philip.race at oracle.com
Thu Dec 19 19:58:16 UTC 2019 

Hi,

> If this can get reviewed, I intend to push this fix to JDK14.

Not for 14. This will take some time to review and test and is too risky at this stage.

You say no TrueType fonts are installed, does that mean there are no scaleable fonts at all,
or are there Type 1 fonts we are skipping over ?

-phil.



On 12/18/19 6:31 AM, Langer, Christoph wrote:
> Hi,
>
> sorry for the long time that it took me to come back to this item.
>
> I eventually spent quite a significant amount of time analyzing what's going wrong here. At least, I have a few AIX LPARs, where we would always encounter this type of Exception:
>
> Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException: class sun.font.CompositeFont cannot be cast to class sun.font.PhysicalFont (sun.font.CompositeFont and sun.font.PhysicalFont are in module java.desktop of loader 'bootstrap')
>          at java.desktop/sun.font.SunFontManager.getDefaultPhysicalFont(SunFontManager.java:1081)
>          at java.desktop/sun.font.SunFontManager.initialiseDeferredFont(SunFontManager.java:960)
>          at java.desktop/sun.font.SunFontManager.findOtherDeferredFont(SunFontManager.java:898)
>          at java.desktop/sun.font.SunFontManager.findDeferredFont(SunFontManager.java:914)
>          at java.desktop/sun.font.SunFontManager.findFont2D(SunFontManager.java:2105)
>          ...
>
> The problem on our systems is triggered by two factors. First is that the font configuration file contains paths to font files that don't exist. Secondly, the system's fontconfig has no TrueType Fonts installed. Now, during loading of fonts, it goes over these non-existing font files and tries to mark their initialization in sun.font.SunFontManager::initialiseDeferredFont(String fileNameKey) by adding the key into the initialisedFonts map. Since there is no font handle available because the font couldn't be loaded but the map's value must not be null, it wants to use the handle of the default physical font. So, calling getDefaultPhysicalFont at this place triggers findFont2D and then recursive calls into initialiseDeferredFont/getDefaultPhysicalFont/findFont2D until a matching default physical font was loaded. But it's quite indeterministic which font is returned at what place in findFont2D when the recursion is unwinded, so this ClassCastException occurs.
>
> I propose to fix this by adding a "NULL FONT HANDLE" to use in initialisedFonts for fonts that can’t be loaded. This will remove the recursion during loading of fonts. And afterwards a default physical font can then still be resolved, even if our font configuration contains less fonts (no true type fonts).
>
> In my change I also add small improvements to the exception cases when trying to load non-existent true type fonts and to method getDefaultPhysicalFont.
>
> The test exercises font loading and it would demonstrate the issue without the fix on several of our AIX systems.
>
> Here is the webrev: http://cr.openjdk.java.net/~clanger/webrevs/8221741.0/
>
> @Ichiroh-san: Can you test this fix in your environment and let me know if it fixes your issue?
>
> I'll run a full platform test here at SAP, including JDK11.
>
> If this can get reviewed, I intend to push this fix to JDK14.
>
> Thanks & Best regards
> Christoph
>
>> -----Original Message-----
>> From: Phil Race <philip.race at oracle.com>
>> Sent: Mittwoch, 30. Oktober 2019 17:07
>> To: Langer, Christoph <christoph.langer at sap.com>; Ichiroh Takiguchi
>> <takiguc at linux.vnet.ibm.com>
>> Cc: 2d-dev at openjdk.java.net; Zeller, Arno <arno.zeller at sap.com>
>> Subject: Re: [OpenJDK 2D-Dev] RFR: 8221741 ClassCastException happen
>> when fontconfig.properties was used
>>
>> Yes probably best if this is reviewed and approved by someone who
>> has access to AIX. I have no idea if the XLFDs are even correct ...
>>
>> -phil.
>>
>> On 10/30/19 8:00 AM, Langer, Christoph wrote:
>>> Hi Ichiroh,
>>>
>>> I'm currently observing a test issue on one of our AIX boxes with that patch
>> in place. Please give me some time to have a closer look...
>>> Best regards
>>> Christoph
>>>
>>>> -----Original Message-----
>>>> From: 2d-dev <2d-dev-bounces at openjdk.java.net> On Behalf Of Ichiroh
>>>> Takiguchi
>>>> Sent: Montag, 28. Oktober 2019 17:59
>>>> To: Philip Race <philip.race at oracle.com>
>>>> Cc: 2d-dev at openjdk.java.net; Zeller, Arno <arno.zeller at sap.com>
>>>> Subject: Re: [OpenJDK 2D-Dev] RFR: 8221741 ClassCastException happen
>>>> when fontconfig.properties was used
>>>>
>>>> Hello Phil and other reviewers.
>>>>
>>>> I appreciate if you give me your comment and suggestion.
>>>>
>>>> Thanks,
>>>> Ichiroh Takiguchi
>>>>
>>>> On 2019-10-15 20:33, Ichiroh Takiguchi wrote:
>>>>> Hello Phil.
>>>>>
>>>>> Sorry for bad response.
>>>>>
>>>>> AIX is following case, but physical font is not defined by default.
>>>>>> If you have fonts installed and have a custom fontconfig.properties
>>>>>> file for AIX
>>>>>> which references those, then you should be able to get a default font
>>>>>> from that
>>>>>> set of known existent physical fonts.
>>>>> Please try following steps to emulate same kind this on linux (RHEL7).
>>>>> 1. Download DefaultFontTestA.java and fontconfig.properties files
>>>>>      Please modify fontconfig.properties if c0419bt_.pfb is not in
>>>>> /usr/share/X11/fonts/Type1 directory.
>>>>>
>>>>> 2. Compile and run with following options and environment variable.
>>>>>       $ javac --add-exports java.desktop/sun.font=ALL-UNNAMED
>>>>> DefaultFontTestA.java
>>>>>       $ USE_J2D_FONTCONFIG=no java --add-opens
>>>>> java.desktop/sun.font=ALL-UNNAMED
>>>>> -Dsun.awt.fontconfigfontconfig.properties DefaultFontTestA
>>>>>       defaultFontName=Dialog
>>>>>       defaultFontFileName=/dialog.ttf
>>>>>       Exception in thread "main" java.lang.ClassCastException: class
>>>>> sun.font.CompositeFont cannot be cast to class sun.font.PhysicalFont
>>>>> (sun.font.CompositeFont and sun.font.PhysicalFont are in module
>>>>> java.desktop of loader 'bootstrap')
>>>>>               at
>>>>>
>> java.desktop/sun.font.SunFontManager.getDefaultPhysicalFont(SunFontMa
>>>> nager.java:1081)
>>>>>               at DefaultFontTestA.main(DefaultFontTestA.java:48)
>>>>>
>>>>>          Font2D font2d =
>>>>>               findFont2D(getDefaultFontFaceName(), Font.PLAIN,
>>>>> NO_FALLBACK);
>>>>>     Note:
>>>>>       USE_J2D_FONTCONFIG is defined into
>>>>> src/java.desktop/unix/native/common/awt/fontpath.c
>>>>>       Dialog and /dialog.ttf are defined into
>>>>> src/java.desktop/unix/classes/sun/awt/FcFontManager.java
>>>>>
>>>>> getDefaultFontFaceName returns defaultFontName, it's "Dialog".
>>>>> findFont2D() returns Dialog CompositeFont instead of physical font.
>>>>> I think we cannot control return value for
>>>>> physicalFonts.values().iterator();
>>>>> "defaultPhysicalFont = ((CompositeFont) font2d).getSlotFont(0);" is
>>>>> useful.
>>>>>
>>>>> Please give me your comment.
>>>>>
>>>>> Thanks,
>>>>> Ichiroh Takiguchi
>>>>>
>>>>> On 2019-10-09 01:06, Philip Race wrote:
>>>>>> I think this needs a little bit more explanation first.
>>>>>> Systems without fontconfig ... meaning without libfontconfig.
>>>>>> So does that mean you just can't find fonts or have none installed ?
>>>>>> If you have fonts installed and have a custom fontconfig.properties
>>>>>> file for AIX
>>>>>> which references those, then you should be able to get a default font
>>>>>> from that
>>>>>> set of known existent physical fonts.
>>>>>>
>>>>>> If you have neither .. then you have a system configuration problem
>>>>>> and without
>>>>>> a physical font installed avoiding an exception here isn't really
>>>>>> going to help you
>>>>>> get much further. Perhaps we should throw InternalError a bit earlier.
>>>>>> I see no point in trying to survive ..
>>>>>>
>>>>>> -phil
>>>>>>
>>>>>>
>>>>>> On 10/8/19, 12:35 AM, Langer, Christoph wrote:
>>>>>>> Hi Ichiroh,
>>>>>>>
>>>>>>> thanks for the update. It looks good to me. I'll run it through test
>>>>>>> system tonight and let you know if we see issues by tomorrow.
>> Should
>>>>>>> you not hear back from me, consider it as reviewed and tested ��
>>>>>>>
>>>>>>> Thanks
>>>>>>> Christoph
>>>>>>>
>>>>>>>> -----Original Message-----
>>>>>>>> From: Ichiroh Takiguchi<takiguc at linux.vnet.ibm.com>
>>>>>>>> Sent: Montag, 7. Oktober 2019 19:16
>>>>>>>> To: Langer, Christoph<christoph.langer at sap.com>
>>>>>>>> Cc: 2d-dev at openjdk.java.net; Zeller, Arno<arno.zeller at sap.com>
>>>>>>>> Subject: RE: [OpenJDK 2D-Dev] RFR: 8221741 ClassCastException
>>>> happen
>>>>>>>> when fontconfig.properties was used
>>>>>>>>
>>>>>>>> Hello Christoph.
>>>>>>>>
>>>>>>>> I appreciate your suggestion.
>>>>>>>> JTreg testcase could throw ClassCastException instead of
>>>>>>>> InvocationTargetException.
>>>>>>>> JTreg results were in JDK-8221741
>>>>>>>>
>>>>>>>> Bug:    https://bugs.openjdk.java.net/browse/JDK-8221741
>>>>>>>> Change:
>> https://cr.openjdk.java.net/~itakiguchi/8221741/webrev.05/
>>>>>>>> Could you review the fix ?
>>>>>>>>
>>>>>>>> Thanks,
>>>>>>>> Ichiroh Takiguchi
>>>>>>>> IBM Japan, Ltd.
>>>>>>>>
>>>>>>>> On 2019-10-07 22:53, Langer, Christoph wrote:
>>>>>>>>> Hi Ichiroh,
>>>>>>>>>
>>>>>>>>> this is great, thanks for doing this. We regularly see this and
>>>>>>>>> just
>>>>>>>>> stumbled over it the other day where the fontconfig of our test
>>>>>>>>> user
>>>>>>>>> was corrupted somehow.
>>>>>>>>>
>>>>>>>>> As for the test, I would reduce the amount of reflection a little
>>>>>>>>> bit.
>>>>>>>>> It should not be necessary to access SunFontManager via
>>>>>>>>> Class.forName,
>>>>>>>>> you already exported it to the test via the @modules statement.
>> You
>>>>>>>>> can probably use this coding (please try as I didn't test it��):
>>>>>>>>>
>>>>>>>>>            SunFontManager sfm = SunFontManager.getInstance();
>>>>>>>>>            Field defaultFontName_fid =
>>>>>>>>> SunFontManager.class.getDeclaredField("defaultFontName");
>>>>>>>>>            defaultFontName_fid.setAccessible(true);
>>>>>>>>>            defaultFontName_fid.set(sfm, "Dialog");
>>>>>>>>>            Method loadFonts_mid =
>>>>>>>>> SunFontManager.class.getDeclaredMethod("loadFonts");
>>>>>>>>>            loadFonts_mid.setAccessible(true);
>>>>>>>>>            loadFonts_mid.invoke(sfm);
>>>>>>>>>            PhysicalFont physicalFont = sfm.getDefaultPhysicalFont();
>>>>>>>>>            System.out.println(physicalFont);
>>>>>>>>>
>>>>>>>>> If you want, I can run your (updated) patch through our test
>>>>>>>>> system.
>>>>>>>>>
>>>>>>>>> Thanks
>>>>>>>>> Christoph
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>> -----Original Message-----
>>>>>>>>>> From: 2d-dev<2d-dev-bounces at openjdk.java.net>  On Behalf Of
>>>>>>>>>> Ichiroh
>>>>>>>>>> Takiguchi
>>>>>>>>>> Sent: Montag, 7. Oktober 2019 09:33
>>>>>>>>>> To: 2d-dev at openjdk.java.net
>>>>>>>>>> Subject: [OpenJDK 2D-Dev] RFR: 8221741 ClassCastException
>> happen
>>>>>>>> when
>>>>>>>>>> fontconfig.properties was used
>>>>>>>>>>
>>>>>>>>>> Hello.
>>>>>>>>>>
>>>>>>>>>> Could you review the fix ?
>>>>>>>>>>
>>>>>>>>>> Bug:    https://bugs.openjdk.java.net/browse/JDK-8221741
>>>>>>>>>> Change:
>>>> https://cr.openjdk.java.net/~itakiguchi/8221741/webrev.04/
>>>>>>>>>> JTreg testcase and results are including JDK-8221741 [1].
>>>>>>>>>>
>>>>>>>>>> [1] https://bugs.openjdk.java.net/browse/JDK-8221741
>>>>>>>>>>
>>>>>>>>>> Thanks,
>>>>>>>>>> Ichiroh Takiguchi
>>>>>>>>>> IBM Japan, Ltd.

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