[OpenJDK 2D-Dev] Suggest a modification to isPostscript exception handling

Sean Chou zhouyx at linux.vnet.ibm.com
Sun Aug 26 12:24:02 UTC 2012


Hi Phil,

On Sat, Aug 25, 2012 at 2:10 AM, Phil Race <philip.race at oracle.com> wrote:

> Hi,
>
> On 8/23/2012 10:23 PM, Sean Chou wrote:
>
>> Hi Phil,
>>
>>     I'm really sorry about this typo, the modification looks so simple
>> that I became careless when porting.
>>
>
> That's a slippery slope. Only send out code that you built and tested.
> What if reviewer also thinks "this must be OK else it wouldn't have built,
> and of course he built it ... "

You are right, that's my fault and it won't happen again.


>
>
>>     The patch is from ibmjdk and it has been tested on Java6 since Oct,
>> 2007 and on Java7 since Feb, 2012.  To be honest, this modification isn't
>> related to a real bug in openjdk for now; it is posted to see if there are
>> any reason that the printer is assumed to be a postscript printer in all
>> exceptions.
>>
>
> The code went into JDK 6u2 on 27th Feb 2007 and would have been released a
> few months later.
> IBM apparently made this change pretty soon after that.
> So the question that should be asked is not why is the openjdk code like
> this,
> but why did IBM make the change they did ?
> I have no record or recollection of any problem reports.
> I can't see any value to it. Unless there's a reflection problem (which
> there should not be!)
> its never going to get executed.
>

The reason is quite straight forward as described in the first
mail. IPPPrintService.**isPostscript catches all IOException and return
true, while the try block in PSPrinterJob catches all Throwable . In our
scenario, an non-io exception is produced in the try block and it get
executed.

As there are some bugs related to "/DeferredMediaSelection true" like
http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6266343; and it is
strange to return true when exceptions are seen because the default
behavior in try block is to return true. We think the expansion from
IOException to Throwable is too much, and return false for exception is
better. Does it return true because it is assumed not to run ?



>
> -phil.
>
>
>>     Many thanks.
>>
>> The false is corrected in this webrev:
>> http://cr.openjdk.java.net/~**zhouyx/OJDK-429/webrev.02/<http://cr.openjdk.java.net/~zhouyx/OJDK-429/webrev.02/><
>> http://cr.openjdk.java.net/%**7Ezhouyx/OJDK-429/webrev.02/<http://cr.openjdk.java.net/%7Ezhouyx/OJDK-429/webrev.02/>
>> >
>>
>>
>> On Fri, Aug 24, 2012 at 12:20 AM, Phil Race <philip.race at oracle.com<mailto:
>> philip.race at oracle.com**>> wrote:
>>
>>     Sean,
>>
>>     Without even commenting on the merits or necessity I note that you
>>     cannot possibly
>>     have even built this patch, much less tested it.
>>
>>     > 625 return Boolean.FLASE;
>>
>>     -phil.
>>
>>
>>     On 8/23/12 1:58 AM, Sean Chou wrote:
>>
>>>     Hello,
>>>
>>>         I updated the repository to 2d, the webrev is now:
>>>     http://cr.openjdk.java.net/~**zhouyx/OJDK-429/webrev.01/<http://cr.openjdk.java.net/~zhouyx/OJDK-429/webrev.01/>
>>>     <http://cr.openjdk.java.net/%**7Ezhouyx/OJDK-429/webrev.01/<http://cr.openjdk.java.net/%7Ezhouyx/OJDK-429/webrev.01/>
>>> >
>>>
>>>     Please take a look.
>>>
>>>     ---------- Forwarded message ----------
>>>     From: *Sean Chou* <zhouyx at linux.vnet.ibm.com
>>>     <mailto:zhouyx at linux.vnet.ibm.**com <zhouyx at linux.vnet.ibm.com>>>
>>>     Date: Thu, Aug 23, 2012 at 2:24 PM
>>>     Subject: Suggest a modification to isPostscript exception handling
>>>     To: 2d-dev at openjdk.java.net <mailto:2d-dev at openjdk.java.**net<2d-dev at openjdk.java.net>
>>> >
>>>
>>>
>>>     Hello,
>>>
>>>          This is a simple modification to sun/print/PSPrinterJob.java.
>>>          When sun.print.IPPPrintService.**isPostscript method checks if
>>>     the printer is a postscript printer, if IOException happens, the
>>>     method assumes the printer is postscript printer
>>>     (IPPPrintService.java, line 1605). In class PSPrinterJob, it
>>>     invoke isPostscript and assumes all  Throwables to be a
>>>     postscript printer ( PSPrinterJob.java, line 625 ).  I think it
>>>     should return false in cases exceptions other
>>>     than IOException are caught, IOException should not be expanded
>>>     to all Throwable.
>>>
>>>     The webrev is at:
>>>     http://cr.openjdk.java.net/~**zhouyx/OJDK-429/webrev.00/<http://cr.openjdk.java.net/~zhouyx/OJDK-429/webrev.00/>
>>>     <http://cr.openjdk.java.net/%**7Ezhouyx/OJDK-429/webrev.00/<http://cr.openjdk.java.net/%7Ezhouyx/OJDK-429/webrev.00/>>
>>>  .
>>>
>>>
>>>     Please take a look.
>>>
>>>     --     Best Regards,
>>>     Sean Chou
>>>
>>>
>>
>>
>>
>> --
>> Best Regards,
>> Sean Chou
>>
>>
>


-- 
Best Regards,
Sean Chou
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