[OpenJDK 2D-Dev] [13] RFR: JDK-8221412: lookupPrintServices() does not always update the list of Windows remote printers

[Alexey Ivanov]

Please see the updated webrev:
http://cr.openjdk.java.net/~aivanov/8221412/webrev.1/

The difference between .0 and .1 is in some minor white-space 
adjustments, like parameter alignment.

On 26/03/2019 17:01, Alexey Ivanov wrote:
> Hi,
>
> Please review the fix for jdk 13:
>
> bug: https://bugs.openjdk.java.net/browse/JDK-8221412
> webrev: http://cr.openjdk.java.net/~aivanov/8221412/webrev.0/
>
> Description:
> The list of printers is not updated in the situation where there are 
> no remote printers on the system and later the user adds a remote 
> printer.
>
> Root cause:
> JDK-8153732 [1] added a new thread which polls remote printers on the 
> system and updates the list if it detects a change. In this case it 
> does not update the print services because of this condition:
> 449 if (prevRemotePrinters != null && prevRemotePrinters.length > 0)
> prevRemotePrinters is not null but its length is zero because no 
> remote printers were initially present on the system.
>
> Fix:
> I removed this if. We have to update the list printers if doCompare() 
> returns true. Either prevRemotePrinters or currentRemotePrinters, or 
> both can be null; doCompare() handles this situation gracefully after 
> JDK-8212202 [2].
>
> The listener called getRemotePrintersNames() twice: in constructor and 
> in run() before entering the first sleep. Now it's done only once.
>
> I consolidated the implementation of getAllPrinterNames() and 
> getRemotePrintersNames(). They were very similar. The old 
> implementation of getRemotePrintersNames() got the list of both local 
> and remote printers and then filtered out local ones. The new 
> implementation gets the list of remote printers only. So the 
> difference between the two is limited to the flags passed to 
> EnumPrinters.
>
> If there are no remote printers, the new version 
> getRemotePrintersNames() returns null instead of empty array. As 
> mentioned earlier, doCompare() handles this situation.
>
> I'll add the bugid (8221412) to the regression test when fixing 
> JDK-8221263 [3]. I'm currently working on it.
>
>
> Thank you in advance.
>
> Regards,
> Alexey
>
> [1] https://bugs.openjdk.java.net/browse/JDK-8153732
> [2] https://bugs.openjdk.java.net/browse/JDK-8212202
> [3] https://bugs.openjdk.java.net/browse/JDK-8221263
-- 
Regards,
Alexey