RFR: 8194653: Deadlock involving FileSystems.getDefault and System.loadLibrary call

[Andrew John Hughes]

On 19/06/2019 11:02, Andrew Dinn wrote:
> Could I please have reviews for the following patch against jdk8u-dev:
> 
>   Webrev: http://cr.openjdk.java.net/~adinn/8194653/webrev.00/
>   JIRA:   https://bugs.openjdk.java.net/browse/JDK-8194653
> 
> Background:
> 
> The email threads discussing this issue were a tad inconclusive for both
> jdk8u and jdk9+.
> 
> On jdk8 a suggestion was left hanging that a fix in the jdk not jvm
> might be better.
> 
> On jdk9+ upwards the deadlock does not manifest but it might do in
> future so an investigation was requested by Alan Bateman which has not
> been followed up.
> 
> Nevertheless, Oracle have applied a jdk8u patch in 8u212, although using
> a different JIRA issue.
> 
>   https://bugs.openjdk.java.net/browse/JDK-8222858
> 
> I am not sure why this has been done as a backport? Note it may be
> relevant that the original JIRA (8194653) is marked as being against 8u231.
> 
> Testing:
> 
> The reproduced supplied with the original patch and included in the
> above webrev fails before applying and works afterwards.
> 
> regards,
> 
> 
> Andrew Dinn
> -----------
> 

The clue is in the build number. The high (30+) build numbers generally
indicate customer builds, as far as we can tell. It's relatively common
for an issue to be listed as fixed in 8ux b30 and 8ux+1 b30, before
finally being in the GA build of 8ux+2. I think this one just looks
extra odd because the main bug is fixed directly in 8, rather than a
later JDK release and all the 8 fixes being backports. Our filter
actually missed some bugs marked as 8u202 b3x last cycle, because it was
assumed they were fixed by the integration of 8u202, before Oracle quit
the project, when actually that work only went up to b08, the GA release.

This one is another example:

https://bugs.openjdk.java.net/browse/JDK-8155951

That given, I think we can include this in the October CPU, rather than
trying to rush in a release for July's, which freezes next week.

Thanks,
-- 
Andrew :)

Senior Free Java Software Engineer
Red Hat, Inc. (http://www.redhat.com)

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