Integrated: 8255598: [PPC64] assert(Universe::heap()->is_in(result)) failed: object not in heap

Martin Doerr mdoerr at openjdk.java.net
Tue Nov 10 11:52:55 UTC 2020


On Thu, 5 Nov 2020 16:46:43 GMT, Martin Doerr <mdoerr at openjdk.org> wrote:

> JDK-8237363 introduced "assert(Universe::heap()->is_in..." check in CompressedOops::decode functions.
> This assertion restricts the usability of the decode functions. There are periods of time (during GC) at which we can't use " Universe::heap()->is_in" because the pointer gets switched between old and new location, but "Universe::heap()->is_in" is not yet accurate.
> PPC64 code has a usage of CompressedOops::decode which is affected by this problem. (It was observed with SerialGC, see JBS.)
> We could also use a weaker assertion, but seems like other people value the stronger assertion more. So I suggest to use decode_raw as workaround for PPC64.

This pull request has now been integrated.

Changeset: 9d07259f
Author:    Martin Doerr <mdoerr at openjdk.org>
URL:       https://git.openjdk.java.net/jdk/commit/9d07259f
Stats:     5 lines in 1 file changed: 4 ins; 0 del; 1 mod

8255598: [PPC64] assert(Universe::heap()->is_in(result)) failed: object not in heap

Reviewed-by: ayang, tschatzl

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PR: https://git.openjdk.java.net/jdk/pull/1078


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