> Hi all, > > can I have reviews for this change that changes the way how archive regions > are managed in general and specifically by the G1 collector, fixing the > crashes caused by adding the module graph into the archive in > [JDK-8244778](https://bugs.openjdk.java.net/browse/JDK-8244778)? > > Previously before the JDK-8244778 change, archived objects could always be > assumed as live, and so the G1 collector did so, not caring about the archive > region's contents at all. With JDK-8244778 however, archived objects could > die, and keep stale references to objects outside of the archive regions, > which obviously causes crashes when walking these objects. > > With this change, open archive region contents are basically handled as any > other objects; to support that, all open archive regions are now reachable > via a single object array root. This hopefully also facilitates > implementation in other collectors. > > This allows us to remove quite a bit of special handling in G1 too; the only > difference is that open archive regions will generally not be collected > unless they are completely empty: we do want to profit from the sharing > across VMs as much as possible. > > Testing: tier1-5, one or two 6-8 runs > > The appcds changes were done by @iklam. These changes are described in this > document: > https://wiki.openjdk.java.net/display/HotSpot/CDS+Archived+Heap+Improvements > > Thanks, > Thomas
Thomas Schatzl has updated the pull request incrementally with one additional commit since the last revision: kbarrett review ------------- Changes: - all: https://git.openjdk.java.net/jdk/pull/1163/files - new: https://git.openjdk.java.net/jdk/pull/1163/files/c29503b6..a324c9c8 Webrevs: - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=1163&range=01 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=1163&range=00-01 Stats: 28 lines in 9 files changed: 4 ins; 0 del; 24 mod Patch: https://git.openjdk.java.net/jdk/pull/1163.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/1163/head:pull/1163 PR: https://git.openjdk.java.net/jdk/pull/1163
