On Fri, 26 Feb 2021 00:03:40 GMT, Yumin Qi <mi...@openjdk.org> wrote:
> Hi, Please review > > Added jcmd option for dumping CDS archive during application runtime. > Before this change, user has to dump shared archive in two steps: first run > application with > `java -XX:DumpLoadedClassList=<classlist> .... ` > to collect shareable class names and saved in file `<classlist>` , then > `java -Xshare:dump -XX:SharedClassListFile=<classlist> > -XX:SharedArchiveFile=<archivefile> ...` > With this change, user can use jcmd to dump CDS without going through above > steps. Also user can choose a moment during the app runtime to dump an > archive. > The bug is associated with the CSR: > https://bugs.openjdk.java.net/browse/JDK-8259798 which has been approved. > New added jcmd option: > `jcmd <pid or AppName> VM.cds static_dump <filename>` > or > `jcmd <pid or AppName> VM.cds dynamic_dump <filename>` > To dump dynamic archive, requires start app with newly added flag > `-XX:+RecordDynamicDumpInfo`, with this flag, some information related to > dynamic dump like loader constraints will be recorded. Note the dumping > process changed some object memory locations so for dumping dynamic archive, > can only done once for a running app. For static dump, user can dump multiple > times against same process. > The file name is optional, if the file name is not supplied, the file name > will take format of `java_pid<number>_static.jsa` or > `java_pid<number>_dynamic.jsa` for static and dynamic respectively. The > `<number>` is the application process ID. > > Tests: tier1,tier2,tier3,tier4 > > Thanks > Yumin This pull request has now been integrated. Changeset: e7cbeba8 Author: Yumin Qi <mi...@openjdk.org> URL: https://git.openjdk.java.net/jdk/commit/e7cbeba8 Stats: 857 lines in 23 files changed: 783 ins; 58 del; 16 mod 8259070: Add jcmd option to dump CDS Reviewed-by: ccheung, iklam, mli ------------- PR: https://git.openjdk.java.net/jdk/pull/2737
