On Wed, 24 Mar 2021 15:35:55 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 > > Yumin Qi has updated the pull request incrementally with one additional > commit since the last revision: > > Remove redundant check for if a class is shareable src/hotspot/share/oops/instanceKlass.cpp line 4269: > 4267: } > 4268: > 4269: if (class_loader == NULL && > ClassLoader::contains_append_entry(stream->source())) { Since the above has been removed, I think the `ClassLoader::contains_append_entry()` function can be removed too. test/hotspot/jtreg/runtime/cds/appcds/jcmd/JCmdTest.java line 59: > 57: public class JCmdTest { > 58: static final String TEST_CLASS[] = {"LingeredTestApp", > "jdk/test/lib/apps/LingeredApp"}; > 59: static final String TEST_JAR = "test.jar"; `TEST_JAR` is unused. test/hotspot/jtreg/runtime/cds/appcds/jcmd/JCmdTest.java line 168: > 166: "-XX:ArchiveClassesAtExit=tmp.jsa", > 167: "-Xshare:auto", > 168: "-Xshare:on"}; The `excludeFlags` doesn't match the ones in CDS.java. 226 private static String[] excludeFlags = { 227 "-XX:DumpLoadedClassList=", 228 "-XX:+DumpSharedSpaces", 229 "-XX:+DynamicDumpSharedSpaces", 230 "-XX:+RecordDynamicDumpInfo", 231 "-Xshare:", 232 "-XX:SharedClassListFile=", 233 "-XX:SharedArchiveFile=", 234 "-XX:ArchiveClassesAtExit=", 235 "-XX:+UseSharedSpaces", 236 "-XX:+RequireSharedSpaces"}; ------------- PR: https://git.openjdk.java.net/jdk/pull/2737
