cc'ing build-dev for the makefile change
Hi Jiangli,
On 25/04/2018 10:53 AM, Jiangli Zhou wrote:
Please review the following changes that streamline the support for application
class data sharing by eliminating the requirement of using -XX:+UseAppCDS to
enable the feature. The support for application class data sharing is now
enabled transparently when application classes or platform classes present in
the classlist or generated archive with -Xshare:dump/on/auto.
RFE: https://bugs.openjdk.java.net/browse/JDK-8193213
Bug: https://bugs.openjdk.java.net/browse/JDK-8182731
These issues are not publicly visible, can you change them to be so?
webrev: http://cr.openjdk.java.net/~jiangli/8193213_8182731/webrev.00/
Overall this seems fine. Thanks for explaining the logic changes below -
much appreciated!
One query: why was UseAppCDS not removed from the tests (or at least the
tests you were modifying anyway) ? They will all need updating before 12
when the flag is expired.
test/hotspot/jtreg/runtime/appcds/SharedArchiveFile.java
Test 2 reference to UseAppCDS seems unnecessary now.
Test 3 is not needed as you're not using any diagnostic flag now.
Test 4 seems unnecessary now.
test/hotspot/jtreg/runtime/appcds/TestCommon.java
makeCommandLineForAppCDS should just be removed (yes that will cause
some churn in the other tests) - but this can be a follow up test cleanup.
test/hotspot/jtreg/runtime/appcds/UseAppCDS.java
This test no longer makes much sense to me. The only tests should be
that app classes get archived and used. It makes no sense to claim to be
testing -XX:+UseAppCDS when that flag is obsolete. Likewise now that it
is obsolete you don't need to test that -XX:-UseAppCDS has no affect.
Thanks,
David
Highlights of the changes:
* UseAppCDS is obsolete in JDK 11
* Remove the +UnlockCommercialFeatures requirement when using application class
data sharing in OracleJDK binary
* SharedArchiveFile is a product flag for all configurations in JDK 11
* DumpLoadedClassList produces a complete classlist including all loaded
library and application classes
Thanks David Holmes for his guidance on CSR process.
Following are the details for the VM and test changes:
- Removed various ‘if (UseAppCDS)’ checks and UseAppCDS asserts.
- Removed some of the CDS/AppCDS specifics from general class loading code.
- Removed scattered checks for non-empty directory. Dump time non-empty
directory check is done at one central place,
FileMapInfo::check_nonempty_dir_in_shared_path_table() after loading all
classes on the classlist. The behavior is backwards compatible:
- If no app/platform classes are loaded, dump time only reports error if
non-empty directory exists in -Xbootclasspath/a path
- If app/platform classes are loaded, dump time reports error for any
non-empty directory exists in -Xbootclasspath/a path, class path, or module path
- Removed unnecessary ‘if (!DumpSharedSpaces)’ from
SharedClassUtil::initialize(). The code path is only executed when
UseSharedSpaces is enabled.
- Return immediately in SystemDictionaryShared::find_or_load_shared_class() if
the archive header indicates there is no app or platform classes in the shared
archive. This reduces overhead in class loading if the shared archive only
contains system classes. It also provides backwards compatibility in cases
where shared application classes should be disabled. For example, when the
default system class loader is replaced by user provided loader, archived
application classes are inactive (not loaded from archive) at runtime without
affecting the use of archived system classes.
- Changed GenerateLinkOptData.gmk to filter out HelloClasslist from the default
classlist in JDK image, which is generated using DumpLoadedClassList option.
Thanks for David and Ioi's input on this.
- Updated various cds/appcds tests to reflect the JVM changes. The use of
-XX:+UseAppCDS in tests remains unchanged.
- Removed -XX:+UnlockCommercialFeatures for -XX:+UseAppCDS in tests
- Removed -XX:+UnlockDiagnosticVMOptions for -XX:SharedArchiveFile in tests
- Updated NonBootLoaderClasses.java: ensure app/platform classes on
classlist are archived without -XX:+UseAppCDS
- Updated DirClasspathTest.java: reflect the change for non-empty directory
handling
- Updated MismatchedUseAppCDS.java: -XX:-UseAppCDS has no effect
Tested with all cds and appcds tests locally with both fastdebug and release
builds. Tested with hs-teir1, hs-tier2, jdk-tier1 and jdk-tier2. The hs-tier3,
hs-tier4 and hs-tier4 are in progress.
Thanks,
Jiangli
