RFR: 8247666: Support Lambda proxy classes in static CDS archive [v9]
Mandy Chung
mchung at openjdk.java.net
Mon Oct 19 16:18:13 UTC 2020
On Mon, 19 Oct 2020 16:04:31 GMT, Calvin Cheung <ccheung at openjdk.org> wrote:
>> Following up on archiving lambda proxy classes in dynamic CDS archive
>> ([JDK-8198698](https://bugs.openjdk.java.net/browse/JDK-8198698)), this RFE adds the functionality of archiving of
>> lambda proxy classes in static CDS archive.
>> When the -XX:DumpLoadedClassList is enabled, the constant pool index related to LambdaMetafactory that are resolved
>> during application execution will be included in the classlist. The entry for a lambda proxy class in a class list will
>> be of the following format:
>> `@lambda-proxy: <classname> <cp index>`
>>
>> e.g.
>> `@lambda-proxy: test/java/lang/invoke/MethodHandlesGeneralTest 233`
>> `@lambda-proxy: test/java/lang/invoke/MethodHandlesGeneralTest 355`
>>
>> When dumping a CDS archive using the -Xshare:dump and -XX:ExtraSharedClassListFile options, when the above
>> `@lambda-proxy` entry is encountered while parsing the classlist, we will resolve the corresponding constant pool
>> indices (233 and 355 in the above example). As a result, lambda proxy classes will be generated for the constant pool
>> entries, and will be cached using a similar mechanism to JDK-8198698. During dumping, there is check on the cp index
>> and on the created BootstrapInfo using the cp index. VM will exit with an error message if the check has failed.
>> During runtime when looking up a lambda proxy class, the lookup will be perform on the static CDS archive and if not
>> found, then lookup from the dynamic archive if one is specified. (Only name change (IsDynamicDumpingEnabled ->
>> IsCDSDumpingEnabled) is involved in the core-libs code.)
>> Testing: tiers 1,2,3,4.
>>
>> Performance results (javac on HelloWorld on linux-x64):
>> Results of " perf stat -r 40 bin/javac -J-Xshare:on -J-XX:SharedArchiveFile=javac2.jsa Bench_HelloWorld.java "
>> 1: 2228016795 2067752708 (-160264087) ----- 377.760 349.110 (-28.650) -----
>> 2: 2223051476 2063016483 (-160034993) ----- 374.580 350.620 (-23.960) ----
>> 3: 2225908334 2067673847 (-158234487) ----- 375.220 350.990 (-24.230) ----
>> 4: 2225835999 2064596883 (-161239116) ----- 374.670 349.840 (-24.830) ----
>> 5: 2226005510 2061694332 (-164311178) ----- 373.512 351.120 (-22.392) ----
>> 6: 2225574949 2062657482 (-162917467) ----- 374.710 348.380 (-26.330) -----
>> 7: 2224702424 2064634122 (-160068302) ----- 373.670 349.510 (-24.160) ----
>> 8: 2226662277 2066301134 (-160361143) ----- 375.350 349.790 (-25.560) ----
>> 9: 2226761470 2063162795 (-163598675) ----- 374.260 351.290 (-22.970) ----
>> 10: 2230149089 2066203307 (-163945782) ----- 374.760 350.620 (-24.140) ----
>> ============================================================
>> 2226266109 2064768307 (-161497801) ----- 374.848 350.126 (-24.722) ----
>> instr delta = -161497801 -7.2542%
>> time delta = -24.722 ms -6.5951%
>
> Calvin Cheung has updated the pull request incrementally with one additional commit since the last revision:
>
> store symbolic name of ref kind (e.g. REF_invokeStatic) in classlist
I reviewed the java.base changes and have no additional comment.
-------------
Marked as reviewed by mchung (Reviewer).
PR: https://git.openjdk.java.net/jdk/pull/364
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