RFR: 8266764: [REDO] JDK-8255493 Support for pre-generated java.lang.invoke classes in CDS dynamic archive
Yumin Qi
minqi at openjdk.java.net
Mon May 10 20:51:08 UTC 2021
On Mon, 10 May 2021 20:31:05 GMT, Calvin Cheung <ccheung at openjdk.org> wrote:
>> Hi, please review
>> This is REDO for jdk-8255493, the integration of the fix caused ParallelLambdaLoadTest.java failed.
>> The old PR description:
>> ------------- old ------------
>> When do dynamic dump, the pre-generated lambda form classes from java.lang.invoke are not stored in dynamic archive. The patch will regenerate the four holder classes,
>> "java.lang.invoke.Invokers$Holder",
>> "java.lang.invoke.DirectMethodHandle$Holder",
>> "java.lang.invoke.DelegatingMethodHandle$Holder",
>> "java.lang.invoke.LambdaForm$Holder"
>> which will include the versions in static archive and new loaded functions all together and stored in dynamic archive. New test case added.
>> ------------ new -------------
>> The new fix (incremental)
>> 1) Added a lock to protect LambdaFormInvokers::_lambdaform_lines, at dynamic dump case, there are potentially concurrent issue the list is added from multiple threads at same time regeneration of holder class is reading from the list.
>> 2) Added a new function to MetaspaceShared, MetaspaceShared::regenerate_lambdaforminvokers_holders which calls into LambdaFormInvokers::LambdaFormInvokers::regenerate_holder_classes, and handle exceptions, this way even the regeneration fails, no affect to normal dump process.
>> 3) Move the call to regenerate holder classes to MetaspaceShared::link_and_cleanup_shared_classes, this is before java shutdown hook execution, since after that, it is not safe to call into java.
>> 4) Since change in 3), jcmd to dynamic dump, we need call MetaspaceShared::regenerate_lambdaforminvokers_holders before do dumping.
>>
>> Tests: tier1,tier2,tier3,tier4
>> local test on runtime/cds
>> local test ParallelLambdaLoadTest.java in loops without crash.
>>
>> Thanks
>> Yumin
>
> The incremental changes look good.
@calvinccheung Thanks for review again!
-------------
PR: https://git.openjdk.java.net/jdk/pull/3953
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