RFR: 8295102: Always load @lambda-form-invoker lines from default classlist [v2]

[Calvin Cheung]

On Tue, 11 Oct 2022 03:40:00 GMT, Ioi Lam <iklam at openjdk.org> wrote:

>> The `@lambda-form-invoker` lines in the default classlist (`$JAVA_HOME/lib/classlist`) control what lambda-form invoker methods are added to these classes that are generated during a CDS dump ([see here](https://github.com/iklam/jdk/blob/5aa997b001367141a6a2d2e69649d41b46199ab4/src/hotspot/share/cds/lambdaFormInvokers.cpp#L230)):
>> 
>> - `java.lang.invoke.Invokers$Holder`
>> - `java.lang.invoke.DirectMethodHandle$Holder`
>> - `java.lang.invoke.DelegatingMethodHandle$Holder`
>> - `java.lang.invoke.LambdaForm$Holder`
>> 
>> The list of these invoker methods is generated as part of the [JDK build process](https://github.com/iklam/jdk/blob/1996f649a3a30b7ac4b547a762417f807f5fa414/make/GenerateLinkOptData.gmk#L64). They are used for invoking MethodHandles of commonly-used types, so that we can avoid generating custom LambdaForm classes.
>> 
>> When a CDS archive is created with a non-default classlist, (e.g., `-XX:SharedClassListFile=foo.classlist`), such a classlist may not contain all the `@lambda-form-invoker` lines as in the default classlist. As a result, at runtime, more custom LambdaForm classes may be generated than necessary.
>> 
>> The solution is to always load the `@lambda-form-invoker` lines from the default classlist, to make sure the CDS image has all the commonly-used invoker methods.
>
> Ioi Lam has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Fixed open/test/hotspot/jtreg:hotspot_appcds_dynamic tests

test/hotspot/jtreg/runtime/cds/appcds/TestCommon.java line 775:

> 773:                                        + ", a=<none>"
> 774:                                        + ", b=" + b[max]);
> 775:         }

Should these checks be done before the "for" loop at line 756? Otherwise, could one of the array be indexed out-out-bound?

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PR: https://git.openjdk.org/jdk/pull/10639