RFR: 8165276: Spec states to invoke the premain method in an agent class if it's public but implementation differs [v10]

[Mandy Chung]

On Tue, 22 Dec 2020 05:47:19 GMT, Serguei Spitsyn <sspitsyn at openjdk.org> wrote:

>> This change have been already reviewed by Mandy, Sundar, Alan and David.
>> Please, see the jdk 15 review thread:
>>   http://mail.openjdk.java.net/pipermail/serviceability-dev/2020-June/031998.html
>> 
>> Now, the PR approval is needed.
>> The push was postponed because the CSR was not approved at that time (it is now):
>>    https://bugs.openjdk.java.net/browse/JDK-8248189
>> Investigation of existing popular java agents was requested by Joe.
>> ----------
>> 
>> The java.lang.instrument spec:
>>   https://docs.oracle.com/en/java/javase/15/docs/api/java.instrument/java/lang/instrument/package-summary.html
>> 
>> Summary:
>>   The java.lang.instrument spec clearly states:
>>     "The agent class must implement a public static premain method
>>      similar in principle to the main application entry point."
>>   Current implementation of sun/instrument/InstrumentationImpl.java
>>   allows the premain method be non-public which violates the spec.
>>   This fix aligns the implementation with the spec.
>> 
>> Testing:
>>   A mach5 run of jdk_instrument tests is in progress.
>
> Serguei Spitsyn has updated the pull request incrementally with one additional commit since the last revision:
> 
>   @summary of some negative tests is corrected

test/jdk/java/lang/instrument/RetransformAgent.java line 26:

> 24: /**
> 25:  * @test
> 26:  * @bug 6274264 6274241 5070281 8165276

The copyright header and `@bug` change should be reverted.

test/jdk/java/lang/instrument/SimpleAgent.java line 2:

> 1: /*
> 2:  * Copyright (c) 2016, 2020, Oracle and/or its affiliates. All rights reserved.

The copyright header change should be reverted.

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PR: https://git.openjdk.java.net/jdk/pull/1694