RFR: 8275775: Add jcmd VM.classes to print details of all classes [v6]

[Ioi Lam]

On Thu, 27 Jan 2022 09:17:09 GMT, Yi Yang <yyang at openjdk.org> wrote:

>> Add VM.classes to print details of all classes, output looks like:
>> 
>> 1. jcmd VM.classes
>> 
>> KlassAddr Size State Flags LoaderName ClassName
>> 0x0000000800c0b400 62 inited W bootstrap java.lang.invoke.LambdaForm$MH/0x0000000800c0b400
>> 0x0000000800c0b000 62 inited W bootstrap java.lang.invoke.LambdaForm$DMH/0x0000000800c0b000
>> 0x0000000800c0ac00 62 inited W bootstrap java.lang.invoke.LambdaForm$MH/0x0000000800c0ac00
>> ...
>> 
>> 2. jcmd VM.classes verbose
>> 
>> KlassAddr Size State Flags LoaderName ClassName
>> 0x0000000800c0b400 62 inited W bootstrap java.lang.invoke.LambdaForm$MH/0x0000000800c0b400
>> java.lang.invoke.LambdaForm$MH/0x0000000800c0b400 {0x0000000800c0b400}
>>  - instance size: 2
>>  - klass size: 62
>>  - access: final synchronized
>>  - state: inited
>>  - name: 'java/lang/invoke/LambdaForm$MH+0x0000000800c0b400'
>>  - super: 'java/lang/Object'
>>  - sub:
>>  - arrays: NULL
>>  - methods: Array<T>(0x00007f620841f210)
>>  - method ordering: Array<T>(0x0000000800a7e5a8)
>>  - default_methods: Array<T>(0x0000000000000000)
>>  - local interfaces: Array<T>(0x00000008005af748)
>>  - trans. interfaces: Array<T>(0x00000008005af748)
>>  - constants: constant pool [41] {0x00007f620841f030} for 'java/lang/invoke/LambdaForm$MH+0x0000000800c0b400' cache=0x00007f620841f380
>>  - class loader data: loader data: 0x00007f61c804a690 of 'bootstrap' has a class holder
>>  - source file: 'LambdaForm$MH'
>>  - class annotations: Array<T>(0x0000000000000000)
>>  - class type annotations: Array<T>(0x0000000000000000)
>>  - field annotations: Array<T>(0x0000000000000000)
>>  - field type annotations: Array<T>(0x0000000000000000)
>>  - inner classes: Array<T>(0x00000008005af6d8)
>>  - nest members: Array<T>(0x00000008005af6d8)
>>  - permitted subclasses: Array<T>(0x00000008005af6d8)
>>  - java mirror: a 'java/lang/Class'{0x000000011f4b3968} = 'java/lang/invoke/LambdaForm$MH+0x0000000800c0b400'
>>  - vtable length 5 (start addr: 0x0000000800c0b5b8)
>>  - itable length 2 (start addr: 0x0000000800c0b5e0)
>>  - ---- static fields (1 words):
>>  - static final '_D_0' 'Ljava/lang/invoke/LambdaForm;' @112
>>  - ---- non-static fields (0 words):
>>  - non-static oop maps:
>> 0x0000000800c0b000 62 inited W bootstrap java.lang.invoke.LambdaForm$DMH/0x0000000800c0b000
>> java.lang.invoke.LambdaForm$DMH/0x0000000800c0b000 {0x0000000800c0b000}
>>  - instance size: 2
>>  - klass size: 62
>>  - access: final synchronized
>>  - state: inited
>>  - name: 'java/lang/invoke/LambdaForm$DMH+0x0000000800c0b000'
>>  - super: 'java/lang/Object'
>>  - sub:
>>  - arrays: NULL
>>  - methods: Array<T>(0x00007f620841ea68)
>>  - method ordering: Array<T>(0x0000000800a7e5a8)
>>  - default_methods: Array<T>(0x0000000000000000)
>>  - local interfaces: Array<T>(0x00000008005af748)
>>  - trans. interfaces: Array<T>(0x00000008005af748)
>>  - constants: constant pool [49] {0x00007f620841e838} for 'java/lang/invoke/LambdaForm$DMH+0x0000000800c0b000' cache=0x00007f620841ebe0
>>  - class loader data: loader data: 0x00007f61c804a750 of 'bootstrap' has a class holder
>>  - source file: 'LambdaForm$DMH'
>>  - class annotations: Array<T>(0x0000000000000000)
>>  - class type annotations: Array<T>(0x0000000000000000)
>>  - field annotations: Array<T>(0x0000000000000000)
>>  - field type annotations: Array<T>(0x0000000000000000)
>>  - inner classes: Array<T>(0x00000008005af6d8)
>>  - nest members: Array<T>(0x00000008005af6d8)
>>  - permitted subclasses: Array<T>(0x00000008005af6d8)
>>  - java mirror: a 'java/lang/Class'{0x000000011f4b0968} = 'java/lang/invoke/LambdaForm$DMH+0x0000000800c0b000'
>>  - vtable length 5 (start addr: 0x0000000800c0b1b8)
>>  - itable length 2 (start addr: 0x0000000800c0b1e0)
>>  - ---- static fields (1 words):
>>  - static final '_D_0' 'Ljava/lang/invoke/LambdaForm;' @112
>>  - ---- non-static fields (0 words):
>> ...
>
> Yi Yang has updated the pull request incrementally with one additional commit since the last revision:
> 
>   fix

LGTM. One minor nit,

Could you update the PR description to include examples of the final output format.

src/hotspot/share/oops/instanceKlass.cpp line 2081:

> 2079:   _st->print(INTPTR_FORMAT "  ", p2i(k));
> 2080:   // klass size
> 2081:   _st->print("%-4d  ", k->size());

Should be `%4d` so that the numbers are aligned correctly.

-------------

Marked as reviewed by iklam (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/7105