On Tue, 18 Jan 2022 02:50:06 GMT, Yi Yang <yy...@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 refreshed the contents of this pull request, and previous commits 
> have been removed. The incremental views will show differences compared to 
> the previous content of the PR. The pull request contains one new commit 
> since the last revision:
> 
>   8275775 Add VM.classes to print details of all classes

Hi,
This seems reasonable in general but a few details to work through - see 
comments below.
Thanks,
David

src/hotspot/share/oops/instanceKlass.cpp line 2069:

> 2067:   ResourceMark rm;
> 2068:   _st->print("%-18s", "KlassAddr");
> 2069:   _st->print("  ");

Can't you just print the two spaces in the previous line:

_st->print("%-18s  ", "KlassAddr");

and save all the additional print calls. This applies throughout where you have 
"  ".

src/hotspot/share/oops/instanceKlass.cpp line 2085:

> 2083:   ResourceMark rm;
> 2084:   // klass pointer
> 2085:   _st->print("" INTPTR_FORMAT "", p2i(k));

Why do you need the two empty string literals ??

src/hotspot/share/oops/instanceKlass.cpp line 2100:

> 2098:   char buf[10];
> 2099:   int i = 0;
> 2100:   if (k->has_finalizer()) buf[i++] = 'F';

Where is the meaning of these flags documented?

src/hotspot/share/oops/instanceKlass.cpp line 2103:

> 2101:   if (k->has_final_method()) buf[i++] = 'f';
> 2102:   if (k->has_vanilla_constructor()) buf[i++] = 'V';
> 2103:   if (k->is_instance_klass()) {

Don't the properties queried in L2100 to L2102 only apply to instance classes?

src/hotspot/share/oops/instanceKlass.cpp line 3425:

> 3423: 
> 3424: static const char* state_names[] = {
> 3425:   "alloc", "load", "link", "initing", "inited", "init_err"

I don't like these short forms - they are mostly computerese not real words. 
Why can't we print the original full names? (Though I'd prefer "initializing" 
and "initialized" to "being_initialized" and "fully_initialized".)

src/hotspot/share/services/diagnosticCommand.hpp line 870:

> 868:   }
> 869:   static const char* description() {
> 870:     return "Prints list of all loaded java classes";

s/java/Java/

src/hotspot/share/services/diagnosticCommand.hpp line 873:

> 871:   }
> 872:   static const char* impact() {
> 873:       return "Medium: Depends on Java content.";

I would think impact is High due to the number of classes.

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

Changes requested by dholmes (Reviewer).

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

Reply via email to