On Tue, 18 Jan 2022 02:50:06 GMT, Yi Yang <[email protected]> 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
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> the previous content of the PR. The pull request contains one new commit
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>
> 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
