Re: RFR: 8271820: Implementation of JEP 416: Reimplement Core Reflection with Method Handle [v7]

2021-08-31 Thread Maurizio Cimadamore
On Tue, 31 Aug 2021 17:14:05 GMT, Mandy Chung  wrote:

>> This reimplements core reflection with method handles.
>> 
>> For `Constructor::newInstance` and `Method::invoke`, the new implementation 
>> uses `MethodHandle`.  For `Field` accessor, the new implementation uses 
>> `VarHandle`.For the first few invocations of one of these reflective 
>> methods on a specific reflective object we invoke the corresponding method 
>> handle directly. After that we spin a dynamic bytecode stub defined in a 
>> hidden class which loads the target `MethodHandle` or `VarHandle` from its 
>> class data as a dynamically computed constant. Loading the method handle 
>> from a constant allows JIT to inline the method-handle invocation in order 
>> to achieve good performance.
>> 
>> The VM's native reflection methods are needed during early startup, before 
>> the method-handle mechanism is initialized. That happens soon after 
>> System::initPhase1 and before System::initPhase2, after which we switch to 
>> using method handles exclusively.
>> 
>> The core reflection and method handle implementation are updated to handle 
>> chained caller-sensitive method calls [1] properly. A caller-sensitive 
>> method can define with a caller-sensitive adapter method that will take an 
>> additional caller class parameter and the adapter method will be annotated 
>> with `@CallerSensitiveAdapter` for better auditing.   See the detailed 
>> description from [2].
>> 
>> Ran tier1-tier8 tests.   
>> 
>> [1] https://bugs.openjdk.java.net/browse/JDK-8013527
>> [2] 
>> https://bugs.openjdk.java.net/browse/JDK-8271820?focusedCommentId=14439430=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-14439430
>
> Mandy Chung has updated the pull request incrementally with one additional 
> commit since the last revision:
> 
>   Rename InvokerBuilder to ReflectionInvokerBuilder

Thanks for the changes - they look good and they make the code initialization 
logic easier to follow. Looks good to me.

-

Marked as reviewed by mcimadamore (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/5027


Re: RFR: 8271820: Implementation of JEP 416: Reimplement Core Reflection with Method Handle [v7]

2021-08-31 Thread Mandy Chung
> This reimplements core reflection with method handles.
> 
> For `Constructor::newInstance` and `Method::invoke`, the new implementation 
> uses `MethodHandle`.  For `Field` accessor, the new implementation uses 
> `VarHandle`.For the first few invocations of one of these reflective 
> methods on a specific reflective object we invoke the corresponding method 
> handle directly. After that we spin a dynamic bytecode stub defined in a 
> hidden class which loads the target `MethodHandle` or `VarHandle` from its 
> class data as a dynamically computed constant. Loading the method handle from 
> a constant allows JIT to inline the method-handle invocation in order to 
> achieve good performance.
> 
> The VM's native reflection methods are needed during early startup, before 
> the method-handle mechanism is initialized. That happens soon after 
> System::initPhase1 and before System::initPhase2, after which we switch to 
> using method handles exclusively.
> 
> The core reflection and method handle implementation are updated to handle 
> chained caller-sensitive method calls [1] properly. A caller-sensitive method 
> can define with a caller-sensitive adapter method that will take an 
> additional caller class parameter and the adapter method will be annotated 
> with `@CallerSensitiveAdapter` for better auditing.   See the detailed 
> description from [2].
> 
> Ran tier1-tier8 tests.   
> 
> [1] https://bugs.openjdk.java.net/browse/JDK-8013527
> [2] 
> https://bugs.openjdk.java.net/browse/JDK-8271820?focusedCommentId=14439430=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-14439430

Mandy Chung has updated the pull request incrementally with one additional 
commit since the last revision:

  Rename InvokerBuilder to ReflectionInvokerBuilder

-

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/5027/files
  - new: https://git.openjdk.java.net/jdk/pull/5027/files/df6fb0a2..68bb9efe

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk=5027=06
 - incr: https://webrevs.openjdk.java.net/?repo=jdk=5027=05-06

  Stats: 12 lines in 3 files changed: 1 ins; 2 del; 9 mod
  Patch: https://git.openjdk.java.net/jdk/pull/5027.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/5027/head:pull/5027

PR: https://git.openjdk.java.net/jdk/pull/5027