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&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-14439430 ------------- Commit messages: - fix whitespace - Merge branch 'master' of https://github.com/openjdk/jdk into reimplement-method-invoke - Merge branch 'master' of https://github.com/openjdk/jdk into reimplement-method-invoke - Merge - clean up test - Merge branch 'master' of https://github.com/openjdk/jdk into reimplement-method-invoke - cleanup - Merge branch 'master' of https://github.com/openjdk/jdk into reimplement-method-invoke - fix ClassByteBuilder to handle short field type properly. Support volatile fields - minor cleanup - ... and 5 more: https://git.openjdk.java.net/jdk/compare/cb368802...c575c3db Changes: https://git.openjdk.java.net/jdk/pull/5027/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=5027&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8271820 Stats: 7572 lines in 75 files changed: 7103 ins; 288 del; 181 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
