JDK-8299089 : Instrument global jni handles with tag to make them distinguishable
  • Type: Enhancement
  • Component: hotspot
  • Sub-Component: gc
  • Affected Version: 21
  • Priority: P4
  • Status: Resolved
  • Resolution: Fixed
  • Submitted: 2022-12-20
  • Updated: 2024-09-19
  • Resolved: 2023-01-18
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JDK 21
21 b06Fixed
Related Reports
Relates :  
JDK-8339416 - [s390x] Provide implementation for resolve_global_jobject
Relates :  
JDK-8301402 - os::print_location gets is_global_handle assert
Description
Weak global jni handles are tagged so the GC can distinguish them when resolving the object. Today there is no cheap way of distinguishing global jni handles from local jni handles. For generational ZGC the OopStorage handles and the thread local handles semantical difference requires the handles to be distinguishable. 

This enhancements instruments the jni handles with a global tag similarly to the jweak tag.
Comments
Changeset: c7056737 Author: Axel Boldt-Christmas <aboldtch@openjdk.org> Date: 2023-01-18 09:21:08 +0000 URL: https://git.openjdk.org/jdk/commit/c7056737e33d3d5a6ec24639d46b9e3e7a8da01a
18-01-2023
A pull request was submitted for review. URL: https://git.openjdk.org/jdk/pull/11740 Date: 2022-12-20 11:44:33 +0000
20-12-2022