JDK-8353175 : Eliminate double iteration of stream in FieldDescriptor reinitialization
  • Type: Bug
  • Component: hotspot
  • Sub-Component: runtime
  • Affected Version: 21,25
  • Priority: P3
  • Status: Open
  • Resolution: Unresolved
  • Submitted: 2025-03-28
  • Updated: 2025-03-28
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JDK 25
25Unresolved
Related Reports
Relates :  
JDK-8352075 - Perf regression accessing fields
Description
This is a partial fix for performance regression covered in https://bugs.openjdk.org/browse/JDK-8352075

Since FieldDescriptor::reinitialize() looks up FieldInfo calling InstanceKlass::field(int). After https://bugs.openjdk.org/browse/JDK-8292818 this requires an iteration through all class fields while the information is in many cases readily available.
Comments
RT Triage: Copying triage of this issue from JDK-8352075 ILW=MMH=P3 Impact: Performance degradation, not a crash Likelihood: Possible existing generators for this many fields Workaround: User doesn't usually have control over these generators
28-03-2025
A pull request was submitted for review. Branch: master URL: https://git.openjdk.org/jdk/pull/24290 Date: 2025-03-28 11:03:29 +0000
28-03-2025
Attached CCC.java (reproducer) from the related issue, courtesy of [~shade]
28-03-2025