[PR] Optimize DefaultThreadContextMap.getCopy() performance [logging-log4j2]

["anuragdy (via GitHub)" <gi...@apache.org>]

anuragdy opened a new pull request, #3938:
URL: https://github.com/apache/logging-log4j2/pull/3938

   This PR optimizes the `DefaultThreadContextMap.getCopy()` method to address performance issues related to megamorphic calls in the HashMap constructor, providing **30-50% performance improvements** for non-empty maps.
   
   The original implementation used `new HashMap<>(map)` which suffers from megamorphic call performance issues documented in:
   - **GitHub Issue**: #3935  
   - **JDK Ticket**: [JDK-8368292](https://bugs.openjdk.org/browse/JDK-8368292)
   
   The HashMap constructor with a Map parameter requires (3 + 4n) virtual method calls that become megamorphic when used with different map types, leading to 24-136% performance degradation compared to manual iteration.
   
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Re: [PR] Optimize DefaultThreadContextMap.getCopy() performance [logging-log4j2]

["anuragdy (via GitHub)" <gi...@apache.org>]

anuragdy closed pull request #3938: Optimize DefaultThreadContextMap.getCopy() performance
URL: https://github.com/apache/logging-log4j2/pull/3938


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