NOTE
Netty PoolThreadCache
Per-thread pooled buffer caching as an allocation optimization, with retention and event-loop affinity trade-offs.
This is a historical learning note and may contain outdated or incomplete understanding.
Pool thread caches reduce synchronization/allocator work by keeping reusable memory entries close to allocation threads, especially long-lived event-loop threads.
Caching trades lower allocation latency for additional retained memory. Thread lifetime and allocation patterns therefore affect native-memory footprint.
Cache structure/size policies are version-specific. Diagnose with the allocator/JVM/process metrics for the exact deployment before tuning internal cache parameters.