fix: CacheManager memory leak by reusing InheritableThreadLocal (#6730)#6732
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CacheManager.clearCache() was creating a new InheritableThreadLocal instance on every call without calling .remove() on the previous one. This caused a progressive memory leak that grows with iteration_count x thread_count when 'Clear cache each iteration' is enabled. The existing TODO comment acknowledged this: // TODO: avoid re-creating the thread local every time, // reset its contents instead Fix by initializing threadCache once at field declaration and calling threadCache.remove() in clearCache() instead of creating a new instance. The next .get() call will lazily create a fresh cache via initialValue(). Also added @SuppressWarnings for ErrorProne's ThreadLocalUsage since InheritableThreadLocal is used intentionally for per-thread caching. Fixes apache#6730 Signed-off-by: Mustafa Senoglu <mmustafasenoglu0@gmail.com>
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Closing as duplicate of #6731 |
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Summary
CacheManager.clearCache()creates a newInheritableThreadLocalinstance on every call without calling.remove()on the previous one, causing a progressive memory leak that grows withiteration_count × thread_countwhen "Clear cache each iteration" is enabled.The existing TODO in the code already acknowledged this:
// TODO: avoid re-creating the thread local every time, reset its contents insteadFix
threadCacheonce at field declarationclearCache()body withthreadCache.remove()instead of creating a new instance.get()call lazily creates a fresh cache viainitialValue()@SuppressWarnings("ThreadLocalUsage")sinceInheritableThreadLocalis intentionally used for per-thread cachingTesting
All 80 CacheManager tests pass (0 failed, 1 skipped):
Fixes #6730