virajjasani commented on a change in pull request #3215: URL: https://github.com/apache/hbase/pull/3215#discussion_r648564135
########## File path: hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/TinyLfuBlockCache.java ########## @@ -158,7 +158,13 @@ public boolean containsBlock(BlockCacheKey cacheKey) { @Override public Cacheable getBlock(BlockCacheKey cacheKey, boolean caching, boolean repeat, boolean updateCacheMetrics) { - Cacheable value = cache.getIfPresent(cacheKey); + Cacheable value = cache.asMap().computeIfPresent(cacheKey, (blockCacheKey, cacheable) -> { + // It will be referenced by RPC path, so increase here. NOTICE: Must do the retain inside + // this block. because if retain outside the map#computeIfPresent, the evictBlock may remove + // the block and release, then we're retaining a block with refCnt=0 which is disallowed. + cacheable.retain(); + return cacheable; + }); Review comment: Sounds good, `map.remove(cacheKey, cb)` too should not be required in this case. Thanks @ben-manes -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org