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Ted Yu commented on HBASE-21292: -------------------------------- Good catch. For the second hunk, would it be more readable if the handling is moved to finally block ? > IdLock.getLockEntry() may hang if interrupted > --------------------------------------------- > > Key: HBASE-21292 > URL: https://issues.apache.org/jira/browse/HBASE-21292 > Project: HBase > Issue Type: Bug > Reporter: Allan Yang > Assignee: Allan Yang > Priority: Major > Fix For: 2.1.0, 2.0.2, 1.4.9 > > Attachments: HBASE-21292.branch-2.0.001.patch > > > This is a rare case found by my colleague which really happened on our > production env. > Thread may hang(or enter a infinite loop ) when try to call > IdLock.getLockEntry(). Here is the case: > 1. Thread1 owned the IdLock, while Thread2(the only one waiting) was waiting > for it. > 2. Thread1 called releaseLockEntry, it will set IdLock.locked = false, but > since Thread2 was waiting, it won't call map.remove(entry.id) > 3. While Thread1 was calling releaseLockEntry, Thread2 was interrupted. So no > one will remove this IdLock from the map. > 4. If another thread try to call getLockEntry on this IdLock, it will end up > in a infinite loop. Since existing = map.putIfAbsent(entry.id, entry)) != > null and existing.locked=false > It is hard to write a UT since it is a very rare race condition. -- This message was sent by Atlassian JIRA (v7.6.3#76005)