[hbase] branch branch-1 updated: HBASE-22706 Backport HBASE-21292 to branch-1

[st...@apache.org]

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stack pushed a commit to branch branch-1
in repository https://gitbox.apache.org/repos/asf/hbase.git


The following commit(s) were added to refs/heads/branch-1 by this push:
     new 3d22604  HBASE-22706 Backport HBASE-21292 to branch-1
3d22604 is described below

commit 3d226043a6768b3b4179f10d055e7ecd26a7d211
Author: Pankaj <pa...@huawei.com>
AuthorDate: Wed Jul 17 21:26:05 2019 +0530

    HBASE-22706 Backport HBASE-21292 to branch-1
---
 .../src/main/java/org/apache/hadoop/hbase/util/IdLock.java    | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/util/IdLock.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/util/IdLock.java
index fedf951..abd53d7 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/util/IdLock.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/util/IdLock.java
@@ -81,6 +81,17 @@ public class IdLock {
               existing.wait();
             } catch (InterruptedException e) {
               --existing.numWaiters;  // Remove ourselves from waiters.
+              // HBASE-21292/HBASE-22706
+              // There is a rare case that interrupting and the lock owner thread call
+              // releaseLockEntry at the same time. Since the owner thread found there
+              // still one waiting, it won't remove the entry from the map. If the interrupted
+              // thread is the last one waiting on the lock, and since an exception is thrown,
+              // the 'existing' entry will stay in the map forever. Later threads which try to
+              // get this lock will stuck in a infinite loop because
+              // existing = map.putIfAbsent(entry.id, entry)) != null and existing.isLocked=false.
+              if (!existing.isLocked && existing.numWaiters == 0) {
+                map.remove(existing.id);
+              }
               throw new InterruptedIOException(
                   "Interrupted waiting to acquire sparse lock");
             }