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The following commit(s) were added to refs/heads/master by this push:
new 58dca69 update row lock comments #1364 (#1380)
58dca69 is described below
commit 58dca69eeaae98a70384d9bcd8f34966b031fef5
Author: Keith Turner <ktur...@apache.org>
AuthorDate: Wed Oct 2 16:06:57 2019 -0400
update row lock comments #1364 (#1380)
---
.../tserver/src/main/java/org/apache/accumulo/tserver/RowLocks.java | 4 ++++
1 file changed, 4 insertions(+)
diff --git
a/server/tserver/src/main/java/org/apache/accumulo/tserver/RowLocks.java
b/server/tserver/src/main/java/org/apache/accumulo/tserver/RowLocks.java
index 46aa253..10885ea 100644
--- a/server/tserver/src/main/java/org/apache/accumulo/tserver/RowLocks.java
+++ b/server/tserver/src/main/java/org/apache/accumulo/tserver/RowLocks.java
@@ -34,6 +34,10 @@ import com.google.common.base.Preconditions;
class RowLocks {
+ // The compute function in Concurrent Hash Map supports atomic execution of
the remapping function
+ // and will only execute it once. Properly computing the reference counts
relies on this specific
+ // behavior. Not all concurrent map implementations have the desired
behavior. For example
+ // ConcurrentSkipListMap.compute is not atomic and may execute the function
multiple times.
private final Map<ByteSequence,RowLock> rowLocks = new ConcurrentHashMap<>();
static class RowLock {
