[pulsar] branch master updated: [ML] Fix thread safety issues in ManagedCursorContainer related to "heap" field access (#16049)

[eolivelli]

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eolivelli pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/pulsar.git


The following commit(s) were added to refs/heads/master by this push:
     new ec9676f6431 [ML] Fix thread safety issues in ManagedCursorContainer 
related to "heap" field access (#16049)
ec9676f6431 is described below

commit ec9676f6431aa5ebd7df2235f6ebd49ddbf92288
Author: Lari Hotari <lhot...@users.noreply.github.com>
AuthorDate: Tue Jun 14 15:21:30 2022 +0300

    [ML] Fix thread safety issues in ManagedCursorContainer related to "heap" 
field access (#16049)
---
 .../bookkeeper/mledger/impl/ManagedCursorContainer.java    | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git 
a/managed-ledger/src/main/java/org/apache/bookkeeper/mledger/impl/ManagedCursorContainer.java
 
b/managed-ledger/src/main/java/org/apache/bookkeeper/mledger/impl/ManagedCursorContainer.java
index ef9a546a507..f9591d9ee6a 100644
--- 
a/managed-ledger/src/main/java/org/apache/bookkeeper/mledger/impl/ManagedCursorContainer.java
+++ 
b/managed-ledger/src/main/java/org/apache/bookkeeper/mledger/impl/ManagedCursorContainer.java
@@ -105,11 +105,21 @@ public class ManagedCursorContainer implements 
Iterable<ManagedCursor> {
     }
 
     public PositionImpl getSlowestReadPositionForActiveCursors() {
-        return heap.isEmpty() ? null : (PositionImpl) 
heap.get(0).cursor.getReadPosition();
+        long stamp = rwLock.readLock();
+        try {
+            return heap.isEmpty() ? null : (PositionImpl) 
heap.get(0).cursor.getReadPosition();
+        } finally {
+            rwLock.unlockRead(stamp);
+        }
     }
 
     public PositionImpl getSlowestMarkDeletedPositionForActiveCursors() {
-        return heap.isEmpty() ? null : (PositionImpl) 
heap.get(0).cursor.getMarkDeletedPosition();
+        long stamp = rwLock.readLock();
+        try {
+            return heap.isEmpty() ? null : (PositionImpl) 
heap.get(0).cursor.getMarkDeletedPosition();
+        } finally {
+            rwLock.unlockRead(stamp);
+        }
     }
 
     public ManagedCursor get(String name) {