From 4c5c8c4ead74c92b6ab0ec55bca709d36ad152d9 Mon Sep 17 00:00:00 2001
From: Mike Drob <mdrob@apache.org>
Date: Tue, 8 Sep 2020 10:13:18 -0500
Subject: [PATCH] LUCENE-9504 Remove extra lock in DocumentsWriterDeleteQueue
 (#1826)

---
 .../index/DocumentsWriterDeleteQueue.java     | 19 +++++--------------
 1 file changed, 5 insertions(+), 14 deletions(-)

diff --git a/lucene/core/src/java/org/apache/lucene/index/DocumentsWriterDeleteQueue.java b/lucene/core/src/java/org/apache/lucene/index/DocumentsWriterDeleteQueue.java
index cb3db7a0ff7..ab5d657a1b0 100644
--- a/lucene/core/src/java/org/apache/lucene/index/DocumentsWriterDeleteQueue.java
+++ b/lucene/core/src/java/org/apache/lucene/index/DocumentsWriterDeleteQueue.java
@@ -509,27 +509,18 @@ final class DocumentsWriterDeleteQueue implements Accountable, Closeable {
     }
   }
   
-  private boolean forceApplyGlobalSlice() {
-    globalBufferLock.lock();
-    final Node<?> currentTail = tail;
+  public int getBufferedUpdatesTermsSize() {
+    final ReentrantLock lock = globalBufferLock; // Trusted final
+    lock.lock();
     try {
+      final Node<?> currentTail = tail;
       if (globalSlice.sliceTail != currentTail) {
         globalSlice.sliceTail = currentTail;
         globalSlice.apply(globalBufferedUpdates, BufferedUpdates.MAX_INT);
       }
-      return globalBufferedUpdates.any();
-    } finally {
-      globalBufferLock.unlock();
-    }
-  }
-
-  public int getBufferedUpdatesTermsSize() {
-    globalBufferLock.lock();
-    try {
-      forceApplyGlobalSlice();
       return globalBufferedUpdates.deleteTerms.size();
     } finally {
-      globalBufferLock.unlock();
+      lock.unlock();
     }
   }