From 8d5b662535fc81cd1a5f825818d4de6658ae787a Mon Sep 17 00:00:00 2001
From: Michael McCandless <mikemccand@apache.org>
Date: Wed, 29 Jul 2009 10:18:30 +0000
Subject: [PATCH] LUCENE-1766: spell out IndexWriter's thread safety in the
 javadocs

git-svn-id: https://svn.apache.org/repos/asf/lucene/java/trunk@798835 13f79535-47bb-0310-9956-ffa450edef68
---
 src/java/org/apache/lucene/index/IndexWriter.java | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/java/org/apache/lucene/index/IndexWriter.java b/src/java/org/apache/lucene/index/IndexWriter.java
index e673bc73cd8..e8c27960cf0 100644
--- a/src/java/org/apache/lucene/index/IndexWriter.java
+++ b/src/java/org/apache/lucene/index/IndexWriter.java
@@ -186,6 +186,15 @@ import java.util.Map;
   last commit.  If you opened the writer with autoCommit
   false you can also just call {@link #rollback()}
   directly.</p>
+
+  <a name="thread-safety"></a><p><b>NOTE</b>: {@link
+  <code>IndexWriter</code>} instances are completely thread
+  safe, meaning multiple threads can call any of its
+  methods, concurrently.  If your application requires
+  external synchronization, you should <b>not</b> use the
+  <code>IndexWriter</code> instance for synchronization as
+  this can lead to deadlock.  Use a private
+  <code>Object</code> instead. </p>
 */
 
 /*