From a85291003cf3e3fd79b6addcf59d4f43dc72d356 Mon Sep 17 00:00:00 2001
From: yliu <yliu@apache.org>
Date: Fri, 13 Mar 2015 02:25:02 +0800
Subject: [PATCH] HADOOP-11710. Make CryptoOutputStream behave like
 DFSOutputStream wrt synchronization. (Sean Busbey via yliu)

---
 .../hadoop-common/CHANGES.txt                 |  3 +++
 .../hadoop/crypto/CryptoOutputStream.java     | 19 ++++++++++++-------
 2 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/hadoop-common-project/hadoop-common/CHANGES.txt b/hadoop-common-project/hadoop-common/CHANGES.txt
index 6970bad0bc4..55028cba067 100644
--- a/hadoop-common-project/hadoop-common/CHANGES.txt
+++ b/hadoop-common-project/hadoop-common/CHANGES.txt
@@ -1097,6 +1097,9 @@ Release 2.7.0 - UNRELEASED
     HADOOP-11693. Azure Storage FileSystem rename operations are throttled too
     aggressively to complete HBase WAL archiving. (Duo Xu via cnauroth)
 
+    HADOOP-11710. Make CryptoOutputStream behave like DFSOutputStream wrt
+    synchronization. (Sean Busbey via yliu)
+
 Release 2.6.1 - UNRELEASED
 
   INCOMPATIBLE CHANGES
diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/crypto/CryptoOutputStream.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/crypto/CryptoOutputStream.java
index f1ea0fccf7d..bc09b8c179f 100644
--- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/crypto/CryptoOutputStream.java
+++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/crypto/CryptoOutputStream.java
@@ -40,6 +40,9 @@
  * padding = pos%(algorithm blocksize); 
  * <p/>
  * The underlying stream offset is maintained as state.
+ *
+ * Note that while some of this class' methods are synchronized, this is just to
+ * match the threadsafety behavior of DFSOutputStream. See HADOOP-11710.
  */
 @InterfaceAudience.Private
 @InterfaceStability.Evolving
@@ -126,7 +129,7 @@ public OutputStream getWrappedStream() {
    * @throws IOException
    */
   @Override
-  public void write(byte[] b, int off, int len) throws IOException {
+  public synchronized void write(byte[] b, int off, int len) throws IOException {
     checkStream();
     if (b == null) {
       throw new NullPointerException();
@@ -213,14 +216,16 @@ private byte[] getTmpBuf() {
   }
   
   @Override
-  public void close() throws IOException {
+  public synchronized void close() throws IOException {
     if (closed) {
       return;
     }
-    
-    super.close();
-    freeBuffers();
-    closed = true;
+    try {
+      super.close();
+      freeBuffers();
+    } finally {
+      closed = true;
+    }
   }
   
   /**
@@ -228,7 +233,7 @@ public void close() throws IOException {
    * underlying stream, then do the flush.
    */
   @Override
-  public void flush() throws IOException {
+  public synchronized void flush() throws IOException {
     checkStream();
     encrypt();
     super.flush();