svn commit: r1339475 - in /hadoop/common/branches/branch-2/hadoop-common-project/hadoop-common: CHANGES.txt src/main/java/org/apache/hadoop/io/compress/CompressionCodecFactory.java

[todd]

Author: todd
Date: Thu May 17 04:28:24 2012
New Revision: 1339475

URL: http://svn.apache.org/viewvc?rev=1339475&view=rev
Log:
HADOOP-8406. CompressionCodecFactory.CODEC_PROVIDERS iteration is 
thread-unsafe. Contributed by Todd Lipcon.

Modified:
    
hadoop/common/branches/branch-2/hadoop-common-project/hadoop-common/CHANGES.txt
    
hadoop/common/branches/branch-2/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/compress/CompressionCodecFactory.java

Modified: 
hadoop/common/branches/branch-2/hadoop-common-project/hadoop-common/CHANGES.txt
URL: 
http://svn.apache.org/viewvc/hadoop/common/branches/branch-2/hadoop-common-project/hadoop-common/CHANGES.txt?rev=1339475&r1=1339474&r2=1339475&view=diff
==============================================================================
--- 
hadoop/common/branches/branch-2/hadoop-common-project/hadoop-common/CHANGES.txt 
(original)
+++ 
hadoop/common/branches/branch-2/hadoop-common-project/hadoop-common/CHANGES.txt 
Thu May 17 04:28:24 2012
@@ -35,6 +35,9 @@ Release 2.0.1-alpha - UNRELEASED
 
     HADOOP-8400. All commands warn "Kerberos krb5 configuration not found" 
when security is not enabled. (tucu)
 
+    HADOOP-8406. CompressionCodecFactory.CODEC_PROVIDERS iteration is
+    thread-unsafe (todd)
+
 Release 2.0.0-alpha - UNRELEASED
 
   INCOMPATIBLE CHANGES

Modified: 
hadoop/common/branches/branch-2/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/compress/CompressionCodecFactory.java
URL: 
http://svn.apache.org/viewvc/hadoop/common/branches/branch-2/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/compress/CompressionCodecFactory.java?rev=1339475&r1=1339474&r2=1339475&view=diff
==============================================================================
--- 
hadoop/common/branches/branch-2/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/compress/CompressionCodecFactory.java
 (original)
+++ 
hadoop/common/branches/branch-2/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/compress/CompressionCodecFactory.java
 Thu May 17 04:28:24 2012
@@ -109,8 +109,12 @@ public class CompressionCodecFactory {
     List<Class<? extends CompressionCodec>> result
       = new ArrayList<Class<? extends CompressionCodec>>();
     // Add codec classes discovered via service loading
-    for (CompressionCodec codec : CODEC_PROVIDERS) {
-      result.add(codec.getClass());
+    synchronized (CODEC_PROVIDERS) {
+      // CODEC_PROVIDERS is a lazy collection. Synchronize so it is
+      // thread-safe. See HADOOP-8406.
+      for (CompressionCodec codec : CODEC_PROVIDERS) {
+        result.add(codec.getClass());
+      }
     }
     // Add codec classes from configuration
     String codecsString = conf.get("io.compression.codecs");