svn commit: r1558886 - in /hadoop/common/branches/branch-0.23/hadoop-common-project/hadoop-common: CHANGES.txt src/main/java/org/apache/hadoop/util/Shell.java

[daryn]

Author: daryn
Date: Thu Jan 16 18:57:55 2014
New Revision: 1558886

URL: http://svn.apache.org/r1558886
Log:
HADOOP-10146. Workaround JDK7 Process fd close bug (daryn)

Modified:
    
hadoop/common/branches/branch-0.23/hadoop-common-project/hadoop-common/CHANGES.txt
    
hadoop/common/branches/branch-0.23/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/Shell.java

Modified: 
hadoop/common/branches/branch-0.23/hadoop-common-project/hadoop-common/CHANGES.txt
URL: 
http://svn.apache.org/viewvc/hadoop/common/branches/branch-0.23/hadoop-common-project/hadoop-common/CHANGES.txt?rev=1558886&r1=1558885&r2=1558886&view=diff
==============================================================================
--- 
hadoop/common/branches/branch-0.23/hadoop-common-project/hadoop-common/CHANGES.txt
 (original)
+++ 
hadoop/common/branches/branch-0.23/hadoop-common-project/hadoop-common/CHANGES.txt
 Thu Jan 16 18:57:55 2014
@@ -19,6 +19,8 @@ Release 0.23.11 - UNRELEASED
     HADOOP-10081. Client.setupIOStreams can leak socket resources on exception
     or error (Tsuyoshi OZAWA via jlowe)
 
+    HADOOP-10146. Workaround JDK7 Process fd close bug (daryn)
+
 Release 0.23.10 - 2013-12-09
 
   INCOMPATIBLE CHANGES

Modified: 
hadoop/common/branches/branch-0.23/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/Shell.java
URL: 
http://svn.apache.org/viewvc/hadoop/common/branches/branch-0.23/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/Shell.java?rev=1558886&r1=1558885&r2=1558886&view=diff
==============================================================================
--- 
hadoop/common/branches/branch-0.23/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/Shell.java
 (original)
+++ 
hadoop/common/branches/branch-0.23/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/Shell.java
 Thu Jan 16 18:57:55 2014
@@ -20,6 +20,7 @@ package org.apache.hadoop.util;
 import java.io.BufferedReader;
 import java.io.File;
 import java.io.IOException;
+import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.util.Map;
 import java.util.Timer;
@@ -210,7 +211,17 @@ abstract public class Shell {
       }
       // close the input stream
       try {
-        inReader.close();
+        // JDK 7 tries to automatically drain the input streams for us
+        // when the process exits, but since close is not synchronized,
+        // it creates a race if we close the stream first and the same
+        // fd is recycled.  the stream draining thread will attempt to
+        // drain that fd!!  it may block, OOM, or cause bizarre behavior
+        // see: https://bugs.openjdk.java.net/browse/JDK-8024521
+        //      issue is fixed in build 7u60
+        InputStream stdout = process.getInputStream();
+        synchronized (stdout) {
+          inReader.close();
+        }
       } catch (IOException ioe) {
         LOG.warn("Error while closing the input stream", ioe);
       }
@@ -218,7 +229,10 @@ abstract public class Shell {
         errThread.interrupt();
       }
       try {
-        errReader.close();
+        InputStream stderr = process.getErrorStream();
+        synchronized (stderr) {
+          errReader.close();
+        }
       } catch (IOException ioe) {
         LOG.warn("Error while closing the error stream", ioe);
       }