From ec8208f5d3480c20f7ad122c5b95bc9a6adafb20 Mon Sep 17 00:00:00 2001
From: Arun Murthy <acmurthy@apache.org>
Date: Fri, 14 Aug 2009 08:16:10 +0000
Subject: [PATCH] HADOOP-6192. Fix Shell.getUlimitMemoryCommand to not rely on
 Map-Reduce specific configs.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@804115 13f79535-47bb-0310-9956-ffa450edef68
---
 CHANGES.txt                                |  3 +++
 src/java/org/apache/hadoop/util/Shell.java | 31 ++++++++++++++++++++--
 2 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/CHANGES.txt b/CHANGES.txt
index 861df2f908..716b9aae5e 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -917,6 +917,9 @@ Trunk (unreleased changes)
     HADOOP-6188. TestTrash uses java.io.File api but not hadoop FileSystem api.
     (Boris Shkolnik via szetszwo)
 
+    HADOOP-6192. Fix Shell.getUlimitMemoryCommand to not rely on Map-Reduce
+    specific configs. (acmurthy) 
+
 Release 0.20.1 - Unreleased
 
   INCOMPATIBLE CHANGES
diff --git a/src/java/org/apache/hadoop/util/Shell.java b/src/java/org/apache/hadoop/util/Shell.java
index 35444c0c74..2c0ab786b8 100644
--- a/src/java/org/apache/hadoop/util/Shell.java
+++ b/src/java/org/apache/hadoop/util/Shell.java
@@ -63,6 +63,31 @@ abstract public class Shell {
   /** If or not script timed out*/
   private AtomicBoolean timedOut;
 
+  /** a Unix command to get ulimit of a process. */
+  public static final String ULIMIT_COMMAND = "ulimit";
+  
+  /** 
+   * Get the Unix command for setting the maximum virtual memory available
+   * to a given child process. This is only relevant when we are forking a
+   * process from within the Mapper or the Reducer implementations.
+   * Also see Hadoop Pipes and Hadoop Streaming.
+   * 
+   * It also checks to ensure that we are running on a *nix platform else 
+   * (e.g. in Cygwin/Windows) it returns <code>null</code>.
+   * @param memoryLimit virtual memory limit
+   * @return a <code>String[]</code> with the ulimit command arguments or 
+   *         <code>null</code> if we are running on a non *nix platform or
+   *         if the limit is unspecified.
+   */
+  public static String[] getUlimitMemoryCommand(int memoryLimit) {
+    // ulimit isn't supported on Windows
+    if (WINDOWS) {
+      return null;
+    }
+    
+    return new String[] {ULIMIT_COMMAND, "-v", String.valueOf(memoryLimit)};
+  }
+  
   /** 
    * Get the Unix command for setting the maximum virtual memory available
    * to a given child process. This is only relevant when we are forking a
@@ -75,7 +100,9 @@ abstract public class Shell {
    * @return a <code>String[]</code> with the ulimit command arguments or 
    *         <code>null</code> if we are running on a non *nix platform or
    *         if the limit is unspecified.
+   * @deprecated Use {@link #getUlimitMemoryCommand(int)}
    */
+  @Deprecated
   public static String[] getUlimitMemoryCommand(Configuration conf) {
     // ulimit isn't supported on Windows
     if (WINDOWS) {
@@ -90,8 +117,8 @@ abstract public class Shell {
     
     // Parse it to ensure it is legal/sane
     int memoryLimit = Integer.valueOf(ulimit);
-
-    return new String[] {"ulimit", "-v", String.valueOf(memoryLimit)};
+    
+    return getUlimitMemoryCommand(memoryLimit);
   }
   
   /** Set to true on Windows platforms */