svn merge -c 1401698 FIXES: YARN-178. Fix custom ProcessTree instance creation (Radim Kolar via bobby)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1401700 13f79535-47bb-0310-9956-ffa450edef68

hadoop-yarn-project/CHANGES.txt

@@ -160,6 +160,8 @@ Release 0.23.5 - UNRELEASED
     YARN-177. CapacityScheduler - adding a queue while the RM is running has 
     wacky results (acmurthy vai tgraves)
 
+    YARN-178. Fix custom ProcessTree instance creation (Radim Kolar via bobby)
+
 Release 0.23.4 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/util/ProcfsBasedProcessTree.java

@@ -114,6 +114,7 @@ public class ProcfsBasedProcessTree extends ResourceCalculatorProcessTree {
    * @param procfsDir the root of a proc file system - only used for testing.
    */
   public ProcfsBasedProcessTree(String pid, String procfsDir) {
+    super(pid);
     this.pid = getValidPID(pid);
     this.procfsDir = procfsDir;
   }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/util/ResourceCalculatorProcessTree.java

@@ -21,16 +21,27 @@ package org.apache.hadoop.yarn.util;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.conf.Configured;
 import org.apache.hadoop.util.ReflectionUtils;
+import java.lang.reflect.Constructor;
 
 /**
  * Interface class to obtain process resource usage
  *
  */
-public abstract class ResourceCalculatorProcessTree {
+public abstract class ResourceCalculatorProcessTree extends Configured {
   static final Log LOG = LogFactory
       .getLog(ResourceCalculatorProcessTree.class);
 
+  /**
+   * Create process-tree instance with specified root process.
+   *
+   * Subclass must override this.
+   * @param root process-tree root-process
+   */
+  public ResourceCalculatorProcessTree(String root) {
+  }
+
   /**
    * Get the process-tree with latest state. If the root-process is not alive,
    * an empty tree will be returned.
@@ -122,10 +133,17 @@ public abstract class ResourceCalculatorProcessTree {
    *         is not available for this system.
    */
   public static ResourceCalculatorProcessTree getResourceCalculatorProcessTree(
-	  String pid, Class<? extends ResourceCalculatorProcessTree> clazz, Configuration conf) {
+    String pid, Class<? extends ResourceCalculatorProcessTree> clazz, Configuration conf) {
 
     if (clazz != null) {
-      return ReflectionUtils.newInstance(clazz, conf);
+      try {
+        Constructor <? extends ResourceCalculatorProcessTree> c = clazz.getConstructor(String.class);
+        ResourceCalculatorProcessTree rctree = c.newInstance(pid);
+        rctree.setConf(conf);
+        return rctree;
+      } catch(Exception e) {
+        throw new RuntimeException(e);
+      }
     }
 
     // No class given, try a os specific class

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/test/java/org/apache/hadoop/yarn/util/TestResourceCalculatorProcessTree.java

@@ -0,0 +1,78 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.yarn.util;
+
+import org.apache.hadoop.conf.Configuration;
+import org.junit.Test;
+import static org.junit.Assert.*;
+import static org.hamcrest.core.IsInstanceOf.*;
+import static org.hamcrest.core.IsSame.*;
+
+/**
+ * A JUnit test to test {@link ResourceCalculatorPlugin}
+ */
+public class TestResourceCalculatorProcessTree {
+
+  public static class EmptyProcessTree extends ResourceCalculatorProcessTree {
+
+    public EmptyProcessTree(String pid) {
+      super(pid);
+    }
+
+    public ResourceCalculatorProcessTree getProcessTree() {
+      return this;
+    }
+
+    public String getProcessTreeDump() {
+      return "Empty tree for testing";
+    }
+
+    public long getCumulativeRssmem(int age) {
+      return 0;
+    }
+
+    public long getCumulativeVmem(int age) {
+      return 0;
+    }
+
+    public long getCumulativeCpuTime() {
+      return 0;
+    }
+
+    public boolean checkPidPgrpidForMatch() {
+      return false;
+    }
+  }
+
+  @Test
+  public void testCreateInstance() {
+    ResourceCalculatorProcessTree tree;
+    tree = ResourceCalculatorProcessTree.getResourceCalculatorProcessTree("1", EmptyProcessTree.class, new Configuration());
+    assertNotNull(tree);
+    assertThat(tree, instanceOf(EmptyProcessTree.class));
+  }
+
+  @Test
+  public void testCreatedInstanceConfigured() {
+    ResourceCalculatorProcessTree tree;
+    Configuration conf = new Configuration();
+    tree = ResourceCalculatorProcessTree.getResourceCalculatorProcessTree("1", EmptyProcessTree.class, conf);
+    assertNotNull(tree);
+    assertThat(tree.getConf(), sameInstance(conf));
+  } 
+}