svn commit: r1398901 - /hadoop/common/branches/branch-0.23/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/ExitUtil.java

[bo...@apache.org]

Author: bobby
Date: Tue Oct 16 17:52:01 2012
New Revision: 1398901

URL: http://svn.apache.org/viewvc?rev=1398901&view=rev
Log:
HDFS-4016. back-port HDFS-3582 to branch-0.23 (Ivan A. Veselovsky via bobby)

Added:
    hadoop/common/branches/branch-0.23/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/ExitUtil.java

Added: hadoop/common/branches/branch-0.23/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/ExitUtil.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/ExitUtil.java?rev=1398901&view=auto
==============================================================================
--- hadoop/common/branches/branch-0.23/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/ExitUtil.java (added)
+++ hadoop/common/branches/branch-0.23/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/ExitUtil.java Tue Oct 16 17:52:01 2012
@@ -0,0 +1,83 @@
+/**
+ * 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.util;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+
+/**
+ * Facilitates hooking process termination for tests and debugging.
+ */
+@InterfaceAudience.LimitedPrivate({"HDFS", "MapReduce"})
+@InterfaceStability.Unstable
+public final class ExitUtil {
+  private final static Log LOG = LogFactory.getLog(ExitUtil.class.getName());
+  private static volatile boolean systemExitDisabled = false;
+  private static volatile boolean terminateCalled = false;
+
+  public static class ExitException extends RuntimeException {
+    private static final long serialVersionUID = 1L;
+    public final int status;
+
+    public ExitException(int status, String msg) {
+      super(msg);
+      this.status = status;
+    }
+  }
+
+  /**
+   * Disable the use of System.exit for testing.
+   */
+  public static void disableSystemExit() {
+    systemExitDisabled = true;
+  }
+
+  /**
+   * @return true if terminate has been called
+   */
+  public static boolean terminateCalled() {
+    return terminateCalled;
+  }
+
+  /**
+   * Terminate the current process. Note that terminate is the *only* method
+   * that should be used to terminate the daemon processes.
+   * @param status exit code
+   * @param msg message used to create the ExitException
+   * @throws ExitException if System.exit is disabled for test purposes
+   */
+  public static void terminate(int status, String msg) throws ExitException {
+    LOG.info("Exiting with status " + status);
+    terminateCalled = true;
+    if (systemExitDisabled) {
+      throw new ExitException(status, msg);
+    }
+    System.exit(status);
+  }
+
+  /**
+   * Like {@link terminate(int, String)} without a message.
+   * @param status
+   * @throws ExitException
+   */
+  public static void terminate(int status) throws ExitException {
+    terminate(status, "ExitException");
+  }
+}
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