| /** |
| * 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 ExitException firstExitException; |
| |
| 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() { |
| // Either we set this member or we actually called System#exit |
| return firstExitException != null; |
| } |
| |
| /** |
| * @return the first ExitException thrown, null if none thrown yet |
| */ |
| public static ExitException getFirstExitException() { |
| return firstExitException; |
| } |
| |
| /** |
| * Reset the tracking of process termination. This is for use |
| * in unit tests where one test in the suite expects an exit |
| * but others do not. |
| */ |
| public static void resetFirstExitException() { |
| firstExitException = null; |
| } |
| |
| /** |
| * 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); |
| if (systemExitDisabled) { |
| ExitException ee = new ExitException(status, msg); |
| LOG.fatal("Terminate called", ee); |
| if (null == firstExitException) { |
| firstExitException = ee; |
| } |
| throw ee; |
| } |
| System.exit(status); |
| } |
| |
| /** |
| * Like {@link terminate(int, String)} but uses the given throwable to |
| * initialize the ExitException. |
| * @param status |
| * @param t throwable used to create the ExitException |
| * @throws ExitException if System.exit is disabled for test purposes |
| */ |
| public static void terminate(int status, Throwable t) throws ExitException { |
| terminate(status, StringUtils.stringifyException(t)); |
| } |
| |
| /** |
| * Like {@link terminate(int, String)} without a message. |
| * @param status |
| * @throws ExitException if System.exit is disabled for test purposes |
| */ |
| public static void terminate(int status) throws ExitException { |
| terminate(status, "ExitException"); |
| } |
| } |