diff options
Diffstat (limited to 'framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/ant/taskdefs/ProcessDestroyer.java')
| -rw-r--r-- | framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/ant/taskdefs/ProcessDestroyer.java | 220 |
1 files changed, 0 insertions, 220 deletions
diff --git a/framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/ant/taskdefs/ProcessDestroyer.java b/framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/ant/taskdefs/ProcessDestroyer.java deleted file mode 100644 index ba9c9d48..00000000 --- a/framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/ant/taskdefs/ProcessDestroyer.java +++ /dev/null @@ -1,220 +0,0 @@ -/* - * 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.tools.ant.taskdefs; - -import java.lang.reflect.InvocationTargetException; -import java.lang.reflect.Method; -import java.util.HashSet; -import java.util.Iterator; - -/** - * Destroys all registered <code>Process</code>es when the VM exits. - * - * @since Ant 1.5 - */ -class ProcessDestroyer implements Runnable { - private static final int THREAD_DIE_TIMEOUT = 20000; - private HashSet processes = new HashSet(); - // methods to register and unregister shutdown hooks - private Method addShutdownHookMethod; - private Method removeShutdownHookMethod; - private ProcessDestroyerImpl destroyProcessThread = null; - - // whether or not this ProcessDestroyer has been registered as a - // shutdown hook - private boolean added = false; - // whether or not this ProcessDestroyer is currently running as - // shutdown hook - private boolean running = false; - - private class ProcessDestroyerImpl extends Thread { - private boolean shouldDestroy = true; - - public ProcessDestroyerImpl() { - super("ProcessDestroyer Shutdown Hook"); - } - public void run() { - if (shouldDestroy) { - ProcessDestroyer.this.run(); - } - } - - public void setShouldDestroy(boolean shouldDestroy) { - this.shouldDestroy = shouldDestroy; - } - } - - /** - * Constructs a <code>ProcessDestroyer</code> and obtains - * <code>Runtime.addShutdownHook()</code> and - * <code>Runtime.removeShutdownHook()</code> through reflection. The - * ProcessDestroyer manages a list of processes to be destroyed when the - * VM exits. If a process is added when the list is empty, - * this <code>ProcessDestroyer</code> is registered as a shutdown hook. If - * removing a process results in an empty list, the - * <code>ProcessDestroyer</code> is removed as a shutdown hook. - */ - ProcessDestroyer() { - try { - // check to see if the shutdown hook methods exists - // (support pre-JDK 1.3 and Non-Sun VMs) - Class[] paramTypes = {Thread.class}; - addShutdownHookMethod = - Runtime.class.getMethod("addShutdownHook", paramTypes); - - removeShutdownHookMethod = - Runtime.class.getMethod("removeShutdownHook", paramTypes); - // wait to add shutdown hook as needed - } catch (NoSuchMethodException e) { - // it just won't be added as a shutdown hook... :( - } catch (Exception e) { - e.printStackTrace(); - } - } - - /** - * Registers this <code>ProcessDestroyer</code> as a shutdown hook, - * uses reflection to ensure pre-JDK 1.3 compatibility. - */ - private void addShutdownHook() { - if (addShutdownHookMethod != null && !running) { - destroyProcessThread = new ProcessDestroyerImpl(); - Object[] args = {destroyProcessThread}; - try { - addShutdownHookMethod.invoke(Runtime.getRuntime(), args); - added = true; - } catch (IllegalAccessException e) { - e.printStackTrace(); - } catch (InvocationTargetException e) { - Throwable t = e.getTargetException(); - if (t != null && t.getClass() == IllegalStateException.class) { - // shutdown already is in progress - running = true; - } else { - e.printStackTrace(); - } - } - } - } - - /** - * Removes this <code>ProcessDestroyer</code> as a shutdown hook, - * uses reflection to ensure pre-JDK 1.3 compatibility - */ - private void removeShutdownHook() { - if (removeShutdownHookMethod != null && added && !running) { - Object[] args = {destroyProcessThread}; - try { - Boolean removed = - (Boolean) removeShutdownHookMethod.invoke( - Runtime.getRuntime(), - args); - if (!removed.booleanValue()) { - System.err.println("Could not remove shutdown hook"); - } - } catch (IllegalAccessException e) { - e.printStackTrace(); - } catch (InvocationTargetException e) { - Throwable t = e.getTargetException(); - if (t != null && t.getClass() == IllegalStateException.class) { - // shutdown already is in progress - running = true; - } else { - e.printStackTrace(); - } - } - // start the hook thread, a unstarted thread may not be - // eligible for garbage collection - // Cf.: http://developer.java.sun.com/developer/bugParade/bugs/4533087.html - destroyProcessThread.setShouldDestroy(false); - if (!destroyProcessThread.getThreadGroup().isDestroyed()) { - // start() would throw IllegalThreadStateException from - // ThreadGroup.add if it were destroyed - destroyProcessThread.start(); - } - // this should return quickly, since it basically is a NO-OP. - try { - destroyProcessThread.join(THREAD_DIE_TIMEOUT); - } catch (InterruptedException ie) { - // the thread didn't die in time - // it should not kill any processes unexpectedly - } - destroyProcessThread = null; - added = false; - } - } - - /** - * Returns whether or not the ProcessDestroyer is registered as - * as shutdown hook - * @return true if this is currently added as shutdown hook - */ - public boolean isAddedAsShutdownHook() { - return added; - } - - /** - * Returns <code>true</code> if the specified <code>Process</code> was - * successfully added to the list of processes to destroy upon VM exit. - * - * @param process the process to add - * @return <code>true</code> if the specified <code>Process</code> was - * successfully added - */ - public boolean add(Process process) { - synchronized (processes) { - // if this list is empty, register the shutdown hook - if (processes.size() == 0) { - addShutdownHook(); - } - return processes.add(process); - } - } - - /** - * Returns <code>true</code> if the specified <code>Process</code> was - * successfully removed from the list of processes to destroy upon VM exit. - * - * @param process the process to remove - * @return <code>true</code> if the specified <code>Process</code> was - * successfully removed - */ - public boolean remove(Process process) { - synchronized (processes) { - boolean processRemoved = processes.remove(process); - if (processRemoved && processes.size() == 0) { - removeShutdownHook(); - } - return processRemoved; - } - } - - /** - * Invoked by the VM when it is exiting. - */ - public void run() { - synchronized (processes) { - running = true; - Iterator e = processes.iterator(); - while (e.hasNext()) { - ((Process) e.next()).destroy(); - } - } - } -} |