001 /* 002 * Copyright (C) 2010 eXo Platform SAS. 003 * 004 * This is free software; you can redistribute it and/or modify it 005 * under the terms of the GNU Lesser General Public License as 006 * published by the Free Software Foundation; either version 2.1 of 007 * the License, or (at your option) any later version. 008 * 009 * This software is distributed in the hope that it will be useful, 010 * but WITHOUT ANY WARRANTY; without even the implied warranty of 011 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 012 * Lesser General Public License for more details. 013 * 014 * You should have received a copy of the GNU Lesser General Public 015 * License along with this software; if not, write to the Free 016 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 017 * 02110-1301 USA, or see the FSF site: http://www.fsf.org. 018 */ 019 020 package org.crsh.shell.concurrent; 021 022 import org.crsh.cmdline.CommandCompletion; 023 import org.crsh.shell.Shell; 024 025 import java.io.Closeable; 026 import java.util.Collections; 027 import java.util.HashSet; 028 import java.util.Set; 029 import java.util.concurrent.CompletionService; 030 import java.util.concurrent.Executor; 031 import java.util.concurrent.ExecutorCompletionService; 032 033 /** 034 * <p></p>The async shell wraps a shell and provides command cancellation. The shell executes the command in a separate thread 035 * allowing using the wrapped shell to which it delegates the business command execution.</p> 036 * 037 * 038 * @author <a href="mailto:julien.viet@exoplatform.com">Julien Viet</a> 039 * @version $Revision$ 040 */ 041 public class AsyncShell implements Shell, Closeable { 042 043 /** . */ 044 final Shell shell; 045 046 /** . */ 047 private AsyncProcess current; 048 049 /** . */ 050 final CompletionService<AsyncProcess> executor; 051 052 /** . */ 053 boolean closed; 054 055 /** . */ 056 final Object lock = new Object(); 057 058 /** . */ 059 final Set<AsyncProcess> processes; 060 061 public AsyncShell(Executor executor, Shell shell) { 062 this.shell = shell; 063 this.current = null; 064 this.executor = new ExecutorCompletionService<AsyncProcess>(executor); 065 this.closed = false; 066 this.processes = Collections.synchronizedSet(new HashSet<AsyncProcess>()); 067 } 068 069 public void close() { 070 071 AsyncProcess[] toCancel = null; 072 synchronized (lock) { 073 if (closed) { 074 toCancel = null; 075 } else { 076 closed = true; 077 toCancel = processes.toArray(new AsyncProcess[processes.size()]); 078 } 079 } 080 081 // Cancel all process 082 if (toCancel != null) { 083 for (AsyncProcess process : toCancel) { 084 process.cancel(); 085 } 086 } 087 } 088 089 // Shell implementation ********************************************************************************************** 090 091 public String getWelcome() { 092 return shell.getWelcome(); 093 } 094 095 public String getPrompt() { 096 return shell.getPrompt(); 097 } 098 099 public CommandCompletion complete(String prefix) { 100 return shell.complete(prefix); 101 } 102 103 public AsyncProcess createProcess(String request) { 104 synchronized (lock) { 105 if (closed) { 106 throw new IllegalStateException(); 107 } 108 } 109 return new AsyncProcess(this, request); 110 } 111 }