org.argeo.slc.core/src/org/argeo/slc/core/execution/ProcessThread.java

   1 /*
   2  * Copyright (C) 2007-2012 Argeo GmbH
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *         http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16 package org.argeo.slc.core.execution;
  17
  18 import java.security.AccessControlContext;
  19 import java.security.AccessController;
  20 import java.security.PrivilegedActionException;
  21 import java.security.PrivilegedExceptionAction;
  22 import java.util.ArrayList;
  23 import java.util.Collections;
  24 import java.util.HashSet;
  25 import java.util.List;
  26 import java.util.Set;
  27
  28 import javax.security.auth.Subject;
  29
  30 import org.apache.commons.logging.Log;
  31 import org.apache.commons.logging.LogFactory;
  32 import org.argeo.slc.SlcException;
  33 import org.argeo.slc.execution.ExecutionModulesManager;
  34 import org.argeo.slc.execution.ExecutionProcess;
  35 import org.argeo.slc.execution.ExecutionStep;
  36 import org.argeo.slc.execution.RealizedFlow;
  37
  38 /**
  39  * Main thread coordinating an {@link ExecutionProcess}, launching parallel or
  40  * sequential {@link ExecutionThread}s.
  41  */
  42 public class ProcessThread extends Thread {
  43         private final static Log log = LogFactory.getLog(ProcessThread.class);
  44
  45         private final ExecutionModulesManager executionModulesManager;
  46         private final ExecutionProcess process;
  47         private final ProcessThreadGroup processThreadGroup;
  48
  49         private Set<ExecutionThread> executionThreads = Collections.synchronizedSet(new HashSet<ExecutionThread>());
  50
  51         // private Boolean hadAnError = false;
  52         private Boolean killed = false;
  53
  54         private final AccessControlContext accessControlContext;
  55
  56         public ProcessThread(ThreadGroup processesThreadGroup, ExecutionModulesManager executionModulesManager,
  57                         ExecutionProcess process) {
  58                 super(processesThreadGroup, "SLC Process #" + process.getUuid());
  59                 this.executionModulesManager = executionModulesManager;
  60                 this.process = process;
  61                 processThreadGroup = new ProcessThreadGroup(process);
  62                 accessControlContext = AccessController.getContext();
  63         }
  64
  65         public final void run() {
  66                 // authenticate thread
  67                 // Authentication authentication = getProcessThreadGroup()
  68                 // .getAuthentication();
  69                 // if (authentication == null)
  70                 // throw new SlcException("Can only execute authenticated threads");
  71                 // SecurityContextHolder.getContext().setAuthentication(authentication);
  72
  73                 log.info("\n##\n## SLC Process #" + process.getUuid() + " STARTED\n##\n");
  74
  75                 // Start logging
  76                 new LoggingThread().start();
  77
  78                 process.setStatus(ExecutionProcess.RUNNING);
  79                 try {
  80                         Subject subject = Subject.getSubject(accessControlContext);
  81                         try {
  82                                 Subject.doAs(subject, new PrivilegedExceptionAction<Void>() {
  83
  84                                         @Override
  85                                         public Void run() throws Exception {
  86                                                 process();
  87                                                 return null;
  88                                         }
  89
  90                                 });
  91                         } catch (PrivilegedActionException privilegedActionException) {
  92                                 Throwable cause = privilegedActionException.getCause();
  93                                 if (cause instanceof InterruptedException)
  94                                         throw (InterruptedException) cause;
  95                                 else
  96                                         throw new SlcException("Cannot process", cause);
  97                         }
  98                         // process();
  99                 } catch (InterruptedException e) {
 100                         die();
 101                         return;
 102                 } catch (Exception e) {
 103                         String msg = "Process " + getProcess().getUuid() + " failed unexpectedly.";
 104                         log.error(msg, e);
 105                         getProcessThreadGroup()
 106                                         .dispatchAddStep(new ExecutionStep("Process", ExecutionStep.ERROR, msg + " " + e.getMessage()));
 107                 }
 108
 109                 // waits for all execution threads to complete (in case they were
 110                 // started asynchronously)
 111                 for (ExecutionThread executionThread : executionThreads) {
 112                         if (executionThread.isAlive()) {
 113                                 try {
 114                                         executionThread.join();
 115                                 } catch (InterruptedException e) {
 116                                         die();
 117                                         return;
 118                                 }
 119                         }
 120                 }
 121
 122                 computeFinalStatus();
 123         }
 124
 125         /** Make sure this is called BEFORE all the threads are interrupted. */
 126         private void computeFinalStatus() {
 127                 // String oldStatus = process.getStatus();
 128                 // TODO: error management at flow level?
 129                 if (killed)
 130                         process.setStatus(ExecutionProcess.KILLED);
 131                 else if (processThreadGroup.hadAnError())
 132                         process.setStatus(ExecutionProcess.ERROR);
 133                 else
 134                         process.setStatus(ExecutionProcess.COMPLETED);
 135                 // executionModulesManager.dispatchUpdateStatus(process, oldStatus,
 136                 // process.getStatus());
 137                 log.info("\n## SLC Process #" + process.getUuid() + " " + process.getStatus() + "\n");
 138         }
 139
 140         /** Called when being killed */
 141         private synchronized void die() {
 142                 killed = true;
 143                 computeFinalStatus();
 144                 for (ExecutionThread executionThread : executionThreads) {
 145                         try {
 146                                 executionThread.interrupt();
 147                         } catch (Exception e) {
 148                                 log.error("Cannot interrupt " + executionThread);
 149                         }
 150                 }
 151                 processThreadGroup.interrupt();
 152         }
 153
 154         /**
 155          * Implementation specific execution. To be overridden in order to deal with
 156          * custom process types. Default expects an {@link SlcExecution}.
 157          */
 158         protected void process() throws InterruptedException {
 159                 List<RealizedFlow> flowsToProcess = new ArrayList<RealizedFlow>();
 160                 flowsToProcess.addAll(process.getRealizedFlows());
 161                 while (flowsToProcess.size() > 0) {
 162                         RealizedFlow realizedFlow = flowsToProcess.remove(0);
 163                         execute(realizedFlow, true);
 164                 }
 165         }
 166
 167         /** @return the (distinct) thread used for this execution */
 168         protected final void execute(RealizedFlow realizedFlow, Boolean synchronous) throws InterruptedException {
 169                 if (killed)
 170                         return;
 171
 172                 ExecutionThread thread = new ExecutionThread(processThreadGroup, executionModulesManager, realizedFlow);
 173                 executionThreads.add(thread);
 174                 thread.start();
 175
 176                 if (synchronous)
 177                         thread.join();
 178
 179                 return;
 180         }
 181
 182         // public void notifyError() {
 183         // hadAnError = true;
 184         // }
 185         //
 186         // public synchronized void flowCompleted() {
 187         // // notifyAll();
 188         // }
 189
 190         public ExecutionProcess getProcess() {
 191                 return process;
 192         }
 193
 194         public ProcessThreadGroup getProcessThreadGroup() {
 195                 return processThreadGroup;
 196         }
 197
 198         public ExecutionModulesManager getExecutionModulesManager() {
 199                 return executionModulesManager;
 200         }
 201
 202         private class LoggingThread extends Thread {
 203
 204                 public LoggingThread() {
 205                         super("SLC Process Logger #" + process.getUuid());
 206                 }
 207
 208                 public void run() {
 209                         boolean run = true;
 210                         while (run) {
 211                                 List<ExecutionStep> newSteps = new ArrayList<ExecutionStep>();
 212                                 processThreadGroup.getSteps().drainTo(newSteps);
 213                                 if (newSteps.size() > 0) {
 214                                         // System.out.println(steps.size() + " steps");
 215                                         process.addSteps(newSteps);
 216                                 }
 217
 218                                 try {
 219                                         Thread.sleep(1000);
 220                                 } catch (InterruptedException e) {
 221                                         break;
 222                                 }
 223
 224                                 if (!ProcessThread.this.isAlive() && processThreadGroup.getSteps().size() == 0)
 225                                         run = false;
 226                         }
 227                 }
 228
 229         }
 230 }