org.argeo.slc.core/src/org/argeo/slc/core/execution/ExecutionThread.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.List;
  24
  25 import javax.security.auth.Subject;
  26
  27 import org.apache.commons.logging.Log;
  28 import org.apache.commons.logging.LogFactory;
  29 import org.argeo.slc.SlcException;
  30 import org.argeo.slc.execution.ExecutionFlowDescriptor;
  31 import org.argeo.slc.execution.ExecutionModulesManager;
  32 import org.argeo.slc.execution.ExecutionStep;
  33 import org.argeo.slc.execution.RealizedFlow;
  34
  35 /** Thread of a single execution */
  36 public class ExecutionThread extends Thread {
  37         public final static String SYSPROP_EXECUTION_AUTO_UPGRADE = "slc.execution.autoupgrade";
  38         private final static Log log = LogFactory.getLog(ExecutionThread.class);
  39
  40         private ExecutionModulesManager executionModulesManager;
  41         private final RealizedFlow realizedFlow;
  42         private final AccessControlContext accessControlContext;
  43
  44         private List<Runnable> destructionCallbacks = new ArrayList<Runnable>();
  45
  46         public ExecutionThread(ProcessThreadGroup processThreadGroup, ExecutionModulesManager executionModulesManager,
  47                         RealizedFlow realizedFlow) {
  48                 super(processThreadGroup, "Flow " + realizedFlow.getFlowDescriptor().getName());
  49                 this.realizedFlow = realizedFlow;
  50                 this.executionModulesManager = executionModulesManager;
  51                 accessControlContext = AccessController.getContext();
  52         }
  53
  54         public void run() {
  55                 // authenticate thread
  56                 // Authentication authentication = getProcessThreadGroup()
  57                 // .getAuthentication();
  58                 // if (authentication == null)
  59                 // throw new SlcException("Can only execute authenticated threads");
  60                 // SecurityContextHolder.getContext().setAuthentication(authentication);
  61
  62                 // Retrieve execution flow descriptor
  63                 ExecutionFlowDescriptor executionFlowDescriptor = realizedFlow.getFlowDescriptor();
  64                 String flowName = executionFlowDescriptor.getName();
  65
  66                 getProcessThreadGroup().dispatchAddStep(
  67                                 new ExecutionStep(realizedFlow.getModuleName(), ExecutionStep.PHASE_START, "Flow " + flowName));
  68
  69                 try {
  70                         Subject subject = Subject.getSubject(accessControlContext);
  71                         try {
  72                                 Subject.doAs(subject, new PrivilegedExceptionAction<Void>() {
  73
  74                                         @Override
  75                                         public Void run() throws Exception {
  76                                                 String autoUpgrade = System.getProperty(SYSPROP_EXECUTION_AUTO_UPGRADE);
  77                                                 if (autoUpgrade != null && autoUpgrade.equals("true"))
  78                                                         executionModulesManager.upgrade(realizedFlow.getModuleNameVersion());
  79                                                 executionModulesManager.start(realizedFlow.getModuleNameVersion());
  80                                                 //
  81                                                 // START FLOW
  82                                                 //
  83                                                 executionModulesManager.execute(realizedFlow);
  84                                                 // END FLOW
  85                                                 return null;
  86                                         }
  87
  88                                 });
  89                         } catch (PrivilegedActionException privilegedActionException) {
  90                                 throw (Exception) privilegedActionException.getCause();
  91                         }
  92                 } catch (FlowConfigurationException e) {
  93                         String msg = "Configuration problem with flow " + flowName + ":\n" + e.getMessage();
  94                         log.error(msg);
  95                         getProcessThreadGroup().dispatchAddStep(
  96                                         new ExecutionStep(realizedFlow.getModuleName(), ExecutionStep.ERROR, msg + " " + e.getMessage()));
  97                 } catch (Exception e) {
  98                         // TODO: re-throw exception ?
  99                         String msg = "Execution of flow " + flowName + " failed.";
 100                         log.error(msg, e);
 101                         getProcessThreadGroup().dispatchAddStep(
 102                                         new ExecutionStep(realizedFlow.getModuleName(), ExecutionStep.ERROR, msg + " " + e.getMessage()));
 103                 } finally {
 104                         getProcessThreadGroup().dispatchAddStep(
 105                                         new ExecutionStep(realizedFlow.getModuleName(), ExecutionStep.PHASE_END, "Flow " + flowName));
 106                         processDestructionCallbacks();
 107                 }
 108         }
 109
 110         private synchronized void processDestructionCallbacks() {
 111                 for (int i = destructionCallbacks.size() - 1; i >= 0; i--) {
 112                         try {
 113                                 destructionCallbacks.get(i).run();
 114                         } catch (Exception e) {
 115                                 log.warn("Could not process destruction callback " + i + " in thread " + getName(), e);
 116                         }
 117                 }
 118         }
 119
 120         /**
 121          * Gather object destruction callback to be called in reverse order at the
 122          * end of the thread
 123          */
 124         synchronized void registerDestructionCallback(String name, Runnable callback) {
 125                 destructionCallbacks.add(callback);
 126         }
 127
 128         protected ProcessThreadGroup getProcessThreadGroup() {
 129                 return (ProcessThreadGroup) getThreadGroup();
 130         }
 131 }