dsf/org.eclipse.cdt.dsf.ui/src/org/eclipse/cdt/dsf/debug/ui/viewmodel/variable/SyncVariableDataAccess.java - cdt/org.eclipse.cdt - Git at Google

 /*******************************************************************************
  * Copyright (c) 2007, 2016 Wind River Systems and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  *     Wind River Systems - initial API and implementation
  *******************************************************************************/
 package org.eclipse.cdt.dsf.debug.ui.viewmodel.variable;

 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;

 import org.eclipse.cdt.dsf.concurrent.DataRequestMonitor;
 import org.eclipse.cdt.dsf.concurrent.IDsfStatusConstants;
 import org.eclipse.cdt.dsf.concurrent.Query;
 import org.eclipse.cdt.dsf.concurrent.ThreadSafe;
 import org.eclipse.cdt.dsf.concurrent.ThreadSafeAndProhibitedFromDsfExecutor;
 import org.eclipse.cdt.dsf.debug.service.IExpressions;
 import org.eclipse.cdt.dsf.debug.service.IExpressions.IExpressionDMContext;
 import org.eclipse.cdt.dsf.debug.service.IExpressions.IExpressionDMData;
 import org.eclipse.cdt.dsf.debug.service.IFormattedValues.FormattedValueDMContext;
 import org.eclipse.cdt.dsf.debug.service.IFormattedValues.FormattedValueDMData;
 import org.eclipse.cdt.dsf.debug.service.IFormattedValues.IFormattedDataDMContext;
 import org.eclipse.cdt.dsf.internal.ui.DsfUIPlugin;
 import org.eclipse.cdt.dsf.service.DsfSession;
 import org.eclipse.cdt.dsf.service.IDsfService;
 import org.eclipse.core.runtime.IAdaptable;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.Status;
 import org.osgi.framework.InvalidSyntaxException;
 import org.osgi.util.tracker.ServiceTracker;

 @ThreadSafeAndProhibitedFromDsfExecutor("fSession#getExecutor")
 public class SyncVariableDataAccess {

     /**
      * The session that this data access operates in.
      */
     private final DsfSession fSession;

     /**
      * Need to use the OSGi service tracker here (instead of DsfServiceTracker),
      * because we're accessing it in non-dispatch thread. DsfServiceTracker is
      * not thread-safe.
      */
     @ThreadSafe
     private ServiceTracker fServiceTracker;


     public SyncVariableDataAccess(DsfSession session) {
         fSession = session;
     }

     @ThreadSafe
     private synchronized IExpressions getService() {

         if (fServiceTracker == null) {
             try {
                 fServiceTracker = new ServiceTracker(
                     DsfUIPlugin.getBundleContext(),
                     DsfUIPlugin.getBundleContext().createFilter(getServiceFilter()), null);
                 fServiceTracker.open();
             } catch (InvalidSyntaxException e) {
                 return null;
             }
         }
         return (IExpressions) fServiceTracker.getService();
     }

     private String getServiceFilter() {
         StringBuilder filter = new StringBuilder();
         filter.append("(&"); //$NON-NLS-1$
         filter.append("(OBJECTCLASS="); //$NON-NLS-1$
         filter.append(IExpressions.class.getName());
         filter.append(')');
         filter.append('(');
         filter.append(IDsfService.PROP_SESSION_ID);
         filter.append('=');
         filter.append(fSession.getId());
         filter.append(')');
         filter.append(')');
         return filter.toString();
     }

     @ThreadSafe
     public synchronized void dispose() {
         if (fServiceTracker != null) {
             fServiceTracker.close();
         }
     }

     public IExpressionDMContext getVariableDMC(Object element) {
         if (element instanceof IAdaptable) {
             return ((IAdaptable) element).getAdapter(IExpressionDMContext.class);
         }
         return null;
     }


     public class GetVariableValueQuery extends Query<IExpressionDMData> {

         private IExpressionDMContext fDmc;

         public GetVariableValueQuery(IExpressionDMContext dmc) {
             super();
             fDmc = dmc;
         }

         @Override
         protected void execute(final DataRequestMonitor<IExpressionDMData> rm) {
             /*
              * Guard against the session being disposed. If session is disposed
              * it could mean that the executor is shut-down, which in turn could
              * mean that we can't complete the RequestMonitor argument. in that
              * case, cancel to notify waiting thread.
              */
             final DsfSession session = DsfSession.getSession(fDmc.getSessionId());
             if (session == null) {
                 rm.setStatus(new Status(IStatus.ERROR, DsfUIPlugin.PLUGIN_ID, IDsfStatusConstants.INVALID_STATE, "Debug session already shut down.", null)); //$NON-NLS-1$
                 rm.done();
                 return;
             }

             IExpressions service = getService();
             if (service == null) {
                 rm.setStatus(new Status(IStatus.ERROR, DsfUIPlugin.PLUGIN_ID, IDsfStatusConstants.INVALID_STATE, "Service not available", null)); //$NON-NLS-1$
                 rm.done();
                 return;
             }

             service.getExpressionData(fDmc, new DataRequestMonitor<IExpressionDMData>(session.getExecutor(), rm) {
                 @Override
                 protected void handleSuccess() {
                     /*
                      * All good set return value.
                      */
                     rm.setData(getData());
                     rm.done();
                 }
             });
         }
     }

     public IExpressionDMContext getExpressionDMC(Object element) {
         if (element instanceof IAdaptable) {
             return ((IAdaptable) element).getAdapter(IExpressionDMContext.class);
         }
         return null;
     }

     public IExpressionDMData readVariable(Object element) {
         /*
          * Get the DMC and the session. If element is not an expression DMC, or
          * session is stale, then bail out.
          */
         IExpressionDMContext dmc = getExpressionDMC(element);
         if (dmc == null) return null;
         DsfSession session = DsfSession.getSession(dmc.getSessionId());
         if (session == null) return null;

         /*
          * Create the query to request the value from service. Note: no need to
          * guard against RejectedExecutionException, because
          * DsfSession.getSession() above would only return an active session.
          */
         GetVariableValueQuery query = new GetVariableValueQuery(dmc);
         session.getExecutor().execute(query);

 		/*
 		 * This class is about synchronous access to the variable, so wait until
 		 * the query has completed on the DSF session thread and return the
 		 * result.
 		 */
         try {
             return query.get();
         } catch (InterruptedException e) {
             assert false;
             return null;
         } catch (ExecutionException e) {
             return null;
         }
     }

     public class SetVariableValueQuery extends Query<Object> {

         private IExpressionDMContext fDmc;
         private String fValue;
         private String fFormatId;

         public SetVariableValueQuery(IExpressionDMContext dmc, String value, String formatId) {
             super();
             fDmc = dmc;
             fValue = value;
             fFormatId = formatId;
         }

         @Override
         protected void execute(final DataRequestMonitor<Object> rm) {
             /*
              * We're in another dispatch, so we must guard against executor
              * shutdown again.
              */
             final DsfSession session = DsfSession.getSession(fDmc.getSessionId());
             if (session == null) {
                 rm.setStatus(new Status(IStatus.ERROR, DsfUIPlugin.PLUGIN_ID, IDsfStatusConstants.INVALID_STATE, "Debug session already shut down.", null)); //$NON-NLS-1$
                 rm.done();
                 return;
             }

             /*
              * Guard against a disposed service
              */
             IExpressions service = getService();
             if (service == null) {
                 rm.setStatus(new Status(IStatus.ERROR, DsfUIPlugin.PLUGIN_ID, IDsfStatusConstants.INVALID_STATE, "Service unavailable", null)); //$NON-NLS-1$
                 rm.done();
                 return;
             }

             /*
              * Write the expression value using a string/format style.
              */
             service.writeExpression(
                fDmc,
                fValue,
                fFormatId,
                new DataRequestMonitor<IExpressionDMData>(session.getExecutor(), rm) {
                     @Override
                     protected void handleSuccess() {
                         /*
                          * All good set return value.
                          */
                         rm.setData(new Object());
                         rm.done();
                     }
                 }
            );
         }
     }

     public void writeVariable(Object element, String value, String formatId) {

         /*
          * Get the DMC and the session. If element is not an register DMC, or
          * session is stale, then bail out.
          */
         IExpressionDMContext dmc = getExpressionDMC(element);
         if (dmc == null) return;
         DsfSession session = DsfSession.getSession(dmc.getSessionId());
         if (session == null) return;

         /*
          * Create the query to write the value to the service. Note: no need to
          * guard against RejectedExecutionException, because
          * DsfSession.getSession() above would only return an active session.
          */
         SetVariableValueQuery query = new SetVariableValueQuery(dmc, value, formatId);
         session.getExecutor().execute(query);

 		/*
 		 * This class is about synchronous access to the variable, so wait until
 		 * the query has completed on the DSF session thread.
 		 */
         try {
             /*
              * Return value is irrelevant, any error would come through with an
              * exception.
              */
             query.get(3000, TimeUnit.MILLISECONDS);
         } catch (InterruptedException e) {
             assert false;
         } catch (ExecutionException e) {
             /*
              * View must be shutting down, no need to show error dialog.
              */
         } catch (TimeoutException e) {
             assert false;
         }
     }

     public IFormattedDataDMContext getFormattedDMC(Object element) {
         if (element instanceof IAdaptable) {
             return ((IAdaptable) element).getAdapter(IFormattedDataDMContext.class);
         }
         return null;
     }

     public class GetSupportFormatsValueQuery extends Query<Object> {

         IFormattedDataDMContext fDmc;

         public GetSupportFormatsValueQuery(IFormattedDataDMContext dmc) {
             super();
             fDmc = dmc;
         }

         @Override
         protected void execute(final DataRequestMonitor<Object> rm) {
             /*
              * We're in another dispatch, so we must guard against executor
              * shutdown again.
              */
             final DsfSession session = DsfSession.getSession(fDmc.getSessionId());
             if (session == null) {
                 rm.setStatus(new Status(IStatus.ERROR, DsfUIPlugin.PLUGIN_ID, IDsfStatusConstants.INVALID_STATE, "Debug session already shut down.", null)); //$NON-NLS-1$
                 rm.done();
                 return;
             }

             /*
              * Guard against a disposed service
              */
             IExpressions service = getService();
             if (service == null) {
                 rm.setStatus(new Status(IStatus.ERROR, DsfUIPlugin.PLUGIN_ID, IDsfStatusConstants.INVALID_STATE, "Service unavailable", null)); //$NON-NLS-1$
                 rm.done();
                 return;
             }

             /*
              * Get the available formats from the service.
              */
             service.getAvailableFormats(
                 fDmc,
                 new DataRequestMonitor<String[]>(session.getExecutor(), rm) {
                     @Override
                     protected void handleSuccess() {
                         /*
                          * All good set return value.
                          */
                         rm.setData(getData());
                         rm.done();
                     }
                 }
             );
         }
     }

     public String[] getSupportedFormats(Object element) {

         /*
          * Get the DMC and the session. If element is not an register DMC, or
          * session is stale, then bail out.
          */
         IFormattedDataDMContext dmc = getFormattedDMC(element);
         if (dmc == null) return null;
         DsfSession session = DsfSession.getSession(dmc.getSessionId());
         if (session == null) return null;

         /*
          * Create the query to write the value to the service. Note: no need to
          * guard against RejectedExecutionException, because
          * DsfSession.getSession() above would only return an active session.
          */
         GetSupportFormatsValueQuery query = new GetSupportFormatsValueQuery(dmc);
         session.getExecutor().execute(query);

         /*
          * Now we have the data, go and get it. Since the call is completed now
          * the ".get()" will not suspend it will immediately return with the
          * data.
          */
         try {
             return (String[]) query.get();
         } catch (InterruptedException e) {
             assert false;
             return null;
         } catch (ExecutionException e) {
             return null;
         }
     }

     public class GetFormattedValueValueQuery extends Query<Object> {

         private IFormattedDataDMContext fDmc;
         private String fFormatId;
         private boolean fEditable;

         public GetFormattedValueValueQuery(IFormattedDataDMContext dmc, String formatId) {
         	this(dmc, formatId, false);
         }

         public GetFormattedValueValueQuery(IFormattedDataDMContext dmc, String formatId, boolean editable) {
         	super();
         	fDmc = dmc;
         	fFormatId = formatId;
         	fEditable = editable;
         }

         @Override
         protected void execute(final DataRequestMonitor<Object> rm) {
             /*
              * We're in another dispatch, so we must guard against executor
              * shutdown again.
              */
             final DsfSession session = DsfSession.getSession(fDmc.getSessionId());
             if (session == null) {
                 rm.setStatus(new Status(IStatus.ERROR, DsfUIPlugin.PLUGIN_ID, IDsfStatusConstants.INVALID_STATE, "Debug session already shut down.", null)); //$NON-NLS-1$
                 rm.done();
                 return;
             }

             /*
              * Guard against a disposed service
              */
             IExpressions service = getService();
             if (service == null) {
                 rm .setStatus(new Status(IStatus.ERROR, DsfUIPlugin.PLUGIN_ID, IDsfStatusConstants.INVALID_STATE, "Service unavailable", null)); //$NON-NLS-1$
                 rm.done();
                 return;
             }

             /*
              * Convert to the proper formatting DMC then go get the formatted value.
              */

             FormattedValueDMContext formDmc = service.getFormattedValueContext(fDmc, fFormatId);

             service.getFormattedExpressionValue(formDmc, new DataRequestMonitor<FormattedValueDMData>(session.getExecutor(), rm) {
                 @Override
                 protected void handleSuccess() {
                     rm.setData(fEditable ? getData().getEditableValue() : getData().getFormattedValue());
                     rm.done();
                 }
             });
         }
     }

     public String getFormattedValue(Object element, String formatId) {
     	return getValue(element, formatId, false);
     }

     public String getEditableValue(Object element, String formatId) {
     	return getValue(element, formatId, true);
     }

     private String getValue(Object element, String formatId, boolean editable) {

         /*
          * Get the DMC and the session. If element is not an register DMC, or
          * session is stale, then bail out.
          */
         IFormattedDataDMContext dmc = getFormattedDMC(element);
         if (dmc == null) return null;
         DsfSession session = DsfSession.getSession(dmc.getSessionId());
         if (session == null) return null;

         /*
          * Create the query to write the value to the service. Note: no need to
          * guard against RejectedExecutionException, because
          * DsfSession.getSession() above would only return an active session.
          */
         GetFormattedValueValueQuery query = new GetFormattedValueValueQuery(dmc, formatId, editable);
         session.getExecutor().execute(query);

         /*
          * Now we have the data, go and get it. Since the call is completed now
          * the ".get()" will not suspend it will immediately return with the
          * data.
          */
         try {
             return (String) query.get();
         } catch (InterruptedException e) {
             assert false;
             return null;
         } catch (ExecutionException e) {
             return null;
         }
     }

     /**
      * @since 1.1
      */
     public class CanWriteExpressionQuery extends Query<Boolean> {

         private IExpressionDMContext fDmc;

         public CanWriteExpressionQuery(IExpressionDMContext dmc) {
         	super();
             fDmc = dmc;
         }

         @Override
         protected void execute(final DataRequestMonitor<Boolean> rm) {
             /*
              * We're in another dispatch, so we must guard against executor
              * shutdown again.
              */
             final DsfSession session = DsfSession.getSession(fDmc.getSessionId());
             if (session == null) {
                 rm.setStatus(new Status(IStatus.ERROR, DsfUIPlugin.PLUGIN_ID, IDsfStatusConstants.INVALID_STATE, "Debug session already shut down.", null)); //$NON-NLS-1$
                 rm.done();
                 return;
             }

             /*
              * Guard against a disposed service
              */
             IExpressions service = getService();
             if (service == null) {
                 rm .setStatus(new Status(IStatus.ERROR, DsfUIPlugin.PLUGIN_ID, IDsfStatusConstants.INVALID_STATE, "Service unavailable", null)); //$NON-NLS-1$
                 rm.done();
                 return;
             }

             service.canWriteExpression(fDmc, new DataRequestMonitor<Boolean>(session.getExecutor(), rm) {
                 @Override
                 protected void handleSuccess() {
                     /*
                      * All good set return value.
                      */
                     rm.setData(getData());
                     rm.done();
                 }
             });
         }
     }

     public boolean canWriteExpression(Object element) {
         /*
          * Get the DMC and the session. If element is not an expression DMC, or
          * session is stale, then bail out.
          */
         IExpressionDMContext dmc = getExpressionDMC(element);
         if (dmc == null) return false;
         DsfSession session = DsfSession.getSession(dmc.getSessionId());
         if (session == null) return false;

         /*
          * Create the query to make the request to the service. Note: no need to
          * guard against RejectedExecutionException, because
          * DsfSession.getSession() above would only return an active session.
          */
         CanWriteExpressionQuery query = new CanWriteExpressionQuery(dmc);
         session.getExecutor().execute(query);

         /*
          * Now we have the data, go and get it. Since the call is completed now
          * the ".get()" will not suspend it will immediately return with the
          * data.
          */
         try {
             return query.get();
         } catch (InterruptedException e) {
             assert false;
             return false;
         } catch (ExecutionException e) {
             return false;
         }
     }


 }
	/*******************************************************************************
	* Copyright (c) 2007, 2016 Wind River Systems and others.
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License v1.0
	* which accompanies this distribution, and is available at
	* http://www.eclipse.org/legal/epl-v10.html
	*
	* Contributors:
	* Wind River Systems - initial API and implementation
	*******************************************************************************/
	package org.eclipse.cdt.dsf.debug.ui.viewmodel.variable;

	import java.util.concurrent.ExecutionException;
	import java.util.concurrent.TimeUnit;
	import java.util.concurrent.TimeoutException;

	import org.eclipse.cdt.dsf.concurrent.DataRequestMonitor;
	import org.eclipse.cdt.dsf.concurrent.IDsfStatusConstants;
	import org.eclipse.cdt.dsf.concurrent.Query;
	import org.eclipse.cdt.dsf.concurrent.ThreadSafe;
	import org.eclipse.cdt.dsf.concurrent.ThreadSafeAndProhibitedFromDsfExecutor;
	import org.eclipse.cdt.dsf.debug.service.IExpressions;
	import org.eclipse.cdt.dsf.debug.service.IExpressions.IExpressionDMContext;
	import org.eclipse.cdt.dsf.debug.service.IExpressions.IExpressionDMData;
	import org.eclipse.cdt.dsf.debug.service.IFormattedValues.FormattedValueDMContext;
	import org.eclipse.cdt.dsf.debug.service.IFormattedValues.FormattedValueDMData;
	import org.eclipse.cdt.dsf.debug.service.IFormattedValues.IFormattedDataDMContext;
	import org.eclipse.cdt.dsf.internal.ui.DsfUIPlugin;
	import org.eclipse.cdt.dsf.service.DsfSession;
	import org.eclipse.cdt.dsf.service.IDsfService;
	import org.eclipse.core.runtime.IAdaptable;
	import org.eclipse.core.runtime.IStatus;
	import org.eclipse.core.runtime.Status;
	import org.osgi.framework.InvalidSyntaxException;
	import org.osgi.util.tracker.ServiceTracker;

	@ThreadSafeAndProhibitedFromDsfExecutor("fSession#getExecutor")
	public class SyncVariableDataAccess {

	/**
	* The session that this data access operates in.
	*/
	private final DsfSession fSession;

	/**
	* Need to use the OSGi service tracker here (instead of DsfServiceTracker),
	* because we're accessing it in non-dispatch thread. DsfServiceTracker is
	* not thread-safe.
	*/
	@ThreadSafe
	private ServiceTracker fServiceTracker;


	public SyncVariableDataAccess(DsfSession session) {
	fSession = session;
	}

	@ThreadSafe
	private synchronized IExpressions getService() {

	if (fServiceTracker == null) {
	try {
	fServiceTracker = new ServiceTracker(
	DsfUIPlugin.getBundleContext(),
	DsfUIPlugin.getBundleContext().createFilter(getServiceFilter()), null);
	fServiceTracker.open();
	} catch (InvalidSyntaxException e) {
	return null;
	}
	}
	return (IExpressions) fServiceTracker.getService();
	}

	private String getServiceFilter() {
	StringBuilder filter = new StringBuilder();
	filter.append("(&"); //$NON-NLS-1$
	filter.append("(OBJECTCLASS="); //$NON-NLS-1$
	filter.append(IExpressions.class.getName());
	filter.append(')');
	filter.append('(');
	filter.append(IDsfService.PROP_SESSION_ID);
	filter.append('=');
	filter.append(fSession.getId());
	filter.append(')');
	filter.append(')');
	return filter.toString();
	}

	@ThreadSafe
	public synchronized void dispose() {
	if (fServiceTracker != null) {
	fServiceTracker.close();
	}
	}

	public IExpressionDMContext getVariableDMC(Object element) {
	if (element instanceof IAdaptable) {
	return ((IAdaptable) element).getAdapter(IExpressionDMContext.class);
	}
	return null;
	}


	public class GetVariableValueQuery extends Query<IExpressionDMData> {

	private IExpressionDMContext fDmc;

	public GetVariableValueQuery(IExpressionDMContext dmc) {
	super();
	fDmc = dmc;
	}

	@Override
	protected void execute(final DataRequestMonitor<IExpressionDMData> rm) {
	/*
	* Guard against the session being disposed. If session is disposed
	* it could mean that the executor is shut-down, which in turn could
	* mean that we can't complete the RequestMonitor argument. in that
	* case, cancel to notify waiting thread.
	*/
	final DsfSession session = DsfSession.getSession(fDmc.getSessionId());
	if (session == null) {
	rm.setStatus(new Status(IStatus.ERROR, DsfUIPlugin.PLUGIN_ID, IDsfStatusConstants.INVALID_STATE, "Debug session already shut down.", null)); //$NON-NLS-1$
	rm.done();
	return;
	}

	IExpressions service = getService();
	if (service == null) {
	rm.setStatus(new Status(IStatus.ERROR, DsfUIPlugin.PLUGIN_ID, IDsfStatusConstants.INVALID_STATE, "Service not available", null)); //$NON-NLS-1$
	rm.done();
	return;
	}

	service.getExpressionData(fDmc, new DataRequestMonitor<IExpressionDMData>(session.getExecutor(), rm) {
	@Override
	protected void handleSuccess() {
	/*
	* All good set return value.
	*/
	rm.setData(getData());
	rm.done();
	}
	});
	}
	}

	public IExpressionDMContext getExpressionDMC(Object element) {
	if (element instanceof IAdaptable) {
	return ((IAdaptable) element).getAdapter(IExpressionDMContext.class);
	}
	return null;
	}

	public IExpressionDMData readVariable(Object element) {
	/*
	* Get the DMC and the session. If element is not an expression DMC, or
	* session is stale, then bail out.
	*/
	IExpressionDMContext dmc = getExpressionDMC(element);
	if (dmc == null) return null;
	DsfSession session = DsfSession.getSession(dmc.getSessionId());
	if (session == null) return null;

	/*
	* Create the query to request the value from service. Note: no need to
	* guard against RejectedExecutionException, because
	* DsfSession.getSession() above would only return an active session.
	*/
	GetVariableValueQuery query = new GetVariableValueQuery(dmc);
	session.getExecutor().execute(query);

	/*
	* This class is about synchronous access to the variable, so wait until
	* the query has completed on the DSF session thread and return the
	* result.
	*/
	try {
	return query.get();
	} catch (InterruptedException e) {
	assert false;
	return null;
	} catch (ExecutionException e) {
	return null;
	}
	}

	public class SetVariableValueQuery extends Query<Object> {

	private IExpressionDMContext fDmc;
	private String fValue;
	private String fFormatId;

	public SetVariableValueQuery(IExpressionDMContext dmc, String value, String formatId) {
	super();
	fDmc = dmc;
	fValue = value;
	fFormatId = formatId;
	}

	@Override
	protected void execute(final DataRequestMonitor<Object> rm) {
	/*
	* We're in another dispatch, so we must guard against executor
	* shutdown again.
	*/
	final DsfSession session = DsfSession.getSession(fDmc.getSessionId());
	if (session == null) {
	rm.setStatus(new Status(IStatus.ERROR, DsfUIPlugin.PLUGIN_ID, IDsfStatusConstants.INVALID_STATE, "Debug session already shut down.", null)); //$NON-NLS-1$
	rm.done();
	return;
	}

	/*
	* Guard against a disposed service
	*/
	IExpressions service = getService();
	if (service == null) {
	rm.setStatus(new Status(IStatus.ERROR, DsfUIPlugin.PLUGIN_ID, IDsfStatusConstants.INVALID_STATE, "Service unavailable", null)); //$NON-NLS-1$
	rm.done();
	return;
	}

	/*
	* Write the expression value using a string/format style.
	*/
	service.writeExpression(
	fDmc,
	fValue,
	fFormatId,
	new DataRequestMonitor<IExpressionDMData>(session.getExecutor(), rm) {
	@Override
	protected void handleSuccess() {
	/*
	* All good set return value.
	*/
	rm.setData(new Object());
	rm.done();
	}
	}
	);
	}
	}

	public void writeVariable(Object element, String value, String formatId) {

	/*
	* Get the DMC and the session. If element is not an register DMC, or
	* session is stale, then bail out.
	*/
	IExpressionDMContext dmc = getExpressionDMC(element);
	if (dmc == null) return;
	DsfSession session = DsfSession.getSession(dmc.getSessionId());
	if (session == null) return;

	/*
	* Create the query to write the value to the service. Note: no need to
	* guard against RejectedExecutionException, because
	* DsfSession.getSession() above would only return an active session.
	*/
	SetVariableValueQuery query = new SetVariableValueQuery(dmc, value, formatId);
	session.getExecutor().execute(query);

	/*
	* This class is about synchronous access to the variable, so wait until
	* the query has completed on the DSF session thread.
	*/
	try {
	/*
	* Return value is irrelevant, any error would come through with an
	* exception.
	*/
	query.get(3000, TimeUnit.MILLISECONDS);
	} catch (InterruptedException e) {
	assert false;
	} catch (ExecutionException e) {
	/*
	* View must be shutting down, no need to show error dialog.
	*/
	} catch (TimeoutException e) {
	assert false;
	}
	}

	public IFormattedDataDMContext getFormattedDMC(Object element) {
	if (element instanceof IAdaptable) {
	return ((IAdaptable) element).getAdapter(IFormattedDataDMContext.class);
	}
	return null;
	}

	public class GetSupportFormatsValueQuery extends Query<Object> {

	IFormattedDataDMContext fDmc;

	public GetSupportFormatsValueQuery(IFormattedDataDMContext dmc) {
	super();
	fDmc = dmc;
	}

	@Override
	protected void execute(final DataRequestMonitor<Object> rm) {
	/*
	* We're in another dispatch, so we must guard against executor
	* shutdown again.
	*/
	final DsfSession session = DsfSession.getSession(fDmc.getSessionId());
	if (session == null) {
	rm.setStatus(new Status(IStatus.ERROR, DsfUIPlugin.PLUGIN_ID, IDsfStatusConstants.INVALID_STATE, "Debug session already shut down.", null)); //$NON-NLS-1$
	rm.done();
	return;
	}

	/*
	* Guard against a disposed service
	*/
	IExpressions service = getService();
	if (service == null) {
	rm.setStatus(new Status(IStatus.ERROR, DsfUIPlugin.PLUGIN_ID, IDsfStatusConstants.INVALID_STATE, "Service unavailable", null)); //$NON-NLS-1$
	rm.done();
	return;
	}

	/*
	* Get the available formats from the service.
	*/
	service.getAvailableFormats(
	fDmc,
	new DataRequestMonitor<String[]>(session.getExecutor(), rm) {
	@Override
	protected void handleSuccess() {
	/*
	* All good set return value.
	*/
	rm.setData(getData());
	rm.done();
	}
	}
	);
	}
	}

	public String[] getSupportedFormats(Object element) {

	/*
	* Get the DMC and the session. If element is not an register DMC, or
	* session is stale, then bail out.
	*/
	IFormattedDataDMContext dmc = getFormattedDMC(element);
	if (dmc == null) return null;
	DsfSession session = DsfSession.getSession(dmc.getSessionId());
	if (session == null) return null;

	/*
	* Create the query to write the value to the service. Note: no need to
	* guard against RejectedExecutionException, because
	* DsfSession.getSession() above would only return an active session.
	*/
	GetSupportFormatsValueQuery query = new GetSupportFormatsValueQuery(dmc);
	session.getExecutor().execute(query);

	/*
	* Now we have the data, go and get it. Since the call is completed now
	* the ".get()" will not suspend it will immediately return with the
	* data.
	*/
	try {
	return (String[]) query.get();
	} catch (InterruptedException e) {
	assert false;
	return null;
	} catch (ExecutionException e) {
	return null;
	}
	}

	public class GetFormattedValueValueQuery extends Query<Object> {

	private IFormattedDataDMContext fDmc;
	private String fFormatId;
	private boolean fEditable;

	public GetFormattedValueValueQuery(IFormattedDataDMContext dmc, String formatId) {
	this(dmc, formatId, false);
	}

	public GetFormattedValueValueQuery(IFormattedDataDMContext dmc, String formatId, boolean editable) {
	super();
	fDmc = dmc;
	fFormatId = formatId;
	fEditable = editable;
	}

	@Override
	protected void execute(final DataRequestMonitor<Object> rm) {
	/*
	* We're in another dispatch, so we must guard against executor
	* shutdown again.
	*/
	final DsfSession session = DsfSession.getSession(fDmc.getSessionId());
	if (session == null) {
	rm.setStatus(new Status(IStatus.ERROR, DsfUIPlugin.PLUGIN_ID, IDsfStatusConstants.INVALID_STATE, "Debug session already shut down.", null)); //$NON-NLS-1$
	rm.done();
	return;
	}

	/*
	* Guard against a disposed service
	*/
	IExpressions service = getService();
	if (service == null) {
	rm .setStatus(new Status(IStatus.ERROR, DsfUIPlugin.PLUGIN_ID, IDsfStatusConstants.INVALID_STATE, "Service unavailable", null)); //$NON-NLS-1$
	rm.done();
	return;
	}

	/*
	* Convert to the proper formatting DMC then go get the formatted value.
	*/

	FormattedValueDMContext formDmc = service.getFormattedValueContext(fDmc, fFormatId);

	service.getFormattedExpressionValue(formDmc, new DataRequestMonitor<FormattedValueDMData>(session.getExecutor(), rm) {
	@Override
	protected void handleSuccess() {
	rm.setData(fEditable ? getData().getEditableValue() : getData().getFormattedValue());
	rm.done();
	}
	});
	}
	}

	public String getFormattedValue(Object element, String formatId) {
	return getValue(element, formatId, false);
	}

	public String getEditableValue(Object element, String formatId) {
	return getValue(element, formatId, true);
	}

	private String getValue(Object element, String formatId, boolean editable) {

	/*
	* Get the DMC and the session. If element is not an register DMC, or
	* session is stale, then bail out.
	*/
	IFormattedDataDMContext dmc = getFormattedDMC(element);
	if (dmc == null) return null;
	DsfSession session = DsfSession.getSession(dmc.getSessionId());
	if (session == null) return null;

	/*
	* Create the query to write the value to the service. Note: no need to
	* guard against RejectedExecutionException, because
	* DsfSession.getSession() above would only return an active session.
	*/
	GetFormattedValueValueQuery query = new GetFormattedValueValueQuery(dmc, formatId, editable);
	session.getExecutor().execute(query);

	/*
	* Now we have the data, go and get it. Since the call is completed now
	* the ".get()" will not suspend it will immediately return with the
	* data.
	*/
	try {
	return (String) query.get();
	} catch (InterruptedException e) {
	assert false;
	return null;
	} catch (ExecutionException e) {
	return null;
	}
	}

	/**
	* @since 1.1
	*/
	public class CanWriteExpressionQuery extends Query<Boolean> {

	private IExpressionDMContext fDmc;

	public CanWriteExpressionQuery(IExpressionDMContext dmc) {
	super();
	fDmc = dmc;
	}

	@Override
	protected void execute(final DataRequestMonitor<Boolean> rm) {
	/*
	* We're in another dispatch, so we must guard against executor
	* shutdown again.
	*/
	final DsfSession session = DsfSession.getSession(fDmc.getSessionId());
	if (session == null) {
	rm.setStatus(new Status(IStatus.ERROR, DsfUIPlugin.PLUGIN_ID, IDsfStatusConstants.INVALID_STATE, "Debug session already shut down.", null)); //$NON-NLS-1$
	rm.done();
	return;
	}

	/*
	* Guard against a disposed service
	*/
	IExpressions service = getService();
	if (service == null) {
	rm .setStatus(new Status(IStatus.ERROR, DsfUIPlugin.PLUGIN_ID, IDsfStatusConstants.INVALID_STATE, "Service unavailable", null)); //$NON-NLS-1$
	rm.done();
	return;
	}

	service.canWriteExpression(fDmc, new DataRequestMonitor<Boolean>(session.getExecutor(), rm) {
	@Override
	protected void handleSuccess() {
	/*
	* All good set return value.
	*/
	rm.setData(getData());
	rm.done();
	}
	});
	}
	}

	public boolean canWriteExpression(Object element) {
	/*
	* Get the DMC and the session. If element is not an expression DMC, or
	* session is stale, then bail out.
	*/
	IExpressionDMContext dmc = getExpressionDMC(element);
	if (dmc == null) return false;
	DsfSession session = DsfSession.getSession(dmc.getSessionId());
	if (session == null) return false;

	/*
	* Create the query to make the request to the service. Note: no need to
	* guard against RejectedExecutionException, because
	* DsfSession.getSession() above would only return an active session.
	*/
	CanWriteExpressionQuery query = new CanWriteExpressionQuery(dmc);
	session.getExecutor().execute(query);

	/*
	* Now we have the data, go and get it. Since the call is completed now
	* the ".get()" will not suspend it will immediately return with the
	* data.
	*/
	try {
	return query.get();
	} catch (InterruptedException e) {
	assert false;
	return false;
	} catch (ExecutionException e) {
	return false;
	}
	}


	}