dsf-gdb/org.eclipse.cdt.dsf.gdb/src/org/eclipse/cdt/dsf/gdb/service/GDBTraceControl_7_2.java

/*******************************************************************************
 * Copyright (c) 2010, 2014 Ericsson and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *   Ericsson - Initial API and implementation
 *   Dmitry Kozlov (Mentor Graphics) - Add support for IGDBTraceControl2 (Bug 390827)
 *******************************************************************************/
package org.eclipse.cdt.dsf.gdb.service;

import java.util.Hashtable;
import java.util.concurrent.TimeUnit;

import org.eclipse.cdt.dsf.concurrent.DataRequestMonitor;
import org.eclipse.cdt.dsf.concurrent.ImmediateDataRequestMonitor;
import org.eclipse.cdt.dsf.concurrent.ImmediateRequestMonitor;
import org.eclipse.cdt.dsf.concurrent.Immutable;
import org.eclipse.cdt.dsf.concurrent.RequestMonitor;
import org.eclipse.cdt.dsf.datamodel.AbstractDMContext;
import org.eclipse.cdt.dsf.datamodel.AbstractDMEvent;
import org.eclipse.cdt.dsf.datamodel.DMContexts;
import org.eclipse.cdt.dsf.datamodel.IDMContext;
import org.eclipse.cdt.dsf.datamodel.IDMEvent;
import org.eclipse.cdt.dsf.debug.service.ICachingService;
import org.eclipse.cdt.dsf.debug.service.IRunControl.IContainerDMContext;
import org.eclipse.cdt.dsf.debug.service.IRunControl.IExecutionDMContext;
import org.eclipse.cdt.dsf.debug.service.command.CommandCache;
import org.eclipse.cdt.dsf.debug.service.command.ICommandControlService;
import org.eclipse.cdt.dsf.debug.service.command.ICommandControlService.ICommandControlDMContext;
import org.eclipse.cdt.dsf.gdb.internal.GdbPlugin;
import org.eclipse.cdt.dsf.gdb.internal.service.command.events.MITracepointSelectedEvent;
import org.eclipse.cdt.dsf.mi.service.IMICommandControl;
import org.eclipse.cdt.dsf.mi.service.IMIProcesses;
import org.eclipse.cdt.dsf.mi.service.command.CommandFactory;
import org.eclipse.cdt.dsf.mi.service.command.events.MIEvent;
import org.eclipse.cdt.dsf.mi.service.command.output.CLITraceDumpInfo;
import org.eclipse.cdt.dsf.mi.service.command.output.MIInfo;
import org.eclipse.cdt.dsf.mi.service.command.output.MIResultRecord;
import org.eclipse.cdt.dsf.mi.service.command.output.MITraceFindInfo;
import org.eclipse.cdt.dsf.mi.service.command.output.MITraceListVariablesInfo;
import org.eclipse.cdt.dsf.mi.service.command.output.MITraceListVariablesInfo.MITraceVariableInfo;
import org.eclipse.cdt.dsf.mi.service.command.output.MITraceStatusInfo;
import org.eclipse.cdt.dsf.mi.service.command.output.MITraceStopInfo;
import org.eclipse.cdt.dsf.service.AbstractDsfService;
import org.eclipse.cdt.dsf.service.DsfSession;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.debug.core.ILaunchConfiguration;
import org.osgi.framework.BundleContext;

/**
 * This class implements the IGDBTraceControl interface which gives access
 * to the debugger's tracing functionality.
 *
 * @since 3.0
 */
public class GDBTraceControl_7_2 extends AbstractDsfService implements IGDBTraceControl2, ICachingService {

	@Immutable
	protected static final class MITraceRecordDMContext extends AbstractDMContext implements ITraceRecordDMContext {

		// The trace record GDB reference
		private final String fReference;

		/**
		 * @param session    the DsfSession for this service
		 * @param parents    the parent contexts
		 * @param reference  the trace record reference
		 * @since 4.0
		 */
		public MITraceRecordDMContext(DsfSession session, ITraceTargetDMContext parent, String reference) {
			super(session.getId(), new IDMContext[] { parent });
			fReference = reference;
		}

		/** @since 4.0 */
		@Override
		public String getRecordId() {
			return fReference;
		}

		/* (non-Javadoc)
		 * @see org.eclipse.cdt.dsf.datamodel.AbstractDMContext#equals(java.lang.Object)
		 */
		@Override
		public boolean equals(Object obj) {
			return baseEquals(obj) && (fReference == null ? ((MITraceRecordDMContext) obj).fReference == null
					: (fReference.equals(((MITraceRecordDMContext) obj).fReference)));
		}

		/* (non-Javadoc)
		 * @see org.eclipse.cdt.dsf.datamodel.AbstractDMContext#hashCode()
		 */
		@Override
		public int hashCode() {
			return baseHashCode() ^ (fReference == null ? 0 : fReference.hashCode());
		}

		/* (non-Javadoc)
		 * @see java.lang.Object#toString()
		 */
		@Override
		public String toString() {
			return baseToString() + ".reference(" + fReference + ")"; //$NON-NLS-1$//$NON-NLS-2$
		}
	}

	/**
	 * Trace record context used to indicate that there is no current trace record selected.
	 */
	@Immutable
	protected static final class InvalidTraceRecordDMContext extends AbstractDMContext
			implements ITraceRecordDMContext {

		/**
		 * @param session    the DsfSession for this service
		 * @param parents    the parent contexts
		 * @param reference  the trace record reference
		 */
		public InvalidTraceRecordDMContext(DsfSession session, ITraceTargetDMContext parent) {
			super(session.getId(), new IDMContext[] { parent });
		}

		/** @since 4.0 */
		@Override
		public String getRecordId() {
			return null;
		}

		/* (non-Javadoc)
		 * @see org.eclipse.cdt.dsf.datamodel.AbstractDMContext#equals(java.lang.Object)
		 */
		@Override
		public boolean equals(Object obj) {
			return baseEquals(obj);
		}

		/* (non-Javadoc)
		 * @see org.eclipse.cdt.dsf.datamodel.AbstractDMContext#hashCode()
		 */
		@Override
		public int hashCode() {
			return baseHashCode();
		}

		/* (non-Javadoc)
		 * @see java.lang.Object#toString()
		 */
		@Override
		public String toString() {
			return baseToString() + ".noTraceRecord"; //$NON-NLS-1$
		}
	}

	private class TraceVariableDMData implements ITraceVariableDMData {
		private String fName;
		private String fValue;
		private String fInitialValue;

		public TraceVariableDMData(String name, String initial, String value) {
			fName = name;
			fInitialValue = initial;
			fValue = value;
		}

		@Override
		public String getName() {
			return fName;
		}

		@Override
		public String getValue() {
			return fValue;
		}

		@Override
		public String getInitialValue() {
			return fInitialValue;
		}
	}

	private class TraceRecordDMData implements ITraceRecordDMData {
		private String fContent;
		private String fTracepointNum;
		private String fTimestamp;
		private String fFrameNumber;

		public TraceRecordDMData(String content, String tracepointNum, String frameNumber, String timestamp) {
			fContent = content;
			fTracepointNum = tracepointNum;
			fTimestamp = timestamp;
			fFrameNumber = frameNumber;
		}

		@Override
		public String getContent() {
			return fContent;
		}

		@Override
		public String getTracepointNumber() {
			return fTracepointNum;
		}

		@Override
		public String getRecordId() {
			return fFrameNumber;
		}

		@Override
		public String getTimestamp() {
			return fTimestamp;
		}
	}

	private class TraceStatusDMData implements ITraceStatusDMData2 {
		private MITraceStatusInfo fInfo;

		public TraceStatusDMData(MITraceStatusInfo info) {
			fInfo = info;
		}

		/**
		 * Create a status when tracing is not supported
		 */
		public TraceStatusDMData() {
			this(null);
		}

		@Override
		public int getFreeBufferSize() {
			if (fInfo == null)
				return 0;
			return fInfo.getFreeBufferSize();
		}

		@Override
		public int getNumberOfCreatedFrames() {
			if (fInfo == null)
				return 0;
			return fInfo.getNumberOfCreatedFrames();
		}

		@Override
		public int getNumberOfCollectedFrame() {
			if (fInfo == null)
				return 0;
			return fInfo.getNumberOfCollectedFrame();
		}

		@Override
		public int getTotalBufferSize() {
			if (fInfo == null)
				return 0;
			return fInfo.getTotalBufferSize();
		}

		@Override
		public boolean isTracingActive() {
			if (fInfo == null)
				return false;
			return fInfo.isTracingActive();
		}

		@Override
		public boolean isTracingSupported() {
			return fInfo != null;
		}

		@Override
		public boolean isCircularBuffer() {
			if (fInfo == null)
				return false;
			return fInfo.isCircularBuffer();
		}

		@Override
		public boolean isTracingFromFile() {
			if (fInfo == null)
				return false;
			return fInfo.isTracingFromFile();
		}

		@Override
		public boolean isDisconnectedTracingEnabled() {
			if (fInfo == null)
				return false;
			return fInfo.isDisconnectedTracingEnabled();
		}

		@Override
		public STOP_REASON_ENUM getStopReason() {
			if (fInfo == null)
				return null;
			return fInfo.getStopReason();
		}

		@Override
		public Integer getStoppingTracepoint() {
			if (fInfo.getStopReason() == null) {
				return null;
			}
			return fInfo.getStopTracepoint();
		}

		@Override
		public String getUserName() {
			if (fInfo == null)
				return ""; //$NON-NLS-1$
			return fInfo.getUserName() == null ? "" : fInfo.getUserName(); //$NON-NLS-1$
		}

		@Override
		public String getNotes() {
			if (fInfo == null)
				return ""; //$NON-NLS-1$
			return fInfo.getNotes() == null ? "" : fInfo.getNotes(); //$NON-NLS-1$
		}

		@Override
		public String getStartTime() {
			if (fInfo == null)
				return ""; //$NON-NLS-1$
			return fInfo.getStartTime() == null ? "" : fInfo.getStartTime(); //$NON-NLS-1$
		}

		@Override
		public String getStopTime() {
			if (fInfo == null)
				return ""; //$NON-NLS-1$
			return fInfo.getStopTime() == null ? "" : fInfo.getStopTime(); //$NON-NLS-1$
		}

		@Override
		public String getStopErrorDescription() {
			if (getStopReason() != STOP_REASON_ENUM.ERROR) {
				return null;
			}
			return fInfo.getStopErrorDescription();
		}

		@Override
		public String getTraceFile() {
			if (!isTracingFromFile()) {
				return null;
			}
			return fInfo.getTraceFile();
		}

		@Override
		public String getCurrentTraceFrameId() {
			// Not currently provided by -trace-status
			if (fCurrentRecordDmc instanceof MITraceRecordDMContext) {
				return ((MITraceRecordDMContext) fCurrentRecordDmc).getRecordId();
			}
			return null;
		}

		@Override
		public Integer getTracepointNumberForCurrentTraceFrame() {
			// Not currently provided by -trace-status
			if (getCurrentTraceFrameId() != null) {
				return fTracepointIndexForTraceRecord;
			}
			return null;
		}
	}

	private static class TracingSupportedChangeEvent extends AbstractDMEvent<ITraceTargetDMContext>
			implements ITracingSupportedChangeDMEvent {
		private final boolean fTracingSupported;

		public TracingSupportedChangeEvent(ITraceTargetDMContext context, boolean supported) {
			super(context);
			fTracingSupported = supported;
		}

		@Override
		public boolean isTracingSupported() {
			return fTracingSupported;
		}
	}

	private static class TracingStartedEvent extends AbstractDMEvent<ITraceTargetDMContext>
			implements ITracingStartedDMEvent {
		public TracingStartedEvent(ITraceTargetDMContext context) {
			super(context);
		}
	}

	private static class TracingStoppedEvent extends AbstractDMEvent<ITraceTargetDMContext>
			implements ITracingStoppedDMEvent {
		public TracingStoppedEvent(ITraceTargetDMContext context) {
			super(context);
		}
	}

	public static class TraceRecordSelectedChangedEvent extends AbstractDMEvent<ITraceRecordDMContext>
			implements ITraceRecordSelectedChangedDMEvent {
		final boolean fVisualModeEnabled;

		public TraceRecordSelectedChangedEvent(ITraceRecordDMContext context) {
			super(context);
			fVisualModeEnabled = !(context instanceof InvalidTraceRecordDMContext);
		}

		@Override
		public boolean isVisualizationModeEnabled() {
			return fVisualModeEnabled;
		}
	}

	private CommandCache fTraceStatusCache;
	private ICommandControlService fConnection;
	private CommandFactory fCommandFactory;
	private IGDBBackend fBackend;

	private ITraceRecordDMContext fCurrentRecordDmc;
	private int fTracepointIndexForTraceRecord;

	private boolean fIsTracingActive;
	private boolean fIsTracingCurrentlySupported;
	private boolean fIsTracingFeatureAvailable = true;
	private int fTraceRecordsStored;

	public GDBTraceControl_7_2(DsfSession session, ILaunchConfiguration config) {
		super(session);
	}

	/**
	 * This method initializes this service.
	 *
	 * @param requestMonitor
	 *            The request monitor indicating the operation is finished
	 */
	@Override
	public void initialize(final RequestMonitor requestMonitor) {
		super.initialize(new ImmediateRequestMonitor(requestMonitor) {
			@Override
			protected void handleSuccess() {
				doInitialize(requestMonitor);
			}
		});
	}

	/**
	 * This method initializes this service after our superclass's initialize()
	 * method succeeds.
	 *
	 * @param requestMonitor
	 *            The call-back object to notify when this service's
	 *            initialization is done.
	 */
	private void doInitialize(RequestMonitor requestMonitor) {
		// Register this service.
		register(new String[] { IGDBTraceControl.class.getName(), IGDBTraceControl2.class.getName() },
				new Hashtable<String, String>());

		fConnection = getServicesTracker().getService(ICommandControlService.class);
		fTraceStatusCache = new CommandCache(getSession(), fConnection);
		fTraceStatusCache.setContextAvailable(fConnection.getContext(), true);

		fBackend = getServicesTracker().getService(IGDBBackend.class);
		fCommandFactory = getServicesTracker().getService(IMICommandControl.class).getCommandFactory();

		requestMonitor.done();
	}

	/**
	 * This method shuts down this service. It unregisters the service, stops
	 * receiving service events, and calls the superclass shutdown() method to
	 * finish the shutdown process.
	 *
	 * @return void
	 */
	@Override
	public void shutdown(RequestMonitor requestMonitor) {
		unregister();
		super.shutdown(requestMonitor);
	}

	/**
	 * @return The bundle context of the plug-in to which this service belongs.
	 */
	@Override
	protected BundleContext getBundleContext() {
		return GdbPlugin.getBundleContext();
	}

	/** @since 4.4 */
	protected boolean isTracingCurrentlySupported() {
		return fIsTracingCurrentlySupported;
	}

	/** @since 4.4 */
	protected CommandCache getTraceStatusCache() {
		return fTraceStatusCache;
	}

	@Override
	public void canStartTracing(ITraceTargetDMContext context, final DataRequestMonitor<Boolean> rm) {
		if (context == null) {
			rm.setStatus(new Status(IStatus.ERROR, GdbPlugin.PLUGIN_ID, INVALID_STATE, "Invalid context", null)); //$NON-NLS-1$
			rm.done();
			return;
		}

		if (fIsTracingCurrentlySupported == false) {
			rm.setStatus(new Status(IStatus.ERROR, GdbPlugin.PLUGIN_ID, NOT_SUPPORTED, "Tracing not supported", null)); //$NON-NLS-1$
			rm.done();
			return;
		}

		if (fBackend.getSessionType() == SessionType.CORE) {
			rm.setData(false);
			rm.done();
			return;
		}

		if (fCurrentRecordDmc != null) {
			// We are visualizing data, no more tracing possible.
			rm.setData(false);
			rm.done();
			return;
		}

		rm.setData(true);
		rm.done();
	}

	@Override
	public void startTracing(final ITraceTargetDMContext context, final RequestMonitor rm) {
		if (context == null) {
			rm.setStatus(new Status(IStatus.ERROR, GdbPlugin.PLUGIN_ID, INVALID_STATE, "Invalid context", null)); //$NON-NLS-1$
			rm.done();
			return;
		}

		canStartTracing(context, new DataRequestMonitor<Boolean>(getExecutor(), rm) {
			@Override
			protected void handleSuccess() {
				if (!getData()) {
					rm.setStatus(new Status(IStatus.ERROR, GdbPlugin.PLUGIN_ID, INVALID_STATE, "Cannot start tracing", //$NON-NLS-1$
							null));
					rm.done();
					return;
				}

				fConnection.queueCommand(fCommandFactory.createMITraceStart(context),
						new DataRequestMonitor<MIInfo>(getExecutor(), rm) {
							@Override
							protected void handleSuccess() {
								fTraceStatusCache.reset(context);

								fIsTracingActive = true;
								getSession().dispatchEvent(new TracingStartedEvent(context), getProperties());
								rm.done();
							}

							@Override
							protected void handleError() {
								// Send an event to cause a refresh of the button states
								IDMEvent<ITraceTargetDMContext> event;
								if (fIsTracingActive) {
									event = new TracingStartedEvent(context);
								} else {
									event = new TracingStoppedEvent(context);
								}
								getSession().dispatchEvent(event, getProperties());
								rm.done();
							}
						});
			}
		});
	}

	@Override
	public void canStopTracing(ITraceTargetDMContext context, DataRequestMonitor<Boolean> rm) {
		if (context == null) {
			rm.setStatus(new Status(IStatus.ERROR, GdbPlugin.PLUGIN_ID, INVALID_STATE, "Invalid context", null)); //$NON-NLS-1$
			rm.done();
			return;
		}

		if (fIsTracingCurrentlySupported == false) {
			rm.setStatus(new Status(IStatus.ERROR, GdbPlugin.PLUGIN_ID, NOT_SUPPORTED, "Tracing not supported", null)); //$NON-NLS-1$
			rm.done();
			return;
		}

		if (fBackend.getSessionType() == SessionType.CORE) {
			rm.setData(false);
			rm.done();
			return;
		}

		if (fCurrentRecordDmc != null) {
			// We are visualizing data, no more tracing possible.
			rm.setData(false);
			rm.done();
			return;
		}

		isTracing(context, rm);
	}

	@Override
	public void stopTracing(final ITraceTargetDMContext context, final RequestMonitor rm) {
		if (context == null) {
			rm.setStatus(new Status(IStatus.ERROR, GdbPlugin.PLUGIN_ID, INVALID_STATE, "Invalid context", null)); //$NON-NLS-1$
			rm.done();
			return;
		}

		canStopTracing(context, new DataRequestMonitor<Boolean>(getExecutor(), rm) {
			@Override
			protected void handleSuccess() {
				if (!getData()) {
					rm.setStatus(
							new Status(IStatus.ERROR, GdbPlugin.PLUGIN_ID, INVALID_STATE, "Cannot stop tracing", null)); //$NON-NLS-1$
					rm.done();
					return;
				}

				fConnection.queueCommand(fCommandFactory.createMITraceStop(context),
						new DataRequestMonitor<MITraceStopInfo>(getExecutor(), rm) {
							@Override
							protected void handleSuccess() {
								fTraceStatusCache.reset(context);

								MITraceStopInfo info = getData();

								// Update the tracing state in case it was stopped by the backend
								if (fIsTracingActive != info.isTracingActive()) {
									fIsTracingActive = info.isTracingActive();
									if (!fIsTracingActive) {
										getSession().dispatchEvent(new TracingStoppedEvent(context), getProperties());
									}
								}

								fTraceRecordsStored = info.getNumberOfCollectedFrame();
								rm.done();
							}
						});
			}
		});
	}

	@Override
	public void isTracing(ITraceTargetDMContext context, final DataRequestMonitor<Boolean> rm) {
		if (context == null) {
			rm.setStatus(new Status(IStatus.ERROR, GdbPlugin.PLUGIN_ID, INVALID_STATE, "Invalid context", null)); //$NON-NLS-1$
			rm.done();
			return;
		}

		if (fBackend.getSessionType() == SessionType.CORE) {
			rm.setData(false);
			rm.done();
			return;
		}

		// Although tracing can be automatically stopped on the target, we
		// don't go to the backend for this call, or we would make too many calls
		// Instead, we can use our buffered state; we simply won't know about an
		// automatic stop until a forced refresh.  (Note that the MI notification
		// about automatic stops, is not available until GDB 7.2 is released)
		rm.setData(fIsTracingActive);
		rm.done();
	}

	@Override
	public void canSaveTraceData(ITraceTargetDMContext context, DataRequestMonitor<Boolean> rm) {
		if (context == null) {
			rm.setStatus(new Status(IStatus.ERROR, GdbPlugin.PLUGIN_ID, INVALID_STATE, "Invalid context", null)); //$NON-NLS-1$
			rm.done();
			return;
		}

		if (fIsTracingCurrentlySupported == false) {
			rm.setStatus(new Status(IStatus.ERROR, GdbPlugin.PLUGIN_ID, NOT_SUPPORTED, "Tracing not supported", null)); //$NON-NLS-1$
			rm.done();
			return;
		}

		if (fBackend.getSessionType() == SessionType.CORE) {
			rm.setData(false);
			rm.done();
			return;
		}

		rm.setData(fTraceRecordsStored > 0);
		rm.done();
	}

	@Override
	public void saveTraceData(final ITraceTargetDMContext context, final String file, final boolean remoteSave,
			final RequestMonitor rm) {
		if (context == null) {
			rm.setStatus(new Status(IStatus.ERROR, GdbPlugin.PLUGIN_ID, INVALID_STATE, "Invalid context", null)); //$NON-NLS-1$
			rm.done();
			return;
		}

		canSaveTraceData(context, new DataRequestMonitor<Boolean>(getExecutor(), rm) {
			@Override
			protected void handleSuccess() {
				if (!getData()) {
					rm.setStatus(new Status(IStatus.ERROR, GdbPlugin.PLUGIN_ID, INVALID_STATE, "Cannot save trace data", //$NON-NLS-1$
							null));
					rm.done();
					return;
				}

				fConnection.queueCommand(fCommandFactory.createMITraceSave(context, file, remoteSave),
						new DataRequestMonitor<MIInfo>(getExecutor(), rm));
			}
		});
	}

	@Override
	public void canLoadTraceData(ITraceTargetDMContext context, DataRequestMonitor<Boolean> rm) {
		if (context == null) {
			rm.setStatus(new Status(IStatus.ERROR, GdbPlugin.PLUGIN_ID, INVALID_STATE, "Invalid context", null)); //$NON-NLS-1$
			rm.done();
			return;
		}

		// If this service has been instantiated, it means we support loading trace data.
		// Unlike the other operations, loading trace data does not require any GDB special state
		// (like being connected to a target)
		rm.setData(true);
		rm.done();
	}

	@Override
	public void loadTraceData(final ITraceTargetDMContext context, final String file, final RequestMonitor rm) {
		if (context == null) {
			rm.setStatus(new Status(IStatus.ERROR, GdbPlugin.PLUGIN_ID, INVALID_STATE, "Invalid context", null)); //$NON-NLS-1$
			rm.done();
			return;
		}

		canLoadTraceData(context, new DataRequestMonitor<Boolean>(getExecutor(), rm) {
			@Override
			protected void handleSuccess() {
				if (!getData()) {
					rm.setStatus(new Status(IStatus.ERROR, GdbPlugin.PLUGIN_ID, INVALID_STATE, "Cannot load trace data", //$NON-NLS-1$
							null));
					rm.done();
					return;
				}

				fConnection.queueCommand(fCommandFactory.createMITargetSelectTFile(context, file),
						new DataRequestMonitor<MIInfo>(getExecutor(), rm) {
							@Override
							protected void handleSuccess() {
								fTraceStatusCache.reset(context);

								fIsTracingCurrentlySupported = true;
								// Workaround for GDB pre-release where we don't get the details
								// of the frame when we load a trace file.
								// To get around this, we can force a select of record 0
								final ITraceRecordDMContext initialRecord = createTraceRecordContext(context, "0"); //$NON-NLS-1$
								selectTraceRecord(initialRecord, new ImmediateRequestMonitor(rm) {
									@Override
									protected void handleSuccess() {
										// This event will indicate to the other services that we are visualizing trace data.
										getSession().dispatchEvent(new TraceRecordSelectedChangedEvent(initialRecord),
												getProperties());
										rm.done();
									}
								});
							}
						});
			}
		});
	}

	@Override
	public void getTraceStatus(final ITraceTargetDMContext context, final DataRequestMonitor<ITraceStatusDMData> rm) {
		if (context == null) {
			rm.setStatus(new Status(IStatus.ERROR, GdbPlugin.PLUGIN_ID, INVALID_STATE, "Invalid context", null)); //$NON-NLS-1$
			rm.done();
			return;
		}

		if (fIsTracingFeatureAvailable == false) {
			rm.setStatus(new Status(IStatus.ERROR, GdbPlugin.PLUGIN_ID, NOT_SUPPORTED, "Tracing not supported", null)); //$NON-NLS-1$
			rm.done();
			return;
		}

		// Start an automatic one-time flushing of the TraceStatusCache.
		// This avoids sending -trace-status multiples time in a very short
		// amount of time.  We still have to clear the cache very quickly
		// because -trace-status can change very fast as it reports
		// the number of frames collected.  Having a small interval of
		// stale data is currently not a big deal, and not user-visible.
		// Bug 353034
		getExecutor().schedule(() -> fTraceStatusCache.reset(context), 300, TimeUnit.MILLISECONDS);

		fTraceStatusCache.execute(fCommandFactory.createMITraceStatus(context),
				new DataRequestMonitor<MITraceStatusInfo>(getExecutor(), rm) {
					@Override
					protected void handleError() {
						// The MI command
						fIsTracingFeatureAvailable = false;
						super.handleError();
					}

					@Override
					protected void handleSuccess() {
						MITraceStatusInfo info = getData();

						if (fIsTracingCurrentlySupported != info.isTracingSupported()) {
							fIsTracingCurrentlySupported = info.isTracingSupported();
							getSession().dispatchEvent(
									new TracingSupportedChangeEvent(context, fIsTracingCurrentlySupported),
									getProperties());
						}

						if (fIsTracingCurrentlySupported) {
							// Update the tracing state in case it was stopped by the backend
							if (fIsTracingActive != info.isTracingActive()) {
								fIsTracingActive = info.isTracingActive();
								if (fIsTracingActive) {
									getSession().dispatchEvent(new TracingStartedEvent(context), getProperties());
								} else {
									getSession().dispatchEvent(new TracingStoppedEvent(context), getProperties());
								}
							}

							fTraceRecordsStored = info.getNumberOfCollectedFrame();

							rm.setData(new TraceStatusDMData(info));
						} else {
							fTraceRecordsStored = 0;
							fIsTracingActive = false;
							rm.setData(new TraceStatusDMData());
						}
						rm.done();
					}
				});
	}

	@Override
	public void createTraceVariable(ITraceTargetDMContext context, String varName, String varValue, RequestMonitor rm) {
		if (context == null) {
			rm.setStatus(new Status(IStatus.ERROR, GdbPlugin.PLUGIN_ID, INVALID_STATE, "Invalid context", null)); //$NON-NLS-1$
			rm.done();
			return;
		}

		if (fIsTracingCurrentlySupported == false) {
			rm.setStatus(new Status(IStatus.ERROR, GdbPlugin.PLUGIN_ID, NOT_SUPPORTED, "Tracing not supported", null)); //$NON-NLS-1$
			rm.done();
			return;
		}

		if (varValue == null) {
			fConnection.queueCommand(fCommandFactory.createMITraceDefineVariable(context, varName),
					new DataRequestMonitor<MIInfo>(getExecutor(), rm));
		} else {
			fConnection.queueCommand(fCommandFactory.createMITraceDefineVariable(context, varName, varValue),
					new DataRequestMonitor<MIInfo>(getExecutor(), rm));
		}
	}

	@Override
	public void getTraceVariables(ITraceTargetDMContext context, final DataRequestMonitor<ITraceVariableDMData[]> rm) {
		if (context == null) {
			rm.setStatus(new Status(IStatus.ERROR, GdbPlugin.PLUGIN_ID, INVALID_STATE, "Invalid context", null)); //$NON-NLS-1$
			rm.done();
			return;
		}

		if (fIsTracingCurrentlySupported == false) {
			rm.setStatus(new Status(IStatus.ERROR, GdbPlugin.PLUGIN_ID, NOT_SUPPORTED, "Tracing not supported", null)); //$NON-NLS-1$
			rm.done();
			return;
		}

		// It may be possible to cache this call, if we can figure out that all the cases
		// where to data can change, to clear the cache in those cases
		fConnection.queueCommand(fCommandFactory.createMITraceListVariables(context),
				new DataRequestMonitor<MITraceListVariablesInfo>(getExecutor(), rm) {
					@Override
					protected void handleSuccess() {
						MITraceVariableInfo[] vars = getData().getTraceVariables();
						TraceVariableDMData[] varDataArray = new TraceVariableDMData[vars.length];
						for (int i = 0; i < vars.length; i++) {
							varDataArray[i] = new TraceVariableDMData(vars[i].getName(), vars[i].getInitialValue(),
									vars[i].getCurrentValue());
						}

						rm.setData(varDataArray);
						rm.done();
					}
				});
	}

	/**
	 * Create a trace record context
	 * @since 4.0
	 */
	@Override
	public ITraceRecordDMContext createTraceRecordContext(ITraceTargetDMContext ctx, String recordId) {
		return new MITraceRecordDMContext(getSession(), ctx, recordId);
	}

	@Override
	public ITraceRecordDMContext createNextRecordContext(ITraceRecordDMContext ctx) {
		ITraceTargetDMContext targetDmc = DMContexts.getAncestorOfType(ctx, ITraceTargetDMContext.class);
		if (ctx instanceof InvalidTraceRecordDMContext) {
			// No specified context, so we return the context for the first
			return createTraceRecordContext(targetDmc, "0"); //$NON-NLS-1$
		}
		if (ctx instanceof MITraceRecordDMContext) {
			String recordId = ((MITraceRecordDMContext) ctx).getRecordId();
			int recordIndex = Integer.parseInt(recordId);
			recordIndex++;
			if (recordIndex == fTraceRecordsStored) {
				// Loop back to the front
				recordIndex = 0;
			}
			return new MITraceRecordDMContext(getSession(), targetDmc, Integer.toString(recordIndex));
		}
		return null;
	}

	@Override
	public ITraceRecordDMContext createPrevRecordContext(ITraceRecordDMContext ctx) {
		if (ctx instanceof MITraceRecordDMContext) {
			ITraceTargetDMContext targetDmc = DMContexts.getAncestorOfType(ctx, ITraceTargetDMContext.class);
			String recordId = ((MITraceRecordDMContext) ctx).getRecordId();
			int recordIndex = Integer.parseInt(recordId);
			if (recordIndex == 0) {
				// Loop back to the end
				recordIndex = fTraceRecordsStored; // The last index of a trace record (zero-based)
			}
			recordIndex--;
			return new MITraceRecordDMContext(getSession(), targetDmc, Integer.toString(recordIndex));
		}
		return null;
	}

	@Override
	public void getCurrentTraceRecordContext(ITraceTargetDMContext context,
			DataRequestMonitor<ITraceRecordDMContext> drm) {
		if (fCurrentRecordDmc == null) {
			drm.setData(new InvalidTraceRecordDMContext(getSession(), context));
		} else {
			drm.setData(fCurrentRecordDmc);
		}
		drm.done();
	}

	@Override
	public void selectTraceRecord(final ITraceRecordDMContext context, final RequestMonitor rm) {
		if (fIsTracingCurrentlySupported == false) {
			rm.setStatus(new Status(IStatus.ERROR, GdbPlugin.PLUGIN_ID, NOT_SUPPORTED, "Tracing not supported", null)); //$NON-NLS-1$
			rm.done();
			return;
		}

		if (context instanceof MITraceRecordDMContext) {
			ITraceTargetDMContext targetDmc = DMContexts.getAncestorOfType(context, ITraceTargetDMContext.class);
			String recordId = ((MITraceRecordDMContext) context).getRecordId();
			final int reference = Integer.parseInt(recordId);

			if (reference < 0) {
				// This was the old way to indicate that we want to exit visualization mode.
				// We continue supporting it for backward compatibility
				stopTraceVisualization(targetDmc, rm);
				return;
			}

			fConnection.queueCommand(fCommandFactory.createMITraceFindFrameNumber(targetDmc, reference),
					new DataRequestMonitor<MITraceFindInfo>(getExecutor(), rm) {
						@Override
						protected void handleSuccess() {
							if (getData().isFound() == false) {
								rm.setStatus(new Status(IStatus.ERROR, GdbPlugin.PLUGIN_ID, INTERNAL_ERROR,
										"Could not find trace record", null)); //$NON-NLS-1$
								rm.done();
								return;
							}

							fCurrentRecordDmc = context;
							fTracepointIndexForTraceRecord = getData().getTraceRecord().getTracepointId();

							// We could rely on the TraceRecordSelectedChangedEvent to update all the views, but this
							// would require a lot of changes.
							// Notice that looking at a new trace record should behave in the same manner
							// as when the debugger suspends during normal execution; therefore we can simply
							// trigger an MIStoppedEvent, as if reported by GDB.  Note that we do this already for
							// cases where GDB is missing such a event (like older versions of GDB when using a CLI command)
							IMIProcesses procService = getServicesTracker().getService(IMIProcesses.class);
							if (procService == null) {
								rm.setStatus(new Status(IStatus.ERROR, GdbPlugin.PLUGIN_ID, INTERNAL_ERROR,
										"Could not find necessary services", null)); //$NON-NLS-1$
								rm.done();
								return;
							}

							final MIResultRecord rr = getData().getMIOutput().getMIResultRecord();
							if (rr == null) {
								assert false;
								rm.done();
								return;
							}

							// First find the process we are using.
							ICommandControlDMContext controlDmc = DMContexts.getAncestorOfType(context,
									ICommandControlDMContext.class);
							procService.getProcessesBeingDebugged(controlDmc,
									new DataRequestMonitor<IDMContext[]>(getExecutor(), rm) {
										@Override
										protected void handleSuccess() {
											assert getData() != null;
											assert getData().length == 1;

											if (getData() == null || getData().length < 1) {
												rm.done();
												return;
											}

											// Choose the first process for now, until gdb can tell
											// us which process the trace record is associated with.
											// Or maybe GDB already tells us by only reporting a single
											// process?
											IContainerDMContext processContainerDmc = (IContainerDMContext) (getData()[0]);

											// Now find the proper thread.  We must do this here because in post-mortem debugging
											// we cannot rely on MIRunControl using 'thread', as it will fail
											IMIProcesses procService = getServicesTracker()
													.getService(IMIProcesses.class);
											if (procService == null) {
												rm.setStatus(new Status(IStatus.ERROR, GdbPlugin.PLUGIN_ID,
														INTERNAL_ERROR, "Could not find necessary services", null)); //$NON-NLS-1$
												rm.done();
												return;
											}

											procService.getProcessesBeingDebugged(processContainerDmc,
													new DataRequestMonitor<IDMContext[]>(getExecutor(), rm) {
														@Override
														protected void handleSuccess() {
															assert getData() != null;
															assert getData().length == 1;

															if (getData() == null || getData().length < 1) {
																rm.done();
																return;
															}

															IExecutionDMContext execDmc = (IExecutionDMContext) getData()[0];
															MIEvent<?> event = MITracepointSelectedEvent.parse(execDmc,
																	rr.getToken(), rr.getMIResults());
															getSession().dispatchEvent(event, getProperties());

															rm.done();
														}
													});
										}
									});
						}
					});
		} else {
			rm.setStatus(new Status(IStatus.ERROR, GdbPlugin.PLUGIN_ID, INTERNAL_ERROR, "Invalid trace record context.", //$NON-NLS-1$
					null));
			rm.done();
		}
	}

	/** @since 4.4 */
	@Override
	public void stopTraceVisualization(final ITraceTargetDMContext context, final RequestMonitor rm) {
		if (fIsTracingCurrentlySupported == false) {
			rm.setStatus(new Status(IStatus.ERROR, GdbPlugin.PLUGIN_ID, NOT_SUPPORTED, "Tracing not supported", null)); //$NON-NLS-1$
			rm.done();
			return;
		}

		if (fBackend.getSessionType() == SessionType.CORE) {
			rm.setStatus(new Status(IStatus.ERROR, GdbPlugin.PLUGIN_ID, NOT_SUPPORTED,
					"Cannot stop visualizing for a post mortem session", null)); //$NON-NLS-1$
			rm.done();
			return;
		}

		fConnection.queueCommand(fCommandFactory.createMITraceFindNone(context),
				new DataRequestMonitor<MITraceFindInfo>(getExecutor(), rm) {
					@Override
					protected void handleSuccess() {
						assert getData().isFound() == false;
						fCurrentRecordDmc = null;
						// This event will indicate to the other services that we are no longer visualizing trace data.
						ITraceRecordDMContext invalidDmc = new InvalidTraceRecordDMContext(getSession(), context);
						getSession().dispatchEvent(new TraceRecordSelectedChangedEvent(invalidDmc), getProperties());

						rm.done();
						return;
					}
				});
	}

	@Override
	public void getTraceRecordData(final ITraceRecordDMContext context,
			final DataRequestMonitor<ITraceRecordDMData> rm) {
		if (context instanceof MITraceRecordDMContext) {

			RequestMonitor tdumpRm = new ImmediateRequestMonitor(rm) {
				@Override
				protected void handleSuccess() {
					fConnection.queueCommand(fCommandFactory.createCLITraceDump(context),
							new DataRequestMonitor<CLITraceDumpInfo>(getExecutor(), rm) {
								@Override
								protected void handleSuccess() {

									TraceRecordDMData data = new TraceRecordDMData(getData().getContent(),
											getData().getTracepointNumber(), getData().getFrameNumber(),
											getData().getTimestamp());
									rm.setData(data);
									rm.done();
								}
							});
				}
			};

			// If we are pointing to the right context, we can do the tdump right away,
			// if not, we should first select the record.
			// This is because 'tdump' does not take any parameters to specify
			// which record we want to dump.
			if (fCurrentRecordDmc.equals(context)) {
				tdumpRm.done();
			} else {
				selectTraceRecord(context, tdumpRm);
			}
		} else {
			rm.setStatus(new Status(IStatus.ERROR, GdbPlugin.PLUGIN_ID, INTERNAL_ERROR, "Invalid trace record context.", //$NON-NLS-1$
					null));
			rm.done();
		}
	}

	/** @since 4.4 */
	@Override
	public void setCircularTraceBuffer(final ITraceTargetDMContext context, boolean useCircularBuffer,
			final RequestMonitor rm) {
		if (context == null) {
			rm.done(new Status(IStatus.ERROR, GdbPlugin.PLUGIN_ID, INVALID_STATE, "Invalid context", null)); //$NON-NLS-1$
			return;
		}

		if (fIsTracingCurrentlySupported == false) {
			rm.done(new Status(IStatus.ERROR, GdbPlugin.PLUGIN_ID, NOT_SUPPORTED, "Tracing not supported", null)); //$NON-NLS-1$
			return;
		}

		fConnection.queueCommand(fCommandFactory.createMIGDBSetCircularTraceBuffer(context, useCircularBuffer),
				new ImmediateDataRequestMonitor<MIInfo>(rm) {
					@Override
					protected void handleSuccess() {
						fTraceStatusCache.reset(context);
						rm.done();
					}
				});
	}

	/** @since 4.4 */
	@Override
	public void setDisconnectedTracing(final ITraceTargetDMContext context, boolean disconnectedTracing,
			final RequestMonitor rm) {
		if (context == null) {
			rm.done(new Status(IStatus.ERROR, GdbPlugin.PLUGIN_ID, INVALID_STATE, "Invalid context", null)); //$NON-NLS-1$
			return;
		}

		if (fIsTracingCurrentlySupported == false) {
			rm.done(new Status(IStatus.ERROR, GdbPlugin.PLUGIN_ID, NOT_SUPPORTED, "Tracing not supported", null)); //$NON-NLS-1$
			return;
		}

		fConnection.queueCommand(fCommandFactory.createMIGDBSetDisconnectedTracing(context, disconnectedTracing),
				new ImmediateDataRequestMonitor<MIInfo>(rm) {
					@Override
					protected void handleSuccess() {
						fTraceStatusCache.reset(context);
						rm.done();
					}
				});
	}

	/** @since 4.4 */
	@Override
	public void setTraceUser(ITraceTargetDMContext context, String userName, RequestMonitor rm) {
		// Only supported started with GDB 7.4
		rm.done(new Status(IStatus.ERROR, GdbPlugin.PLUGIN_ID, INVALID_STATE, Messages.ErrorNotSupported, null));
	}

	/** @since 4.4 */
	@Override
	public void setTraceNotes(ITraceTargetDMContext context, String note, RequestMonitor rm) {
		// Only supported started with GDB 7.4
		rm.done(new Status(IStatus.ERROR, GdbPlugin.PLUGIN_ID, INVALID_STATE, Messages.ErrorNotSupported, null));
	}

	@Override
	public void flushCache(IDMContext context) {
		fTraceStatusCache.reset(context);
	}
}