path: root/dsf-gdb/org.eclipse.cdt.dsf.gdb.ui/src/org/eclipse/cdt/dsf/gdb/internal/ui/GdbAdapterFactory.java

/*******************************************************************************
 * Copyright (c) 2006, 2016 Wind River Systems 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:
 *     Wind River Systems - initial API and implementation
 *     Navid Mehregani (TI) - Bug 289526 - Migrate the Restart feature to the new one, as supported by the platform
 *     Patrick Chuong (Texas Instruments) - Add support for icon overlay in the debug view (Bug 334566)
 *     Alvaro Sanchez-Leon (Ericsson AB) - Support for Step into selection (bug 244865)
 *     Marc Khouzam (Ericsson) - Extracted GdbSessionAdapters to allow overriding
 *******************************************************************************/
package org.eclipse.cdt.dsf.gdb.internal.ui;

import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.WeakHashMap;

import org.eclipse.cdt.debug.core.model.IConnectHandler;
import org.eclipse.cdt.debug.core.model.IDebugNewExecutableHandler;
import org.eclipse.cdt.dsf.concurrent.ThreadSafe;
import org.eclipse.cdt.dsf.gdb.launching.GdbLaunch;
import org.eclipse.cdt.dsf.service.DsfSession;
import org.eclipse.core.runtime.IAdapterFactory;
import org.eclipse.debug.core.DebugPlugin;
import org.eclipse.debug.core.ILaunch;
import org.eclipse.debug.core.ILaunchesListener2;
import org.eclipse.debug.core.commands.IDisconnectHandler;
import org.eclipse.debug.core.commands.ITerminateHandler;
import org.eclipse.debug.internal.ui.viewers.model.provisional.IColumnPresentationFactory;
import org.eclipse.debug.internal.ui.viewers.model.provisional.IElementContentProvider;
import org.eclipse.debug.internal.ui.viewers.model.provisional.IModelProxyFactory;
import org.eclipse.debug.ui.contexts.ISuspendTrigger;

/**
 * This implementation of platform adapter factory only retrieves the adapters
 * for the launch object.  But it also manages the creation and destruction
 * of the session-based adapters which are returned by the
 * IDMContext.getAdapter() methods.
 *
 * When extending the GdbAdapterFactory, it is important to register all the
 * types declaratively (in the plugin.xml) that the factory can adapt the
 * extended launch to.
 *
 * See the plugin.xml that references GdbAdapterFactory for the current list,
 * and it should match {@link #getAdapterList()}.
 */
@ThreadSafe
public class GdbAdapterFactory implements IAdapterFactory, ILaunchesListener2 {
	/**
	 * Active adapter sets.  They are accessed using the launch instance
	 * which owns the debug services session.
	 */
	private static Map<GdbLaunch, GdbSessionAdapters> fgLaunchAdapterSets = Collections
			.synchronizedMap(new HashMap<>());

	/**
	 * Map of launches for which adapter sets have already been disposed.
	 * This map (used as a set) is maintained in order to avoid re-creating an
	 * adapter set after the launch was removed from the launch manager, but
	 * while the launch is still being held by other classes which may
	 * request its adapters.  A weak map is used to avoid leaking
	 * memory once the launches are no longer referenced.
	 * <p>
	 * Access to this map is synchronized using the fgLaunchAdapterSets
	 * instance.
	 * </p>
	 */
	private static Map<ILaunch, GdbSessionAdapters> fgDisposedLaunchAdapterSets = new WeakHashMap<>();

	static void disposeAdapterSet(ILaunch launch) {
		synchronized (fgLaunchAdapterSets) {
			if (fgLaunchAdapterSets.containsKey(launch)) {
				fgLaunchAdapterSets.remove(launch).dispose();
				fgDisposedLaunchAdapterSets.put(launch, null);
			}
		}
	}

	public GdbAdapterFactory() {
		DebugPlugin.getDefault().getLaunchManager().addLaunchListener(this);
	}

	/**
	 * This method only actually returns adapters for the launch object.
	 */
	@Override
	public <T> T getAdapter(Object adaptableObject, Class<T> adapterType) {
		if (!(adaptableObject instanceof GdbLaunch))
			return null;

		GdbLaunch launch = (GdbLaunch) adaptableObject;

		// Check for valid session.
		// Note: even if the session is no longer active, the adapter set
		// should still be returned.  This is because the view model may still
		// need to show elements representing a terminated process/thread/etc.
		DsfSession session = launch.getSession();
		if (session == null)
			return null;

		// Find the correct set of adapters based on the launch session-ID.  If not found
		// it means that we have a new launch and new session, and we have to create a
		// new set of adapters.

		GdbSessionAdapters adapterSet;
		synchronized (fgLaunchAdapterSets) {
			// The adapter set for the given launch was already disposed.
			// Return a null adapter.
			if (fgDisposedLaunchAdapterSets.containsKey(launch)) {
				return null;
			}
			adapterSet = fgLaunchAdapterSets.get(launch);
			if (adapterSet == null) {
				// If the first time we attempt to create an adapterSet is once the session is
				// already inactive, we should not create it and return null.
				// This can happen, for example, when we run JUnit tests and we don't actually
				// have a need for any adapters until the launch is actually being removed.
				// Note that we must do this here because fgDisposedLaunchAdapterSets
				// may not already know that the launch has been removed because of a race
				// condition with the caller which is also processing a launchRemoved method.
				// Bug 334687
				if (session.isActive() == false) {
					return null;
				}
				adapterSet = createGdbSessionAdapters(launch, session);
				fgLaunchAdapterSets.put(launch, adapterSet);
			}
		}

		// Returns the adapter type for the launch object.
		return adapterSet.getLaunchAdapter(adapterType);
	}

	/**
	 * This list must match the list in the plugin.xml. See class comment.
	 */
	@Override
	public Class<?>[] getAdapterList() {
		return new Class<?>[] { IElementContentProvider.class, IModelProxyFactory.class, ISuspendTrigger.class,
				IColumnPresentationFactory.class, ITerminateHandler.class, IConnectHandler.class,
				IDisconnectHandler.class, IDebugNewExecutableHandler.class, };
	}

	@Override
	public void launchesRemoved(ILaunch[] launches) {
		// Dispose the set of adapters for a launch only after the launch is
		// removed.
		for (ILaunch launch : launches) {
			if (launch instanceof GdbLaunch) {
				disposeAdapterSet(launch);
			}
		}
	}

	@Override
	public void launchesTerminated(ILaunch[] launches) {
	}

	@Override
	public void launchesAdded(ILaunch[] launches) {
	}

	@Override
	public void launchesChanged(ILaunch[] launches) {
	}

	protected GdbSessionAdapters createGdbSessionAdapters(ILaunch launch, DsfSession session) {
		return new GdbSessionAdapters(launch, session, getAdapterList());
	}
}