plugins/org.eclipse.ease.lang.python.py4j/src/org/eclipse/ease/lang/python/py4j/internal/Py4jScriptEngine.java - ease/org.eclipse.ease.core - Git at Google

 /*******************************************************************************
  * Copyright (c) 2016 Kichwa Coders and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v2.0
  * which accompanies this distribution, and is available at
  * https://www.eclipse.org/legal/epl-2.0/
  *
  * Contributors:
  *     Jonah Graham (Kichwa Coders) - initial API and implementation
  *******************************************************************************/
 package org.eclipse.ease.lang.python.py4j.internal;

 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.net.MalformedURLException;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.net.URL;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;

 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.FileLocator;
 import org.eclipse.core.runtime.Platform;
 import org.eclipse.core.runtime.URIUtil;
 import org.eclipse.core.variables.IStringVariableManager;
 import org.eclipse.core.variables.VariablesPlugin;
 import org.eclipse.ease.AbstractReplScriptEngine;
 import org.eclipse.ease.Logger;
 import org.eclipse.ease.Script;
 import org.eclipse.ease.ScriptEngineException;
 import org.eclipse.ease.ScriptExecutionException;
 import org.eclipse.ease.debugging.ScriptStackTrace;
 import org.eclipse.ease.tools.RunnableWithResult;
 import org.eclipse.jface.preference.IPreferenceStore;
 import org.eclipse.swt.widgets.Display;
 import org.osgi.framework.Bundle;

 import py4j.ClientServer;
 import py4j.ClientServer.ClientServerBuilder;
 import py4j.JavaServer;

 public class Py4jScriptEngine extends AbstractReplScriptEngine {

 	/**
 	 * The ID of the Engine, to match the declaration in the plugin.xml
 	 */
 	public static final String ENGINE_ID = "org.eclipse.ease.lang.python.py4j.engine";

 	// TODO: Add preference for this
 	private static final int PYTHON_STARTUP_TIMEOUT_SECONDS = 10;

 	// TODO: Add preference for this
 	private static final int PYTHON_SHUTDOWN_TIMEOUT_SECONDS = 10;

 	/**
 	 * Path within this plug-in to the main python file.
 	 */
 	private static final String PYSRC_EASE_PY4J_MAIN_PY = "/pysrc/ease_py4j_main.py";

 	/**
 	 * The ID of the py4j sources plug-in, needs to match the name of the dependent plug-in.
 	 */
 	private static final String PY4J_PYTHON_BUNDLE_ID = "py4j-python";

 	private ClientServer fGatewayServer;
 	protected IPythonSideEngine fPythonSideEngine;
 	private Process fPythonProcess;
 	private Thread fInputGobbler, fErrorGobbler;

 	private CountDownLatch fPythonStartupComplete;

 	/**
 	 * Standard StreamGobbler.
 	 */
 	private static class StreamGobbler implements Runnable {
 		private final InputStream fReader;
 		private final OutputStream fWriter;
 		private final String fStreamName;

 		public StreamGobbler(final InputStream stream, final OutputStream output, final String streamName) {
 			fReader = stream;
 			fWriter = output;
 			fStreamName = streamName;
 		}

 		@Override
 		public void run() {
 			try {
 				final byte[] bytes = new byte[512];
 				int readCount;
 				while ((readCount = fReader.read(bytes)) >= 0) {
 					try {
 						fWriter.write(bytes, 0, readCount);
 					} catch (final IOException e) {
 						Logger.error(Activator.PLUGIN_ID, "Failed to write data read from Python's " + fStreamName + " stream.", e);
 					}
 				}
 			} catch (final IOException e) {
 				Logger.error(Activator.PLUGIN_ID, "Failed to read data from Python's " + fStreamName + " stream.", e);
 			}
 		}
 	}

 	public Py4jScriptEngine() {
 		super("Python (Py4J)");
 	}

 	@Override
 	protected void setupEngine() throws ScriptEngineException {
 		try {
 			fPythonStartupComplete = new CountDownLatch(1);
 			fGatewayServer = new ClientServerBuilder(this).javaPort(0).pythonPort(0).build();
 			fGatewayServer.startServer(true);
 			final int javaListeningPort = ((JavaServer) fGatewayServer.getJavaServer()).getListeningPort();

 			fPythonProcess = startPythonProcess(javaListeningPort);
 			fInputGobbler = new Thread(new StreamGobbler(fPythonProcess.getInputStream(), getOutputStream(), "stdout"),
 					"EASE py4j engine output stream gobbler");
 			fInputGobbler.start();
 			fErrorGobbler = new Thread(new StreamGobbler(fPythonProcess.getErrorStream(), getErrorStream(), "stderr"), "EASE py4j engine error stream gobbler");
 			fErrorGobbler.start();

 			// TODO Handle python's stdin (fPythonProcess.getOutputStream())

 			if (!fPythonStartupComplete.await(PYTHON_STARTUP_TIMEOUT_SECONDS, TimeUnit.SECONDS)) {
 				throw new ScriptEngineException("Python process did not start within " + PYTHON_STARTUP_TIMEOUT_SECONDS + " seconds");
 			}
 		} catch (final ScriptEngineException e) {
 			teardownEngine();
 			throw e;
 		} catch (final Exception e) {
 			teardownEngine();
 			throw new ScriptEngineException("Failed to start Python process. Please check the setting for the Python interpreter"
 					+ " in Preferences -> Scripting -> Python Scripting:\n" + e.getMessage(), e);
 		}
 	}

 	private Process startPythonProcess(final int javaListeningPort) throws IOException, MalformedURLException, URISyntaxException, CoreException {
 		final ProcessBuilder pb = new ProcessBuilder();

 		final List<String> prependsPythonPath = new ArrayList<>();

 		prependsPythonPath.add(getPy4jPythonSrc().toString());

 		// Add EASE Python directory to python path
 		final Bundle bundle = Platform.getBundle("org.eclipse.ease.lang.python");
 		try {
 			URL url = bundle.getEntry("pysrc");
 			url = FileLocator.toFileURL(url);
 			final URI uri = new URI(url.getProtocol(), url.getPath(), null);
 			prependsPythonPath.add(new File(uri).getAbsolutePath());
 		} catch (final IllegalStateException e) {
 			Logger.error(Activator.PLUGIN_ID, "Cannot get entry pysrc because the plugin has not been initialized properly.", e);
 		} catch (final IOException | URISyntaxException e) {
 			Logger.error(Activator.PLUGIN_ID, "Cannot append additional Python modules to search path.", e);
 		}

 		final IPreferenceStore preferenceStore = Activator.getDefault().getPreferenceStore();
 		String interpreter = preferenceStore.getString(Py4JScriptEnginePrefConstants.INTERPRETER);
 		final boolean ignorePythonEnvVariables = preferenceStore.getBoolean(Py4JScriptEnginePrefConstants.IGNORE_PYTHON_ENV_VARIABLES);
 		final IStringVariableManager variableManager = VariablesPlugin.getDefault().getStringVariableManager();
 		interpreter = variableManager.performStringSubstitution(interpreter);

 		pb.command().add(interpreter);
 		pb.command().add("-u");
 		if (ignorePythonEnvVariables) {
 			pb.command().add("-E");
 		}
 		pb.command().add(getPy4jEaseMainPy().toString());
 		pb.command().add(Integer.toString(javaListeningPort));
 		pb.command().addAll(prependsPythonPath);

 		final Process start = pb.start();
 		return start;
 	}

 	private File getPy4jPythonSrc() throws IOException {
 		final File py4jPythonBundleFile = FileLocator.getBundleFile(Platform.getBundle(PY4J_PYTHON_BUNDLE_ID));
 		final File py4jPythonSrc = new File(py4jPythonBundleFile, "/src");
 		final File py4j = new File(py4jPythonSrc, "py4j");
 		if (!py4j.exists() || !py4j.isDirectory()) {
 			throw new IOException("Failed to find py4j python directory, expected it here: " + py4j);
 		}
 		return py4jPythonSrc;
 	}

 	private File getPy4jEaseMainPy() throws MalformedURLException, IOException, URISyntaxException {
 		final URL url = new URL("platform:/plugin/" + Activator.PLUGIN_ID + PYSRC_EASE_PY4J_MAIN_PY);
 		final URL fileURL = FileLocator.toFileURL(url);
 		final File py4jEaseMain = new File(URIUtil.toURI(fileURL));
 		if (!py4jEaseMain.exists()) {
 			throw new IOException("Failed to find " + PYSRC_EASE_PY4J_MAIN_PY + ", expected it here: " + py4jEaseMain);
 		}
 		return py4jEaseMain;
 	}

 	public void pythonStartupComplete(final int pythonPort, final IPythonSideEngine pythonSideEngine) {
 		final JavaServer javaServer = (JavaServer) fGatewayServer.getJavaServer();
 		javaServer.resetCallbackClient(javaServer.getCallbackClient().getAddress(), pythonPort);
 		fPythonSideEngine = pythonSideEngine;
 		fPythonStartupComplete.countDown();
 	}

 	@Override
 	protected Object execute(final Script script, final Object reference, final String fileName, final boolean uiThread) throws Throwable {
 		if (uiThread) {
 			// run in UI thread
 			final RunnableWithResult<Object> runnable = new RunnableWithResult<Object>() {

 				@Override
 				public Object runWithTry() throws Throwable {
 					return internalExecute(script, fileName);
 				}
 			};

 			Display.getDefault().syncExec(runnable);
 			return runnable.getResultOrThrow();

 		} else {
 			return internalExecute(script, fileName);
 		}
 	}

 	protected Object internalExecute(final Script script, final String fileName) throws Throwable, Exception {

 		if (hasVariable("argv"))
 			fPythonSideEngine.executeScript("import sys\nsys.argv = argv\n", "<dynamic>");

 		IInteractiveReturn interactiveReturn;
 		if (script.isShellMode()) {
 			interactiveReturn = fPythonSideEngine.executeInteractive(script.getCode());
 		} else {
 			final String code = script.getCode();
 			interactiveReturn = fPythonSideEngine.executeScript(code, fileName);
 		}
 		final Object exception = interactiveReturn.getException();
 		if (exception instanceof Throwable) {
 			throw (Throwable) exception;
 		} else if (exception != null) {
 			throw new ScriptExecutionException(exception.toString(), 0, null, null, new ScriptStackTrace(), null);
 		} else {
 			return interactiveReturn.getResult();
 		}
 	}

 	@Override
 	public void terminateCurrent() {
 		// TODO: It isn't possible to safely/reliablily interrupt a thread in
 		// Python
 		// For now, as terminateCurrent is called when the running script is
 		// called,
 		// we tear down the engine instead. This prevent the script from having
 		// a chance
 		// to cleanup.
 		// XXX: This is an issue solved by PyDev, resolving it here fully is not
 		// the logical course of action.
 		if (fPythonProcess != null) {
 			fPythonProcess.destroyForcibly();
 		}
 	}

 	@Override
 	protected void teardownEngine() {
 		// TODO: this clean shutdown isn't working as intended.
 		// Sometimes (on Linux) the Python process seems to shutdown
 		// before fully acknowledging the call to teardownEngine, leaving
 		// us in a worst state than if we shutdown not-cleanly.
 		// When/if this is resurrected, the fPythonProcess.destroy();
 		// below should be removed.
 		// if (fPythonSideEngine != null) {
 		// // try a clean shutdown
 		// fPythonSideEngine.teardownEngine();
 		// }

 		if (fPythonProcess != null) {
 			fPythonProcess.destroy();

 			try {
 				fPythonProcess.waitFor(PYTHON_SHUTDOWN_TIMEOUT_SECONDS, TimeUnit.SECONDS);
 			} catch (final InterruptedException e) {
 				// finish the teardown, but don't wait around
 				Thread.currentThread().interrupt();
 			}
 		}

 		if (fGatewayServer != null) {
 			fGatewayServer.shutdown();
 		}
 		if (fPythonProcess != null) {
 			// The clean shutdown had a chance, now time for a force shutdown
 			fPythonProcess.destroyForcibly();
 		}

 		try {
 			// Wait until the gobblers have shovelled all their
 			// inputs before allowing the engine to considered terminated
 			if (fInputGobbler != null) {
 				fInputGobbler.join();
 			}
 			if (fErrorGobbler != null) {
 				fErrorGobbler.join();
 			}
 		} catch (final InterruptedException e) {
 			Thread.currentThread().interrupt();
 		}
 	}

 	@Override
 	public void registerJar(final URL url) {
 		throw new UnsupportedOperationException();
 	}

 	@Override
 	protected Object internalGetVariable(final String name) {
 		return fPythonSideEngine.internalGetVariable(name);
 	}

 	@Override
 	protected Map<String, Object> internalGetVariables() {
 		return fPythonSideEngine.internalGetVariables();
 	}

 	@Override
 	protected boolean internalHasVariable(final String name) {
 		return fPythonSideEngine.internalHasVariable(name);
 	}

 	@Override
 	protected void internalSetVariable(final String name, final Object content) {
 		fPythonSideEngine.internalSetVariable(name, content);
 	}

 	@SuppressWarnings("unchecked")
 	@Override
 	public <T> T getAdapter(final Class<T> adapter) {
 		if (adapter.isInstance(fPythonProcess)) {
 			return (T) fPythonProcess;
 		}
 		return super.getAdapter(adapter);
 	}

 	@Override
 	public String toString(Object object) {
 		if (object == null)
 			return "None";

 		return super.toString(object);
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2016 Kichwa Coders and others.
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License v2.0
	* which accompanies this distribution, and is available at
	* https://www.eclipse.org/legal/epl-2.0/
	*
	* Contributors:
	* Jonah Graham (Kichwa Coders) - initial API and implementation
	*******************************************************************************/
	package org.eclipse.ease.lang.python.py4j.internal;

	import java.io.File;
	import java.io.IOException;
	import java.io.InputStream;
	import java.io.OutputStream;
	import java.net.MalformedURLException;
	import java.net.URI;
	import java.net.URISyntaxException;
	import java.net.URL;
	import java.util.ArrayList;
	import java.util.List;
	import java.util.Map;
	import java.util.concurrent.CountDownLatch;
	import java.util.concurrent.TimeUnit;

	import org.eclipse.core.runtime.CoreException;
	import org.eclipse.core.runtime.FileLocator;
	import org.eclipse.core.runtime.Platform;
	import org.eclipse.core.runtime.URIUtil;
	import org.eclipse.core.variables.IStringVariableManager;
	import org.eclipse.core.variables.VariablesPlugin;
	import org.eclipse.ease.AbstractReplScriptEngine;
	import org.eclipse.ease.Logger;
	import org.eclipse.ease.Script;
	import org.eclipse.ease.ScriptEngineException;
	import org.eclipse.ease.ScriptExecutionException;
	import org.eclipse.ease.debugging.ScriptStackTrace;
	import org.eclipse.ease.tools.RunnableWithResult;
	import org.eclipse.jface.preference.IPreferenceStore;
	import org.eclipse.swt.widgets.Display;
	import org.osgi.framework.Bundle;

	import py4j.ClientServer;
	import py4j.ClientServer.ClientServerBuilder;
	import py4j.JavaServer;

	public class Py4jScriptEngine extends AbstractReplScriptEngine {

	/**
	* The ID of the Engine, to match the declaration in the plugin.xml
	*/
	public static final String ENGINE_ID = "org.eclipse.ease.lang.python.py4j.engine";

	// TODO: Add preference for this
	private static final int PYTHON_STARTUP_TIMEOUT_SECONDS = 10;

	// TODO: Add preference for this
	private static final int PYTHON_SHUTDOWN_TIMEOUT_SECONDS = 10;

	/**
	* Path within this plug-in to the main python file.
	*/
	private static final String PYSRC_EASE_PY4J_MAIN_PY = "/pysrc/ease_py4j_main.py";

	/**
	* The ID of the py4j sources plug-in, needs to match the name of the dependent plug-in.
	*/
	private static final String PY4J_PYTHON_BUNDLE_ID = "py4j-python";

	private ClientServer fGatewayServer;
	protected IPythonSideEngine fPythonSideEngine;
	private Process fPythonProcess;
	private Thread fInputGobbler, fErrorGobbler;

	private CountDownLatch fPythonStartupComplete;

	/**
	* Standard StreamGobbler.
	*/
	private static class StreamGobbler implements Runnable {
	private final InputStream fReader;
	private final OutputStream fWriter;
	private final String fStreamName;

	public StreamGobbler(final InputStream stream, final OutputStream output, final String streamName) {
	fReader = stream;
	fWriter = output;
	fStreamName = streamName;
	}

	@Override
	public void run() {
	try {
	final byte[] bytes = new byte[512];
	int readCount;
	while ((readCount = fReader.read(bytes)) >= 0) {
	try {
	fWriter.write(bytes, 0, readCount);
	} catch (final IOException e) {
	Logger.error(Activator.PLUGIN_ID, "Failed to write data read from Python's " + fStreamName + " stream.", e);
	}
	}
	} catch (final IOException e) {
	Logger.error(Activator.PLUGIN_ID, "Failed to read data from Python's " + fStreamName + " stream.", e);
	}
	}
	}

	public Py4jScriptEngine() {
	super("Python (Py4J)");
	}

	@Override
	protected void setupEngine() throws ScriptEngineException {
	try {
	fPythonStartupComplete = new CountDownLatch(1);
	fGatewayServer = new ClientServerBuilder(this).javaPort(0).pythonPort(0).build();
	fGatewayServer.startServer(true);
	final int javaListeningPort = ((JavaServer) fGatewayServer.getJavaServer()).getListeningPort();

	fPythonProcess = startPythonProcess(javaListeningPort);
	fInputGobbler = new Thread(new StreamGobbler(fPythonProcess.getInputStream(), getOutputStream(), "stdout"),
	"EASE py4j engine output stream gobbler");
	fInputGobbler.start();
	fErrorGobbler = new Thread(new StreamGobbler(fPythonProcess.getErrorStream(), getErrorStream(), "stderr"), "EASE py4j engine error stream gobbler");
	fErrorGobbler.start();

	// TODO Handle python's stdin (fPythonProcess.getOutputStream())

	if (!fPythonStartupComplete.await(PYTHON_STARTUP_TIMEOUT_SECONDS, TimeUnit.SECONDS)) {
	throw new ScriptEngineException("Python process did not start within " + PYTHON_STARTUP_TIMEOUT_SECONDS + " seconds");
	}
	} catch (final ScriptEngineException e) {
	teardownEngine();
	throw e;
	} catch (final Exception e) {
	teardownEngine();
	throw new ScriptEngineException("Failed to start Python process. Please check the setting for the Python interpreter"
	+ " in Preferences -> Scripting -> Python Scripting:\n" + e.getMessage(), e);
	}
	}

	private Process startPythonProcess(final int javaListeningPort) throws IOException, MalformedURLException, URISyntaxException, CoreException {
	final ProcessBuilder pb = new ProcessBuilder();

	final List<String> prependsPythonPath = new ArrayList<>();

	prependsPythonPath.add(getPy4jPythonSrc().toString());

	// Add EASE Python directory to python path
	final Bundle bundle = Platform.getBundle("org.eclipse.ease.lang.python");
	try {
	URL url = bundle.getEntry("pysrc");
	url = FileLocator.toFileURL(url);
	final URI uri = new URI(url.getProtocol(), url.getPath(), null);
	prependsPythonPath.add(new File(uri).getAbsolutePath());
	} catch (final IllegalStateException e) {
	Logger.error(Activator.PLUGIN_ID, "Cannot get entry pysrc because the plugin has not been initialized properly.", e);
	} catch (final IOException \| URISyntaxException e) {
	Logger.error(Activator.PLUGIN_ID, "Cannot append additional Python modules to search path.", e);
	}

	final IPreferenceStore preferenceStore = Activator.getDefault().getPreferenceStore();
	String interpreter = preferenceStore.getString(Py4JScriptEnginePrefConstants.INTERPRETER);
	final boolean ignorePythonEnvVariables = preferenceStore.getBoolean(Py4JScriptEnginePrefConstants.IGNORE_PYTHON_ENV_VARIABLES);
	final IStringVariableManager variableManager = VariablesPlugin.getDefault().getStringVariableManager();
	interpreter = variableManager.performStringSubstitution(interpreter);

	pb.command().add(interpreter);
	pb.command().add("-u");
	if (ignorePythonEnvVariables) {
	pb.command().add("-E");
	}
	pb.command().add(getPy4jEaseMainPy().toString());
	pb.command().add(Integer.toString(javaListeningPort));
	pb.command().addAll(prependsPythonPath);

	final Process start = pb.start();
	return start;
	}

	private File getPy4jPythonSrc() throws IOException {
	final File py4jPythonBundleFile = FileLocator.getBundleFile(Platform.getBundle(PY4J_PYTHON_BUNDLE_ID));
	final File py4jPythonSrc = new File(py4jPythonBundleFile, "/src");
	final File py4j = new File(py4jPythonSrc, "py4j");
	if (!py4j.exists() \|\| !py4j.isDirectory()) {
	throw new IOException("Failed to find py4j python directory, expected it here: " + py4j);
	}
	return py4jPythonSrc;
	}

	private File getPy4jEaseMainPy() throws MalformedURLException, IOException, URISyntaxException {
	final URL url = new URL("platform:/plugin/" + Activator.PLUGIN_ID + PYSRC_EASE_PY4J_MAIN_PY);
	final URL fileURL = FileLocator.toFileURL(url);
	final File py4jEaseMain = new File(URIUtil.toURI(fileURL));
	if (!py4jEaseMain.exists()) {
	throw new IOException("Failed to find " + PYSRC_EASE_PY4J_MAIN_PY + ", expected it here: " + py4jEaseMain);
	}
	return py4jEaseMain;
	}

	public void pythonStartupComplete(final int pythonPort, final IPythonSideEngine pythonSideEngine) {
	final JavaServer javaServer = (JavaServer) fGatewayServer.getJavaServer();
	javaServer.resetCallbackClient(javaServer.getCallbackClient().getAddress(), pythonPort);
	fPythonSideEngine = pythonSideEngine;
	fPythonStartupComplete.countDown();
	}

	@Override
	protected Object execute(final Script script, final Object reference, final String fileName, final boolean uiThread) throws Throwable {
	if (uiThread) {
	// run in UI thread
	final RunnableWithResult<Object> runnable = new RunnableWithResult<Object>() {

	@Override
	public Object runWithTry() throws Throwable {
	return internalExecute(script, fileName);
	}
	};

	Display.getDefault().syncExec(runnable);
	return runnable.getResultOrThrow();

	} else {
	return internalExecute(script, fileName);
	}
	}

	protected Object internalExecute(final Script script, final String fileName) throws Throwable, Exception {

	if (hasVariable("argv"))
	fPythonSideEngine.executeScript("import sys\nsys.argv = argv\n", "<dynamic>");

	IInteractiveReturn interactiveReturn;
	if (script.isShellMode()) {
	interactiveReturn = fPythonSideEngine.executeInteractive(script.getCode());
	} else {
	final String code = script.getCode();
	interactiveReturn = fPythonSideEngine.executeScript(code, fileName);
	}
	final Object exception = interactiveReturn.getException();
	if (exception instanceof Throwable) {
	throw (Throwable) exception;
	} else if (exception != null) {
	throw new ScriptExecutionException(exception.toString(), 0, null, null, new ScriptStackTrace(), null);
	} else {
	return interactiveReturn.getResult();
	}
	}

	@Override
	public void terminateCurrent() {
	// TODO: It isn't possible to safely/reliablily interrupt a thread in
	// Python
	// For now, as terminateCurrent is called when the running script is
	// called,
	// we tear down the engine instead. This prevent the script from having
	// a chance
	// to cleanup.
	// XXX: This is an issue solved by PyDev, resolving it here fully is not
	// the logical course of action.
	if (fPythonProcess != null) {
	fPythonProcess.destroyForcibly();
	}
	}

	@Override
	protected void teardownEngine() {
	// TODO: this clean shutdown isn't working as intended.
	// Sometimes (on Linux) the Python process seems to shutdown
	// before fully acknowledging the call to teardownEngine, leaving
	// us in a worst state than if we shutdown not-cleanly.
	// When/if this is resurrected, the fPythonProcess.destroy();
	// below should be removed.
	// if (fPythonSideEngine != null) {
	// // try a clean shutdown
	// fPythonSideEngine.teardownEngine();
	// }

	if (fPythonProcess != null) {
	fPythonProcess.destroy();

	try {
	fPythonProcess.waitFor(PYTHON_SHUTDOWN_TIMEOUT_SECONDS, TimeUnit.SECONDS);
	} catch (final InterruptedException e) {
	// finish the teardown, but don't wait around
	Thread.currentThread().interrupt();
	}
	}

	if (fGatewayServer != null) {
	fGatewayServer.shutdown();
	}
	if (fPythonProcess != null) {
	// The clean shutdown had a chance, now time for a force shutdown
	fPythonProcess.destroyForcibly();
	}

	try {
	// Wait until the gobblers have shovelled all their
	// inputs before allowing the engine to considered terminated
	if (fInputGobbler != null) {
	fInputGobbler.join();
	}
	if (fErrorGobbler != null) {
	fErrorGobbler.join();
	}
	} catch (final InterruptedException e) {
	Thread.currentThread().interrupt();
	}
	}

	@Override
	public void registerJar(final URL url) {
	throw new UnsupportedOperationException();
	}

	@Override
	protected Object internalGetVariable(final String name) {
	return fPythonSideEngine.internalGetVariable(name);
	}

	@Override
	protected Map<String, Object> internalGetVariables() {
	return fPythonSideEngine.internalGetVariables();
	}

	@Override
	protected boolean internalHasVariable(final String name) {
	return fPythonSideEngine.internalHasVariable(name);
	}

	@Override
	protected void internalSetVariable(final String name, final Object content) {
	fPythonSideEngine.internalSetVariable(name, content);
	}

	@SuppressWarnings("unchecked")
	@Override
	public <T> T getAdapter(final Class<T> adapter) {
	if (adapter.isInstance(fPythonProcess)) {
	return (T) fPythonProcess;
	}
	return super.getAdapter(adapter);
	}

	@Override
	public String toString(Object object) {
	if (object == null)
	return "None";

	return super.toString(object);
	}
	}