langtools/src/jdk.jshell/share/classes/jdk/jshell/execution/Util.java - platform/libcore - Git at Google

 /*
  * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.  Oracle designates this
  * particular file as subject to the "Classpath" exception as provided
  * by Oracle in the LICENSE file that accompanied this code.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */
 package jdk.jshell.execution;

 import jdk.jshell.spi.ExecutionEnv;

 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InterruptedIOException;
 import java.io.ObjectInput;
 import java.io.ObjectInputStream;
 import java.io.ObjectOutput;
 import java.io.ObjectOutputStream;
 import java.io.OutputStream;
 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.function.BiFunction;
 import java.util.function.Consumer;

 import com.sun.jdi.VirtualMachine;
 import jdk.jshell.spi.ExecutionControl;
 import jdk.jshell.spi.ExecutionControl.ExecutionControlException;


 /**
  * Miscellaneous utility methods for setting-up implementations of
  * {@link ExecutionControl}. Particularly implementations with remote
  * execution.
  *
  * @author Jan Lahoda
  * @author Robert Field
  */
 public class Util {

     private static final int TAG_DATA = 0;
     private static final int TAG_CLOSED = 1;
     private static final int TAG_EXCEPTION = 2;

     // never instanciated
     private Util() {}

     /**
      * Forward commands from the input to the specified {@link ExecutionControl}
      * instance, then responses back on the output.
      * @param ec the direct instance of {@link ExecutionControl} to process commands
      * @param in the command input
      * @param out the command response output
      */
     public static void forwardExecutionControl(ExecutionControl ec,
             ObjectInput in, ObjectOutput out) {
         new ExecutionControlForwarder(ec, in, out).commandLoop();
     }

     /**
      * Forward commands from the input to the specified {@link ExecutionControl}
      * instance, then responses back on the output.
      * @param ec the direct instance of {@link ExecutionControl} to process commands
      * @param inStream the stream from which to create the command input
      * @param outStream the stream that will carry any specified auxiliary channels (like
      *                  {@code System.out} and {@code System.err}), and the command response output.
      * @param outputStreamMap a map between names of additional streams to carry and setters
      *                        for the stream. Names starting with '$' are reserved for internal use.
      * @param inputStreamMap a map between names of additional streams to carry and setters
      *                       for the stream. Names starting with '$' are reserved for internal use.
      * @throws IOException if there are errors using the passed streams
      */
     public static void forwardExecutionControlAndIO(ExecutionControl ec,
             InputStream inStream, OutputStream outStream,
             Map<String, Consumer<OutputStream>> outputStreamMap,
             Map<String, Consumer<InputStream>> inputStreamMap) throws IOException {
         for (Entry<String, Consumer<OutputStream>> e : outputStreamMap.entrySet()) {
             e.getValue().accept(multiplexingOutputStream(e.getKey(), outStream));
         }

         ObjectOutputStream cmdOut = new ObjectOutputStream(multiplexingOutputStream("$command", outStream));
         PipeInputStream cmdInPipe = new PipeInputStream();
         Map<String, OutputStream> inputs = new HashMap<>();
         inputs.put("$command", cmdInPipe.createOutput());
         for (Entry<String, Consumer<InputStream>> e : inputStreamMap.entrySet()) {
             OutputStream inputSignal = multiplexingOutputStream("$" + e.getKey() + "-input-requested", outStream);
             PipeInputStream inputPipe = new PipeInputStream() {
                 @Override protected void inputNeeded() throws IOException {
                     inputSignal.write('1');
                     inputSignal.flush();
                 }
                 @Override
                 public synchronized int read() throws IOException {
                     int tag = super.read();
                     switch (tag) {
                         case TAG_DATA: return super.read();
                         case TAG_CLOSED: close(); return -1;
                         case TAG_EXCEPTION:
                             int len = (super.read() << 0) + (super.read() << 8) + (super.read() << 16) + (super.read() << 24);
                             byte[] message = new byte[len];
                             for (int i = 0; i < len; i++) {
                                 message[i] = (byte) super.read();
                             }
                             throw new IOException(new String(message, "UTF-8"));
                         case -1:
                             return -1;
                         default:
                             throw new IOException("Internal error: unrecognized message tag: " + tag);
                     }
                 }
             };
             inputs.put(e.getKey(), inputPipe.createOutput());
             e.getValue().accept(inputPipe);
         }
         new DemultiplexInput(inStream, inputs, inputs.values()).start();
         ObjectInputStream cmdIn = new ObjectInputStream(cmdInPipe);

         forwardExecutionControl(ec, cmdIn, cmdOut);
     }

     static OutputStream multiplexingOutputStream(String label, OutputStream outputStream) {
         return new MultiplexingOutputStream(label, outputStream);
     }

     /**
      * Creates an ExecutionControl for given packetized input and output. The given InputStream
      * is de-packetized, and content forwarded to ObjectInput and given OutputStreams. The ObjectOutput
      * and values read from the given InputStream are packetized and sent to the given OutputStream.
      *
      * @param input the packetized input stream
      * @param output the packetized output stream
      * @param outputStreamMap a map between stream names and the output streams to forward.
      *                        Names starting with '$' are reserved for internal use.
      * @param inputStreamMap a map between stream names and the input streams to forward.
      *                       Names starting with '$' are reserved for internal use.
      * @param factory to create the ExecutionControl from ObjectInput and ObjectOutput.
      * @return the created ExecutionControl
      * @throws IOException if setting up the streams raised an exception
      */
     public static ExecutionControl remoteInputOutput(InputStream input, OutputStream output,
             Map<String, OutputStream> outputStreamMap, Map<String, InputStream> inputStreamMap,
             BiFunction<ObjectInput, ObjectOutput, ExecutionControl> factory) throws IOException {
         ExecutionControl[] result = new ExecutionControl[1];
         Map<String, OutputStream> augmentedStreamMap = new HashMap<>(outputStreamMap);
         ObjectOutput commandOut = new ObjectOutputStream(Util.multiplexingOutputStream("$command", output));
         for (Entry<String, InputStream> e : inputStreamMap.entrySet()) {
             InputStream  in = e.getValue();
             OutputStream inTarget = Util.multiplexingOutputStream(e.getKey(), output);
             augmentedStreamMap.put("$" + e.getKey() + "-input-requested", new OutputStream() {
                 @Override
                 public void write(int b) throws IOException {
                     //value ignored, just a trigger to read from the input
                     try {
                         int r = in.read();
                         if (r == (-1)) {
                             inTarget.write(TAG_CLOSED);
                         } else {
                             inTarget.write(new byte[] {TAG_DATA, (byte) r});
                         }
                     } catch (InterruptedIOException exc) {
                         try {
                             result[0].stop();
                         } catch (ExecutionControlException ex) {
                             debug(ex, "$" + e.getKey() + "-input-requested.write");
                         }
                     } catch (IOException exc) {
                         byte[] message = exc.getMessage().getBytes("UTF-8");
                         inTarget.write(TAG_EXCEPTION);
                         inTarget.write((message.length >>  0) & 0xFF);
                         inTarget.write((message.length >>  8) & 0xFF);
                         inTarget.write((message.length >> 16) & 0xFF);
                         inTarget.write((message.length >> 24) & 0xFF);
                         inTarget.write(message);
                     }
                 }
             });
         }
         PipeInputStream commandIn = new PipeInputStream();
         OutputStream commandInTarget = commandIn.createOutput();
         augmentedStreamMap.put("$command", commandInTarget);
         new DemultiplexInput(input, augmentedStreamMap, Arrays.asList(commandInTarget)).start();
         return result[0] = factory.apply(new ObjectInputStream(commandIn), commandOut);
     }

     /**
      * Monitor the JDI event stream for {@link com.sun.jdi.event.VMDeathEvent}
      * and {@link com.sun.jdi.event.VMDisconnectEvent}. If encountered, invokes
      * {@code unbiddenExitHandler}.
      *
      * @param vm the virtual machine to check
      * @param unbiddenExitHandler the handler, which will accept the exit
      * information
      */
     public static void detectJdiExitEvent(VirtualMachine vm, Consumer<String> unbiddenExitHandler) {
         if (vm.canBeModified()) {
             new JdiEventHandler(vm, unbiddenExitHandler).start();
         }
     }

     /**
      * Log a serious unexpected internal exception.
      *
      * @param ex the exception
      * @param where a description of the context of the exception
      */
     private static void debug(Throwable ex, String where) {
         // Reserved for future logging
     }
 }
	/*
	* Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/
	package jdk.jshell.execution;

	import jdk.jshell.spi.ExecutionEnv;

	import java.io.IOException;
	import java.io.InputStream;
	import java.io.InterruptedIOException;
	import java.io.ObjectInput;
	import java.io.ObjectInputStream;
	import java.io.ObjectOutput;
	import java.io.ObjectOutputStream;
	import java.io.OutputStream;
	import java.util.Arrays;
	import java.util.HashMap;
	import java.util.Map;
	import java.util.Map.Entry;
	import java.util.function.BiFunction;
	import java.util.function.Consumer;

	import com.sun.jdi.VirtualMachine;
	import jdk.jshell.spi.ExecutionControl;
	import jdk.jshell.spi.ExecutionControl.ExecutionControlException;


	/**
	* Miscellaneous utility methods for setting-up implementations of
	* {@link ExecutionControl}. Particularly implementations with remote
	* execution.
	*
	* @author Jan Lahoda
	* @author Robert Field
	*/
	public class Util {

	private static final int TAG_DATA = 0;
	private static final int TAG_CLOSED = 1;
	private static final int TAG_EXCEPTION = 2;

	// never instanciated
	private Util() {}

	/**
	* Forward commands from the input to the specified {@link ExecutionControl}
	* instance, then responses back on the output.
	* @param ec the direct instance of {@link ExecutionControl} to process commands
	* @param in the command input
	* @param out the command response output
	*/
	public static void forwardExecutionControl(ExecutionControl ec,
	ObjectInput in, ObjectOutput out) {
	new ExecutionControlForwarder(ec, in, out).commandLoop();
	}

	/**
	* Forward commands from the input to the specified {@link ExecutionControl}
	* instance, then responses back on the output.
	* @param ec the direct instance of {@link ExecutionControl} to process commands
	* @param inStream the stream from which to create the command input
	* @param outStream the stream that will carry any specified auxiliary channels (like
	* {@code System.out} and {@code System.err}), and the command response output.
	* @param outputStreamMap a map between names of additional streams to carry and setters
	* for the stream. Names starting with '$' are reserved for internal use.
	* @param inputStreamMap a map between names of additional streams to carry and setters
	* for the stream. Names starting with '$' are reserved for internal use.
	* @throws IOException if there are errors using the passed streams
	*/
	public static void forwardExecutionControlAndIO(ExecutionControl ec,
	InputStream inStream, OutputStream outStream,
	Map<String, Consumer<OutputStream>> outputStreamMap,
	Map<String, Consumer<InputStream>> inputStreamMap) throws IOException {
	for (Entry<String, Consumer<OutputStream>> e : outputStreamMap.entrySet()) {
	e.getValue().accept(multiplexingOutputStream(e.getKey(), outStream));
	}

	ObjectOutputStream cmdOut = new ObjectOutputStream(multiplexingOutputStream("$command", outStream));
	PipeInputStream cmdInPipe = new PipeInputStream();
	Map<String, OutputStream> inputs = new HashMap<>();
	inputs.put("$command", cmdInPipe.createOutput());
	for (Entry<String, Consumer<InputStream>> e : inputStreamMap.entrySet()) {
	OutputStream inputSignal = multiplexingOutputStream("$" + e.getKey() + "-input-requested", outStream);
	PipeInputStream inputPipe = new PipeInputStream() {
	@Override protected void inputNeeded() throws IOException {
	inputSignal.write('1');
	inputSignal.flush();
	}
	@Override
	public synchronized int read() throws IOException {
	int tag = super.read();
	switch (tag) {
	case TAG_DATA: return super.read();
	case TAG_CLOSED: close(); return -1;
	case TAG_EXCEPTION:
	int len = (super.read() << 0) + (super.read() << 8) + (super.read() << 16) + (super.read() << 24);
	byte[] message = new byte[len];
	for (int i = 0; i < len; i++) {
	message[i] = (byte) super.read();
	}
	throw new IOException(new String(message, "UTF-8"));
	case -1:
	return -1;
	default:
	throw new IOException("Internal error: unrecognized message tag: " + tag);
	}
	}
	};
	inputs.put(e.getKey(), inputPipe.createOutput());
	e.getValue().accept(inputPipe);
	}
	new DemultiplexInput(inStream, inputs, inputs.values()).start();
	ObjectInputStream cmdIn = new ObjectInputStream(cmdInPipe);

	forwardExecutionControl(ec, cmdIn, cmdOut);
	}

	static OutputStream multiplexingOutputStream(String label, OutputStream outputStream) {
	return new MultiplexingOutputStream(label, outputStream);
	}

	/**
	* Creates an ExecutionControl for given packetized input and output. The given InputStream
	* is de-packetized, and content forwarded to ObjectInput and given OutputStreams. The ObjectOutput
	* and values read from the given InputStream are packetized and sent to the given OutputStream.
	*
	* @param input the packetized input stream
	* @param output the packetized output stream
	* @param outputStreamMap a map between stream names and the output streams to forward.
	* Names starting with '$' are reserved for internal use.
	* @param inputStreamMap a map between stream names and the input streams to forward.
	* Names starting with '$' are reserved for internal use.
	* @param factory to create the ExecutionControl from ObjectInput and ObjectOutput.
	* @return the created ExecutionControl
	* @throws IOException if setting up the streams raised an exception
	*/
	public static ExecutionControl remoteInputOutput(InputStream input, OutputStream output,
	Map<String, OutputStream> outputStreamMap, Map<String, InputStream> inputStreamMap,
	BiFunction<ObjectInput, ObjectOutput, ExecutionControl> factory) throws IOException {
	ExecutionControl[] result = new ExecutionControl[1];
	Map<String, OutputStream> augmentedStreamMap = new HashMap<>(outputStreamMap);
	ObjectOutput commandOut = new ObjectOutputStream(Util.multiplexingOutputStream("$command", output));
	for (Entry<String, InputStream> e : inputStreamMap.entrySet()) {
	InputStream in = e.getValue();
	OutputStream inTarget = Util.multiplexingOutputStream(e.getKey(), output);
	augmentedStreamMap.put("$" + e.getKey() + "-input-requested", new OutputStream() {
	@Override
	public void write(int b) throws IOException {
	//value ignored, just a trigger to read from the input
	try {
	int r = in.read();
	if (r == (-1)) {
	inTarget.write(TAG_CLOSED);
	} else {
	inTarget.write(new byte[] {TAG_DATA, (byte) r});
	}
	} catch (InterruptedIOException exc) {
	try {
	result[0].stop();
	} catch (ExecutionControlException ex) {
	debug(ex, "$" + e.getKey() + "-input-requested.write");
	}
	} catch (IOException exc) {
	byte[] message = exc.getMessage().getBytes("UTF-8");
	inTarget.write(TAG_EXCEPTION);
	inTarget.write((message.length >> 0) & 0xFF);
	inTarget.write((message.length >> 8) & 0xFF);
	inTarget.write((message.length >> 16) & 0xFF);
	inTarget.write((message.length >> 24) & 0xFF);
	inTarget.write(message);
	}
	}
	});
	}
	PipeInputStream commandIn = new PipeInputStream();
	OutputStream commandInTarget = commandIn.createOutput();
	augmentedStreamMap.put("$command", commandInTarget);
	new DemultiplexInput(input, augmentedStreamMap, Arrays.asList(commandInTarget)).start();
	return result[0] = factory.apply(new ObjectInputStream(commandIn), commandOut);
	}

	/**
	* Monitor the JDI event stream for {@link com.sun.jdi.event.VMDeathEvent}
	* and {@link com.sun.jdi.event.VMDisconnectEvent}. If encountered, invokes
	* {@code unbiddenExitHandler}.
	*
	* @param vm the virtual machine to check
	* @param unbiddenExitHandler the handler, which will accept the exit
	* information
	*/
	public static void detectJdiExitEvent(VirtualMachine vm, Consumer<String> unbiddenExitHandler) {
	if (vm.canBeModified()) {
	new JdiEventHandler(vm, unbiddenExitHandler).start();
	}
	}

	/**
	* Log a serious unexpected internal exception.
	*
	* @param ex the exception
	* @param where a description of the context of the exception
	*/
	private static void debug(Throwable ex, String where) {
	// Reserved for future logging
	}
	}