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

 /*
  * Copyright (c) 2016, 2018, 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 java.io.IOException;
 import java.io.ObjectInput;
 import java.io.ObjectOutput;
 import jdk.jshell.JShellException;
 import jdk.jshell.spi.ExecutionControl;
 import static jdk.jshell.execution.ExecutionControlForwarder.NULL_MARKER;
 import static jdk.jshell.execution.RemoteCodes.*;

 /**
  * An implementation of the {@link jdk.jshell.spi.ExecutionControl}
  * execution engine SPI which streams requests to a remote agent where
  * execution takes place.
  *
  * @author Robert Field
  * @since 9
  */
 public class StreamingExecutionControl implements ExecutionControl {

     private final ObjectOutput out;
     private final ObjectInput in;

     /**
      * Creates an instance.
      *
      * @param out the output for commands
      * @param in the input for command responses
      */
     public StreamingExecutionControl(ObjectOutput out, ObjectInput in) {
         this.out = out;
         this.in = in;
     }

     @Override
     public void load(ClassBytecodes[] cbcs)
             throws ClassInstallException, NotImplementedException, EngineTerminationException {
         try {
             // Send a load command to the remote agent.
             writeCommand(CMD_LOAD);
             out.writeObject(cbcs);
             out.flush();
             // Retrieve and report results from the remote agent.
             readAndReportClassInstallResult();
         } catch (IOException ex) {
             throw new EngineTerminationException("Exception writing remote load: " + ex);
         }
     }

     @Override
     public void redefine(ClassBytecodes[] cbcs)
             throws ClassInstallException, NotImplementedException, EngineTerminationException {
         try {
             // Send a load command to the remote agent.
             writeCommand(CMD_REDEFINE);
             out.writeObject(cbcs);
             out.flush();
             // Retrieve and report results from the remote agent.
             readAndReportClassInstallResult();
         } catch (IOException ex) {
             throw new EngineTerminationException("Exception writing remote redefine: " + ex);
         }
     }

     @Override
     public String invoke(String classname, String methodname)
             throws RunException, EngineTerminationException, InternalException {
         try {
             // Send the invoke command to the remote agent.
             writeCommand(CMD_INVOKE);
             out.writeUTF(classname);
             out.writeUTF(methodname);
             out.flush();
             // Retrieve and report results from the remote agent.
             readAndReportExecutionResult();
             String result = in.readUTF();
             return result;
         } catch (IOException ex) {
             throw new EngineTerminationException("Exception writing remote invoke: " + ex);
         }
     }

     @Override
     public String varValue(String classname, String varname)
             throws RunException, EngineTerminationException, InternalException {
         try {
             // Send the variable-value command to the remote agent.
             writeCommand(CMD_VAR_VALUE);
             out.writeUTF(classname);
             out.writeUTF(varname);
             out.flush();
             // Retrieve and report results from the remote agent.
             readAndReportExecutionResult();
             String result = in.readUTF();
             return result;
         } catch (IOException ex) {
             throw new EngineTerminationException("Exception writing remote varValue: " + ex);
         }
     }


     @Override
     public void addToClasspath(String path)
             throws EngineTerminationException, InternalException {
         try {
             // Send the classpath addition command to the remote agent.
             writeCommand(CMD_ADD_CLASSPATH);
             out.writeUTF(path);
             out.flush();
             // Retrieve and report results from the remote agent.
             readAndReportClassSimpleResult();
         } catch (IOException ex) {
             throw new EngineTerminationException("Exception writing remote add to classpath: " + ex);
         }
     }

     @Override
     public void stop()
             throws EngineTerminationException, InternalException {
         try {
             // Send the variable-value command to the remote agent.
             writeCommand(CMD_STOP);
             out.flush();
         } catch (IOException ex) {
             throw new EngineTerminationException("Exception writing remote stop: " + ex);
         }
     }

     @Override
     public Object extensionCommand(String command, Object arg)
             throws RunException, EngineTerminationException, InternalException {
         try {
             writeCommand(command);
             out.writeObject(arg);
             out.flush();
             // Retrieve and report results from the remote agent.
             readAndReportExecutionResult();
             Object result = in.readObject();
             return result;
         } catch (IOException | ClassNotFoundException ex) {
             throw new EngineTerminationException("Exception transmitting remote extensionCommand: "
                     + command + " -- " + ex);
         }
     }

     /**
      * Closes the execution engine. Send an exit command to the remote agent.
      */
     @Override
     public void close() {
         try {
             writeCommand(CMD_CLOSE);
             out.flush();
         } catch (IOException ex) {
             // ignore;
         }
     }

     private void writeCommand(String cmd) throws IOException {
         out.writeInt(COMMAND_PREFIX);
         out.writeUTF(cmd);
     }

     /**
      * Read a UTF or a null encoded as a null marker.
      * @return a string or null
      * @throws IOException passed through from readUTF()
      */
     private String readNullOrUTF() throws IOException {
         String s = in.readUTF();
         return s.equals(NULL_MARKER) ? null : s;
     }

     /**
      * Reports results from a remote agent command that does not expect
      * exceptions.
      */
     private void readAndReportClassSimpleResult() throws EngineTerminationException, InternalException {
         try {
             int status = in.readInt();
             switch (status) {
                 case RESULT_SUCCESS:
                     return;
                 case RESULT_NOT_IMPLEMENTED: {
                     String message = in.readUTF();
                     throw new NotImplementedException(message);
                 }
                 case RESULT_INTERNAL_PROBLEM: {
                     String message = in.readUTF();
                     throw new InternalException(message);
                 }
                 case RESULT_TERMINATED: {
                     String message = in.readUTF();
                     throw new EngineTerminationException(message);
                 }
                 default: {
                     throw new EngineTerminationException("Bad remote result code: " + status);
                 }
             }
         } catch (IOException ex) {
             throw new EngineTerminationException(ex.toString());
         }
     }

     /**
      * Reports results from a remote agent command that does not expect
      * exceptions.
      */
     private void readAndReportClassInstallResult() throws ClassInstallException,
             NotImplementedException, EngineTerminationException {
         try {
             int status = in.readInt();
             switch (status) {
                 case RESULT_SUCCESS:
                     return;
                 case RESULT_NOT_IMPLEMENTED: {
                     String message = in.readUTF();
                     throw new NotImplementedException(message);
                 }
                 case RESULT_CLASS_INSTALL_EXCEPTION: {
                     String message = in.readUTF();
                     boolean[] loaded = (boolean[]) in.readObject();
                     throw new ClassInstallException(message, loaded);
                 }
                 case RESULT_TERMINATED: {
                     String message = in.readUTF();
                     throw new EngineTerminationException(message);
                 }
                 default: {
                     throw new EngineTerminationException("Bad remote result code: " + status);
                 }
             }
         } catch (IOException | ClassNotFoundException ex) {
             throw new EngineTerminationException(ex.toString());
         }
     }

     /**
      * Reports results from a remote agent command that expects runtime
      * exceptions.
      *
      * @return true if successful
      * @throws IOException if the connection has dropped
      * @throws JShellException {@link jdk.jshell.EvalException}, if a user
      * exception was encountered on invoke;
      * {@link jdk.jshell.UnresolvedReferenceException}, if an unresolved
      * reference was encountered
      * @throws java.lang.ClassNotFoundException
      */
     private void readAndReportExecutionResult() throws RunException,
             EngineTerminationException, InternalException {
         try {
             int status = in.readInt();
             switch (status) {
                 case RESULT_SUCCESS:
                     return;
                 case RESULT_NOT_IMPLEMENTED: {
                     String message = in.readUTF();
                     throw new NotImplementedException(message);
                 }
                 case RESULT_USER_EXCEPTION: {
                     // A user exception was encountered.  Handle pre JDK 11 back-ends
                     throw readUserException();
                 }
                 case RESULT_CORRALLED: {
                     // An unresolved reference was encountered.
                     throw readResolutionException();
                 }
                 case RESULT_USER_EXCEPTION_CHAINED: {
                     // A user exception was encountered -- transmit chained.
                     in.readInt(); // always RESULT_USER_EXCEPTION
                     UserException result = readUserException();
                     RunException caused = result;
                     // Loop through the chained causes (if any) building a chained exception
                     loop: while (true) {
                         RunException ex;
                         int cstatus = in.readInt();
                         switch (cstatus) {
                             case RESULT_USER_EXCEPTION: {
                                 // A user exception was the proximal cause.
                                 ex = readUserException();
                                 break;
                             }
                             case RESULT_CORRALLED: {
                                 // An unresolved reference was the underlying cause.
                                 ex = readResolutionException();
                                 break;
                             }
                             case RESULT_SUCCESS: {
                                 // End of chained exceptions
                                 break loop;
                             }
                             default: {
                                 throw new EngineTerminationException("Bad chained remote result code: " + cstatus);
                             }
                         }
                         caused.initCause(ex);
                         caused = ex;
                     }
                     caused.initCause(null); // root cause has no cause
                     throw result;
                 }
                 case RESULT_STOPPED: {
                     // Execution was aborted by the stop()
                     throw new StoppedException();
                 }
                 case RESULT_INTERNAL_PROBLEM: {
                     // An internal error has occurred.
                     String message = in.readUTF();
                     throw new InternalException(message);
                 }
                 case RESULT_TERMINATED: {
                     String message = in.readUTF();
                     throw new EngineTerminationException(message);
                 }
                 default: {
                     throw new EngineTerminationException("Bad remote result code: " + status);
                 }
             }
         } catch (IOException | ClassNotFoundException ex) {
             ex.printStackTrace();
             throw new EngineTerminationException(ex.toString());
         }
     }

     private UserException readUserException() throws IOException, ClassNotFoundException {
         String message = readNullOrUTF();
         String exceptionClassName = in.readUTF();
         StackTraceElement[] elems = (StackTraceElement[]) in.readObject();
         return new UserException(message, exceptionClassName, elems);
     }

     private ResolutionException readResolutionException() throws IOException, ClassNotFoundException {
         int id = in.readInt();
         StackTraceElement[] elems = (StackTraceElement[]) in.readObject();
         return new ResolutionException(id, elems);
     }
 }
	/*
	* Copyright (c) 2016, 2018, 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 java.io.IOException;
	import java.io.ObjectInput;
	import java.io.ObjectOutput;
	import jdk.jshell.JShellException;
	import jdk.jshell.spi.ExecutionControl;
	import static jdk.jshell.execution.ExecutionControlForwarder.NULL_MARKER;
	import static jdk.jshell.execution.RemoteCodes.*;

	/**
	* An implementation of the {@link jdk.jshell.spi.ExecutionControl}
	* execution engine SPI which streams requests to a remote agent where
	* execution takes place.
	*
	* @author Robert Field
	* @since 9
	*/
	public class StreamingExecutionControl implements ExecutionControl {

	private final ObjectOutput out;
	private final ObjectInput in;

	/**
	* Creates an instance.
	*
	* @param out the output for commands
	* @param in the input for command responses
	*/
	public StreamingExecutionControl(ObjectOutput out, ObjectInput in) {
	this.out = out;
	this.in = in;
	}

	@Override
	public void load(ClassBytecodes[] cbcs)
	throws ClassInstallException, NotImplementedException, EngineTerminationException {
	try {
	// Send a load command to the remote agent.
	writeCommand(CMD_LOAD);
	out.writeObject(cbcs);
	out.flush();
	// Retrieve and report results from the remote agent.
	readAndReportClassInstallResult();
	} catch (IOException ex) {
	throw new EngineTerminationException("Exception writing remote load: " + ex);
	}
	}

	@Override
	public void redefine(ClassBytecodes[] cbcs)
	throws ClassInstallException, NotImplementedException, EngineTerminationException {
	try {
	// Send a load command to the remote agent.
	writeCommand(CMD_REDEFINE);
	out.writeObject(cbcs);
	out.flush();
	// Retrieve and report results from the remote agent.
	readAndReportClassInstallResult();
	} catch (IOException ex) {
	throw new EngineTerminationException("Exception writing remote redefine: " + ex);
	}
	}

	@Override
	public String invoke(String classname, String methodname)
	throws RunException, EngineTerminationException, InternalException {
	try {
	// Send the invoke command to the remote agent.
	writeCommand(CMD_INVOKE);
	out.writeUTF(classname);
	out.writeUTF(methodname);
	out.flush();
	// Retrieve and report results from the remote agent.
	readAndReportExecutionResult();
	String result = in.readUTF();
	return result;
	} catch (IOException ex) {
	throw new EngineTerminationException("Exception writing remote invoke: " + ex);
	}
	}

	@Override
	public String varValue(String classname, String varname)
	throws RunException, EngineTerminationException, InternalException {
	try {
	// Send the variable-value command to the remote agent.
	writeCommand(CMD_VAR_VALUE);
	out.writeUTF(classname);
	out.writeUTF(varname);
	out.flush();
	// Retrieve and report results from the remote agent.
	readAndReportExecutionResult();
	String result = in.readUTF();
	return result;
	} catch (IOException ex) {
	throw new EngineTerminationException("Exception writing remote varValue: " + ex);
	}
	}


	@Override
	public void addToClasspath(String path)
	throws EngineTerminationException, InternalException {
	try {
	// Send the classpath addition command to the remote agent.
	writeCommand(CMD_ADD_CLASSPATH);
	out.writeUTF(path);
	out.flush();
	// Retrieve and report results from the remote agent.
	readAndReportClassSimpleResult();
	} catch (IOException ex) {
	throw new EngineTerminationException("Exception writing remote add to classpath: " + ex);
	}
	}

	@Override
	public void stop()
	throws EngineTerminationException, InternalException {
	try {
	// Send the variable-value command to the remote agent.
	writeCommand(CMD_STOP);
	out.flush();
	} catch (IOException ex) {
	throw new EngineTerminationException("Exception writing remote stop: " + ex);
	}
	}

	@Override
	public Object extensionCommand(String command, Object arg)
	throws RunException, EngineTerminationException, InternalException {
	try {
	writeCommand(command);
	out.writeObject(arg);
	out.flush();
	// Retrieve and report results from the remote agent.
	readAndReportExecutionResult();
	Object result = in.readObject();
	return result;
	} catch (IOException \| ClassNotFoundException ex) {
	throw new EngineTerminationException("Exception transmitting remote extensionCommand: "
	+ command + " -- " + ex);
	}
	}

	/**
	* Closes the execution engine. Send an exit command to the remote agent.
	*/
	@Override
	public void close() {
	try {
	writeCommand(CMD_CLOSE);
	out.flush();
	} catch (IOException ex) {
	// ignore;
	}
	}

	private void writeCommand(String cmd) throws IOException {
	out.writeInt(COMMAND_PREFIX);
	out.writeUTF(cmd);
	}

	/**
	* Read a UTF or a null encoded as a null marker.
	* @return a string or null
	* @throws IOException passed through from readUTF()
	*/
	private String readNullOrUTF() throws IOException {
	String s = in.readUTF();
	return s.equals(NULL_MARKER) ? null : s;
	}

	/**
	* Reports results from a remote agent command that does not expect
	* exceptions.
	*/
	private void readAndReportClassSimpleResult() throws EngineTerminationException, InternalException {
	try {
	int status = in.readInt();
	switch (status) {
	case RESULT_SUCCESS:
	return;
	case RESULT_NOT_IMPLEMENTED: {
	String message = in.readUTF();
	throw new NotImplementedException(message);
	}
	case RESULT_INTERNAL_PROBLEM: {
	String message = in.readUTF();
	throw new InternalException(message);
	}
	case RESULT_TERMINATED: {
	String message = in.readUTF();
	throw new EngineTerminationException(message);
	}
	default: {
	throw new EngineTerminationException("Bad remote result code: " + status);
	}
	}
	} catch (IOException ex) {
	throw new EngineTerminationException(ex.toString());
	}
	}

	/**
	* Reports results from a remote agent command that does not expect
	* exceptions.
	*/
	private void readAndReportClassInstallResult() throws ClassInstallException,
	NotImplementedException, EngineTerminationException {
	try {
	int status = in.readInt();
	switch (status) {
	case RESULT_SUCCESS:
	return;
	case RESULT_NOT_IMPLEMENTED: {
	String message = in.readUTF();
	throw new NotImplementedException(message);
	}
	case RESULT_CLASS_INSTALL_EXCEPTION: {
	String message = in.readUTF();
	boolean[] loaded = (boolean[]) in.readObject();
	throw new ClassInstallException(message, loaded);
	}
	case RESULT_TERMINATED: {
	String message = in.readUTF();
	throw new EngineTerminationException(message);
	}
	default: {
	throw new EngineTerminationException("Bad remote result code: " + status);
	}
	}
	} catch (IOException \| ClassNotFoundException ex) {
	throw new EngineTerminationException(ex.toString());
	}
	}

	/**
	* Reports results from a remote agent command that expects runtime
	* exceptions.
	*
	* @return true if successful
	* @throws IOException if the connection has dropped
	* @throws JShellException {@link jdk.jshell.EvalException}, if a user
	* exception was encountered on invoke;
	* {@link jdk.jshell.UnresolvedReferenceException}, if an unresolved
	* reference was encountered
	* @throws java.lang.ClassNotFoundException
	*/
	private void readAndReportExecutionResult() throws RunException,
	EngineTerminationException, InternalException {
	try {
	int status = in.readInt();
	switch (status) {
	case RESULT_SUCCESS:
	return;
	case RESULT_NOT_IMPLEMENTED: {
	String message = in.readUTF();
	throw new NotImplementedException(message);
	}
	case RESULT_USER_EXCEPTION: {
	// A user exception was encountered. Handle pre JDK 11 back-ends
	throw readUserException();
	}
	case RESULT_CORRALLED: {
	// An unresolved reference was encountered.
	throw readResolutionException();
	}
	case RESULT_USER_EXCEPTION_CHAINED: {
	// A user exception was encountered -- transmit chained.
	in.readInt(); // always RESULT_USER_EXCEPTION
	UserException result = readUserException();
	RunException caused = result;
	// Loop through the chained causes (if any) building a chained exception
	loop: while (true) {
	RunException ex;
	int cstatus = in.readInt();
	switch (cstatus) {
	case RESULT_USER_EXCEPTION: {
	// A user exception was the proximal cause.
	ex = readUserException();
	break;
	}
	case RESULT_CORRALLED: {
	// An unresolved reference was the underlying cause.
	ex = readResolutionException();
	break;
	}
	case RESULT_SUCCESS: {
	// End of chained exceptions
	break loop;
	}
	default: {
	throw new EngineTerminationException("Bad chained remote result code: " + cstatus);
	}
	}
	caused.initCause(ex);
	caused = ex;
	}
	caused.initCause(null); // root cause has no cause
	throw result;
	}
	case RESULT_STOPPED: {
	// Execution was aborted by the stop()
	throw new StoppedException();
	}
	case RESULT_INTERNAL_PROBLEM: {
	// An internal error has occurred.
	String message = in.readUTF();
	throw new InternalException(message);
	}
	case RESULT_TERMINATED: {
	String message = in.readUTF();
	throw new EngineTerminationException(message);
	}
	default: {
	throw new EngineTerminationException("Bad remote result code: " + status);
	}
	}
	} catch (IOException \| ClassNotFoundException ex) {
	ex.printStackTrace();
	throw new EngineTerminationException(ex.toString());
	}
	}

	private UserException readUserException() throws IOException, ClassNotFoundException {
	String message = readNullOrUTF();
	String exceptionClassName = in.readUTF();
	StackTraceElement[] elems = (StackTraceElement[]) in.readObject();
	return new UserException(message, exceptionClassName, elems);
	}

	private ResolutionException readResolutionException() throws IOException, ClassNotFoundException {
	int id = in.readInt();
	StackTraceElement[] elems = (StackTraceElement[]) in.readObject();
	return new ResolutionException(id, elems);
	}
	}