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

 /*
  * Copyright (c) 2014, 2015, 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;

 import static jdk.internal.jshell.remote.RemoteCodes.*;
 import java.io.IOException;
 import java.io.ObjectInputStream;
 import java.io.ObjectOutputStream;
 import java.net.ServerSocket;
 import java.net.Socket;
 import com.sun.jdi.*;
 import java.io.EOFException;
 import java.util.List;
 import java.util.Map;
 import jdk.jshell.ClassTracker.ClassInfo;
 import static jdk.internal.jshell.debug.InternalDebugControl.DBG_GEN;

 /**
  * Controls the remote execution environment.
  *
  * @author Robert Field
  */
 class ExecutionControl {

     private final JDIEnv env;
     private final SnippetMaps maps;
     private JDIEventHandler handler;
     private Socket socket;
     private ObjectInputStream in;
     private ObjectOutputStream out;
     private final JShell proc;

     ExecutionControl(JDIEnv env, SnippetMaps maps, JShell proc) {
         this.env = env;
         this.maps = maps;
         this.proc = proc;
     }

     void launch() throws IOException {
         try (ServerSocket listener = new ServerSocket(0)) {
             // timeout after 60 seconds
             listener.setSoTimeout(60000);
             int port = listener.getLocalPort();
             jdiGo(port);
             socket = listener.accept();
             // out before in -- match remote creation so we don't hang
             out = new ObjectOutputStream(socket.getOutputStream());
             in = new ObjectInputStream(socket.getInputStream());
         }
     }

     void commandExit() {
         try {
             if (out != null) {
                 out.writeInt(CMD_EXIT);
                 out.flush();
             }
             JDIConnection c = env.connection();
             if (c != null) {
                 c.disposeVM();
             }
         } catch (IOException ex) {
             proc.debug(DBG_GEN, "Exception on JDI exit: %s\n", ex);
         }
     }


     boolean commandLoad(List<ClassInfo> cil) {
         try {
             out.writeInt(CMD_LOAD);
             out.writeInt(cil.size());
             for (ClassInfo ci : cil) {
                 out.writeUTF(ci.getClassName());
                 out.writeObject(ci.getBytes());
             }
             out.flush();
             return readAndReportResult();
         } catch (IOException ex) {
             proc.debug(DBG_GEN, "IOException on remote load operation: %s\n", ex);
             return false;
         }
     }

     String commandInvoke(String classname) throws EvalException, UnresolvedReferenceException {
         try {
             synchronized (STOP_LOCK) {
                 userCodeRunning = true;
             }
             out.writeInt(CMD_INVOKE);
             out.writeUTF(classname);
             out.flush();
             if (readAndReportExecutionResult()) {
                 String result = in.readUTF();
                 return result;
             }
         } catch (EOFException ex) {
             env.shutdown();
         } catch (IOException | ClassNotFoundException ex) {
             proc.debug(DBG_GEN, "Exception on remote invoke: %s\n", ex);
             return "Execution failure: " + ex.getMessage();
         } finally {
             synchronized (STOP_LOCK) {
                 userCodeRunning = false;
             }
         }
         return "";
     }

     String commandVarValue(String classname, String varname) {
         try {
             out.writeInt(CMD_VARVALUE);
             out.writeUTF(classname);
             out.writeUTF(varname);
             out.flush();
             if (readAndReportResult()) {
                 String result = in.readUTF();
                 return result;
             }
         } catch (EOFException ex) {
             env.shutdown();
         } catch (IOException ex) {
             proc.debug(DBG_GEN, "Exception on remote var value: %s\n", ex);
             return "Execution failure: " + ex.getMessage();
         }
         return "";
     }

     boolean commandAddToClasspath(String cp) {
         try {
             out.writeInt(CMD_CLASSPATH);
             out.writeUTF(cp);
             out.flush();
             return readAndReportResult();
         } catch (IOException ex) {
             throw new InternalError("Classpath addition failed: " + cp, ex);
         }
     }

     boolean commandRedefine(Map<ReferenceType, byte[]> mp) {
         try {
             env.vm().redefineClasses(mp);
             return true;
         } catch (UnsupportedOperationException ex) {
             return false;
         } catch (Exception ex) {
             proc.debug(DBG_GEN, "Exception on JDI redefine: %s\n", ex);
             return false;
         }
     }

     ReferenceType nameToRef(String name) {
         List<ReferenceType> rtl = env.vm().classesByName(name);
         if (rtl.size() != 1) {
             return null;
         }
         return rtl.get(0);
     }

     private boolean readAndReportResult() throws IOException {
         int ok = in.readInt();
         switch (ok) {
             case RESULT_SUCCESS:
                 return true;
             case RESULT_FAIL: {
                 String ex = in.readUTF();
                 proc.debug(DBG_GEN, "Exception on remote operation: %s\n", ex);
                 return false;
             }
             default: {
                 proc.debug(DBG_GEN, "Bad remote result code: %s\n", ok);
                 return false;
             }
         }
     }

     private boolean readAndReportExecutionResult() throws IOException, ClassNotFoundException, EvalException, UnresolvedReferenceException {
         int ok = in.readInt();
         switch (ok) {
             case RESULT_SUCCESS:
                 return true;
             case RESULT_FAIL: {
                 String ex = in.readUTF();
                 proc.debug(DBG_GEN, "Exception on remote operation: %s\n", ex);
                 return false;
             }
             case RESULT_EXCEPTION: {
                 String exceptionClassName = in.readUTF();
                 String message = in.readUTF();
                 StackTraceElement[] elems = readStackTrace();
                 EvalException ee = new EvalException(message, exceptionClassName, elems);
                 throw ee;
             }
             case RESULT_CORRALLED: {
                 int id = in.readInt();
                 StackTraceElement[] elems = readStackTrace();
                 Snippet si = maps.getSnippet(id);
                 throw new UnresolvedReferenceException((MethodSnippet) si, elems);
             }
             case RESULT_KILLED: {
                 proc.out.println("Killed.");
                 return false;
             }
             default: {
                 proc.debug(DBG_GEN, "Bad remote result code: %s\n", ok);
                 return false;
             }
         }
     }

     private StackTraceElement[] readStackTrace() throws IOException {
         int elemCount = in.readInt();
         StackTraceElement[] elems = new StackTraceElement[elemCount];
         for (int i = 0; i < elemCount; ++i) {
             String className = in.readUTF();
             String methodName = in.readUTF();
             String fileName = in.readUTF();
             int line = in.readInt();
             elems[i] = new StackTraceElement(className, methodName, fileName, line);
         }
         return elems;
     }

     private void jdiGo(int port) {
         //MessageOutput.textResources = ResourceBundle.getBundle("impl.TTYResources",
         //        Locale.getDefault());

         String connect = "com.sun.jdi.CommandLineLaunch:";
         String cmdLine = "jdk.internal.jshell.remote.RemoteAgent";
         String classPath = System.getProperty("java.class.path");
         String bootclassPath = System.getProperty("sun.boot.class.path");
         String javaArgs = "-classpath " + classPath + " -Xbootclasspath:" + bootclassPath;

         String connectSpec = connect + "main=" + cmdLine + " " + port + ",options=" + javaArgs + ",";
         boolean launchImmediately = true;
         int traceFlags = 0;// VirtualMachine.TRACE_SENDS | VirtualMachine.TRACE_EVENTS;

         env.init(connectSpec, launchImmediately, traceFlags);

         if (env.connection().isOpen() && env.vm().canBeModified()) {
             /*
              * Connection opened on startup. Start event handler
              * immediately, telling it (through arg 2) to stop on the
              * VM start event.
              */
             handler = new JDIEventHandler(env);
         }
     }

     private final Object STOP_LOCK = new Object();
     private boolean userCodeRunning = false;

     void commandStop() {
         synchronized (STOP_LOCK) {
             if (!userCodeRunning)
                 return ;

             VirtualMachine vm = handler.env.vm();
             vm.suspend();
             try {
                 OUTER: for (ThreadReference thread : vm.allThreads()) {
                     // could also tag the thread (e.g. using name), to find it easier
                     for (StackFrame frame : thread.frames()) {
                         String remoteAgentName = "jdk.internal.jshell.remote.RemoteAgent";
                         if (remoteAgentName.equals(frame.location().declaringType().name()) &&
                             "commandLoop".equals(frame.location().method().name())) {
                             ObjectReference thiz = frame.thisObject();
                             if (((BooleanValue) thiz.getValue(thiz.referenceType().fieldByName("inClientCode"))).value()) {
                                 thiz.setValue(thiz.referenceType().fieldByName("expectingStop"), vm.mirrorOf(true));
                                 ObjectReference stopInstance = (ObjectReference) thiz.getValue(thiz.referenceType().fieldByName("stopException"));

                                 vm.resume();
                                 proc.debug(DBG_GEN, "Attempting to stop the client code...\n");
                                 thread.stop(stopInstance);
                                 thiz.setValue(thiz.referenceType().fieldByName("expectingStop"), vm.mirrorOf(false));
                             }

                             break OUTER;
                         }
                     }
                 }
             } catch (ClassNotLoadedException | IncompatibleThreadStateException | InvalidTypeException  ex) {
                 proc.debug(DBG_GEN, "Exception on remote stop: %s\n", ex);
             } finally {
                 vm.resume();
             }
         }
     }
 }
	/*
	* Copyright (c) 2014, 2015, 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;

	import static jdk.internal.jshell.remote.RemoteCodes.*;
	import java.io.IOException;
	import java.io.ObjectInputStream;
	import java.io.ObjectOutputStream;
	import java.net.ServerSocket;
	import java.net.Socket;
	import com.sun.jdi.*;
	import java.io.EOFException;
	import java.util.List;
	import java.util.Map;
	import jdk.jshell.ClassTracker.ClassInfo;
	import static jdk.internal.jshell.debug.InternalDebugControl.DBG_GEN;

	/**
	* Controls the remote execution environment.
	*
	* @author Robert Field
	*/
	class ExecutionControl {

	private final JDIEnv env;
	private final SnippetMaps maps;
	private JDIEventHandler handler;
	private Socket socket;
	private ObjectInputStream in;
	private ObjectOutputStream out;
	private final JShell proc;

	ExecutionControl(JDIEnv env, SnippetMaps maps, JShell proc) {
	this.env = env;
	this.maps = maps;
	this.proc = proc;
	}

	void launch() throws IOException {
	try (ServerSocket listener = new ServerSocket(0)) {
	// timeout after 60 seconds
	listener.setSoTimeout(60000);
	int port = listener.getLocalPort();
	jdiGo(port);
	socket = listener.accept();
	// out before in -- match remote creation so we don't hang
	out = new ObjectOutputStream(socket.getOutputStream());
	in = new ObjectInputStream(socket.getInputStream());
	}
	}

	void commandExit() {
	try {
	if (out != null) {
	out.writeInt(CMD_EXIT);
	out.flush();
	}
	JDIConnection c = env.connection();
	if (c != null) {
	c.disposeVM();
	}
	} catch (IOException ex) {
	proc.debug(DBG_GEN, "Exception on JDI exit: %s\n", ex);
	}
	}


	boolean commandLoad(List<ClassInfo> cil) {
	try {
	out.writeInt(CMD_LOAD);
	out.writeInt(cil.size());
	for (ClassInfo ci : cil) {
	out.writeUTF(ci.getClassName());
	out.writeObject(ci.getBytes());
	}
	out.flush();
	return readAndReportResult();
	} catch (IOException ex) {
	proc.debug(DBG_GEN, "IOException on remote load operation: %s\n", ex);
	return false;
	}
	}

	String commandInvoke(String classname) throws EvalException, UnresolvedReferenceException {
	try {
	synchronized (STOP_LOCK) {
	userCodeRunning = true;
	}
	out.writeInt(CMD_INVOKE);
	out.writeUTF(classname);
	out.flush();
	if (readAndReportExecutionResult()) {
	String result = in.readUTF();
	return result;
	}
	} catch (EOFException ex) {
	env.shutdown();
	} catch (IOException \| ClassNotFoundException ex) {
	proc.debug(DBG_GEN, "Exception on remote invoke: %s\n", ex);
	return "Execution failure: " + ex.getMessage();
	} finally {
	synchronized (STOP_LOCK) {
	userCodeRunning = false;
	}
	}
	return "";
	}

	String commandVarValue(String classname, String varname) {
	try {
	out.writeInt(CMD_VARVALUE);
	out.writeUTF(classname);
	out.writeUTF(varname);
	out.flush();
	if (readAndReportResult()) {
	String result = in.readUTF();
	return result;
	}
	} catch (EOFException ex) {
	env.shutdown();
	} catch (IOException ex) {
	proc.debug(DBG_GEN, "Exception on remote var value: %s\n", ex);
	return "Execution failure: " + ex.getMessage();
	}
	return "";
	}

	boolean commandAddToClasspath(String cp) {
	try {
	out.writeInt(CMD_CLASSPATH);
	out.writeUTF(cp);
	out.flush();
	return readAndReportResult();
	} catch (IOException ex) {
	throw new InternalError("Classpath addition failed: " + cp, ex);
	}
	}

	boolean commandRedefine(Map<ReferenceType, byte[]> mp) {
	try {
	env.vm().redefineClasses(mp);
	return true;
	} catch (UnsupportedOperationException ex) {
	return false;
	} catch (Exception ex) {
	proc.debug(DBG_GEN, "Exception on JDI redefine: %s\n", ex);
	return false;
	}
	}

	ReferenceType nameToRef(String name) {
	List<ReferenceType> rtl = env.vm().classesByName(name);
	if (rtl.size() != 1) {
	return null;
	}
	return rtl.get(0);
	}

	private boolean readAndReportResult() throws IOException {
	int ok = in.readInt();
	switch (ok) {
	case RESULT_SUCCESS:
	return true;
	case RESULT_FAIL: {
	String ex = in.readUTF();
	proc.debug(DBG_GEN, "Exception on remote operation: %s\n", ex);
	return false;
	}
	default: {
	proc.debug(DBG_GEN, "Bad remote result code: %s\n", ok);
	return false;
	}
	}
	}

	private boolean readAndReportExecutionResult() throws IOException, ClassNotFoundException, EvalException, UnresolvedReferenceException {
	int ok = in.readInt();
	switch (ok) {
	case RESULT_SUCCESS:
	return true;
	case RESULT_FAIL: {
	String ex = in.readUTF();
	proc.debug(DBG_GEN, "Exception on remote operation: %s\n", ex);
	return false;
	}
	case RESULT_EXCEPTION: {
	String exceptionClassName = in.readUTF();
	String message = in.readUTF();
	StackTraceElement[] elems = readStackTrace();
	EvalException ee = new EvalException(message, exceptionClassName, elems);
	throw ee;
	}
	case RESULT_CORRALLED: {
	int id = in.readInt();
	StackTraceElement[] elems = readStackTrace();
	Snippet si = maps.getSnippet(id);
	throw new UnresolvedReferenceException((MethodSnippet) si, elems);
	}
	case RESULT_KILLED: {
	proc.out.println("Killed.");
	return false;
	}
	default: {
	proc.debug(DBG_GEN, "Bad remote result code: %s\n", ok);
	return false;
	}
	}
	}

	private StackTraceElement[] readStackTrace() throws IOException {
	int elemCount = in.readInt();
	StackTraceElement[] elems = new StackTraceElement[elemCount];
	for (int i = 0; i < elemCount; ++i) {
	String className = in.readUTF();
	String methodName = in.readUTF();
	String fileName = in.readUTF();
	int line = in.readInt();
	elems[i] = new StackTraceElement(className, methodName, fileName, line);
	}
	return elems;
	}

	private void jdiGo(int port) {
	//MessageOutput.textResources = ResourceBundle.getBundle("impl.TTYResources",
	// Locale.getDefault());

	String connect = "com.sun.jdi.CommandLineLaunch:";
	String cmdLine = "jdk.internal.jshell.remote.RemoteAgent";
	String classPath = System.getProperty("java.class.path");
	String bootclassPath = System.getProperty("sun.boot.class.path");
	String javaArgs = "-classpath " + classPath + " -Xbootclasspath:" + bootclassPath;

	String connectSpec = connect + "main=" + cmdLine + " " + port + ",options=" + javaArgs + ",";
	boolean launchImmediately = true;
	int traceFlags = 0;// VirtualMachine.TRACE_SENDS \| VirtualMachine.TRACE_EVENTS;

	env.init(connectSpec, launchImmediately, traceFlags);

	if (env.connection().isOpen() && env.vm().canBeModified()) {
	/*
	* Connection opened on startup. Start event handler
	* immediately, telling it (through arg 2) to stop on the
	* VM start event.
	*/
	handler = new JDIEventHandler(env);
	}
	}

	private final Object STOP_LOCK = new Object();
	private boolean userCodeRunning = false;

	void commandStop() {
	synchronized (STOP_LOCK) {
	if (!userCodeRunning)
	return ;

	VirtualMachine vm = handler.env.vm();
	vm.suspend();
	try {
	OUTER: for (ThreadReference thread : vm.allThreads()) {
	// could also tag the thread (e.g. using name), to find it easier
	for (StackFrame frame : thread.frames()) {
	String remoteAgentName = "jdk.internal.jshell.remote.RemoteAgent";
	if (remoteAgentName.equals(frame.location().declaringType().name()) &&
	"commandLoop".equals(frame.location().method().name())) {
	ObjectReference thiz = frame.thisObject();
	if (((BooleanValue) thiz.getValue(thiz.referenceType().fieldByName("inClientCode"))).value()) {
	thiz.setValue(thiz.referenceType().fieldByName("expectingStop"), vm.mirrorOf(true));
	ObjectReference stopInstance = (ObjectReference) thiz.getValue(thiz.referenceType().fieldByName("stopException"));

	vm.resume();
	proc.debug(DBG_GEN, "Attempting to stop the client code...\n");
	thread.stop(stopInstance);
	thiz.setValue(thiz.referenceType().fieldByName("expectingStop"), vm.mirrorOf(false));
	}

	break OUTER;
	}
	}
	}
	} catch (ClassNotLoadedException \| IncompatibleThreadStateException \| InvalidTypeException ex) {
	proc.debug(DBG_GEN, "Exception on remote stop: %s\n", ex);
	} finally {
	vm.resume();
	}
	}
	}
	}