--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/src/jdk.jshell/share/classes/jdk/jshell/execution/JdiDefaultExecutionControl.java Sun Nov 06 22:50:46 2016 -0800
@@ -0,0 +1,282 @@
+/*
+ * 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 java.io.IOException;
+import java.io.InputStream;
+import java.io.ObjectInput;
+import java.io.ObjectOutput;
+import java.io.OutputStream;
+import java.net.ServerSocket;
+import java.net.Socket;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.function.Consumer;
+import com.sun.jdi.BooleanValue;
+import com.sun.jdi.ClassNotLoadedException;
+import com.sun.jdi.Field;
+import com.sun.jdi.IncompatibleThreadStateException;
+import com.sun.jdi.InvalidTypeException;
+import com.sun.jdi.ObjectReference;
+import com.sun.jdi.StackFrame;
+import com.sun.jdi.ThreadReference;
+import com.sun.jdi.VMDisconnectedException;
+import com.sun.jdi.VirtualMachine;
+import jdk.jshell.spi.ExecutionControl;
+import jdk.jshell.spi.ExecutionEnv;
+import static jdk.jshell.execution.Util.remoteInputOutput;
+
+/**
+ * The implementation of {@link jdk.jshell.spi.ExecutionControl} that the
+ * JShell-core uses by default.
+ * Launches a remote process -- the "remote agent".
+ * Interfaces to the remote agent over a socket and via JDI.
+ * Designed to work with {@link RemoteExecutionControl}.
+ *
+ * @author Robert Field
+ * @author Jan Lahoda
+ */
+public class JdiDefaultExecutionControl extends JdiExecutionControl {
+
+ private static final String REMOTE_AGENT = RemoteExecutionControl.class.getName();
+
+ private VirtualMachine vm;
+ private Process process;
+
+ private final Object STOP_LOCK = new Object();
+ private boolean userCodeRunning = false;
+
+ /**
+ * Creates an ExecutionControl instance based on a JDI
+ * {@code LaunchingConnector}.
+ *
+ * @return the generator
+ */
+ public static ExecutionControl.Generator launch() {
+ return env -> create(env, true, null);
+ }
+
+ /**
+ * Creates an ExecutionControl instance based on a JDI
+ * {@code ListeningConnector}.
+ *
+ * @param host explicit hostname to use, if null use discovered
+ * hostname, applies to listening only (!isLaunch)
+ * @return the generator
+ */
+ public static ExecutionControl.Generator listen(String host) {
+ return env -> create(env, false, host);
+ }
+
+ /**
+ * Creates an ExecutionControl instance based on a JDI
+ * {@code ListeningConnector} or {@code LaunchingConnector}.
+ *
+ * Initialize JDI and use it to launch the remote JVM. Set-up a socket for
+ * commands and results. This socket also transports the user
+ * input/output/error.
+ *
+ * @param env the context passed by
+ * {@link jdk.jshell.spi.ExecutionControl#start(jdk.jshell.spi.ExecutionEnv) }
+ * @param isLaunch does JDI do the launch? That is, LaunchingConnector,
+ * otherwise we start explicitly and use ListeningConnector
+ * @param host explicit hostname to use, if null use discovered
+ * hostname, applies to listening only (!isLaunch)
+ * @return the channel
+ * @throws IOException if there are errors in set-up
+ */
+ private static ExecutionControl create(ExecutionEnv env,
+ boolean isLaunch, String host) throws IOException {
+ try (final ServerSocket listener = new ServerSocket(0)) {
+ // timeout after 60 seconds
+ listener.setSoTimeout(60000);
+ int port = listener.getLocalPort();
+
+ // Set-up the JDI connection
+ JdiInitiator jdii = new JdiInitiator(port,
+ env.extraRemoteVMOptions(), REMOTE_AGENT, isLaunch, host);
+ VirtualMachine vm = jdii.vm();
+ Process process = jdii.process();
+
+ List<Consumer<String>> deathListeners = new ArrayList<>();
+ deathListeners.add(s -> env.closeDown());
+ Util.detectJdiExitEvent(vm, s -> {
+ for (Consumer<String> h : deathListeners) {
+ h.accept(s);
+ }
+ });
+
+ // Set-up the commands/reslts on the socket. Piggy-back snippet
+ // output.
+ Socket socket = listener.accept();
+ // out before in -- match remote creation so we don't hang
+ OutputStream out = socket.getOutputStream();
+ Map<String, OutputStream> outputs = new HashMap<>();
+ outputs.put("out", env.userOut());
+ outputs.put("err", env.userErr());
+ Map<String, InputStream> input = new HashMap<>();
+ input.put("in", env.userIn());
+ return remoteInputOutput(socket.getInputStream(), out, outputs, input, (objIn, objOut) -> new JdiDefaultExecutionControl(objOut, objIn, vm, process, deathListeners));
+ }
+ }
+
+ /**
+ * Create an instance.
+ *
+ * @param cmdout the output for commands
+ * @param cmdin the input for responses
+ */
+ private JdiDefaultExecutionControl(ObjectOutput cmdout, ObjectInput cmdin,
+ VirtualMachine vm, Process process, List<Consumer<String>> deathListeners) {
+ super(cmdout, cmdin);
+ this.vm = vm;
+ this.process = process;
+ deathListeners.add(s -> disposeVM());
+ }
+
+ @Override
+ public String invoke(String classname, String methodname)
+ throws RunException,
+ EngineTerminationException, InternalException {
+ String res;
+ synchronized (STOP_LOCK) {
+ userCodeRunning = true;
+ }
+ try {
+ res = super.invoke(classname, methodname);
+ } finally {
+ synchronized (STOP_LOCK) {
+ userCodeRunning = false;
+ }
+ }
+ return res;
+ }
+
+ /**
+ * Interrupts a running remote invoke by manipulating remote variables
+ * and sending a stop via JDI.
+ *
+ * @throws EngineTerminationException the execution engine has terminated
+ * @throws InternalException an internal problem occurred
+ */
+ @Override
+ public void stop() throws EngineTerminationException, InternalException {
+ synchronized (STOP_LOCK) {
+ if (!userCodeRunning) {
+ return;
+ }
+
+ 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()) {
+ if (REMOTE_AGENT.equals(frame.location().declaringType().name()) &&
+ ( "invoke".equals(frame.location().method().name())
+ || "varValue".equals(frame.location().method().name()))) {
+ ObjectReference thiz = frame.thisObject();
+ Field inClientCode = thiz.referenceType().fieldByName("inClientCode");
+ Field expectingStop = thiz.referenceType().fieldByName("expectingStop");
+ Field stopException = thiz.referenceType().fieldByName("stopException");
+ if (((BooleanValue) thiz.getValue(inClientCode)).value()) {
+ thiz.setValue(expectingStop, vm().mirrorOf(true));
+ ObjectReference stopInstance = (ObjectReference) thiz.getValue(stopException);
+
+ vm().resume();
+ debug("Attempting to stop the client code...\n");
+ thread.stop(stopInstance);
+ thiz.setValue(expectingStop, vm().mirrorOf(false));
+ }
+
+ break OUTER;
+ }
+ }
+ }
+ } catch (ClassNotLoadedException | IncompatibleThreadStateException | InvalidTypeException ex) {
+ throw new InternalException("Exception on remote stop: " + ex);
+ } finally {
+ vm().resume();
+ }
+ }
+ }
+
+ @Override
+ public void close() {
+ super.close();
+ disposeVM();
+ }
+
+ private synchronized void disposeVM() {
+ try {
+ if (vm != null) {
+ vm.dispose(); // This could NPE, so it is caught below
+ vm = null;
+ }
+ } catch (VMDisconnectedException ex) {
+ // Ignore if already closed
+ } catch (Throwable ex) {
+ debug(ex, "disposeVM");
+ } finally {
+ if (process != null) {
+ process.destroy();
+ process = null;
+ }
+ }
+ }
+
+ @Override
+ protected synchronized VirtualMachine vm() throws EngineTerminationException {
+ if (vm == null) {
+ throw new EngineTerminationException("VM closed");
+ } else {
+ return vm;
+ }
+ }
+
+ /**
+ * Log debugging information. Arguments as for {@code printf}.
+ *
+ * @param format a format string as described in Format string syntax
+ * @param args arguments referenced by the format specifiers in the format
+ * string.
+ */
+ private static void debug(String format, Object... args) {
+ // Reserved for future logging
+ }
+
+ /**
+ * 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
+ }
+
+}