src/jdk.jshell/share/classes/jdk/jshell/execution/RemoteExecutionControl.java
changeset 47216 71c04702a3d5
parent 45044 7c50549b7744
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.jshell/share/classes/jdk/jshell/execution/RemoteExecutionControl.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,172 @@
+/*
+ * Copyright (c) 2014, 2017, 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.InputStream;
+import java.io.OutputStream;
+import java.io.PrintStream;
+import java.lang.reflect.Method;
+import java.net.Socket;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.function.Consumer;
+import jdk.jshell.spi.ExecutionControl;
+import static jdk.jshell.execution.Util.forwardExecutionControlAndIO;
+
+/**
+ * The remote agent runs in the execution process (separate from the main JShell
+ * process). This agent loads code over a socket from the main JShell process,
+ * executes the code, and other misc, Specialization of
+ * {@link DirectExecutionControl} which adds stop support controlled by
+ * an external process. Designed to work with {@link JdiDefaultExecutionControl}.
+ *
+ * @author Jan Lahoda
+ * @author Robert Field
+ * @since 9
+ */
+public class RemoteExecutionControl extends DirectExecutionControl implements ExecutionControl {
+
+    /**
+     * Launch the agent, connecting to the JShell-core over the socket specified
+     * in the command-line argument.
+     *
+     * @param args standard command-line arguments, expectation is the socket
+     * number is the only argument
+     * @throws Exception any unexpected exception
+     */
+    public static void main(String[] args) throws Exception {
+        String loopBack = null;
+        Socket socket = new Socket(loopBack, Integer.parseInt(args[0]));
+        InputStream inStream = socket.getInputStream();
+        OutputStream outStream = socket.getOutputStream();
+        Map<String, Consumer<OutputStream>> outputs = new HashMap<>();
+        outputs.put("out", st -> System.setOut(new PrintStream(st, true)));
+        outputs.put("err", st -> System.setErr(new PrintStream(st, true)));
+        Map<String, Consumer<InputStream>> input = new HashMap<>();
+        input.put("in", System::setIn);
+        forwardExecutionControlAndIO(new RemoteExecutionControl(), inStream, outStream, outputs, input);
+    }
+
+    // These three variables are used by the main JShell process in interrupting
+    // the running process.  Access is via JDI, so the reference is not visible
+    // to code inspection.
+    private boolean inClientCode; // Queried by the main process (in superclass)
+    private boolean expectingStop; // Set by the main process
+// Set by the main process
+
+    // thrown by the main process via JDI:
+    private final StopExecutionException stopException = new StopExecutionException();
+
+    /**
+     * Creates an instance, delegating loader operations to the specified
+     * delegate.
+     *
+     * @param loaderDelegate the delegate to handle loading classes
+     */
+    public RemoteExecutionControl(LoaderDelegate loaderDelegate) {
+        super(loaderDelegate);
+    }
+
+    /**
+     * Create an instance using the default class loading.
+     */
+    public RemoteExecutionControl() {
+    }
+
+    /**
+     * Redefine processing on the remote end is only to register the redefined classes
+     */
+    @Override
+    public void redefine(ClassBytecodes[] cbcs)
+            throws ClassInstallException, NotImplementedException, EngineTerminationException {
+        classesRedefined(cbcs);
+    }
+
+    @Override
+    public void stop() throws EngineTerminationException, InternalException {
+        // handled by JDI
+    }
+
+    // Overridden only so this stack frame is seen
+    @Override
+    protected String invoke(Method doitMethod) throws Exception {
+        return super.invoke(doitMethod);
+    }
+
+    // Overridden only so this stack frame is seen
+    @Override
+    public String varValue(String className, String varName) throws RunException, EngineTerminationException, InternalException {
+        return super.varValue(className, varName);
+    }
+
+    @Override
+    protected String throwConvertedInvocationException(Throwable cause) throws RunException, InternalException {
+        if (cause instanceof StopExecutionException) {
+            expectingStop = false;
+            throw new StoppedException();
+        } else {
+            return super.throwConvertedInvocationException(cause);
+        }
+    }
+
+    @Override
+    protected String throwConvertedOtherException(Throwable ex) throws RunException, InternalException {
+        if (ex instanceof StopExecutionException ||
+                 ex.getCause() instanceof StopExecutionException) {
+            expectingStop = false;
+            throw new StoppedException();
+        }
+        return super.throwConvertedOtherException(ex);
+    }
+
+    @Override
+    protected void clientCodeEnter() {
+        expectingStop = false;
+        inClientCode = true;
+    }
+
+    @Override
+    protected void clientCodeLeave() throws InternalException {
+        inClientCode = false;
+        while (expectingStop) {
+            try {
+                Thread.sleep(0);
+            } catch (InterruptedException ex) {
+                throw new InternalException("*** Sleep interrupted while waiting for stop exception: " + ex);
+            }
+        }
+    }
+
+    @SuppressWarnings("serial")             // serialVersionUID intentionally omitted
+    private class StopExecutionException extends ThreadDeath {
+
+        @Override
+        public synchronized Throwable fillInStackTrace() {
+            return this;
+        }
+    }
+
+}