langtools/src/jdk.jshell/share/classes/jdk/jshell/execution/JdiInitiator.java
changeset 41941 a935ac3f5274
parent 40764 29ded021f809
child 42272 82e273c4f2b3
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/src/jdk.jshell/share/classes/jdk/jshell/execution/JdiInitiator.java	Sun Nov 06 22:50:46 2016 -0800
@@ -0,0 +1,223 @@
+/*
+ * 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.File;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
+import com.sun.jdi.Bootstrap;
+import com.sun.jdi.VirtualMachine;
+import com.sun.jdi.connect.Connector;
+import com.sun.jdi.connect.LaunchingConnector;
+import com.sun.jdi.connect.ListeningConnector;
+
+/**
+ * Sets up a JDI connection, providing the resulting JDI {@link VirtualMachine}
+ * and the {@link Process} the remote agent is running in.
+ */
+public class JdiInitiator {
+
+    private VirtualMachine vm;
+    private Process process = null;
+    private final Connector connector;
+    private final String remoteAgent;
+    private final Map<String, com.sun.jdi.connect.Connector.Argument> connectorArgs;
+
+    /**
+     * Start the remote agent and establish a JDI connection to it.
+     *
+     * @param port the socket port for (non-JDI) commands
+     * @param remoteVMOptions any user requested VM options
+     * @param remoteAgent full class name of remote agent to launch
+     * @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)
+     */
+    public JdiInitiator(int port, List<String> remoteVMOptions, String remoteAgent,
+            boolean isLaunch, String host) {
+        this.remoteAgent = remoteAgent;
+        String connectorName
+                = isLaunch
+                        ? "com.sun.jdi.CommandLineLaunch"
+                        : "com.sun.jdi.SocketListen";
+        this.connector = findConnector(connectorName);
+        if (connector == null) {
+            throw new IllegalArgumentException("No connector named: " + connectorName);
+        }
+        Map<String, String> argumentName2Value
+                = isLaunch
+                        ? launchArgs(port, String.join(" ", remoteVMOptions))
+                        : new HashMap<>();
+        if (host != null && !isLaunch) {
+            argumentName2Value.put("localAddress", host);
+        }
+        this.connectorArgs = mergeConnectorArgs(connector, argumentName2Value);
+        this.vm = isLaunch
+                ? launchTarget()
+                : listenTarget(port, remoteVMOptions);
+
+    }
+
+    /**
+     * Returns the resulting {@code VirtualMachine} instance.
+     *
+     * @return the virtual machine
+     */
+    public VirtualMachine vm() {
+        return vm;
+    }
+
+    /**
+     * Returns the launched process.
+     *
+     * @return the remote agent process
+     */
+    public Process process() {
+        return process;
+    }
+
+    /* launch child target vm */
+    private VirtualMachine launchTarget() {
+        LaunchingConnector launcher = (LaunchingConnector) connector;
+        try {
+            VirtualMachine new_vm = launcher.launch(connectorArgs);
+            process = new_vm.process();
+            return new_vm;
+        } catch (Exception ex) {
+            reportLaunchFail(ex, "launch");
+        }
+        return null;
+    }
+
+    /**
+     * Directly launch the remote agent and connect JDI to it with a
+     * ListeningConnector.
+     */
+    private VirtualMachine listenTarget(int port, List<String> remoteVMOptions) {
+        ListeningConnector listener = (ListeningConnector) connector;
+        try {
+            // Start listening, get the JDI connection address
+            String addr = listener.startListening(connectorArgs);
+            debug("Listening at address: " + addr);
+
+            // Launch the RemoteAgent requesting a connection on that address
+            String javaHome = System.getProperty("java.home");
+            List<String> args = new ArrayList<>();
+            args.add(javaHome == null
+                    ? "java"
+                    : javaHome + File.separator + "bin" + File.separator + "java");
+            args.add("-agentlib:jdwp=transport=" + connector.transport().name() +
+                    ",address=" + addr);
+            args.addAll(remoteVMOptions);
+            args.add(remoteAgent);
+            args.add("" + port);
+            ProcessBuilder pb = new ProcessBuilder(args);
+            process = pb.start();
+
+            // Forward out, err, and in
+            // Accept the connection from the remote agent
+            vm = listener.accept(connectorArgs);
+            listener.stopListening(connectorArgs);
+            return vm;
+        } catch (Exception ex) {
+            reportLaunchFail(ex, "listen");
+        }
+        return null;
+    }
+
+    private Connector findConnector(String name) {
+        for (Connector cntor
+                : Bootstrap.virtualMachineManager().allConnectors()) {
+            if (cntor.name().equals(name)) {
+                return cntor;
+            }
+        }
+        return null;
+    }
+
+    private Map<String, Connector.Argument> mergeConnectorArgs(Connector connector, Map<String, String> argumentName2Value) {
+        Map<String, Connector.Argument> arguments = connector.defaultArguments();
+
+        for (Entry<String, String> argumentEntry : argumentName2Value.entrySet()) {
+            String name = argumentEntry.getKey();
+            String value = argumentEntry.getValue();
+            Connector.Argument argument = arguments.get(name);
+
+            if (argument == null) {
+                throw new IllegalArgumentException("Argument is not defined for connector:" +
+                        name + " -- " + connector.name());
+            }
+
+            argument.setValue(value);
+        }
+
+        return arguments;
+    }
+
+    /**
+     * The JShell specific Connector args for the LaunchingConnector.
+     *
+     * @param portthe socket port for (non-JDI) commands
+     * @param remoteVMOptions any user requested VM options
+     * @return the argument map
+     */
+    private Map<String, String> launchArgs(int port, String remoteVMOptions) {
+        Map<String, String> argumentName2Value = new HashMap<>();
+        argumentName2Value.put("main", remoteAgent + " " + port);
+        argumentName2Value.put("options", remoteVMOptions);
+        return argumentName2Value;
+    }
+
+    private void reportLaunchFail(Exception ex, String context) {
+        throw new InternalError("Failed remote " + context + ": " + connector +
+                " -- " + connectorArgs, ex);
+    }
+
+    /**
+     * 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 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 void debug(Throwable ex, String where) {
+        // Reserved for future logging
+    }
+
+}