1/*
2 * Copyright (c) 2016, 2017, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.  Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25package jdk.jshell.execution;
26
27import java.io.File;
28import java.io.IOException;
29import java.nio.charset.StandardCharsets;
30import java.nio.file.Files;
31import java.util.ArrayList;
32import java.util.HashMap;
33import java.util.List;
34import java.util.Map;
35import java.util.Map.Entry;
36import com.sun.jdi.Bootstrap;
37import com.sun.jdi.VirtualMachine;
38import com.sun.jdi.connect.Connector;
39import com.sun.jdi.connect.LaunchingConnector;
40import com.sun.jdi.connect.ListeningConnector;
41import java.util.concurrent.Callable;
42import java.util.concurrent.ExecutorService;
43import java.util.concurrent.Executors;
44import java.util.concurrent.Future;
45import java.util.concurrent.TimeUnit;
46import java.util.concurrent.TimeoutException;
47import com.sun.jdi.connect.IllegalConnectorArgumentsException;
48
49/**
50 * Sets up a JDI connection, providing the resulting JDI {@link VirtualMachine}
51 * and the {@link Process} the remote agent is running in.
52 *
53 * @since 9
54 */
55public class JdiInitiator {
56
57    // factor for the timeout on all of connect
58    private static final double CONNECT_TIMEOUT_FACTOR = 1.5;
59
60    // Over-all connect time-out
61    private final int connectTimeout;
62
63    private VirtualMachine vm;
64    private Process process = null;
65    private final Connector connector;
66    private final String remoteAgent;
67    private final Map<String, com.sun.jdi.connect.Connector.Argument> connectorArgs;
68
69    /**
70     * Start the remote agent and establish a JDI connection to it.
71     *
72     * @param port the socket port for (non-JDI) commands
73     * @param remoteVMOptions any user requested VM command-line options
74     * @param remoteAgent full class name of remote agent to launch
75     * @param isLaunch does JDI do the launch? That is, LaunchingConnector,
76     * otherwise we start explicitly and use ListeningConnector
77     * @param host explicit hostname to use, if null use discovered
78     * hostname, applies to listening only (!isLaunch)
79     * @param timeout the start-up time-out in milliseconds. If zero or negative,
80     * will not wait thus will timeout immediately if not already started.
81     * @param customConnectorArgs custom arguments passed to the connector.
82     * These are JDI com.sun.jdi.connect.Connector arguments.
83     */
84    public JdiInitiator(int port, List<String> remoteVMOptions, String remoteAgent,
85            boolean isLaunch, String host, int timeout,
86            Map<String, String> customConnectorArgs) {
87        this.remoteAgent = remoteAgent;
88        this.connectTimeout = (int) (timeout * CONNECT_TIMEOUT_FACTOR);
89        String connectorName
90                = isLaunch
91                        ? "com.sun.jdi.CommandLineLaunch"
92                        : "com.sun.jdi.SocketListen";
93        this.connector = findConnector(connectorName);
94        if (connector == null) {
95            throw new IllegalArgumentException("No connector named: " + connectorName);
96        }
97        Map<String, String> argumentName2Value
98                = isLaunch
99                        ? launchArgs(port, String.join(" ", remoteVMOptions))
100                        : new HashMap<>();
101        if (!isLaunch) {
102            argumentName2Value.put("timeout", ""+timeout);
103            if (host != null && !isLaunch) {
104                argumentName2Value.put("localAddress", host);
105            }
106        }
107        argumentName2Value.putAll(customConnectorArgs);
108        this.connectorArgs = mergeConnectorArgs(connector, argumentName2Value);
109        this.vm = isLaunch
110                ? launchTarget()
111                : listenTarget(port, remoteVMOptions);
112
113    }
114
115    /**
116     * Returns the resulting {@code VirtualMachine} instance.
117     *
118     * @return the virtual machine
119     */
120    public VirtualMachine vm() {
121        return vm;
122    }
123
124    /**
125     * Returns the launched process.
126     *
127     * @return the remote agent process
128     */
129    public Process process() {
130        return process;
131    }
132
133    /* launch child target vm */
134    private VirtualMachine launchTarget() {
135        LaunchingConnector launcher = (LaunchingConnector) connector;
136        try {
137            VirtualMachine new_vm = timedVirtualMachineCreation(() -> launcher.launch(connectorArgs), null);
138            process = new_vm.process();
139            return new_vm;
140        } catch (Throwable ex) {
141            throw reportLaunchFail(ex, "launch");
142        }
143    }
144
145    /**
146     * Directly launch the remote agent and connect JDI to it with a
147     * ListeningConnector.
148     */
149    private VirtualMachine listenTarget(int port, List<String> remoteVMOptions) {
150        ListeningConnector listener = (ListeningConnector) connector;
151        // Files to collection to output of a start-up failure
152        File crashErrorFile = createTempFile("error");
153        File crashOutputFile = createTempFile("output");
154        try {
155            // Start listening, get the JDI connection address
156            String addr = listener.startListening(connectorArgs);
157            debug("Listening at address: " + addr);
158
159            // Launch the RemoteAgent requesting a connection on that address
160            String javaHome = System.getProperty("java.home");
161            List<String> args = new ArrayList<>();
162            args.add(javaHome == null
163                    ? "java"
164                    : javaHome + File.separator + "bin" + File.separator + "java");
165            args.add("-agentlib:jdwp=transport=" + connector.transport().name() +
166                    ",address=" + addr);
167            args.addAll(remoteVMOptions);
168            args.add(remoteAgent);
169            args.add("" + port);
170            ProcessBuilder pb = new ProcessBuilder(args);
171            pb.redirectError(crashErrorFile);
172            pb.redirectOutput(crashOutputFile);
173            process = pb.start();
174
175            // Accept the connection from the remote agent
176            vm = timedVirtualMachineCreation(() -> listener.accept(connectorArgs),
177                    () -> process.waitFor());
178            try {
179                listener.stopListening(connectorArgs);
180            } catch (IOException | IllegalConnectorArgumentsException ex) {
181                // ignore
182            }
183            crashErrorFile.delete();
184            crashOutputFile.delete();
185            return vm;
186        } catch (Throwable ex) {
187            if (process != null) {
188                process.destroyForcibly();
189            }
190            try {
191                listener.stopListening(connectorArgs);
192            } catch (IOException | IllegalConnectorArgumentsException iex) {
193                // ignore
194            }
195            String text = readFile(crashErrorFile) + readFile(crashOutputFile);
196            crashErrorFile.delete();
197            crashOutputFile.delete();
198            if (text.isEmpty()) {
199                throw reportLaunchFail(ex, "listen");
200            } else {
201                throw new IllegalArgumentException(text);
202            }
203        }
204    }
205
206    private File createTempFile(String label) {
207        try {
208            File f = File.createTempFile("remote", label);
209            f.deleteOnExit();
210            return f;
211        } catch (IOException ex) {
212            throw new InternalError("Failed create temp ", ex);
213        }
214    }
215
216    private String readFile(File f) {
217        try {
218            return new String(Files.readAllBytes(f.toPath()),
219                    StandardCharsets.UTF_8);
220        } catch (IOException ex) {
221            return "error reading " + f + " : " + ex.toString();
222        }
223    }
224
225    VirtualMachine timedVirtualMachineCreation(Callable<VirtualMachine> creator,
226            Callable<Integer> processComplete) throws Exception {
227        VirtualMachine result;
228        ExecutorService executor = Executors.newCachedThreadPool(runnable -> {
229            Thread thread = Executors.defaultThreadFactory().newThread(runnable);
230            thread.setDaemon(true);
231            return thread;
232        });
233        try {
234            Future<VirtualMachine> future = executor.submit(creator);
235            if (processComplete != null) {
236                executor.submit(() -> {
237                    Integer i = processComplete.call();
238                    future.cancel(true);
239                    return i;
240                });
241            }
242
243            try {
244                result = future.get(connectTimeout, TimeUnit.MILLISECONDS);
245            } catch (TimeoutException ex) {
246                future.cancel(true);
247                throw ex;
248            }
249        } finally {
250            executor.shutdownNow();
251        }
252        return result;
253    }
254
255    private Connector findConnector(String name) {
256        for (Connector cntor
257                : Bootstrap.virtualMachineManager().allConnectors()) {
258            if (cntor.name().equals(name)) {
259                return cntor;
260            }
261        }
262        return null;
263    }
264
265    private Map<String, Connector.Argument> mergeConnectorArgs(Connector connector, Map<String, String> argumentName2Value) {
266        Map<String, Connector.Argument> arguments = connector.defaultArguments();
267
268        for (Entry<String, String> argumentEntry : argumentName2Value.entrySet()) {
269            String name = argumentEntry.getKey();
270            String value = argumentEntry.getValue();
271            Connector.Argument argument = arguments.get(name);
272
273            if (argument == null) {
274                throw new IllegalArgumentException("Argument is not defined for connector:" +
275                        name + " -- " + connector.name());
276            }
277
278            argument.setValue(value);
279        }
280
281        return arguments;
282    }
283
284    /**
285     * The JShell specific Connector args for the LaunchingConnector.
286     *
287     * @param portthe socket port for (non-JDI) commands
288     * @param remoteVMOptions any user requested VM options
289     * @return the argument map
290     */
291    private Map<String, String> launchArgs(int port, String remoteVMOptions) {
292        Map<String, String> argumentName2Value = new HashMap<>();
293        argumentName2Value.put("main", remoteAgent + " " + port);
294        argumentName2Value.put("options", remoteVMOptions);
295        return argumentName2Value;
296    }
297
298    private InternalError reportLaunchFail(Throwable ex, String context) {
299        return new InternalError("Failed remote " + context + ": "
300                + ex.toString()
301                + " @ " + connector +
302                " -- " + connectorArgs, ex);
303    }
304
305    /**
306     * Log debugging information. Arguments as for {@code printf}.
307     *
308     * @param format a format string as described in Format string syntax
309     * @param args arguments referenced by the format specifiers in the format
310     * string.
311     */
312    private void debug(String format, Object... args) {
313        // Reserved for future logging
314    }
315
316    /**
317     * Log a serious unexpected internal exception.
318     *
319     * @param ex the exception
320     * @param where a description of the context of the exception
321     */
322    private void debug(Throwable ex, String where) {
323        // Reserved for future logging
324    }
325
326}
327