| /* |
| * 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. |
| * |
| * 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. |
| */ |
| |
| import com.sun.management.OperatingSystemMXBean; |
| import java.io.File; |
| import java.io.InputStream; |
| import java.io.OutputStream; |
| import java.io.InputStreamReader; |
| import java.io.BufferedReader; |
| import java.io.IOException; |
| import java.io.Reader; |
| import java.io.PrintWriter; |
| import java.lang.InterruptedException; |
| import java.lang.Override; |
| import java.lang.management.ManagementFactory; |
| import java.time.Instant; |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.Collections; |
| import java.util.concurrent.CompletableFuture; |
| import java.util.concurrent.ExecutionException; |
| import java.util.HashSet; |
| import java.util.List; |
| import java.util.Set; |
| import java.util.Optional; |
| import java.util.function.Consumer; |
| |
| |
| /** |
| * Command driven subprocess with useful child functions. |
| */ |
| public class JavaChild extends Process { |
| |
| private static volatile int commandSeq = 0; // Command sequence number |
| private static final ProcessHandle self = ProcessHandle.current(); |
| private static int finalStatus = 0; |
| private static final List<JavaChild> children = new ArrayList<>(); |
| private static final Set<JavaChild> completedChildren = |
| Collections.synchronizedSet(new HashSet<>()); |
| |
| private final Process delegate; |
| private final PrintWriter inputWriter; |
| private final BufferedReader outputReader; |
| |
| |
| /** |
| * Create a JavaChild control instance that delegates to the spawned process. |
| * {@link #sendAction} is used to send commands via the processes stdin. |
| * {@link #forEachOutputLine} can be used to process output from the child |
| * @param delegate the process to delegate and send commands to and get responses from |
| */ |
| private JavaChild(ProcessBuilder pb) throws IOException { |
| allArgs = pb.command(); |
| delegate = pb.start(); |
| // Initialize PrintWriter with autoflush (on println) |
| inputWriter = new PrintWriter(delegate.getOutputStream(), true); |
| outputReader = new BufferedReader(new InputStreamReader(delegate.getInputStream())); |
| } |
| |
| @Override |
| public void destroy() { |
| delegate.destroy(); |
| } |
| |
| @Override |
| public int exitValue() { |
| return delegate.exitValue(); |
| } |
| |
| @Override |
| public int waitFor() throws InterruptedException { |
| return delegate.waitFor(); |
| } |
| |
| @Override |
| public OutputStream getOutputStream() { |
| return delegate.getOutputStream(); |
| } |
| |
| @Override |
| public InputStream getInputStream() { |
| return delegate.getInputStream(); |
| } |
| |
| @Override |
| public InputStream getErrorStream() { |
| return delegate.getErrorStream(); |
| } |
| |
| @Override |
| public ProcessHandle toHandle() { |
| return delegate.toHandle(); |
| } |
| |
| @Override |
| public CompletableFuture<Process> onExit() { |
| return delegate.onExit(); |
| } |
| @Override |
| public String toString() { |
| return "delegate: " + delegate.toString(); |
| } |
| |
| public List<String> getArgs() { |
| return allArgs; |
| } |
| |
| public CompletableFuture<JavaChild> onJavaChildExit() { |
| return onExit().thenApply(ph -> this); |
| } |
| |
| /** |
| * Send an action and arguments to the child via stdin. |
| * @param action the action |
| * @param args additional arguments |
| * @throws IOException if something goes wrong writing to the child |
| */ |
| void sendAction(String action, Object... args) throws IOException { |
| StringBuilder sb = new StringBuilder(); |
| sb.append(action); |
| for (Object arg :args) { |
| sb.append(" "); |
| sb.append(arg); |
| } |
| String cmd = sb.toString(); |
| synchronized (this) { |
| inputWriter.println(cmd); |
| } |
| } |
| |
| public BufferedReader outputReader() { |
| return outputReader; |
| } |
| |
| /** |
| * Asynchronously evaluate each line of output received back from the child process. |
| * @param consumer a Consumer of each line read from the child |
| * @return a CompletableFuture that is completed when the child closes System.out. |
| */ |
| CompletableFuture<String> forEachOutputLine(Consumer<String> consumer) { |
| final CompletableFuture<String> future = new CompletableFuture<>(); |
| String name = "OutputLineReader-" + pid(); |
| Thread t = new Thread(() -> { |
| try (BufferedReader reader = outputReader()) { |
| String line; |
| while ((line = reader.readLine()) != null) { |
| consumer.accept(line); |
| } |
| } catch (IOException | RuntimeException ex) { |
| consumer.accept("IOE (" + pid() + "):" + ex.getMessage()); |
| future.completeExceptionally(ex); |
| } |
| future.complete("success"); |
| }, name); |
| t.start(); |
| return future; |
| } |
| |
| /** |
| * Spawn a JavaChild with the provided arguments. |
| * Commands can be send to the child with {@link #sendAction}. |
| * Output lines from the child can be processed with {@link #forEachOutputLine}. |
| * System.err is set to inherit and is the unstructured async logging |
| * output for all subprocesses. |
| * @param args the command line arguments to JavaChild |
| * @return the JavaChild that was started |
| * @throws IOException thrown by ProcessBuilder.start |
| */ |
| static JavaChild spawnJavaChild(Object... args) throws IOException { |
| String[] stringArgs = new String[args.length]; |
| for (int i = 0; i < args.length; i++) { |
| stringArgs[i] = args[i].toString(); |
| } |
| ProcessBuilder pb = build(stringArgs); |
| pb.redirectError(ProcessBuilder.Redirect.INHERIT); |
| return new JavaChild(pb); |
| } |
| |
| /** |
| * Spawn a JavaChild with the provided arguments. |
| * Sets the process to inherit the I/O channels. |
| * @param args the command line arguments to JavaChild |
| * @return the Process that was started |
| * @throws IOException thrown by ProcessBuilder.start |
| */ |
| static Process spawn(String... args) throws IOException { |
| ProcessBuilder pb = build(args); |
| pb.inheritIO(); |
| return pb.start(); |
| } |
| |
| /** |
| * Return a ProcessBuilder with the javaChildArgs and |
| * any additional supplied args. |
| * |
| * @param args the command line arguments to JavaChild |
| * @return the ProcessBuilder |
| */ |
| static ProcessBuilder build(String ... args) { |
| ProcessBuilder pb = new ProcessBuilder(); |
| List<String> list = new ArrayList<>(javaChildArgs); |
| for (String arg : args) |
| list.add(arg); |
| pb.command(list); |
| return pb; |
| } |
| |
| static final String javaHome = (System.getProperty("test.jdk") != null) |
| ? System.getProperty("test.jdk") |
| : System.getProperty("java.home"); |
| |
| static final String javaExe = |
| javaHome + File.separator + "bin" + File.separator + "java"; |
| |
| static final String classpath = |
| System.getProperty("java.class.path"); |
| |
| static final List<String> javaChildArgs = |
| Arrays.asList(javaExe, |
| "-XX:+DisplayVMOutputToStderr", |
| "-Dtest.jdk=" + javaHome, |
| "-classpath", absolutifyPath(classpath), |
| "JavaChild"); |
| |
| // Will hold the complete list of arguments which was given to Processbuilder.command() |
| private List<String> allArgs; |
| |
| private static String absolutifyPath(String path) { |
| StringBuilder sb = new StringBuilder(); |
| for (String file : path.split(File.pathSeparator)) { |
| if (sb.length() != 0) |
| sb.append(File.pathSeparator); |
| sb.append(new File(file).getAbsolutePath()); |
| } |
| return sb.toString(); |
| } |
| |
| /** |
| * Main program that interprets commands from the command line args or stdin. |
| * Each command produces output to stdout confirming the command and |
| * providing results. |
| * System.err is used for unstructured information. |
| * @param args an array of strings to be interpreted as commands; |
| * each command uses additional arguments as needed |
| */ |
| public static void main(String[] args) { |
| System.out.printf("args: %s %s%n", ProcessHandle.current(), Arrays.toString(args)); |
| interpretCommands(args); |
| System.exit(finalStatus); |
| } |
| |
| /** |
| * Interpret an array of strings as a command line. |
| * @param args an array of strings to be interpreted as commands; |
| * each command uses additional arguments as needed |
| */ |
| private static void interpretCommands(String[] args) { |
| try { |
| int nextArg = 0; |
| while (nextArg < args.length) { |
| String action = args[nextArg++]; |
| switch (action) { |
| case "help": |
| sendResult(action, ""); |
| help(); |
| break; |
| case "sleep": |
| int millis = Integer.valueOf(args[nextArg++]); |
| Thread.sleep(millis); |
| sendResult(action, Integer.toString(millis)); |
| break; |
| case "cpuloop": |
| long cpuMillis = Long.valueOf(args[nextArg++]); |
| long cpuTarget = getCpuTime() + cpuMillis * 1_000_000L; |
| while (getCpuTime() < cpuTarget) { |
| // burn the cpu until the time is up |
| } |
| sendResult(action, cpuMillis); |
| break; |
| case "cputime": |
| sendResult(action, getCpuTime()); |
| break; |
| case "out": |
| case "err": |
| String value = args[nextArg++]; |
| sendResult(action, value); |
| if (action.equals("err")) { |
| System.err.println(value); |
| } |
| break; |
| case "stdin": |
| // Read commands from stdin; at eof, close stdin of |
| // children and wait for each to exit |
| sendResult(action, "start"); |
| try (Reader reader = new InputStreamReader(System.in); |
| BufferedReader input = new BufferedReader(reader)) { |
| String line; |
| while ((line = input.readLine()) != null) { |
| line = line.trim(); |
| if (!line.isEmpty()) { |
| String[] split = line.split("\\s"); |
| interpretCommands(split); |
| } |
| } |
| // EOF on stdin, close stdin on all spawned processes |
| for (JavaChild p : children) { |
| try { |
| p.getOutputStream().close(); |
| } catch (IOException ie) { |
| sendResult("stdin_closing", p.pid(), |
| "exception", ie.getMessage()); |
| } |
| } |
| |
| for (JavaChild p : children) { |
| do { |
| try { |
| p.waitFor(); |
| break; |
| } catch (InterruptedException e) { |
| // retry |
| } |
| } while (true); |
| } |
| // Wait for all children to be gone |
| Instant timeOut = Instant.now().plusSeconds(10L); |
| while (!completedChildren.containsAll(children)) { |
| if (Instant.now().isBefore(timeOut)) { |
| Thread.sleep(100L); |
| } else { |
| System.err.printf("Timeout waiting for " + |
| "children to terminate%n"); |
| children.removeAll(completedChildren); |
| for (JavaChild c : children) { |
| sendResult("stdin_noterm", c.pid()); |
| System.err.printf(" Process not terminated: " + |
| "pid: %d%n", c.pid()); |
| } |
| System.exit(2); |
| } |
| } |
| } |
| sendResult(action, "done"); |
| return; // normal exit from JavaChild Process |
| case "parent": |
| sendResult(action, self.parent().toString()); |
| break; |
| case "pid": |
| sendResult(action, self.toString()); |
| break; |
| case "exit": |
| int exitValue = (nextArg < args.length) |
| ? Integer.valueOf(args[nextArg]) : 0; |
| sendResult(action, exitValue); |
| System.exit(exitValue); |
| break; |
| case "spawn": { |
| if (args.length - nextArg < 2) { |
| throw new RuntimeException("not enough args for respawn: " + |
| (args.length - 2)); |
| } |
| // Spawn as many children as requested and |
| // pass on rest of the arguments |
| int ncount = Integer.valueOf(args[nextArg++]); |
| Object[] subargs = new String[args.length - nextArg]; |
| System.arraycopy(args, nextArg, subargs, 0, subargs.length); |
| for (int i = 0; i < ncount; i++) { |
| JavaChild p = spawnJavaChild(subargs); |
| sendResult(action, p.pid()); |
| p.forEachOutputLine(JavaChild::sendRaw); |
| p.onJavaChildExit().thenAccept((p1) -> { |
| int excode = p1.exitValue(); |
| sendResult("child_exit", p1.pid(), excode); |
| completedChildren.add(p1); |
| }); |
| children.add(p); // Add child to spawned list |
| } |
| nextArg = args.length; |
| break; |
| } |
| case "child": { |
| // Send the command to all the live children; |
| // ignoring those that are not alive |
| int sentCount = 0; |
| Object[] result = |
| Arrays.copyOfRange(args, nextArg - 1, args.length); |
| Object[] subargs = |
| Arrays.copyOfRange(args, nextArg + 1, args.length); |
| for (JavaChild p : children) { |
| if (p.isAlive()) { |
| sentCount++; |
| // overwrite with current pid |
| result[0] = Long.toString(p.pid()); |
| sendResult(action, result); |
| p.sendAction(args[nextArg], subargs); |
| } |
| } |
| if (sentCount == 0) { |
| sendResult(action, "n/a"); |
| } |
| nextArg = args.length; |
| break; |
| } |
| case "child_eof" : |
| // Close the InputStream of all the live children; |
| // ignoring those that are not alive |
| for (JavaChild p : children) { |
| if (p.isAlive()) { |
| sendResult(action, p.pid()); |
| p.getOutputStream().close(); |
| } |
| } |
| break; |
| case "property": |
| String name = args[nextArg++]; |
| sendResult(action, name, System.getProperty(name)); |
| break; |
| case "threaddump": |
| Thread.dumpStack(); |
| break; |
| case "waitpid": |
| long pid = Long.parseLong(args[nextArg++]); |
| Optional<String> s = ProcessHandle.of(pid).map(ph -> waitAlive(ph)); |
| sendResult(action, s.orElse("pid not valid: " + pid)); |
| break; |
| default: |
| throw new Error("JavaChild action unknown: " + action); |
| } |
| } |
| } catch (Throwable t) { |
| t.printStackTrace(System.err); |
| System.exit(1); |
| } |
| } |
| |
| private static String waitAlive(ProcessHandle ph) { |
| String status; |
| try { |
| boolean isAlive = ph.onExit().get().isAlive(); |
| status = Boolean.toString(isAlive); |
| } catch (InterruptedException | ExecutionException ex ) { |
| status = "interrupted"; |
| } |
| return status; |
| } |
| |
| static synchronized void sendRaw(String s) { |
| System.out.println(s); |
| System.out.flush(); |
| } |
| static void sendResult(String action, Object... results) { |
| sendRaw(new Event(action, results).toString()); |
| } |
| |
| static long getCpuTime() { |
| OperatingSystemMXBean osMbean = |
| (OperatingSystemMXBean)ManagementFactory.getOperatingSystemMXBean(); |
| return osMbean.getProcessCpuTime(); |
| } |
| |
| /** |
| * Print command usage to stderr. |
| */ |
| private static void help() { |
| System.err.println("Commands:"); |
| System.err.println(" help"); |
| System.err.println(" pid"); |
| System.err.println(" parent"); |
| System.err.println(" cpuloop <loopcount>"); |
| System.err.println(" cputime"); |
| System.err.println(" stdin - read commands from stdin"); |
| System.err.println(" sleep <millis>"); |
| System.err.println(" spawn <n> command... - spawn n new children and send command"); |
| System.err.println(" child command... - send command to all live children"); |
| System.err.println(" child_eof - send eof to all live children"); |
| System.err.println(" waitpid <pid> - wait for the pid to exit"); |
| System.err.println(" exit <exitcode>"); |
| System.err.println(" out arg..."); |
| System.err.println(" err arg..."); |
| } |
| |
| static class Event { |
| long pid; |
| long seq; |
| String command; |
| Object[] results; |
| Event(String command, Object... results) { |
| this(self.pid(), ++commandSeq, command, results); |
| } |
| Event(long pid, int seq, String command, Object... results) { |
| this.pid = pid; |
| this.seq = seq; |
| this.command = command; |
| this.results = results; |
| } |
| |
| /** |
| * Create a String encoding the pid, seq, command, and results. |
| * |
| * @return a String formatted to send to the stream. |
| */ |
| String format() { |
| StringBuilder sb = new StringBuilder(); |
| sb.append(pid); |
| sb.append(":"); |
| sb.append(seq); |
| sb.append(" "); |
| sb.append(command); |
| for (int i = 0; i < results.length; i++) { |
| sb.append(" "); |
| sb.append(results[i]); |
| } |
| return sb.toString(); |
| } |
| |
| Event(String encoded) { |
| String[] split = encoded.split("\\s"); |
| String[] pidSeq = split[0].split(":"); |
| pid = Long.valueOf(pidSeq[0]); |
| seq = Integer.valueOf(pidSeq[1]); |
| command = split[1]; |
| Arrays.copyOfRange(split, 1, split.length); |
| } |
| |
| public String toString() { |
| return format(); |
| } |
| |
| } |
| } |