/*
* Copyright 2008 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.google.gwt.dev;
import com.google.gwt.core.ext.TreeLogger;
import com.google.gwt.core.ext.UnableToCompleteException;
import com.google.gwt.dev.jjs.PermutationResult;
import com.google.gwt.dev.jjs.UnifiedAst;
import com.google.gwt.dev.util.FileBackedObject;
import com.google.gwt.dev.util.Util;
import com.google.gwt.util.tools.shared.StringUtils;
import java.io.BufferedReader;
import java.io.EOFException;
import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.lang.management.ManagementFactory;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.SocketTimeoutException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Random;
import java.util.Set;
/**
* A PermutationWorkerFactory designed to launch instances of
* {@link CompilePermsServer}. The system property
* {@value #JAVA_COMMAND_PROPERTY} can be used to change the command used to
* launch the JVM. The system property {@link #JVM_ARGS_PROPERTY} can be used to
* override the JVM args passed to the subprocess.
*/
public class ExternalPermutationWorkerFactory extends PermutationWorkerFactory {
/**
* Allows accept() to be called a finite number of times on a ServerSocket
* before closing the socket.
*/
private static class CountedServerSocket {
private int accepts;
private ServerSocket sock;
public CountedServerSocket(ServerSocket sock, int maxAccepts) {
assert sock != null;
assert maxAccepts >= 1;
this.accepts = maxAccepts;
this.sock = sock;
}
public synchronized Socket accept() throws IOException {
assert accepts >= 0;
if (accepts == 0) {
throw new IllegalStateException("Too many calls to accept()");
}
try {
return sock.accept();
} finally {
if (--accepts == 0) {
sock.close();
sock = null;
}
}
}
}
private static class ExternalPermutationWorker implements PermutationWorker {
private final File astFile;
private final Set<String> cookies;
private ObjectInputStream in;
private ObjectOutputStream out;
private final CountedServerSocket serverSocket;
private Socket workerSocket;
public ExternalPermutationWorker(CountedServerSocket sock, File astFile,
Set<String> cookies) {
this.astFile = astFile;
this.cookies = cookies;
this.serverSocket = sock;
}
public void compile(TreeLogger logger, Permutation permutation,
FileBackedObject<PermutationResult> resultFile)
throws TransientWorkerException, UnableToCompleteException {
// If we've just started, we need to get a connection from a subprocess
if (workerSocket == null) {
try {
/*
* We've set SO_TIMEOUT, so this may fail if the remote process never
* connects back.
*/
workerSocket = serverSocket.accept();
in = new ObjectInputStream(workerSocket.getInputStream());
out = new ObjectOutputStream(workerSocket.getOutputStream());
// Verify we're talking to the right worker
String c = in.readUTF();
if (!cookies.contains(c)) {
throw new TransientWorkerException("Received unknown cookie " + c,
null);
}
out.writeObject(astFile);
// Get the remote worker's estimate of memory use
long memoryUse = in.readLong();
if (logger.isLoggable(TreeLogger.SPAM)) {
logger.log(TreeLogger.SPAM, "Remote process indicates " + memoryUse
+ " bytes of memory used");
}
} catch (SocketTimeoutException e) {
throw new TransientWorkerException(
"Remote process did not connect within timeout period", e);
} catch (IOException e) {
throw new TransientWorkerException(
"Unable to communicate with worker", e);
}
}
try {
out.writeBoolean(true);
out.writeObject(resultFile);
out.writeObject(permutation);
out.flush();
Throwable t = (Throwable) in.readObject();
if (t != null) {
logger.log(TreeLogger.ERROR, "Error from external worker", t);
throw new UnableToCompleteException();
}
} catch (IOException e) {
logger.log(TreeLogger.WARN, "Lost communication with remote process", e);
throw new TransientWorkerException(
"Lost communication with remote process", e);
} catch (ClassNotFoundException e) {
logger.log(TreeLogger.ERROR, "Unable to receive response", e);
throw new UnableToCompleteException();
}
}
public String getName() {
return "External worker "
+ (workerSocket != null ? workerSocket.getRemoteSocketAddress()
: "unconnected");
}
public void shutdown() {
if (out != null) {
try {
out.writeBoolean(false);
out.flush();
out.close();
} catch (IOException e) {
// Not much to do here
}
}
if (in != null) {
try {
in.close();
} catch (IOException e) {
// Not much to do here
}
}
if (workerSocket != null) {
try {
workerSocket.close();
} catch (IOException e) {
// Nothing to do
}
}
}
}
/**
* A system property that can be used to override the command used to invoke a
* JVM instance.
*/
public static final String JAVA_COMMAND_PROPERTY = "gwt.jjs.javaCommand";
/**
* A system property that can be used to override the JVM args passed to the
* subprocess.
*/
public static final String JVM_ARGS_PROPERTY = "gwt.jjs.javaArgs";
/**
* Random number generator used for keys to worker threads.
*/
private static Random random = new Random();
/**
* Launches an external worker and returns the cookie that worker should
* return via the network connection.
*/
private static String launchExternalWorker(TreeLogger logger, int port)
throws UnableToCompleteException {
String javaCommand = System.getProperty(JAVA_COMMAND_PROPERTY,
System.getProperty("java.home") + File.separator + "bin"
+ File.separator + "java");
if (logger.isLoggable(TreeLogger.TRACE)) {
logger.log(TreeLogger.TRACE, "javaCommand = " + javaCommand);
}
// Construct the arguments
List<String> args = new ArrayList<String>();
args.add(javaCommand);
// This will include -Xmx, -D, etc...
String userJvmArgs = System.getProperty(JVM_ARGS_PROPERTY);
if (userJvmArgs == null) {
args.addAll(ManagementFactory.getRuntimeMXBean().getInputArguments());
} else {
args.addAll(Arrays.asList(userJvmArgs.split(" ")));
}
// Determine the logLevel for the external program
TreeLogger.Type logLevel = TreeLogger.ERROR;
for (TreeLogger.Type t : TreeLogger.Type.values()) {
if (logger.isLoggable(t)) {
logLevel = t;
} else {
break;
}
}
byte[] cookieBytes = new byte[16];
random.nextBytes(cookieBytes);
String cookie = StringUtils.toHexString(cookieBytes);
// Cook up the classpath, main class, and extra args
args.addAll(Arrays.asList("-classpath",
ManagementFactory.getRuntimeMXBean().getClassPath(),
CompilePermsServer.class.getName(), "-host", "localhost", "-port",
String.valueOf(port), "-logLevel", logLevel.toString(), "-cookie",
cookie));
// Filter undesirable arguments
for (Iterator<String> iter = args.iterator(); iter.hasNext();) {
String arg = iter.next();
if (arg.startsWith("-agentlib")) {
iter.remove();
}
}
ProcessBuilder builder = new ProcessBuilder();
builder.command(args);
try {
final Process proc = builder.start();
final BufferedReader bin = new BufferedReader(new InputStreamReader(
proc.getInputStream()));
final BufferedReader berr = new BufferedReader(new InputStreamReader(
proc.getErrorStream()));
final TreeLogger procLogger = logger.branch(TreeLogger.DEBUG,
"Process output");
// Threads to copy stdout, stderr to the logger
new Thread(new Runnable() {
public void run() {
while (true) {
try {
String line = bin.readLine();
if (line == null) {
break;
}
procLogger.log(TreeLogger.INFO, line);
} catch (EOFException e) {
// Ignore
} catch (IOException e) {
procLogger.log(TreeLogger.ERROR,
"Unable to read from subprocess", e);
}
}
}
}).start();
new Thread(new Runnable() {
public void run() {
while (true) {
try {
String line = berr.readLine();
if (line == null) {
break;
}
procLogger.log(TreeLogger.ERROR, line);
} catch (EOFException e) {
// Ignore
} catch (IOException e) {
procLogger.log(TreeLogger.ERROR,
"Unable to read from subprocess", e);
}
}
}
}).start();
// The child process should not outlive this JVM
Runtime.getRuntime().addShutdownHook(new Thread(new Runnable() {
public void run() {
try {
proc.exitValue();
} catch (IllegalThreadStateException e) {
proc.destroy();
}
}
}));
return cookie;
} catch (IOException e) {
logger.log(TreeLogger.ERROR, "Unable to start external process", e);
throw new UnableToCompleteException();
}
}
private ServerSocket sock;
@Override
public Collection<PermutationWorker> getWorkers(TreeLogger logger,
UnifiedAst unifiedAst, int numWorkers) throws UnableToCompleteException {
File astFile;
try {
astFile = File.createTempFile("externalPermutationWorkerFactory", ".ser");
astFile.deleteOnExit();
Util.writeObjectAsFile(logger, astFile, unifiedAst);
} catch (IOException e) {
logger.log(TreeLogger.ERROR, "Unable to create temporary file", e);
throw new UnableToCompleteException();
}
Set<String> cookies = Collections.synchronizedSet(new HashSet<String>(
numWorkers));
CountedServerSocket countedSock = new CountedServerSocket(sock, numWorkers);
List<PermutationWorker> toReturn = new ArrayList<PermutationWorker>(
numWorkers);
// TODO(spoon): clean up already-launched processes if we get an exception?
for (int i = 0; i < numWorkers; i++) {
String cookie = launchExternalWorker(logger, sock.getLocalPort());
cookies.add(cookie);
toReturn.add(new ExternalPermutationWorker(countedSock, astFile, cookies));
}
return toReturn;
}
@Override
public void init(TreeLogger logger) throws UnableToCompleteException {
try {
sock = new ServerSocket();
/*
* Have accept() wait no more than one minute for a connection. This
* prevents dead-head behavior.
*/
sock.setSoTimeout(60000);
sock.bind(null);
if (logger.isLoggable(TreeLogger.SPAM)) {
logger.log(TreeLogger.SPAM, "Listening for external workers on port "
+ sock.getLocalPort());
}
} catch (IOException e) {
logger.log(TreeLogger.ERROR, "Unable to create socket", e);
throw new UnableToCompleteException();
}
}
@Override
public boolean isLocal() {
return true;
}
}