/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 org.apache.tomcat.util.net;
import java.io.IOException;
import java.io.InterruptedIOException;
import java.net.BindException;
import java.net.InetAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.SocketException;
import java.security.AccessControlException;
import java.util.Stack;
import java.util.Vector;
import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;
import org.apache.tomcat.util.res.StringManager;
import org.apache.tomcat.util.threads.ThreadPool;
import org.apache.tomcat.util.threads.ThreadPoolRunnable;
/* Similar with MPM module in Apache2.0. Handles all the details related with
"tcp server" functionality - thread management, accept policy, etc.
It should do nothing more - as soon as it get a socket ( and all socket options
are set, etc), it just handle the stream to ConnectionHandler.processConnection. (costin)
*/
/**
* Handle incoming TCP connections.
*
* This class implement a simple server model: one listener thread accepts on a socket and
* creates a new worker thread for each incoming connection.
*
* More advanced Endpoints will reuse the threads, use queues, etc.
*
* @author James Duncan Davidson [duncan@eng.sun.com]
* @author Jason Hunter [jch@eng.sun.com]
* @author James Todd [gonzo@eng.sun.com]
* @author Costin@eng.sun.com
* @author Gal Shachor [shachor@il.ibm.com]
* @author Yoav Shapira <yoavs@apache.org>
*/
public class PoolTcpEndpoint implements Runnable { // implements Endpoint {
static Log log=LogFactory.getLog(PoolTcpEndpoint.class );
private StringManager sm =
StringManager.getManager("org.apache.tomcat.util.net.res");
private static final int BACKLOG = 100;
private static final int TIMEOUT = 1000;
private final Object threadSync = new Object();
private int backlog = BACKLOG;
private int serverTimeout = TIMEOUT;
private InetAddress inet;
private int port;
private ServerSocketFactory factory;
private ServerSocket serverSocket;
private volatile boolean running = false;
private volatile boolean paused = false;
private boolean initialized = false;
private boolean reinitializing = false;
static final int debug=0;
protected boolean tcpNoDelay=false;
protected int linger=100;
protected int socketTimeout=-1;
private boolean lf = true;
// ------ Leader follower fields
TcpConnectionHandler handler;
ThreadPoolRunnable listener;
ThreadPool tp;
// ------ Master slave fields
/* The background thread. */
private Thread thread = null;
/* Available processors. */
private Stack workerThreads = new Stack();
private int curThreads = 0;
private int maxThreads = 20;
/* All processors which have been created. */
private Vector created = new Vector();
public PoolTcpEndpoint() {
tp = new ThreadPool();
}
public PoolTcpEndpoint( ThreadPool tp ) {
this.tp=tp;
}
// -------------------- Configuration --------------------
public void setMaxThreads(int maxThreads) {
if( maxThreads > 0)
tp.setMaxThreads(maxThreads);
}
public int getMaxThreads() {
return tp.getMaxThreads();
}
public void setMaxSpareThreads(int maxThreads) {
if(maxThreads > 0)
tp.setMaxSpareThreads(maxThreads);
}
public int getMaxSpareThreads() {
return tp.getMaxSpareThreads();
}
public void setMinSpareThreads(int minThreads) {
if(minThreads > 0)
tp.setMinSpareThreads(minThreads);
}
public int getMinSpareThreads() {
return tp.getMinSpareThreads();
}
public void setThreadPriority(int threadPriority) {
tp.setThreadPriority(threadPriority);
}
public int getThreadPriority() {
return tp.getThreadPriority();
}
public int getPort() {
return port;
}
public void setPort(int port ) {
this.port=port;
}
public InetAddress getAddress() {
return inet;
}
public void setAddress(InetAddress inet) {
this.inet=inet;
}
public void setServerSocket(ServerSocket ss) {
serverSocket = ss;
}
public void setServerSocketFactory( ServerSocketFactory factory ) {
this.factory=factory;
}
ServerSocketFactory getServerSocketFactory() {
return factory;
}
public void setConnectionHandler( TcpConnectionHandler handler ) {
this.handler=handler;
}
public TcpConnectionHandler getConnectionHandler() {
return handler;
}
public boolean isRunning() {
return running;
}
public boolean isPaused() {
return paused;
}
/**
* Allows the server developer to specify the backlog that
* should be used for server sockets. By default, this value
* is 100.
*/
public void setBacklog(int backlog) {
if( backlog>0)
this.backlog = backlog;
}
public int getBacklog() {
return backlog;
}
/**
* Sets the timeout in ms of the server sockets created by this
* server. This method allows the developer to make servers
* more or less responsive to having their server sockets
* shut down.
*
* <p>By default this value is 1000ms.
*/
public void setServerTimeout(int timeout) {
this.serverTimeout = timeout;
}
public boolean getTcpNoDelay() {
return tcpNoDelay;
}
public void setTcpNoDelay( boolean b ) {
tcpNoDelay=b;
}
public int getSoLinger() {
return linger;
}
public void setSoLinger( int i ) {
linger=i;
}
public int getSoTimeout() {
return socketTimeout;
}
public void setSoTimeout( int i ) {
socketTimeout=i;
}
public int getServerSoTimeout() {
return serverTimeout;
}
public void setServerSoTimeout( int i ) {
serverTimeout=i;
}
public String getStrategy() {
if (lf) {
return "lf";
} else {
return "ms";
}
}
public void setStrategy(String strategy) {
if ("ms".equals(strategy)) {
lf = false;
} else {
lf = true;
}
}
public int getCurrentThreadCount() {
return curThreads;
}
public int getCurrentThreadsBusy() {
return curThreads - workerThreads.size();
}
// -------------------- Public methods --------------------
public void initEndpoint() throws IOException, InstantiationException {
try {
if(factory==null)
factory=ServerSocketFactory.getDefault();
if(serverSocket==null) {
try {
if (inet == null) {
serverSocket = factory.createSocket(port, backlog);
} else {
serverSocket = factory.createSocket(port, backlog, inet);
}
} catch (BindException orig) {
String msg;
if (inet == null)
msg = orig.getMessage() + "<null>:" + port;
else
msg = orig.getMessage() + " " +
inet.toString() + ":" + port;
BindException be = new BindException(msg);
be.initCause(orig);
throw be;
}
}
if( serverTimeout >= 0 )
serverSocket.setSoTimeout( serverTimeout );
} catch( IOException ex ) {
throw ex;
} catch( InstantiationException ex1 ) {
throw ex1;
}
initialized = true;
}
public void startEndpoint() throws IOException, InstantiationException {
if (!initialized) {
initEndpoint();
}
if (lf) {
tp.start();
}
running = true;
paused = false;
if (lf) {
listener = new LeaderFollowerWorkerThread(this);
tp.runIt(listener);
} else {
maxThreads = getMaxThreads();
threadStart();
}
}
public void pauseEndpoint() {
if (running && !paused) {
paused = true;
unlockAccept();
}
}
public void resumeEndpoint() {
if (running) {
paused = false;
}
}
public void stopEndpoint() {
if (running) {
if (lf) {
tp.shutdown();
}
running = false;
if (serverSocket != null) {
closeServerSocket();
}
if (!lf) {
threadStop();
}
initialized=false ;
}
}
protected void closeServerSocket() {
if (!paused)
unlockAccept();
try {
if( serverSocket!=null)
serverSocket.close();
} catch(Exception e) {
log.error(sm.getString("endpoint.err.close"), e);
}
serverSocket = null;
}
protected void unlockAccept() {
Socket s = null;
try {
// Need to create a connection to unlock the accept();
if (inet == null) {
s = new Socket(InetAddress.getByName("localhost").getHostAddress(), port);
} else {
s = new Socket(inet, port);
// setting soLinger to a small value will help shutdown the
// connection quicker
s.setSoLinger(true, 0);
}
} catch(Exception e) {
if (log.isDebugEnabled()) {
log.debug(sm.getString("endpoint.debug.unlock", "" + port), e);
}
} finally {
if (s != null) {
try {
s.close();
} catch (Exception e) {
// Ignore
}
}
}
}
// -------------------- Private methods
Socket acceptSocket() {
if( !running || serverSocket==null ) return null;
Socket accepted = null;
try {
if(factory==null) {
accepted = serverSocket.accept();
} else {
accepted = factory.acceptSocket(serverSocket);
}
if (null == accepted) {
log.warn(sm.getString("endpoint.warn.nullSocket"));
} else {
if (!running) {
accepted.close(); // rude, but unlikely!
accepted = null;
} else if (factory != null) {
factory.initSocket( accepted );
}
}
}
catch(InterruptedIOException iioe) {
// normal part -- should happen regularly so
// that the endpoint can release if the server
// is shutdown.
}
catch (AccessControlException ace) {
// When using the Java SecurityManager this exception
// can be thrown if you are restricting access to the
// socket with SocketPermission's.
// Log the unauthorized access and continue
String msg = sm.getString("endpoint.warn.security",
serverSocket, ace);
log.warn(msg);
}
catch (IOException e) {
String msg = null;
if (running) {
msg = sm.getString("endpoint.err.nonfatal",
serverSocket, e);
log.error(msg, e);
}
if (accepted != null) {
try {
accepted.close();
} catch(Throwable ex) {
msg = sm.getString("endpoint.err.nonfatal",
accepted, ex);
log.warn(msg, ex);
}
accepted = null;
}
if( ! running ) return null;
reinitializing = true;
// Restart endpoint when getting an IOException during accept
synchronized (threadSync) {
if (reinitializing) {
reinitializing = false;
// 1) Attempt to close server socket
closeServerSocket();
initialized = false;
// 2) Reinit endpoint (recreate server socket)
try {
msg = sm.getString("endpoint.warn.reinit");
log.warn(msg);
initEndpoint();
} catch (Throwable t) {
msg = sm.getString("endpoint.err.nonfatal",
serverSocket, t);
log.error(msg, t);
}
// 3) If failed, attempt to restart endpoint
if (!initialized) {
msg = sm.getString("endpoint.warn.restart");
log.warn(msg);
try {
stopEndpoint();
initEndpoint();
startEndpoint();
} catch (Throwable t) {
msg = sm.getString("endpoint.err.fatal",
serverSocket, t);
log.error(msg, t);
}
// Current thread is now invalid: kill it
throw new ThreadDeath();
}
}
}
}
return accepted;
}
void setSocketOptions(Socket socket)
throws SocketException {
if(linger >= 0 )
socket.setSoLinger( true, linger);
if( tcpNoDelay )
socket.setTcpNoDelay(tcpNoDelay);
if( socketTimeout > 0 )
socket.setSoTimeout( socketTimeout );
}
void processSocket(Socket s, TcpConnection con, Object[] threadData) {
// Process the connection
int step = 1;
try {
// 1: Set socket options: timeout, linger, etc
setSocketOptions(s);
// 2: SSL handshake
step = 2;
if (getServerSocketFactory() != null) {
getServerSocketFactory().handshake(s);
}
// 3: Process the connection
step = 3;
con.setEndpoint(this);
con.setSocket(s);
getConnectionHandler().processConnection(con, threadData);
} catch (SocketException se) {
log.debug(sm.getString("endpoint.err.socket", s.getInetAddress()),
se);
// Try to close the socket
try {
s.close();
} catch (IOException e) {
}
} catch (Throwable t) {
if (step == 2) {
if (log.isDebugEnabled()) {
log.debug(sm.getString("endpoint.err.handshake"), t);
}
} else {
log.error(sm.getString("endpoint.err.unexpected"), t);
}
// Try to close the socket
try {
s.close();
} catch (IOException e) {
}
} finally {
if (con != null) {
con.recycle();
}
}
}
// -------------------------------------------------- Master Slave Methods
/**
* Create (or allocate) and return an available processor for use in
* processing a specific HTTP request, if possible. If the maximum
* allowed processors have already been created and are in use, return
* <code>null</code> instead.
*/
private MasterSlaveWorkerThread createWorkerThread() {
synchronized (workerThreads) {
if (workerThreads.size() > 0) {
return ((MasterSlaveWorkerThread) workerThreads.pop());
}
if ((maxThreads > 0) && (curThreads < maxThreads)) {
return (newWorkerThread());
} else {
if (maxThreads < 0) {
return (newWorkerThread());
} else {
return (null);
}
}
}
}
/**
* Create and return a new processor suitable for processing HTTP
* requests and returning the corresponding responses.
*/
private MasterSlaveWorkerThread newWorkerThread() {
MasterSlaveWorkerThread workerThread =
new MasterSlaveWorkerThread(this, tp.getName() + "-" + (++curThreads));
workerThread.start();
created.addElement(workerThread);
return (workerThread);
}
/**
* Recycle the specified Processor so that it can be used again.
*
* @param processor The processor to be recycled
*/
void recycleWorkerThread(MasterSlaveWorkerThread workerThread) {
workerThreads.push(workerThread);
}
/**
* The background thread that listens for incoming TCP/IP connections and
* hands them off to an appropriate processor.
*/
public void run() {
// Loop until we receive a shutdown command
while (running) {
// Loop if endpoint is paused
while (paused) {
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// Ignore
}
}
// Allocate a new worker thread
MasterSlaveWorkerThread workerThread = createWorkerThread();
if (workerThread == null) {
try {
// Wait a little for load to go down: as a result,
// no accept will be made until the concurrency is
// lower than the specified maxThreads, and current
// connections will wait for a little bit instead of
// failing right away.
Thread.sleep(100);
} catch (InterruptedException e) {
// Ignore
}
continue;
}
// Accept the next incoming connection from the server socket
Socket socket = acceptSocket();
// Hand this socket off to an appropriate processor
workerThread.assign(socket);
// The processor will recycle itself when it finishes
}
// Notify the threadStop() method that we have shut ourselves down
synchronized (threadSync) {
threadSync.notifyAll();
}
}
/**
* Start the background processing thread.
*/
private void threadStart() {
thread = new Thread(this, tp.getName());
thread.setPriority(getThreadPriority());
thread.setDaemon(true);
thread.start();
}
/**
* Stop the background processing thread.
*/
private void threadStop() {
thread = null;
}
}