/*
* Copyright 1999-2004 The Apache Software Foundation
*
* 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 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 org.apache.commons.logging.Log;
import org.apache.commons.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]
*/
public class PoolTcpEndpoint { // implements Endpoint {
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 boolean isPool = true;
private int backlog = BACKLOG;
private int serverTimeout = TIMEOUT;
TcpConnectionHandler handler;
private InetAddress inet;
private int port;
private ServerSocketFactory factory;
private ServerSocket serverSocket;
ThreadPoolRunnable listener;
private volatile boolean running = false;
private volatile boolean paused = false;
private boolean initialized = false;
private boolean reinitializing = false;
static final int debug=0;
ThreadPool tp;
// XXX Do we need it for backward compat ?
//protected Log _log=Log.getLog("tc/PoolTcpEndpoint", "PoolTcpEndpoint");
static Log log=LogFactory.getLog(PoolTcpEndpoint.class );
protected boolean tcpNoDelay=false;
protected int linger=100;
protected int socketTimeout=-1;
public PoolTcpEndpoint() {
// super("tc_log"); // initialize default logger
tp = new ThreadPool();
}
public PoolTcpEndpoint( ThreadPool tp ) {
this.tp=tp;
}
// -------------------- Configuration --------------------
public void setPoolOn(boolean isPool) {
this.isPool = isPool;
}
public boolean isPoolOn() {
return isPool;
}
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 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 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 be ) {
throw new BindException(be.getMessage() + ":" + port);
}
}
if( serverTimeout >= 0 )
serverSocket.setSoTimeout( serverTimeout );
} catch( IOException ex ) {
// log("couldn't start endpoint", ex, Logger.DEBUG);
throw ex;
} catch( InstantiationException ex1 ) {
// log("couldn't start endpoint", ex1, Logger.DEBUG);
throw ex1;
}
initialized = true;
}
public void startEndpoint() throws IOException, InstantiationException {
if (!initialized) {
initEndpoint();
}
if(isPool) {
tp.start();
}
running = true;
paused = false;
if(isPool) {
listener = new TcpWorkerThread(this);
tp.runIt(listener);
} else {
log.error("XXX Error - need pool !");
}
}
public void pauseEndpoint() {
if (running && !paused) {
paused = true;
unlockAccept();
}
}
public void resumeEndpoint() {
if (running) {
paused = false;
}
}
public void stopEndpoint() {
if (running) {
tp.shutdown();
running = false;
if (serverSocket != null) {
closeServerSocket();
}
}
}
protected void closeServerSocket() {
if (!paused)
unlockAccept();
try {
if( serverSocket!=null)
serverSocket.close();
} catch(Exception e) {
log.error("Caught exception trying to close socket.", 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("127.0.0.1", 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) {
log.debug("Caught exception trying to unlock accept on " + port
+ " " + e.toString());
} 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("Null socket returned by accept");
} 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);
} finally {
// Current thread is now invalid: kill it
throw new ThreadDeath();
}
}
}
}
}
return accepted;
}
/** @deprecated
*/
public void log(String msg)
{
log.info(msg);
}
/** @deprecated
*/
public void log(String msg, Throwable t)
{
log.error( msg, t );
}
/** @deprecated
*/
public void log(String msg, int level)
{
log.info( msg );
}
/** @deprecated
*/
public void log(String msg, Throwable t, int level) {
log.error( msg, t );
}
void setSocketOptions(Socket socket)
throws SocketException {
if(linger >= 0 )
socket.setSoLinger( true, linger);
if( tcpNoDelay )
socket.setTcpNoDelay(tcpNoDelay);
if( socketTimeout > 0 )
socket.setSoTimeout( socketTimeout );
}
}
// -------------------- Threads --------------------
/*
* I switched the threading model here.
*
* We used to have a "listener" thread and a "connection"
* thread, this results in code simplicity but also a needless
* thread switch.
*
* Instead I am now using a pool of threads, all the threads are
* simmetric in their execution and no thread switch is needed.
*/
class TcpWorkerThread implements ThreadPoolRunnable {
/* This is not a normal Runnable - it gets attached to an existing
thread, runs and when run() ends - the thread keeps running.
It's better to keep the name ThreadPoolRunnable - avoid confusion.
We also want to use per/thread data and avoid sync wherever possible.
*/
PoolTcpEndpoint endpoint;
public TcpWorkerThread(PoolTcpEndpoint endpoint) {
this.endpoint = endpoint;
}
public Object[] getInitData() {
// no synchronization overhead, but 2 array access
Object obj[]=new Object[2];
obj[1]= endpoint.getConnectionHandler().init();
obj[0]=new TcpConnection();
return obj;
}
public void runIt(Object perThrData[]) {
// Create per-thread cache
if (endpoint.isRunning()) {
// Loop if endpoint is paused
while (endpoint.isPaused()) {
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// Ignore
}
}
// Accept a new connection
Socket s = null;
try {
s = endpoint.acceptSocket();
} finally {
// Continue accepting on another thread...
if (endpoint.isRunning()) {
endpoint.tp.runIt(this);
}
}
// Process the connection
if (null != s) {
TcpConnection con = null;
int step = 1;
try {
// 1: Set socket options: timeout, linger, etc
endpoint.setSocketOptions(s);
// 2: SSL handshake
step = 2;
if (endpoint.getServerSocketFactory() != null) {
endpoint.getServerSocketFactory().handshake(s);
}
// 3: Process the connection
step = 3;
con = (TcpConnection) perThrData[0];
con.setEndpoint(endpoint);
con.setSocket(s);
endpoint.getConnectionHandler().processConnection(
con,
(Object[]) perThrData[1]);
} catch (SocketException se) {
PoolTcpEndpoint.log.error(
"Remote Host "
+ s.getInetAddress()
+ " SocketException: "
+ se.getMessage());
// Try to close the socket
try {
s.close();
} catch (IOException e) {
}
} catch (Throwable t) {
if (step == 2) {
PoolTcpEndpoint.log.debug("Handshake failed", t);
} else {
PoolTcpEndpoint.log.error("Unexpected error", t);
}
// Try to close the socket
try {
s.close();
} catch (IOException e) {
}
} finally {
if (con != null) {
con.recycle();
}
}
}
}
}
}