package org.jgroups.blocks;
import org.jgroups.logging.Log;
import org.jgroups.Address;
import org.jgroups.Global;
import org.jgroups.stack.IpAddress;
import org.jgroups.util.ShutdownRejectedExecutionHandler;
import java.io.IOException;
import java.net.*;
import java.nio.ByteBuffer;
import java.nio.channels.*;
import java.nio.channels.spi.SelectorProvider;
import java.util.*;
import java.util.concurrent.*;
/**
* Manages incoming and outgoing TCP connections. For each outgoing message to destination P, if there
* is not yet a connection for P, one will be created. Subsequent outgoing messages will use this
* connection. For incoming messages, one server socket is created at startup. For each new incoming
* client connecting, a new thread from a thread pool is allocated and listens for incoming messages
* until the socket is closed by the peer.<br>Sockets/threads with no activity will be killed
* after some time.
* <p/>
* Incoming messages from any of the sockets can be received by setting the message listener.
*
* @author Bela Ban, Scott Marlow, Alex Fu
*/
public class ConnectionTableNIO extends BasicConnectionTable implements Runnable {
private ServerSocketChannel m_serverSocketChannel;
private Selector m_acceptSelector;
private WriteHandler[] m_writeHandlers;
private int m_nextWriteHandler = 0;
private final Object m_lockNextWriteHandler = new Object();
private ReadHandler[] m_readHandlers;
private int m_nextReadHandler = 0;
private final Object m_lockNextReadHandler = new Object();
// thread pool for processing read requests
private Executor m_requestProcessors;
private volatile boolean serverStopping=false;
private final List<Thread> m_backGroundThreads = new LinkedList<Thread>(); // Collection of all created threads
private int m_reader_threads = 3;
private int m_writer_threads = 3;
private int m_processor_threads = 5; // PooledExecutor.createThreads()
private int m_processor_minThreads = 5; // PooledExecutor.setMinimumPoolSize()
private int m_processor_maxThreads = 5; // PooledExecutor.setMaxThreads()
private int m_processor_queueSize=100; // Number of queued requests that can be pending waiting
// for a background thread to run the request.
private long m_processor_keepAliveTime = Long.MAX_VALUE; // PooledExecutor.setKeepAliveTime( milliseconds);
// negative value used to mean to wait forever, instead set to Long.MAX_VALUE to wait forever
/**
* @param srv_port
* @throws Exception
*/
public ConnectionTableNIO(int srv_port) throws Exception {
this.srv_port=srv_port;
start();
}
/**
* @param srv_port
* @param reaper_interval
* @param conn_expire_time
* @throws Exception
*/
public ConnectionTableNIO(int srv_port, long reaper_interval,
long conn_expire_time) throws Exception {
this.srv_port=srv_port;
this.reaper_interval=reaper_interval;
this.conn_expire_time=conn_expire_time;
start();
}
/**
* @param r
* @param bind_addr
* @param external_addr
* @param srv_port
* @param max_port
* @throws Exception
*/
public ConnectionTableNIO(Receiver r, InetAddress bind_addr, InetAddress external_addr, int external_port, int srv_port, int max_port)
throws Exception
{
setReceiver(r);
this.external_addr=external_addr;
this.external_port=external_port;
this.bind_addr=bind_addr;
this.srv_port=srv_port;
this.max_port=max_port;
use_reaper=true;
start();
}
public ConnectionTableNIO(Receiver r, InetAddress bind_addr, InetAddress external_addr, int external_port,
int srv_port, int max_port, boolean doStart)
throws Exception
{
setReceiver(r);
this.external_addr=external_addr;
this.external_port=external_port;
this.bind_addr=bind_addr;
this.srv_port=srv_port;
this.max_port=max_port;
use_reaper=true;
if(doStart)
start();
}
/**
* @param r
* @param bind_addr
* @param external_addr
* @param srv_port
* @param max_port
* @param reaper_interval
* @param conn_expire_time
* @throws Exception
*/
public ConnectionTableNIO(Receiver r, InetAddress bind_addr, InetAddress external_addr, int external_port,
int srv_port, int max_port,
long reaper_interval, long conn_expire_time
) throws Exception
{
setReceiver(r);
this.bind_addr=bind_addr;
this.external_addr=external_addr;
this.external_port=external_port;
this.srv_port=srv_port;
this.max_port=max_port;
this.reaper_interval=reaper_interval;
this.conn_expire_time=conn_expire_time;
use_reaper=true;
start();
}
public ConnectionTableNIO(Receiver r, InetAddress bind_addr, InetAddress external_addr, int external_port,
int srv_port, int max_port,
long reaper_interval, long conn_expire_time, boolean doStart
) throws Exception
{
setReceiver(r);
this.bind_addr=bind_addr;
this.external_addr=external_addr;
this.external_port=external_port;
this.srv_port=srv_port;
this.max_port=max_port;
this.reaper_interval=reaper_interval;
this.conn_expire_time=conn_expire_time;
use_reaper=true;
if(doStart)
start();
}
public int getReaderThreads() { return m_reader_threads; }
public void setReaderThreads(int m_reader_threads) {
this.m_reader_threads=m_reader_threads;
}
public int getWriterThreads() { return m_writer_threads; }
public void setWriterThreads(int m_writer_threads) {
this.m_writer_threads=m_writer_threads;
}
public int getProcessorThreads() { return m_processor_threads; }
public void setProcessorThreads(int m_processor_threads) {
this.m_processor_threads=m_processor_threads;
}
public int getProcessorMinThreads() { return m_processor_minThreads;}
public void setProcessorMinThreads(int m_processor_minThreads) {
this.m_processor_minThreads=m_processor_minThreads;
}
public int getProcessorMaxThreads() { return m_processor_maxThreads;}
public void setProcessorMaxThreads(int m_processor_maxThreads) {
this.m_processor_maxThreads=m_processor_maxThreads;
}
public int getProcessorQueueSize() { return m_processor_queueSize; }
public void setProcessorQueueSize(int m_processor_queueSize) {
this.m_processor_queueSize=m_processor_queueSize;
}
public long getProcessorKeepAliveTime() { return m_processor_keepAliveTime; }
public void setProcessorKeepAliveTime(long m_processor_keepAliveTime) {
this.m_processor_keepAliveTime=m_processor_keepAliveTime;
}
/**
* Try to obtain correct Connection (or create one if not yet existent)
*/
BasicConnectionTable.Connection getConnection(Address dest) throws Exception
{
Connection conn;
SocketChannel sock_ch;
synchronized (conns)
{
conn = (Connection) conns.get(dest);
if (conn == null)
{
InetSocketAddress destAddress = new InetSocketAddress(((IpAddress) dest).getIpAddress(),
((IpAddress) dest).getPort());
sock_ch = SocketChannel.open(destAddress);
sock_ch.socket().setTcpNoDelay(tcp_nodelay);
conn = new Connection(sock_ch, dest);
conn.sendLocalAddress(local_addr);
// This outbound connection is ready
sock_ch.configureBlocking(false);
try
{
if (log.isTraceEnabled())
log.trace("About to change new connection send buff size from " + sock_ch.socket().getSendBufferSize() + " bytes");
sock_ch.socket().setSendBufferSize(send_buf_size);
if (log.isTraceEnabled())
log.trace("Changed new connection send buff size to " + sock_ch.socket().getSendBufferSize() + " bytes");
}
catch (IllegalArgumentException ex)
{
if (log.isErrorEnabled()) log.error("exception setting send buffer size to " +
send_buf_size + " bytes: " + ex);
}
try
{
if (log.isTraceEnabled())
log.trace("About to change new connection receive buff size from " + sock_ch.socket().getReceiveBufferSize() + " bytes");
sock_ch.socket().setReceiveBufferSize(recv_buf_size);
if (log.isTraceEnabled())
log.trace("Changed new connection receive buff size to " + sock_ch.socket().getReceiveBufferSize() + " bytes");
}
catch (IllegalArgumentException ex)
{
if (log.isErrorEnabled()) log.error("exception setting receive buffer size to " +
send_buf_size + " bytes: " + ex);
}
int idx;
synchronized (m_lockNextWriteHandler)
{
idx = m_nextWriteHandler = (m_nextWriteHandler + 1) % m_writeHandlers.length;
}
conn.setupWriteHandler(m_writeHandlers[idx]);
// Put the new connection to the queue
try
{
synchronized (m_lockNextReadHandler)
{
idx = m_nextReadHandler = (m_nextReadHandler + 1) % m_readHandlers.length;
}
m_readHandlers[idx].add(conn);
} catch (InterruptedException e)
{
if (log.isWarnEnabled())
log.warn("Thread (" +Thread.currentThread().getName() + ") was interrupted, closing connection", e);
// What can we do? Remove it from table then.
conn.destroy();
throw e;
}
// Add connection to table
addConnection(dest, conn);
notifyConnectionOpened(dest);
if (log.isTraceEnabled()) log.trace("created socket to " + dest);
}
return conn;
}
}
public final void start() throws Exception {
super.start();
init();
srv_sock=createServerSocket(srv_port, max_port);
if (external_addr!=null) {
local_addr=new IpAddress(external_addr, external_port == 0? srv_sock.getLocalPort() : external_port);
}
else if (bind_addr != null)
local_addr=new IpAddress(bind_addr, srv_sock.getLocalPort());
else
local_addr=new IpAddress(srv_sock.getLocalPort());
if(log.isDebugEnabled()) log.debug("server socket created on " + local_addr);
// Roland Kurmann 4/7/2003, put in thread_group -- removed bela Nov 2012
acceptor=getThreadFactory().newThread(this, "ConnectionTable.AcceptorThread");
acceptor.setDaemon(true);
acceptor.start();
m_backGroundThreads.add(acceptor);
// start the connection reaper - will periodically remove unused connections
if(use_reaper && reaper == null) {
reaper=new Reaper();
reaper.start();
}
}
protected void init()
throws Exception
{
// use directExector if max thread pool size is less than or equal to zero.
if(getProcessorMaxThreads() <= 0) {
m_requestProcessors = new Executor() {
public void execute(Runnable command) {
command.run();
}
};
}
else
{
// Create worker thread pool for processing incoming buffers
ThreadPoolExecutor requestProcessors = new ThreadPoolExecutor(getProcessorMinThreads(), getProcessorMaxThreads(),
getProcessorKeepAliveTime(), TimeUnit.MILLISECONDS,
new LinkedBlockingQueue<Runnable>(getProcessorQueueSize()));
requestProcessors.setThreadFactory(new ThreadFactory() {
public Thread newThread(Runnable runnable) {
Thread new_thread=new Thread(runnable, "ConnectionTableNIO.Thread");
new_thread.setDaemon(true);
m_backGroundThreads.add(new_thread);
return new_thread;
}
});
requestProcessors.setRejectedExecutionHandler(new ShutdownRejectedExecutionHandler(requestProcessors.getRejectedExecutionHandler()));
m_requestProcessors = requestProcessors;
}
m_writeHandlers = WriteHandler.create(getThreadFactory(),getWriterThreads(), m_backGroundThreads, log);
m_readHandlers = ReadHandler.create(getThreadFactory(),getReaderThreads(), this, m_backGroundThreads, log);
}
/**
* Closes all open sockets, the server socket and all threads waiting for incoming messages
*/
public void stop()
{
super.stop();
serverStopping = true;
if(reaper != null)
reaper.stop();
// Stop the main selector
if(m_acceptSelector != null)
m_acceptSelector.wakeup();
// Stop selector threads
if(m_readHandlers != null)
{
for (int i = 0; i < m_readHandlers.length; i++)
{
try
{
m_readHandlers[i].add(new Shutdown());
} catch (InterruptedException e)
{
log.error("Thread ("+Thread.currentThread().getName() +") was interrupted, failed to shutdown selector", e);
}
}
}
if(m_writeHandlers != null)
{
for (int i = 0; i < m_writeHandlers.length; i++)
{
try
{
m_writeHandlers[i].queue.put(new Shutdown());
m_writeHandlers[i].selector.wakeup();
} catch (InterruptedException e)
{
log.error("Thread ("+Thread.currentThread().getName() +") was interrupted, failed to shutdown selector", e);
}
}
}
// Stop the callback thread pool
if(m_requestProcessors instanceof ThreadPoolExecutor)
((ThreadPoolExecutor)m_requestProcessors).shutdownNow();
if(m_requestProcessors instanceof ThreadPoolExecutor){
try{
((ThreadPoolExecutor) m_requestProcessors).awaitTermination(Global.THREADPOOL_SHUTDOWN_WAIT_TIME,
TimeUnit.MILLISECONDS);
}catch(InterruptedException e){
}
}
// then close the connections
synchronized(conns) {
Iterator it=conns.values().iterator();
while(it.hasNext()) {
Connection conn=(Connection)it.next();
conn.destroy();
}
conns.clear();
}
while(!m_backGroundThreads.isEmpty()) {
Thread t =m_backGroundThreads.remove(0);
try {
t.join();
} catch(InterruptedException e) {
log.error("Thread ("+Thread.currentThread().getName() +") was interrupted while waiting on thread " + t.getName() + " to finish.");
}
}
m_backGroundThreads.clear();
}
/**
* Acceptor thread. Continuously accept new connections and assign readhandler/writehandler
* to them.
*/
public void run() {
Connection conn;
while(m_serverSocketChannel.isOpen() && !serverStopping) {
int num;
try {
num=m_acceptSelector.select();
}
catch(IOException e) {
if(log.isWarnEnabled())
log.warn("Select operation on listening socket failed", e);
continue; // Give up this time
}
if(num > 0) {
Set<SelectionKey> readyKeys=m_acceptSelector.selectedKeys();
for(Iterator<SelectionKey> i=readyKeys.iterator(); i.hasNext();) {
SelectionKey key=i.next();
i.remove();
// We only deal with new incoming connections
ServerSocketChannel readyChannel=(ServerSocketChannel)key.channel();
SocketChannel client_sock_ch;
try {
client_sock_ch=readyChannel.accept();
}
catch(IOException e) {
if(log.isWarnEnabled())
log.warn("Attempt to accept new connection from listening socket failed", e);
// Give up this connection
continue;
}
if(log.isTraceEnabled())
log.trace("accepted connection, client_sock=" + client_sock_ch.socket());
try {
client_sock_ch.socket().setSendBufferSize(send_buf_size);
}
catch(IllegalArgumentException ex) {
if(log.isErrorEnabled()) log.error("exception setting send buffer size to " + send_buf_size + " bytes: ", ex);
}
catch(SocketException e) {
if(log.isErrorEnabled()) log.error("exception setting send buffer size to " + send_buf_size + " bytes: ", e);
}
try {
client_sock_ch.socket().setReceiveBufferSize(recv_buf_size);
}
catch(IllegalArgumentException ex) {
if(log.isErrorEnabled()) log.error("exception setting receive buffer size to " + send_buf_size + " bytes: ", ex);
}
catch(SocketException e) {
if(log.isErrorEnabled()) log.error("exception setting receive buffer size to " + recv_buf_size + " bytes: ", e);
}
conn=new Connection(client_sock_ch, null);
try {
Address peer_addr=conn.readPeerAddress(client_sock_ch.socket());
conn.peer_addr=peer_addr;
synchronized(conns) {
Connection tmp=(Connection)conns.get(peer_addr);
if(tmp != null) {
if(peer_addr.compareTo(local_addr) > 0) {
if(log.isTraceEnabled())
log.trace("peer's address (" + peer_addr + ") is greater than our local address (" +
local_addr + "), replacing our existing connection");
// peer's address is greater, add peer's connection to ConnectionTable, destroy existing connection
addConnection(peer_addr, conn);
tmp.destroy();
notifyConnectionOpened(peer_addr);
}
else {
if(log.isTraceEnabled())
log.trace("peer's address (" + peer_addr + ") is smaller than our local address (" +
local_addr + "), rejecting peer connection request");
conn.destroy();
continue;
}
}
else {
addConnection(peer_addr, conn);
}
}
notifyConnectionOpened(peer_addr);
client_sock_ch.configureBlocking(false);
}
catch(IOException e) {
if(log.isWarnEnabled())
log.warn("Attempt to configure non-blocking mode failed", e);
conn.destroy();
continue;
}
catch(Exception e) {
if(log.isWarnEnabled())
log.warn("Attempt to handshake with other peer failed", e);
conn.destroy();
continue;
}
int idx;
synchronized(m_lockNextWriteHandler) {
idx=m_nextWriteHandler=(m_nextWriteHandler + 1) % m_writeHandlers.length;
}
conn.setupWriteHandler(m_writeHandlers[idx]);
try {
synchronized(m_lockNextReadHandler) {
idx=m_nextReadHandler=(m_nextReadHandler + 1) % m_readHandlers.length;
}
m_readHandlers[idx].add(conn);
}
catch(InterruptedException e) {
if(log.isWarnEnabled())
log.warn("Attempt to configure read handler for accepted connection failed", e);
// close connection
conn.destroy();
}
} // end of iteration
} // end of selected key > 0
} // end of thread
if(m_serverSocketChannel.isOpen()) {
try {
m_serverSocketChannel.close();
}
catch(Exception e) {
log.error("exception closing server listening socket", e);
}
}
if(log.isTraceEnabled())
log.trace("acceptor thread terminated");
}
/**
* Finds first available port starting at start_port and returns server socket. Sets srv_port
*/
protected ServerSocket createServerSocket(int start_port, int end_port) throws Exception
{
this.m_acceptSelector = Selector.open();
m_serverSocketChannel = ServerSocketChannel.open();
m_serverSocketChannel.configureBlocking(false);
while (true)
{
try
{
SocketAddress sockAddr;
if (bind_addr == null)
{
sockAddr=new InetSocketAddress(start_port);
m_serverSocketChannel.socket().bind(sockAddr);
}
else
{
sockAddr=new InetSocketAddress(bind_addr, start_port);
m_serverSocketChannel.socket().bind(sockAddr, backlog);
}
}
catch (BindException bind_ex)
{
if (start_port == end_port)
throw (BindException) ((new BindException("No available port to bind to (start_port=" + start_port + ")")).initCause(bind_ex));
start_port++;
continue;
}
catch (SocketException bind_ex)
{
if (start_port == end_port)
throw (BindException) ((new BindException("No available port to bind to (start_port=" + start_port + ")")).initCause(bind_ex));
start_port++;
continue;
}
catch (IOException io_ex)
{
if (log.isErrorEnabled()) log.error("Attempt to bind serversocket failed, port="+start_port+", bind addr=" + bind_addr ,io_ex);
throw io_ex;
}
srv_port = start_port;
break;
}
m_serverSocketChannel.register(this.m_acceptSelector, SelectionKey.OP_ACCEPT);
return m_serverSocketChannel.socket();
}
protected void runRequest(Address addr, ByteBuffer buf) throws InterruptedException {
m_requestProcessors.execute(new ExecuteTask(addr, buf));
}
// Represents shutdown
private static class Shutdown {
}
// ReadHandler has selector to deal with read, it runs in seperated thread
private static class ReadHandler implements Runnable {
private final Selector selector= initHandler();
private final LinkedBlockingQueue<Object> queue= new LinkedBlockingQueue<Object>();
private final ConnectionTableNIO connectTable;
private final Log log;
ReadHandler(ConnectionTableNIO ct, Log log) {
connectTable= ct;
this.log=log;
}
public Selector initHandler()
{
// Open the selector
try
{
return Selector.open();
} catch (IOException e)
{
if (log.isErrorEnabled()) log.error(e.toString());
throw new IllegalStateException(e.getMessage());
}
}
/**
* create instances of ReadHandler threads for receiving data.
*
* @param workerThreads is the number of threads to create.
*/
private static ReadHandler[] create(org.jgroups.util.ThreadFactory f,int workerThreads, ConnectionTableNIO ct, List<Thread> backGroundThreads, Log log)
{
ReadHandler[] handlers = new ReadHandler[workerThreads];
for (int looper = 0; looper < workerThreads; looper++)
{
handlers[looper] = new ReadHandler(ct, log);
Thread thread = f.newThread(handlers[looper], "nioReadHandlerThread");
thread.setDaemon(true);
thread.start();
backGroundThreads.add(thread);
}
return handlers;
}
private void add(Object conn) throws InterruptedException
{
queue.put(conn);
wakeup();
}
private void wakeup()
{
selector.wakeup();
}
public void run()
{
while (true)
{ // m_s can be closed by the management thread
int events;
try
{
events = selector.select();
} catch (IOException e)
{
if (log.isWarnEnabled())
log.warn("Select operation on socket failed", e);
continue; // Give up this time
} catch (ClosedSelectorException e)
{
if (log.isWarnEnabled())
log.warn("Select operation on socket failed" , e);
return; // Selector gets closed, thread stops
}
if (events > 0)
{ // there are read-ready channels
Set readyKeys = selector.selectedKeys();
try
{
for (Iterator i = readyKeys.iterator(); i.hasNext();)
{
SelectionKey key = (SelectionKey) i.next();
i.remove();
// Do partial read and handle call back
Connection conn = (Connection) key.attachment();
if(conn != null && conn.getSocketChannel() != null)
{
try
{
if (conn.getSocketChannel().isOpen())
readOnce(conn);
else
{ // socket connection is already closed, clean up connection state
conn.closed();
}
} catch (IOException e)
{
if (log.isTraceEnabled()) log.trace("Read operation on socket failed" , e);
// The connection must be bad, cancel the key, close socket, then
// remove it from table!
key.cancel();
conn.destroy();
conn.closed();
}
}
}
}
catch(ConcurrentModificationException e) {
if (log.isTraceEnabled()) log.trace("Selection set changed", e);
// valid events should still be in the selection set the next time
}
}
// Now we look at the connection queue to get any new connections added
Object o;
try
{
o = queue.poll(0L, TimeUnit.MILLISECONDS); // get a connection
} catch (InterruptedException e)
{
if (log.isTraceEnabled()) log.trace("Thread ("+Thread.currentThread().getName() +") was interrupted while polling queue" ,e);
// We must give up
continue;
}
if (null == o)
continue;
if (o instanceof Shutdown) { // shutdown command?
try {
selector.close();
} catch(IOException e) {
if (log.isTraceEnabled()) log.trace("Read selector close operation failed" , e);
}
return; // stop reading
}
Connection conn = (Connection) o;// must be a new connection
SocketChannel sc = conn.getSocketChannel();
try
{
sc.register(selector, SelectionKey.OP_READ, conn);
} catch (ClosedChannelException e)
{
if (log.isTraceEnabled()) log.trace("Socket channel was closed while we were trying to register it to selector" , e);
// Channel becomes bad. The connection must be bad,
// close socket, then remove it from table!
conn.destroy();
conn.closed();
}
} // end of the while true loop
}
private void readOnce(Connection conn)
throws IOException
{
ConnectionReadState readState = conn.getReadState();
if (!readState.isHeadFinished())
{ // a brand new message coming or header is not completed
// Begin or continue to read header
int size = readHeader(conn);
if (0 == size)
{ // header is not completed
return;
}
}
// Begin or continue to read body
if (readBody(conn) > 0)
{ // not finish yet
return;
}
Address addr = conn.getPeerAddress();
ByteBuffer buf = readState.getReadBodyBuffer();
// Clear status
readState.bodyFinished();
// Assign worker thread to execute call back
try
{
connectTable.runRequest(addr, buf);
} catch (InterruptedException e)
{
// Cannot do call back, what can we do?
// Give up handling the message then
log.error("Thread ("+Thread.currentThread().getName() +") was interrupted while assigning executor to process read request" , e);
}
}
/**
* Read message header from channel. It doesn't try to complete. If there is nothing in
* the channel, the method returns immediately.
*
* @param conn The connection
* @return 0 if header hasn't been read completely, otherwise the size of message body
* @throws IOException
*/
private int readHeader(Connection conn)
throws IOException
{
ConnectionReadState readState = conn.getReadState();
ByteBuffer headBuf = readState.getReadHeadBuffer();
SocketChannel sc = conn.getSocketChannel();
while (headBuf.remaining() > 0)
{
int num = sc.read(headBuf);
if (-1 == num)
{// EOS
throw new IOException("Peer closed socket");
}
if (0 == num) // no more data
return 0;
}
// OK, now we get the whole header, change the status and return message size
return readState.headFinished();
}
/**
* Read message body from channel. It doesn't try to complete. If there is nothing in
* the channel, the method returns immediately.
*
* @param conn The connection
* @return remaining bytes for the message
* @throws IOException
*/
private int readBody(Connection conn)
throws IOException
{
ByteBuffer bodyBuf = conn.getReadState().getReadBodyBuffer();
SocketChannel sc = conn.getSocketChannel();
while (bodyBuf.remaining() > 0)
{
int num = sc.read(bodyBuf);
if (-1 == num) // EOS
throw new IOException("Couldn't read from socket as peer closed the socket");
if (0 == num) // no more data
return bodyBuf.remaining();
}
// OK, we finished reading the whole message! Flip it (not necessary though)
bodyBuf.flip();
return 0;
}
}
private class ExecuteTask implements Runnable {
Address m_addr = null;
ByteBuffer m_buf = null;
public ExecuteTask(Address addr, ByteBuffer buf)
{
m_addr = addr;
m_buf = buf;
}
public void run()
{
receive(m_addr, m_buf.array(), m_buf.arrayOffset(), m_buf.limit());
}
}
private class ConnectionReadState {
private final Connection m_conn;
// Status for receiving message
private boolean m_headFinished = false;
private ByteBuffer m_readBodyBuf = null;
private final ByteBuffer m_readHeadBuf = ByteBuffer.allocate(Connection.HEADER_SIZE);
public ConnectionReadState(Connection conn)
{
m_conn = conn;
}
ByteBuffer getReadBodyBuffer()
{
return m_readBodyBuf;
}
ByteBuffer getReadHeadBuffer()
{
return m_readHeadBuf;
}
void bodyFinished()
{
m_headFinished = false;
m_readHeadBuf.clear();
m_readBodyBuf = null;
m_conn.updateLastAccessed();
}
/**
* Status change for finishing reading the message header (data already in buffer)
*
* @return message size
*/
int headFinished()
{
m_headFinished = true;
m_readHeadBuf.flip();
int messageSize = m_readHeadBuf.getInt();
m_readBodyBuf = ByteBuffer.allocate(messageSize);
m_conn.updateLastAccessed();
return messageSize;
}
boolean isHeadFinished()
{
return m_headFinished;
}
}
class Connection extends BasicConnectionTable.Connection {
private SocketChannel sock_ch = null;
private WriteHandler m_writeHandler;
private SelectorWriteHandler m_selectorWriteHandler;
private final ConnectionReadState m_readState;
private static final int HEADER_SIZE = 4;
final ByteBuffer headerBuffer = ByteBuffer.allocate(HEADER_SIZE);
Connection(SocketChannel s, Address peer_addr)
{
super(s.socket(), peer_addr);
sock_ch = s;
m_readState = new ConnectionReadState(this);
is_running=true;
}
private ConnectionReadState getReadState()
{
return m_readState;
}
private void setupWriteHandler(WriteHandler hdlr)
{
m_writeHandler = hdlr;
m_selectorWriteHandler = hdlr.add(sock_ch);
}
void doSend(byte[] buffie, int offset, int length) throws Exception
{
MyFuture result = new MyFuture();
m_writeHandler.write(sock_ch, ByteBuffer.wrap(buffie, offset, length), result, m_selectorWriteHandler);
Object ex = result.get();
if (ex instanceof Exception)
{
if (log.isErrorEnabled())
log.error("failed sending message", (Exception)ex);
if (((Exception)ex).getCause() instanceof IOException)
throw (IOException) ((Exception)ex).getCause();
throw (Exception)ex;
}
result.get();
}
SocketChannel getSocketChannel()
{
return sock_ch;
}
synchronized void closeSocket()
{
if (sock_ch != null)
{
try
{
if(sock_ch.isConnected() && sock_ch.isOpen()) {
sock_ch.close();
}
}
catch (Exception e)
{
log.error("error closing socket connection", e);
}
sock_ch = null;
}
}
void closed()
{
Address peerAddr = getPeerAddress();
synchronized (conns)
{
conns.remove(peerAddr);
}
notifyConnectionClosed(peerAddr);
}
}
/**
* Handle writing to non-blocking NIO connection.
*/
private static class WriteHandler implements Runnable {
// Create a queue for write requests (unbounded)
private final LinkedBlockingQueue<Object> queue= new LinkedBlockingQueue<Object>();
private final Selector selector= initSelector();
private int m_pendingChannels; // count of the number of channels that have pending writes
// note that this variable is only accessed by one thread.
// allocate and reuse the header for all buffer write operations
private ByteBuffer m_headerBuffer = ByteBuffer.allocate(Connection.HEADER_SIZE);
private final Log log;
public WriteHandler(Log log) {
this.log=log;
}
Selector initSelector() {
try
{
return SelectorProvider.provider().openSelector();
}
catch (IOException e)
{
if (log.isErrorEnabled()) log.error(e.toString());
throw new IllegalStateException(e.getMessage());
}
}
/**
* create instances of WriteHandler threads for sending data.
*
* @param workerThreads is the number of threads to create.
*/
private static WriteHandler[] create(org.jgroups.util.ThreadFactory f, int workerThreads, List<Thread> backGroundThreads, Log log)
{
WriteHandler[] handlers = new WriteHandler[workerThreads];
for (int looper = 0; looper < workerThreads; looper++)
{
handlers[looper] = new WriteHandler(log);
Thread thread = f.newThread(handlers[looper], "nioWriteHandlerThread");
thread.setDaemon(true);
thread.start();
backGroundThreads.add(thread);
}
return handlers;
}
/**
* Add a new channel to be handled.
*
* @param channel
*/
private SelectorWriteHandler add(SocketChannel channel)
{
return new SelectorWriteHandler(channel, selector, m_headerBuffer);
}
/**
* Writes buffer to the specified socket connection. This is always performed asynchronously. If you want
* to perform a synchrounous write, call notification.`get() which will block until the write operation is complete.
* Best practice is to call notification.getException() which may return any exceptions that occured during the write
* operation.
*
* @param channel is where the buffer is written to.
* @param buffer is what we write.
* @param notification may be specified if you want to know how many bytes were written and know if an exception
* occurred.
*/
private void write(SocketChannel channel, ByteBuffer buffer, MyFuture notification, SelectorWriteHandler hdlr) throws InterruptedException
{
queue.put(new WriteRequest(channel, buffer, notification, hdlr));
}
private static void close(SelectorWriteHandler entry)
{
entry.cancel();
}
private static void handleChannelError( SelectorWriteHandler entry, Throwable error)
{
// notify callers of the exception and drain all of the send buffers for this channel.
do
{
if (error != null)
entry.notifyError(error);
}
while (entry.next());
close(entry);
}
// process the write operation
private void processWrite(Selector selector)
{
Set keys = selector.selectedKeys();
Object arr[] = keys.toArray();
for (Object anArr : arr) {
SelectionKey key = (SelectionKey) anArr;
SelectorWriteHandler entry = (SelectorWriteHandler) key.attachment();
boolean needToDecrementPendingChannels = false;
try {
if (0 == entry.write()) { // write the buffer and if the remaining bytes is zero,
// notify the caller of number of bytes written.
entry.notifyObject(entry.getBytesWritten());
// switch to next write buffer or clear interest bit on socket channel.
if (!entry.next()) {
needToDecrementPendingChannels = true;
}
}
}
catch (IOException e) {
needToDecrementPendingChannels = true;
// connection must of closed
handleChannelError(entry, e);
}
finally {
if (needToDecrementPendingChannels)
m_pendingChannels--;
}
}
keys.clear();
}
public void run()
{
while (selector.isOpen())
{
try
{
WriteRequest queueEntry;
Object o;
// When there are no more commands in the Queue, we will hit the blocking code after this loop.
while (null != (o = queue.poll(0L, TimeUnit.MILLISECONDS)))
{
if (o instanceof Shutdown) // Stop the thread
{
try {
selector.close();
} catch(IOException e) {
if (log.isTraceEnabled()) log.trace("Write selector close operation failed" , e);
}
return;
}
queueEntry = (WriteRequest) o;
if (queueEntry.getHandler().add(queueEntry))
{
// If the add operation returns true, than means that a buffer is available to be written to the
// corresponding channel and channel's selection key has been modified to indicate interest in the
// 'write' operation.
// If the add operation threw an exception, we will not increment m_pendingChannels which
// seems correct as long as a new buffer wasn't added to be sent.
// Another way to view this is that we don't have to protect m_pendingChannels on the increment
// side, only need to protect on the decrement side (this logic of this run() will be incorrect
// if m_pendingChannels is set incorrectly).
m_pendingChannels++;
}
try
{
// process any connections ready to be written to.
if (selector.selectNow() > 0)
{
processWrite(selector);
}
}
catch (IOException e)
{ // need to understand what causes this error so we can handle it properly
if (log.isErrorEnabled()) log.error("SelectNow operation on write selector failed, didn't expect this to occur, please report this", e);
return; // if select fails, give up so we don't go into a busy loop.
}
}
// if there isn't any pending work to do, block on queue to get next request.
if (m_pendingChannels == 0)
{
o = queue.take();
if (o instanceof Shutdown){ // Stop the thread
try {
selector.close();
} catch(IOException e) {
if (log.isTraceEnabled()) log.trace("Write selector close operation failed" , e);
}
return;
}
queueEntry = (WriteRequest) o;
if (queueEntry.getHandler().add(queueEntry))
m_pendingChannels++;
}
// otherwise do a blocking wait select operation.
else
{
try
{
if ((selector.select()) > 0)
{
processWrite(selector);
}
}
catch (IOException e)
{ // need to understand what causes this error
if (log.isErrorEnabled()) log.error("Failure while writing to socket",e);
}
}
}
catch (InterruptedException e)
{
if (log.isErrorEnabled()) log.error("Thread ("+Thread.currentThread().getName() +") was interrupted", e);
}
catch (Throwable e) // Log throwable rather than terminating this thread.
{ // We are a daemon thread so we shouldn't prevent the process from terminating if
// the controlling thread decides that should happen.
if (log.isErrorEnabled()) log.error("Thread ("+Thread.currentThread().getName() +") caught Throwable" , e);
}
}
}
}
// Wrapper class for passing Write requests. There will be an instance of this class for each socketChannel
// mapped to a Selector.
public static class SelectorWriteHandler {
private final List<WriteRequest> m_writeRequests = new LinkedList<WriteRequest>(); // Collection of writeRequests
private boolean m_headerSent = false;
private SocketChannel m_channel;
private SelectionKey m_key;
private Selector m_selector;
private int m_bytesWritten = 0;
private boolean m_enabled = false;
private ByteBuffer m_headerBuffer;
SelectorWriteHandler(SocketChannel channel, Selector selector, ByteBuffer headerBuffer)
{
m_channel = channel;
m_selector = selector;
m_headerBuffer = headerBuffer;
}
private void register(Selector selector, SocketChannel channel) throws ClosedChannelException
{
// register the channel but don't enable OP_WRITE until we have a write request.
m_key = channel.register(selector, 0, this);
}
// return true if selection key is enabled when it wasn't previous to call.
private boolean enable()
{
boolean rc = false;
try
{
if (m_key == null)
{ // register the socket on first access,
// we are the only thread using this variable, so no sync needed.
register(m_selector, m_channel);
}
}
catch (ClosedChannelException e)
{
return rc;
}
if (!m_enabled)
{
rc = true;
try
{
m_key.interestOps(SelectionKey.OP_WRITE);
}
catch (CancelledKeyException e)
{ // channel must of closed
return false;
}
m_enabled = true;
}
return rc;
}
private void disable()
{
if (m_enabled)
{
try
{
m_key.interestOps(0); // pass zero which means that we are not interested in being
// notified of anything for this channel.
}
catch (CancelledKeyException eat) // If we finished writing and didn't get an exception, then
{ // we probably don't need to throw this exception (if they try to write
// again, we will then throw an exception).
}
m_enabled = false;
}
}
private void cancel()
{
m_key.cancel();
}
boolean add(WriteRequest entry)
{
m_writeRequests.add(entry);
return enable();
}
WriteRequest getCurrentRequest()
{
return m_writeRequests.get(0);
}
SocketChannel getChannel()
{
return m_channel;
}
ByteBuffer getBuffer()
{
return getCurrentRequest().getBuffer();
}
MyFuture getCallback()
{
return getCurrentRequest().getCallback();
}
int getBytesWritten()
{
return m_bytesWritten;
}
void notifyError(Throwable error)
{
if (getCallback() != null)
getCallback().setException(error);
}
void notifyObject(Object result)
{
if (getCallback() != null)
getCallback().set(result);
}
/**
* switch to next request or disable write interest bit if there are no more buffers.
*
* @return true if another request was found to be processed.
*/
boolean next()
{
m_headerSent = false;
m_bytesWritten = 0;
m_writeRequests.remove(0); // remove current entry
boolean rc = !m_writeRequests.isEmpty();
if (!rc) // disable select for this channel if no more entries
disable();
return rc;
}
/**
* @return bytes remaining to write. This function will only throw IOException, unchecked exceptions are not
* expected to be thrown from here. It is very important for the caller to know if an unchecked exception can
* be thrown in here. Please correct the following throws list to include any other exceptions and update
* caller to handle them.
* @throws IOException
*/
int write() throws IOException
{
// Send header first. Note that while we are writing the shared header buffer,
// no other threads can access the header buffer as we are the only thread that has access to it.
if (!m_headerSent)
{
m_headerSent = true;
m_headerBuffer.clear();
m_headerBuffer.putInt(getBuffer().remaining());
m_headerBuffer.flip();
do
{
getChannel().write(m_headerBuffer);
} // we should be able to handle writing the header in one action but just in case, just do a busy loop
while (m_headerBuffer.remaining() > 0);
}
m_bytesWritten += (getChannel().write(getBuffer()));
return getBuffer().remaining();
}
}
public static class WriteRequest {
private final SocketChannel m_channel;
private final ByteBuffer m_buffer;
private final MyFuture m_callback;
private final SelectorWriteHandler m_hdlr;
WriteRequest(SocketChannel channel, ByteBuffer buffer, MyFuture callback, SelectorWriteHandler hdlr)
{
m_channel = channel;
m_buffer = buffer;
m_callback = callback;
m_hdlr = hdlr;
}
SelectorWriteHandler getHandler()
{
return m_hdlr;
}
SocketChannel getChannel()
{
return m_channel;
}
ByteBuffer getBuffer()
{
return m_buffer;
}
MyFuture getCallback()
{
return m_callback;
}
}
private static class NullCallable implements Callable {
public Object call() {
System.out.println("nullCallable.call invoked");
return null;
}
}
private static final NullCallable NULLCALL = new NullCallable();
public static class MyFuture extends FutureTask { // make FutureTask work like the old FutureResult
public MyFuture() {
super(NULLCALL);
}
protected void set(Object o) {
super.set(o);
}
protected void setException(Throwable t) {
super.setException(t);
}
}
}