mina线程总结

今天对mina的线程做了些实验，先上代码

MyCodecFactory:

public class MyCodecFactory implements ProtocolCodecFactory{    ProtocolEncoderAdapter encoder = new MyEncoder();    ProtocolDecoder decoder = new MyDecoder();    public ProtocolDecoder getDecoder(IoSession session) throws Exception    {        return decoder;    }    public ProtocolEncoder getEncoder(IoSession session) throws Exception    {        return encoder;    }}

MyDecoder:

public class MyDecoder extends ProtocolDecoderAdapter{    @Override    public void decode(IoSession session, IoBuffer in, ProtocolDecoderOutput out) throws Exception    {        int   id  = in.getInt();          int   len = in.getInt();          byte []  dst =  new   byte [len];                    in.get(dst);                    String name = new  String(dst,"GBK");                    Item item = new  Item();          item.setId(id);          item.setName(name);          out.write(item);       }    }

MyEncoder:

public class MyEncoder extends ProtocolEncoderAdapter{    public void encode(IoSession session, Object message, ProtocolEncoderOutput out) throws Exception    {        Item item = (Item) message;        int byteLen = 8 + item.getName().getBytes("GBK").length;        IoBuffer buf = IoBuffer.allocate(byteLen);        buf.putInt(item.getId());        buf.putInt(item.getName().getBytes("GBK").length);        buf.put(item.getName().getBytes("GBK"));        buf.flip();        out.write(buf);    }}

ClientSessionHandle:

public class ClientSessionHandle implements IoHandler{    @Override    public void sessionCreated(IoSession session) throws Exception    {        System.out.println("client sessionCreated" + System.currentTimeMillis());    }    @Override    public void sessionOpened(IoSession session) throws Exception    {        System.out.println("client sessionOpened" + System.currentTimeMillis());    }    @Override    public void sessionClosed(IoSession session) throws Exception    {        System.out.println("client sessionClosed" + System.currentTimeMillis());    }    @Override    public void sessionIdle(IoSession session, IdleStatus status) throws Exception    {        System.out.println("client sessionIdle" + System.currentTimeMillis());    }    @Override    public void exceptionCaught(IoSession session, Throwable cause) throws Exception    {        cause.printStackTrace();        System.out.println("client exceptionCaught" + System.currentTimeMillis());    }    @Override    public void messageReceived(IoSession session, Object message) throws Exception    {        System.out.println("recieveMsg:" + System.currentTimeMillis());    }    @Override    public void messageSent(IoSession session, Object message) throws Exception    {//      Thread.sleep(3000);        System.out.println("client messageSent" + System.currentTimeMillis());    }}

ServerSessionHandle:

public class ServerSessionHandle implements IoHandler{    @Override    public void sessionCreated(IoSession session) throws Exception    {        System.out.println("server sessionCreated" + System.currentTimeMillis());    }    @Override    public void sessionOpened(IoSession session) throws Exception    {        System.out.println("server sessionOpened" + System.currentTimeMillis());    }    @Override    public void sessionClosed(IoSession session) throws Exception    {        System.out.println("server sessionClosed" + System.currentTimeMillis());    }    @Override    public void sessionIdle(IoSession session, IdleStatus status) throws Exception    {        System.out.println("server sessionIdle" + System.currentTimeMillis());    }    @Override    public void exceptionCaught(IoSession session, Throwable cause) throws Exception    {        cause.printStackTrace();        System.out.println("server exceptionCaught");    }    @Override    public void messageReceived(IoSession session, Object message) throws Exception    {//        Thread.sleep(3000);        System.out.println("server recieveMsg:" + System.currentTimeMillis());    }    @Override    public void messageSent(IoSession session, Object message) throws Exception    {        System.out.println("server messageSent" + System.currentTimeMillis());    }}

Client:

public class Client{    public static void main(String[] args) throws IOException    {        IoConnector connector = new NioSocketConnector();        connector.getFilterChain().addLast("protocol", new ProtocolCodecFilter(new MyCodecFactory()));        connector.setHandler(new ClientSessionHandle());//        connector.getFilterChain().addLast("threadPool", new ExecutorFilter(Executors.newCachedThreadPool()));        ConnectFuture future = connector.connect(new InetSocketAddress(8888));        future.awaitUninterruptibly();        IoSession session = future.getSession();        Item item = new Item();        item.setId(1);        item.setName("aaa");        session.write(item);        session.write(item);        session.write(item);        session.write(item);        session.write(item);    }}

Server:

public class Server{    public static void main(String[] args) throws IOException    {        IoAcceptor acceptor = new NioSocketAcceptor();        acceptor.getFilterChain().addLast("protocol", new ProtocolCodecFilter(new MyCodecFactory()));//        acceptor.getFilterChain().addLast("threadPool", new ExecutorFilter(Executors.newCachedThreadPool()));         acceptor.setHandler(new ServerSessionHandle());        acceptor.bind(new InetSocketAddress(8888));    }}

mina简介

mina的工作模式如下图所示

acceptor用于处理客户端的连接，当有客户端连接时，将连接交给Processor处理，Process是多线程的，在内部由一个线程池来处理，线程的个数由创建Acceptor时参数指定，默认是cpu核数加1，filter主要用来对消息进行过虑，经常用来做编码解码，消息经过filter过虑之后由handler来处理，我们做开发时业务也都是在handler层做。

一个客户端连接到服务器端之后，由一个且只会有一个processor来处理。服务器启动后，processor的数量是0，每一个客户端连接上来，就会创建一个Processor，直到达到最高数量。当所有的processor都在处理客户端的信息时，后续的客户端都会产生阻塞，所以当同时处理消息量过多，io不多，但是handler处理时间较长时，我们就要采用另一种处理方式 ，即把handler放在另外的线程来处理，代码如下：

acceptor.getFilterChain().addLast("threadPool", new ExecutorFilter(Executors.newCachedThreadPool()));

实验过程

这篇文章的重点内容是来实验mina的线程问题，主要是processor和handler使用不同线程处理客户端消息的情况，实验内容是客户端连接成功之后连续发送5条消息

（1）客户端与服务器端都不采用handler单独线程，客户端ClientSessionHandle的messageSent方法延迟3s发送，结果如下，消息是排着队发送

           客户端结果

client sessionCreated1384482297824
client sessionOpened1384482297825
client messageSent1384482300829
client messageSent1384482303829
client messageSent1384482306830
client messageSent1384482309830
client messageSent1384482312830

           服务器结果

server sessionCreated1384482297813
server sessionOpened1384482297813
server recieveMsg:1384482297828
server recieveMsg:1384482300829
server recieveMsg:1384482303830
server recieveMsg:1384482306830
server recieveMsg:1384482309830

（2）客户端采用handler单独线程，客户端ClientSessionHandle的messageSent方法延迟3s发送，结果如下，消息是连接成功之后延迟3s并行发送出去

           客户端结果

client sessionCreated1384482710537
client sessionOpened1384482710538
client messageSent1384482713542
client messageSent1384482713542
client messageSent1384482713542
client messageSent1384482713542
client messageSent1384482713542

           服务器结果

server sessionCreated1384482710525
server sessionOpened1384482710526
server recieveMsg:1384482710541
server recieveMsg:1384482710541
server recieveMsg:1384482710542
server recieveMsg:1384482710542
server recieveMsg:1384482710542

（3）客户端采用handler单独线程，客户端连接成功之后不延迟3s直接发送5条消息，服务器端ServerSessionHandle延迟3s接收，结果如下，5条消息是一起发出，但服务器端每3s处理一条消息，jconcle监控发现只有一个processor线程，由此验证了：一个客户端只会有一个processor进行处理，handler与processor同一线程的情况下，消息是排队的。

           客户端结果

client sessionCreated1384482908375
client sessionOpened1384482908377
client messageSent1384482908380
client messageSent1384482908380
client messageSent1384482908381
client messageSent1384482908381
client messageSent1384482908381

           服务器结果

server sessionCreated1384482908372
server sessionOpened1384482908372
server recieveMsg:1384482911381
server recieveMsg:1384482914382
server recieveMsg:1384482917382
server recieveMsg:1384482920382
server recieveMsg:1384482923382

（4）客户端与服务器端都采用handler单独线程，客户端连接成功之后不延迟3s直接发送5条消息，服务器端ServerSessionHandle延迟3s接收，结果如下，5条消息是一起发出，服务端延迟3s后一起处理了5条消息，jconcle监控发现还是只有一个processor线程，但还会创建另外5个线程，这五个线程各自处理了一条消息，由此验证了：一个客户端只会有一个processor进行处理，processor接收到客户端的消息之后，放到了handler处理线程中处理。

           客户端结果

client sessionCreated1384483318084
client sessionOpened1384483318086
client messageSent1384483318088
client messageSent1384483318089
client messageSent1384483318089
client messageSent1384483318089
client messageSent1384483318089

           服务器结果

server sessionCreated1384483318081
server sessionOpened1384483318082
server recieveMsg:1384483321090
server recieveMsg:1384483321091
server recieveMsg:1384483321091
server recieveMsg:1384483321091
server recieveMsg:1384483321091