解析Tomcat处理请求的类Connector<二>

shuaiwei588

　　这次主要解析采用IO方式处理请求.在Server.xml的配置如下:

   <Connector port="8080" protocol="HTTP/1.1"
connectionTimeout="20000"
redirectPort="8443" />
　　在tomcat启动的时候,会调用Connector类的Start()方法,根据以上配置,Connector的start()方法里会调用Http11Protocol类的start()方法,如下:

       try {
protocolHandler.start();
} catch (Exception e) {
String errPrefix = "";
if(this.service != null) {
errPrefix += "service.getName(): \"" + this.service.getName() + "\"; ";
}
throw new LifecycleException
(errPrefix + " " + sm.getString
("coyoteConnector.protocolHandlerStartFailed", e));
}
　　Http11Protocol类的start()方法又会调用JIoEndpoint类的start()方法,如下:

try {
endpoint.start();
} catch (Exception ex) {
log.error(sm.getString("http11protocol.endpoint.starterror"), ex);
throw ex;
}
　　JIoEndpoint类的start()方法如下:

public void start()
throws Exception {
// Initialize socket if not done before
if (!initialized) {
init();
}
if (!running) {
running = true;
paused = false;
// Create worker collection
if (executor == null) {
workers = new WorkerStack(maxThreads);
}
// Start acceptor threads
for (int i = 0; i < acceptorThreadCount; i++) {
Thread acceptorThread = new Thread(new Acceptor(), getName() + "-Acceptor-" + i);
acceptorThread.setPriority(threadPriority);
acceptorThread.setDaemon(daemon);
acceptorThread.start();
}
}
}
　　该方法主要初始化了接受Socket的线程Acceptor类,处理Socket的线程池WorkerStack.Acceptor类的run()方法如下:

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
}
}
// Accept the next incoming connection from the server socket
try {
Socket socket = serverSocketFactory.acceptSocket(serverSocket);
serverSocketFactory.initSocket(socket);
// Hand this socket off to an appropriate processor
if (!processSocket(socket)) {//将socket交给线程池WorkerStack处理
// Close socket right away
try {
socket.close();
} catch (IOException e) {
// Ignore
}
}
}catch ( IOException x ) {
if ( running ) log.error(sm.getString("endpoint.accept.fail"), x);
} catch (Throwable t) {
log.error(sm.getString("endpoint.accept.fail"), t);
}
// The processor will recycle itself when it finishes
}
}
}
　　processSocket(socket)方法如下:

    protected boolean processSocket(Socket socket) {
try {
if (executor == null) {
getWorkerThread().assign(socket);//将socket分给独立的线程worker处理
} else {
executor.execute(new SocketProcessor(socket));
}
} catch (Throwable t) {
// This means we got an OOM or similar creating a thread, or that
// the pool and its queue are full
log.error(sm.getString("endpoint.process.fail"), t);
return false;
}
return true;
}
　　worker的run()方法如下:

public void run() {
// Process requests until we receive a shutdown signal
while (running) {
// Wait for the next socket to be assigned
Socket socket = await();
if (socket == null)
continue;
// 将socket交给Http11ConnectionHandler处理
if (!setSocketOptions(socket) || !handler.process(socket)) {
// Close socket
try {
socket.close();
} catch (IOException e) {
}
}
// Finish up this request
socket = null;
recycleWorkerThread(this);
}
}
　　handler.process(socket)方法如下:

if (processor == null) {
processor = createProcessor();
}
if (processor instanceof ActionHook) {
((ActionHook) processor).action(ActionCode.ACTION_START, null);
}
if (proto.isSSLEnabled() && (proto.sslImplementation != null)) {
processor.setSSLSupport
(proto.sslImplementation.getSSLSupport(socket));
} else {
processor.setSSLSupport(null);
}
//socket交由Http11Processor的process()方法处理
processor.process(socket);
return false;
　　processor.process(socket)负责解析http协议并返回结果内容