public static class NioSocketWrapper extends SocketWrapperBase { private final NioSelectorPool pool; private Poller poller = null; // 轮询的Poller private int interestOps = 0; private CountDownLatch readLatch = null; private CountDownLatch writeLatch = null; private volatile SendfileData sendfileData = null; private volatile long lastRead = System.currentTimeMillis(); private volatile long lastWrite = lastRead; private volatile boolean closed = false;

（6）NioEndPoint.SocketProcessor（Worker）继承了Runnable接口，负责对socket的g各种事件进行处理。读事件、写事件、停止时间、超时事件、断连事件、错误时间、连接失败事件。

@Override protected void doRun() { NioChannel socket = socketWrapper.getSocket(); SelectionKey key = socket.getIOChannel().keyFor(socket.getPoller().getSelector()); try { int handshake = -1; try { if (key != null) { if (socket.isHandshakeComplete()) { // 是否已经握手成功，不需要TLS(加密)握手，就让处理器对socket和event的组合进行处理。 handshake = 0; } else if (event == SocketEvent.STOP || event == SocketEvent.DISCONNECT || event == SocketEvent.ERROR) { // 不能够完成TLS握手，就把他认为是TLS握手失败。 handshake = -1; } else { handshake = socket.handshake(key.isReadable(), key.isWritable()); // The handshake process reads/writes from/to the // socket. status may therefore be OPEN_WRITE once // the handshake completes. However, the handshake // happens when the socket is opened so the status // must always be OPEN_READ after it completes. It // is OK to always set this as it is only used if // the handshake completes. // 握手从/向socket读/写时，握手一旦完成状态应该为OPEN_WRITE， // 握手是在套接字打开时发生的，因此在完成后状态必须始终为OPEN_READ // 始终设置此选项是可以的，因为它仅在握手完成时使用。 event = SocketEvent.OPEN_READ; } } } catch (IOException x) { handshake = -1; if (log.isDebugEnabled()) log.debug("Error during SSL handshake", x); } catch (CancelledKeyException ckx) { handshake = -1; } if (handshake == 0) { SocketState state = SocketState.OPEN; // Process the request from this socket if (event == null) { // 调用处理器进行处理。 // NioEndPoint的默认Handler是Http11的 // 这里的Handler是AbstractProtocol.ConnectionHandler // 这个Handler的设置方法是： // 首先在Connector类的构造函数中，将默认的ProtocolHandler设置为org.apache.coyote.http11.Http11NioProtocol // AbstractHttp11Protocol的构造函数里面创建了Handler类ConnectionHandler state = getHandler().process(socketWrapper, SocketEvent.OPEN_READ); } else { state = getHandler().process(socketWrapper, event); } // 如果返回的状态是SocketState，那么就关掉连接 if (state == SocketState.CLOSED) { close(socket, key); } } else if (handshake == -1) { getHandler().process(socketWrapper, SocketEvent.CONNECT_FAIL); close(socket, key); } else if (handshake == SelectionKey.OP_READ) { // 如果是SelectionKey.OP_READ，也就是读事件的话，就将OP_READ时间设置到socketWrapper socketWrapper.registerReadInterest(); } else if (handshake == SelectionKey.OP_WRITE) { // 如果是SelectionKey.OP_WRITE，也就是读事件的话，就将OP_WRITE事件设置到socketWrapper socketWrapper.registerWriteInterest(); }二、ConnectionHandler

（1）ConnectionHandler用于根据Socket连接找到相应的Engine处理器。

protected static class ConnectionHandler implements AbstractEndpoint.Handler { private final AbstractProtocol proto; private final RequestGroupInfo global = new RequestGroupInfo(); private final AtomicLong registerCount = new AtomicLong(0); // 终于找到了这个集合，给Socket和处理器建立连接 // 对每个有效链接都会缓存进这里，用于连接选择一个合适的Processor实现以进行请求处理。 private final Map connections = new ConcurrentHashMap<>(); // 可循环的处理器栈 private final RecycledProcessors recycledProcessors = new RecycledProcessors(this); @Override public SocketState process(SocketWrapperBase wrapper, SocketEvent status) { if (getLog().isDebugEnabled()) { getLog().debug(sm.getString("abstractConnectionHandler.process", wrapper.getSocket(), status)); } if (wrapper == null) { // wrapper == null 表示Socket已经被关闭了，所以不需要做任何操作。 return SocketState.CLOSED; } // 得到wrapper内的Socket对象 S socket = wrapper.getSocket(); // 从Map缓冲区中得到socket对应的处理器。 Processor processor = connections.get(socket); if (getLog().isDebugEnabled()) { getLog().debug(sm.getString("abstractConnectionHandler.connectionsGet", processor, socket)); } // Timeouts are calculated on a dedicated thread and then // dispatched. Because of delays in the dispatch process, the // timeout may no longer be required. Check here and avoid // unnecessary processing. // 超时是在专用线程上计算的，然后被调度。 // 因为调度过程中的延迟，可能不再需要超时。检查这里，避免不必要的处理。 if (SocketEvent.TIMEOUT == status && (processor == null || !processor.isAsync() && !processor.isUpgrade() || processor.isAsync() && !processor.checkAsyncTimeoutGeneration())) { // This is effectively a NO-OP return SocketState.OPEN; } // 如果Map缓存存在该socket相关的处理器 if (processor != null) { // Make sure an async timeout doesn't fire // 确保没有触发异步超时 getProtocol().removeWaitingProcessor(processor); } else if (status == SocketEvent.DISCONNECT || status == SocketEvent.ERROR) { // Nothing to do. Endpoint requested a close and there is no // longer a processor associated with this socket. // SocketEvent事件是关闭，或者SocketEvent时间出错，此时不需要做任何操作。 // Endpoint需要一个CLOSED的信号，并且这里不再有与这个socket有关联了 return SocketState.CLOSED; } ContainerThreadMarker.set(); try { // Map缓存不存在该socket相关的处理器 if (processor == null) { String negotiatedProtocol = wrapper.getNegotiatedProtocol(); // OpenSSL typically returns null whereas JSSE typically // returns "" when no protocol is negotiated // OpenSSL通常返回null，而JSSE通常在没有协议协商时返回"" if (negotiatedProtocol != null && negotiatedProtocol.length() > 0) { // 获取协商协议 UpgradeProtocol upgradeProtocol = getProtocol().getNegotiatedProtocol(negotiatedProtocol); if (upgradeProtocol != null) { // 升级协议为空 processor = upgradeProtocol.getProcessor(wrapper, getProtocol().getAdapter()); if (getLog().isDebugEnabled()) { getLog().debug(sm.getString("abstractConnectionHandler.processorCreate", processor)); } } else if (negotiatedProtocol.equals("http/1.1")) { // Explicitly negotiated the default protocol. // Obtain a processor below. } else { // TODO: // OpenSSL 1.0.2's ALPN callback doesn't support // failing the handshake with an error if no // protocol can be negotiated. Therefore, we need to // fail the connection here. Once this is fixed, // replace the code below with the commented out // block. if (getLog().isDebugEnabled()) { getLog().debug(sm.getString("abstractConnectionHandler.negotiatedProcessor.fail", negotiatedProtocol)); } return SocketState.CLOSED; /* * To replace the code above once OpenSSL 1.1.0 is * used. // Failed to create processor. This is a bug. throw new IllegalStateException(sm.getString( "abstractConnectionHandler.negotiatedProcessor.fail", negotiatedProtocol)); */ } } } // 经过上面的操作，processor还是null的话。 if (processor == null) { // 从recycledProcessors可循环processors中获取processor processor = recycledProcessors.pop(); if (getLog().isDebugEnabled()) { getLog().debug(sm.getString("abstractConnectionHandler.processorPop", processor)); } } if (processor == null) { // 创建处理器 processor = getProtocol().createProcessor(); register(processor); if (getLog().isDebugEnabled()) { getLog().debug(sm.getString("abstractConnectionHandler.processorCreate", processor)); } } processor.setSslSupport( wrapper.getSslSupport(getProtocol().getClientCertProvider())); // 将socket和processor建立关联。 connections.put(socket, processor); SocketState state = SocketState.CLOSED; do { // 调用processor的process方法。 state = processor.process(wrapper, status); // processor的process方法返回升级状态 if (state == SocketState.UPGRADING) { // Get the HTTP upgrade handler // 得到HTTP的升级句柄 UpgradeToken upgradeToken = processor.getUpgradeToken(); // Retrieve leftover input // 检索剩余输入 ByteBuffer leftOverInput = processor.getLeftoverInput(); if (upgradeToken == null) { // Assume direct HTTP/2 connection UpgradeProtocol upgradeProtocol = getProtocol().getUpgradeProtocol("h2c"); if (upgradeProtocol != null) { // Release the Http11 processor to be re-used release(processor); // Create the upgrade processor processor = upgradeProtocol.getProcessor(wrapper, getProtocol().getAdapter()); wrapper.unRead(leftOverInput); // Associate with the processor with the connection connections.put(socket, processor); } else { if (getLog().isDebugEnabled()) { getLog().debug(sm.getString( "abstractConnectionHandler.negotiatedProcessor.fail", "h2c")); } // Exit loop and trigger appropriate clean-up state = SocketState.CLOSED; } } else { HttpUpgradeHandler httpUpgradeHandler = upgradeToken.getHttpUpgradeHandler(); // Release the Http11 processor to be re-used release(processor); // Create the upgrade processor processor = getProtocol().createUpgradeProcessor(wrapper, upgradeToken); if (getLog().isDebugEnabled()) { getLog().debug(sm.getString("abstractConnectionHandler.upgradeCreate", processor, wrapper)); } wrapper.unRead(leftOverInput); // Associate with the processor with the connection connections.put(socket, processor); // Initialise the upgrade handler (which may trigger // some IO using the new protocol which is why the lines // above are necessary) // This cast should be safe. If it fails the error // handling for the surrounding try/catch will deal with // it. if (upgradeToken.getInstanceManager() == null) { httpUpgradeHandler.init((WebConnection) processor); } else { ClassLoader oldCL = upgradeToken.getContextBind().bind(false, null); try { httpUpgradeHandler.init((WebConnection) processor); } finally { upgradeToken.getContextBind().unbind(false, oldCL); } } } } } while (state == SocketState.UPGRADING);