解析Tomcat处理请求的类Connector<一>
?????? Connector类的相关配置在Tomcat的安装目录conf下的Server.xml文件里,我这次主要解析采用NIO方式处理请求的情况.在Server.xml的配置如下:
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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Http11NioProtocol类的start()方法,如下:
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?? Http11NioProtocol类的start()方法又会调用NioEndpoint类的start()方法,如下:
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??? 该方式初始化了处理接受Sockt的线程Acceptor,轮询sockt的线程Poller,真正处理socket的线程池executor 或workers.Acceptor类的run方法如下:
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public void run() { // Loop until we receive a shutdown command while (running) { try { // Loop if endpoint is paused while (paused && (!close) ) { try { Thread.sleep(100); } catch (InterruptedException e) { // Ignore } } boolean hasEvents = false; hasEvents = (hasEvents | events());//往Selector注册Socket事件 // Time to terminate? if (close) { timeout(0, false); break; } int keyCount = 0; try { if ( !close ) { if (wakeupCounter.getAndSet(-1) > 0) { //if we are here, means we have other stuff to do //do a non blocking select keyCount = selector.selectNow(); } else { keyCount = selector.select(selectorTimeout); } wakeupCounter.set(0); } if (close) { timeout(0, false); selector.close(); break; } } catch ( NullPointerException x ) { //sun bug 5076772 on windows JDK 1.5 if ( log.isDebugEnabled() ) log.debug("Possibly encountered sun bug 5076772 on windows JDK 1.5",x); if ( wakeupCounter == null || selector == null ) throw x; continue; } catch ( CancelledKeyException x ) { //sun bug 5076772 on windows JDK 1.5 if ( log.isDebugEnabled() ) log.debug("Possibly encountered sun bug 5076772 on windows JDK 1.5",x); if ( wakeupCounter == null || selector == null ) throw x; continue; } catch (Throwable x) { log.error("",x); continue; } //either we timed out or we woke up, process events first if ( keyCount == 0 ) hasEvents = (hasEvents | events()); Iterator iterator = keyCount > 0 ? selector.selectedKeys().iterator() : null; // Walk through the collection of ready keys and dispatch // any active event. while (iterator != null && iterator.hasNext()) { SelectionKey sk = (SelectionKey) iterator.next(); KeyAttachment attachment = (KeyAttachment)sk.attachment(); // Attachment may be null if another thread has called // cancelledKey() if (attachment == null) { iterator.remove(); } else { attachment.access(); iterator.remove(); processKey(sk, attachment);//将Socket交由线程池executor 或workers处理 } }//while //process timeouts timeout(keyCount,hasEvents); if ( oomParachute > 0 && oomParachuteData == null ) checkParachute(); } catch (OutOfMemoryError oom) { try { oomParachuteData = null; releaseCaches(); log.error("", oom); }catch ( Throwable oomt ) { try { System.err.println(oomParachuteMsg); oomt.printStackTrace(); }catch (Throwable letsHopeWeDontGetHere){} } } }//while synchronized (this) { this.notifyAll(); } stopLatch.countDown(); }?
?????? 后续就是处理sockt请求,返回处理结果到浏览器端
