socketacceptor.java

apache 的一个socket框架

                                try {
                                    selector.close();
                                } catch (IOException e) {
                                    ExceptionMonitor.getInstance()
                                            .exceptionCaught(e);
                                } finally {
                                    selector = null;
                                }
                                break;
                            }
                        }
                    }
                } catch (IOException e) {
                    ExceptionMonitor.getInstance().exceptionCaught(e);

                    try {
                        Thread.sleep(1000);
                    } catch (InterruptedException e1) {
                        ExceptionMonitor.getInstance().exceptionCaught(e1);
                    }
                }
            }
        }

        private void processSessions(Set<SelectionKey> keys) throws IOException {
            Iterator<SelectionKey> it = keys.iterator();
            while (it.hasNext()) {
                SelectionKey key = it.next();

                it.remove();

                if (!key.isAcceptable()) {
                    continue;
                }

                ServerSocketChannel ssc = (ServerSocketChannel) key.channel();

                SocketChannel ch = ssc.accept();

                if (ch == null) {
                    continue;
                }

                boolean success = false;
                try {
                    RegistrationRequest req = (RegistrationRequest) key
                            .attachment();
                    SocketSessionImpl session = new SocketSessionImpl(
                            SocketAcceptor.this, nextProcessor(),
                            getListeners(), req.config, ch, req.handler,
                            req.address);
                    getFilterChainBuilder().buildFilterChain(
                            session.getFilterChain());
                    req.config.getFilterChainBuilder().buildFilterChain(
                            session.getFilterChain());
                    req.config.getThreadModel().buildFilterChain(
                            session.getFilterChain());
                    session.getIoProcessor().addNew(session);
                    success = true;
                } catch (Throwable t) {
                    ExceptionMonitor.getInstance().exceptionCaught(t);
                } finally {
                    if (!success) {
                        ch.close();
                    }
                }
            }
        }
    }

    private SocketIoProcessor nextProcessor() {
        if (this.processorDistributor == Integer.MAX_VALUE) {
            this.processorDistributor = Integer.MAX_VALUE % this.processorCount;
        }

        return ioProcessors[processorDistributor++ % processorCount];
    }

    public SocketAcceptorConfig getDefaultConfig() {
        return defaultConfig;
    }

    /**
     * Sets the config this acceptor will use by default.
     *
     * @param defaultConfig the default config.
     * @throws NullPointerException if the specified value is <code>null</code>.
     */
    public void setDefaultConfig(SocketAcceptorConfig defaultConfig) {
        if (defaultConfig == null) {
            throw new NullPointerException("defaultConfig");
        }
        this.defaultConfig = defaultConfig;
    }

    private void registerNew() {
        if (registerQueue.isEmpty()) {
            return;
        }

        for (;;) {
            RegistrationRequest req = registerQueue.poll();

            if (req == null) {
                break;
            }

            ServerSocketChannel ssc = null;

            try {
                ssc = ServerSocketChannel.open();
                ssc.configureBlocking(false);

                // Configure the server socket,
                SocketAcceptorConfig cfg;
                if (req.config instanceof SocketAcceptorConfig) {
                    cfg = (SocketAcceptorConfig) req.config;
                } else {
                    cfg = getDefaultConfig();
                }

                ssc.socket().setReuseAddress(cfg.isReuseAddress());
                ssc.socket().setReceiveBufferSize(
                        cfg.getSessionConfig().getReceiveBufferSize());

                // and bind.
                ssc.socket().bind(req.address, cfg.getBacklog());
                if (req.address == null || req.address.getPort() == 0) {
                    req.address = (InetSocketAddress) ssc.socket()
                            .getLocalSocketAddress();
                }
                ssc.register(selector, SelectionKey.OP_ACCEPT, req);

                channels.put(req.address, ssc);

                getListeners().fireServiceActivated(this, req.address,
                        req.handler, req.config);
            } catch (IOException e) {
                req.exception = e;
            } finally {
                req.done.countDown();

                if (ssc != null && req.exception != null) {
                    try {
                        ssc.close();
                    } catch (IOException e) {
                        ExceptionMonitor.getInstance().exceptionCaught(e);
                    }
                }
            }
        }
    }

    private void cancelKeys() {
        if (cancelQueue.isEmpty()) {
            return;
        }

        for (;;) {
            CancellationRequest request = cancelQueue.poll();

            if (request == null) {
                break;
            }

            ServerSocketChannel ssc = channels.remove(request.address);

            // close the channel
            try {
                if (ssc == null) {
                    request.exception = new IllegalArgumentException(
                            "Address not bound: " + request.address);
                } else {
                    SelectionKey key = ssc.keyFor(selector);
                    request.registrationRequest = (RegistrationRequest) key
                            .attachment();
                    key.cancel();

                    selector.wakeup(); // wake up again to trigger thread death

                    ssc.close();
                }
            } catch (IOException e) {
                ExceptionMonitor.getInstance().exceptionCaught(e);
            } finally {
                request.done.countDown();

                if (request.exception == null) {
                    getListeners().fireServiceDeactivated(this,
                            request.address,
                            request.registrationRequest.handler,
                            request.registrationRequest.config);
                }
            }
        }
    }

    private static class RegistrationRequest {
        private InetSocketAddress address;

        private final IoHandler handler;

        private final IoServiceConfig config;

        private final CountDownLatch done = new CountDownLatch(1);

        private volatile IOException exception;

        private RegistrationRequest(SocketAddress address, IoHandler handler,
                IoServiceConfig config) {
            this.address = (InetSocketAddress) address;
            this.handler = handler;
            this.config = config;
        }
    }

    private static class CancellationRequest {
        private final SocketAddress address;

        private final CountDownLatch done = new CountDownLatch(1);

        private RegistrationRequest registrationRequest;

        private volatile RuntimeException exception;

        private CancellationRequest(SocketAddress address) {
            this.address = address;
        }
    }
}