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事件
while (running) {
try {
// 执行队列中的任务
Runnable task;
while ((task = taskQueue.poll()) != null) {
task.run();
}
selector.select(1000);
// 获取查询结果
Set<SelectionKey> selectionKeys = selector.selectedKeys();
// 遍历查询结果
Iterator<SelectionKey> keyIterator = selectionKeys.iterator();
while (keyIterator.hasNext()) {
// 被封装的查询结果
SelectionKey selectionKey = keyIterator.next();
keyIterator.remove();
int readyOps = selectionKey.readyOps();
// 关注 Read 和 Accept两个事件
if ((readyOps & (SelectionKey.OP_READ | SelectionKey.OP_ACCEPT)) != 0
|| readyOps == 0) {
try {
SelectableChannel channel = (SelectableChannel) selectionKey.attachment();
channel.configureBlocking(false);
handler(channel);
// 如果关闭了,就取消这个KEY的订阅
if (!channel.isOpen()) {
selectionKey.cancel();
}
} catch (Exception e) {
// 如果有异常,就取消这个KEY的订阅
selectionKey.cancel();
e.printStackTrace();
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
private SelectionKey register(SelectableChannel channel) throws Exception {
// 为什么register要以任务提交的形式，让reactor线程去处理？
// 因为线程在执行channel注册到selector的过程中，会和调用selector.select()方法的线程争用同一把锁
// 而select()方法实在eventLoop中通过while循环调用的，争抢的可能性很高，
// 为了让register能更快的执行，就放到同一个线程来处理
FutureTask<SelectionKey> futureTask =
new FutureTask<>(() -> channel.register(selector, 0, channel));
taskQueue.add(futureTask);
return futureTask.get();
}
private void doStart() {
if (!running) {
running = true;
start();
}
}
}
private ServerSocketChannel serverSocketChannel;
// 1、创建多个线程 - accept处理reactor线程 (accept线程)
private ReactorThread[] mainReactorThreads = new ReactorThread[1];
// 2、创建多个线程 - io处理reactor线程 (I/O线程)
private ReactorThread[] subReactorThreads = new ReactorThread[8];
// 初始化线程组
private void newGroup() throws IOException {
// 创建mainReactor线程, 只负责处理serverSocketChannel
for (int i = 0; i < mainReactorThreads.length; i++) {
mainReactorThreads[i] =
new ReactorThread() {
AtomicInteger incr = new AtomicInteger(0);
@Override
public void handler(SelectableChannel channel) throws Exception {
// 只做请求分发，不做具体的数据读取
ServerSocketChannel ch = (ServerSocketChannel) channel;
SocketChannel socketChannel = ch.accept();
socketChannel.configureBlocking(false);
// 收到连接建立的通知之后，分发给I/O线程继续去读取数据
int index = incr.getAndIncrement() % subReactorThreads.length;
ReactorThread workEventLoop = subReactorThreads[index];
workEventLoop.doStart();
SelectionKey selectionKey = workEventLoop.register(socketChannel);
selectionKey.interestOps(SelectionKey.OP_READ);
System.out.println(
Thread.currentThread().getName() + "收到新连接 : " + socketChannel.getRemoteAddress());
}
};
}
// 创建IO线程,负责处理客户端连接以后socketChannel的IO读写
for (int i = 0; i < subReactorThreads.length; i++) {
subReactorThreads[i] =
new ReactorThread() {
@Override
public void handler(SelectableChannel channel) throws Exception {
// work线程只负责处理IO处理，不处理accept事件
SocketChannel ch = (SocketChannel) channel;
ByteBuffer requestBuffer = ByteBuffer.allocate(1024);
while (ch.isOpen() && ch.read(requestBuffer) != -1) {
// 长连接情况下,需要手动判断数据有没有读取结束 (此处做一个简单的判断: 超过0字节就认为请求结束了)
if (requestBuffer.position() > 0) break;
}
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