src/main/java/com/alipay/remoting/util/NettyEventLoopUtil.java
public static EventLoopGroup newEventLoopGroup(int nThreads, ThreadFactory threadFactory) {
        return epollEnabled ? new EpollEventLoopGroup(nThreads, threadFactory)
            : new NioEventLoopGroup(nThreads, threadFactory);
    }
public static EventLoopGroup newEventLoopGroup(int nThreads, ThreadFactory threadFactory) {
        return epollEnabled ? new EpollEventLoopGroup(nThreads, threadFactory)
            : new NioEventLoopGroup(nThreads, threadFactory);
    }
Create the right event loop according to current platform and system property, fallback to NIO when epoll not enabled.

@param nThreads
@param threadFactory
@return an EventLoopGroup suitable for the current platform