Examples of com.flipkart.phantom.netty.uds.OioServerSocketChannelFactory

A {@link ServerSocketChannelFactory} which creates a server-side blockingI/O based {@link ServerSocketChannel}. It utilizes the good old blocking I/O API which is known to yield better throughput and latency when there are relatively small number of connections to serve.

How threads work

There are two types of threads in a {@link OioServerSocketChannelFactory}; one is boss thread and the other is worker thread.

Boss threads

Each bound {@link ServerSocketChannel} has its own boss thread.For example, if you opened two server ports such as 80 and 443, you will have two boss threads. A boss thread accepts incoming connections until the port is unbound. Once a connection is accepted successfully, the boss thread passes the accepted {@link Channel} to one of the workerthreads that the {@link OioServerSocketChannelFactory} manages.

Worker threads

Each connected {@link Channel} has a dedicated worker thread, just like atraditional blocking I/O thread model.

Life cycle of threads and graceful shutdown

All threads are acquired from the {@link Executor}s which were specified when a {@link OioServerSocketChannelFactory} was created. Boss threads areacquired from the {@code bossExecutor}, and worker threads are acquired from the {@code workerExecutor}. Therefore, you should make sure the specified {@link Executor}s are able to lend the sufficient number of threads.

Both boss and worker threads are acquired lazily, and then released when there's nothing left to process. All the related resources are also released when the boss and worker threads are released. Therefore, to shut down a service gracefully, you should do the following:

unbind all channels created by the factory,
close all child channels accepted by the unbound channels, (these two steps so far is usually done using {@link ChannelGroup#close()})
call {@link #releaseExternalResources()}.

Please make sure not to shut down the executor until all channels are closed. Otherwise, you will end up with a {@link RejectedExecutionException}and the related resources might not be released properly.

Limitation

A {@link ServerSocketChannel} created by this factory and its child channelsdo not support asynchronous operations. Any I/O requests such as {@code "write"} will be performed in a blocking manner. @apiviz.landmark Ported to com.flipkart.phantom.runtime.impl.server.netty.oio for package compatibility OIO package modified to work for Unix Domain Sockets instead of ServerSocket. @author devashishshankar @version 1.0, April 19th, 2013