What is epoll and Kqueue?

What is epoll and Kqueue?

Kqueue allows one to batch modify watcher states and to retrieve watcher states in a single system call. With epoll, you have to call a system call for every modification. Kqueue also allows one to watch for things like filesystem changes and process state changes, epoll is limited to socket/pipe I/O only.

What is epoll used for?

epoll is a Linux kernel system call for a scalable I/O event notification mechanism, first introduced in version 2.5. 44 of the Linux kernel. Its function is to monitor multiple file descriptors to see whether I/O is possible on any of them.

What is Kqueue poll?

Kqueue provides efficient input and output event pipelines between the kernel and userland. Some other operating systems which traditionally only supported select(2) and poll(2) also currently provide more efficient polling alternatives, such as epoll on Linux and I/O completion ports on Windows and Solaris.

Does Windows support epoll?

That is, epoll on Linux, kqueue on Macintosh, IOCPs on Windows. It does not support file I/O.

How do I use epoll?

To use epoll method you need to make following steps in your application:

  1. Create specific file descriptor for epoll calls:
  2. After first step you can add your descriptors to epoll with following call:
  3. When all your descriptors will be added to epoll, your process can idle and wait to something to do with epoll’ed sockets:

How does epoll work in Linux?

epoll stands for event poll and is a Linux specific construct. It allows for a process to monitor multiple file descriptors and get notifications when I/O is possible on them. It allows for both edge-triggered as well as level-triggered notifications.

Does Java use epoll?

A new java. nio. channels. SelectorProvider implementation that is based on the Linux epoll event notification facility is included.

What is Netty epoll?

Epoll. io.netty.channel.epoll. Uses JNI for epoll() and non-blocking IO. This transport supports features available only on Linux, such as SO_REUSEPORT, and is faster than the NIO transport as well as fully non-blocking.

Does Netty use epoll?

2 Answers. Netty’s epoll transport uses epoll edge-triggered while java’s nio library uses level-triggered.

What is Netty transport native epoll?

Netty provides native transport libraries which generally generate less garbage and improve performance when compared to the default NIO-based transport. While the epoll transport may in general improve performance, we expect the improvement to be marginal for a lot of use cases.