Skip to content

Instantly share code, notes, and snippets.

@wolfeidau
Created July 25, 2014 08:25
Show Gist options
  • Save wolfeidau/33dcf2ea2648a10bb9e7 to your computer and use it in GitHub Desktop.
Save wolfeidau/33dcf2ea2648a10bb9e7 to your computer and use it in GitHub Desktop.
Epoll example in golang starting point
package main
//
// Starting point is from http://gcmurphy.wordpress.com/2012/11/30/using-epoll-in-go/
//
import (
"fmt"
"os"
"syscall"
)
const (
MaxEpollEvents = 32
KB = 1024
)
func echo(in, out int) {
var buf [KB]byte
for {
nbytes, e := syscall.Read(in, buf[:])
if nbytes > 0 {
syscall.Write(out, buf[:nbytes])
}
if e != nil {
break
}
}
}
func main() {
var event syscall.EpollEvent
var events [MaxEpollEvents]syscall.EpollEvent
file, e := os.Open("/dev/kmsg")
if e != nil {
fmt.Println(e)
os.Exit(1)
}
defer file.Close()
fd := int(file.Fd())
if e = syscall.SetNonblock(fd, true); e != nil {
fmt.Println("setnonblock1: ", e)
os.Exit(1)
}
epfd, e := syscall.EpollCreate1(0)
if e != nil {
fmt.Println("epoll_create1: ", e)
os.Exit(1)
}
defer syscall.Close(epfd)
event.Events = syscall.EPOLLIN
event.Fd = int32(fd)
if e = syscall.EpollCtl(epfd, syscall.EPOLL_CTL_ADD, fd, &event); e != nil {
fmt.Println("epoll_ctl: ", e)
os.Exit(1)
}
for {
nevents, e := syscall.EpollWait(epfd, events[:], -1)
if e != nil {
fmt.Println("epoll_wait: ", e)
break
}
for ev := 0; ev < nevents; ev++ {
go echo(int(events[ev].Fd), syscall.Stdout)
}
}
}
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment