Skip to content
Permalink
 
 
Cannot retrieve contributors at this time
// Copyright 2013 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build linux
package runtime
import "unsafe"
func epollcreate(size int32) int32
func epollcreate1(flags int32) int32
//go:noescape
func epollctl(epfd, op, fd int32, ev *epollevent) int32
//go:noescape
func epollwait(epfd int32, ev *epollevent, nev, timeout int32) int32
func closeonexec(fd int32)
var (
epfd int32 = -1 // epoll descriptor
)
func netpollinit() {
epfd = epollcreate1(_EPOLL_CLOEXEC)
if epfd >= 0 {
return
}
epfd = epollcreate(1024)
if epfd >= 0 {
closeonexec(epfd)
return
}
println("netpollinit: failed to create epoll descriptor", -epfd)
throw("netpollinit: failed to create descriptor")
}
func netpollopen(fd uintptr, pd *pollDesc) int32 {
var ev epollevent
ev.events = _EPOLLIN | _EPOLLOUT | _EPOLLRDHUP | _EPOLLET
*(**pollDesc)(unsafe.Pointer(&ev.data)) = pd
return -epollctl(epfd, _EPOLL_CTL_ADD, int32(fd), &ev)
}
func netpollclose(fd uintptr) int32 {
var ev epollevent
return -epollctl(epfd, _EPOLL_CTL_DEL, int32(fd), &ev)
}
func netpollarm(pd *pollDesc, mode int) {
throw("unused")
}
// polls for ready network connections
// returns list of goroutines that become runnable
func netpoll(block bool) *g {
if epfd == -1 {
return nil
}
waitms := int32(-1)
if !block {
waitms = 0
}
var events [128]epollevent
retry:
n := epollwait(epfd, &events[0], int32(len(events)), waitms)
if n < 0 {
if n != -_EINTR {
println("runtime: epollwait on fd", epfd, "failed with", -n)
throw("epollwait failed")
}
goto retry
}
var gp guintptr
for i := int32(0); i < n; i++ {
ev := &events[i]
if ev.events == 0 {
continue
}
var mode int32
if ev.events&(_EPOLLIN|_EPOLLRDHUP|_EPOLLHUP|_EPOLLERR) != 0 {
mode += 'r'
}
if ev.events&(_EPOLLOUT|_EPOLLHUP|_EPOLLERR) != 0 {
mode += 'w'
}
if mode != 0 {
pd := *(**pollDesc)(unsafe.Pointer(&ev.data))
netpollready(&gp, pd, mode)
}
}
if block && gp == 0 {
goto retry
}
return gp.ptr()
}