134 lines
3.0 KiB
Go
134 lines
3.0 KiB
Go
// 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 darwin dragonfly freebsd netbsd openbsd
|
|
|
|
package runtime
|
|
|
|
// Integrated network poller (kqueue-based implementation).
|
|
|
|
import "unsafe"
|
|
|
|
//extern kqueue
|
|
func kqueue() int32
|
|
|
|
//go:noescape
|
|
//extern kevent
|
|
func kevent(kq int32, ch *keventt, nch uintptr, ev *keventt, nev uintptr, ts *timespec) int32
|
|
|
|
//extern __go_fcntl_uintptr
|
|
func fcntlUintptr(fd, cmd, arg uintptr) (uintptr, uintptr)
|
|
|
|
//go:nosplit
|
|
func closeonexec(fd int32) {
|
|
fcntlUintptr(uintptr(fd), _F_SETFD, _FD_CLOEXEC)
|
|
}
|
|
|
|
var (
|
|
kq int32 = -1
|
|
)
|
|
|
|
func netpollinit() {
|
|
kq = kqueue()
|
|
if kq < 0 {
|
|
println("netpollinit: kqueue failed with", errno())
|
|
throw("runtime: netpollinit failed")
|
|
}
|
|
closeonexec(kq)
|
|
}
|
|
|
|
func netpolldescriptor() uintptr {
|
|
return uintptr(kq)
|
|
}
|
|
|
|
func netpollopen(fd uintptr, pd *pollDesc) int32 {
|
|
// Arm both EVFILT_READ and EVFILT_WRITE in edge-triggered mode (EV_CLEAR)
|
|
// for the whole fd lifetime. The notifications are automatically unregistered
|
|
// when fd is closed.
|
|
var ev [2]keventt
|
|
*(*uintptr)(unsafe.Pointer(&ev[0].ident)) = fd
|
|
ev[0].filter = _EVFILT_READ
|
|
ev[0].flags = _EV_ADD | _EV_CLEAR
|
|
ev[0].fflags = 0
|
|
ev[0].data = 0
|
|
ev[0].udata = (*byte)(unsafe.Pointer(pd))
|
|
ev[1] = ev[0]
|
|
ev[1].filter = _EVFILT_WRITE
|
|
n := kevent(kq, &ev[0], 2, nil, 0, nil)
|
|
if n < 0 {
|
|
return int32(errno())
|
|
}
|
|
return 0
|
|
}
|
|
|
|
func netpollclose(fd uintptr) int32 {
|
|
// Don't need to unregister because calling close()
|
|
// on fd will remove any kevents that reference the descriptor.
|
|
return 0
|
|
}
|
|
|
|
func netpollarm(pd *pollDesc, mode int) {
|
|
throw("runtime: unused")
|
|
}
|
|
|
|
// Polls for ready network connections.
|
|
// Returns list of goroutines that become runnable.
|
|
func netpoll(block bool) gList {
|
|
if kq == -1 {
|
|
return gList{}
|
|
}
|
|
var tp *timespec
|
|
var ts timespec
|
|
if !block {
|
|
tp = &ts
|
|
}
|
|
var events [64]keventt
|
|
retry:
|
|
n := kevent(kq, nil, 0, &events[0], uintptr(len(events)), tp)
|
|
if n < 0 {
|
|
e := errno()
|
|
if e != _EINTR {
|
|
println("runtime: kevent on fd", kq, "failed with", e)
|
|
throw("runtime: netpoll failed")
|
|
}
|
|
goto retry
|
|
}
|
|
var toRun gList
|
|
for i := 0; i < int(n); i++ {
|
|
ev := &events[i]
|
|
var mode int32
|
|
switch ev.filter {
|
|
case _EVFILT_READ:
|
|
mode += 'r'
|
|
|
|
// On some systems when the read end of a pipe
|
|
// is closed the write end will not get a
|
|
// _EVFILT_WRITE event, but will get a
|
|
// _EVFILT_READ event with EV_EOF set.
|
|
// Note that setting 'w' here just means that we
|
|
// will wake up a goroutine waiting to write;
|
|
// that goroutine will try the write again,
|
|
// and the appropriate thing will happen based
|
|
// on what that write returns (success, EPIPE, EAGAIN).
|
|
if ev.flags&_EV_EOF != 0 {
|
|
mode += 'w'
|
|
}
|
|
case _EVFILT_WRITE:
|
|
mode += 'w'
|
|
}
|
|
if mode != 0 {
|
|
pd := (*pollDesc)(unsafe.Pointer(ev.udata))
|
|
pd.everr = false
|
|
if ev.flags == _EV_ERROR {
|
|
pd.everr = true
|
|
}
|
|
netpollready(&toRun, pd, mode)
|
|
}
|
|
}
|
|
if block && toRun.empty() {
|
|
goto retry
|
|
}
|
|
return toRun
|
|
}
|