1 // Copyright 2009 The Go Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
5 // Waiting for FDs via kqueue/kevent.
14 type pollster struct {
16 eventbuf [10]syscall.Kevent_t
17 events []syscall.Kevent_t
19 // An event buffer for AddFD/DelFD.
20 // Must hold pollServer lock.
21 kbuf [1]syscall.Kevent_t
24 func newpollster() (p *pollster, err error) {
26 if p.kq, err = syscall.Kqueue(); err != nil {
27 return nil, os.NewSyscallError("kqueue", err)
29 syscall.CloseOnExec(p.kq)
30 p.events = p.eventbuf[0:0]
34 func (p *pollster) AddFD(fd int, mode int, repeat bool) (bool, error) {
35 // pollServer is locked.
39 kmode = syscall.EVFILT_READ
41 kmode = syscall.EVFILT_WRITE
44 // EV_ADD - add event to kqueue list
45 // EV_ONESHOT - delete the event the first time it triggers
46 flags := syscall.EV_ADD
48 flags |= syscall.EV_ONESHOT
50 syscall.SetKevent(ev, fd, kmode, flags)
52 n, err := syscall.Kevent(p.kq, p.kbuf[:], nil, nil)
54 return false, os.NewSyscallError("kevent", err)
56 if n != 1 || (ev.Flags&syscall.EV_ERROR) == 0 || int(ev.Ident) != fd || int(ev.Filter) != kmode {
57 return false, os.NewSyscallError("kqueue phase error", err)
60 return false, syscall.Errno(int(ev.Data))
65 func (p *pollster) DelFD(fd int, mode int) {
66 // pollServer is locked.
70 kmode = syscall.EVFILT_READ
72 kmode = syscall.EVFILT_WRITE
75 // EV_DELETE - delete event from kqueue list
76 syscall.SetKevent(ev, fd, kmode, syscall.EV_DELETE)
77 syscall.Kevent(p.kq, p.kbuf[:], nil, nil)
80 func (p *pollster) WaitFD(s *pollServer, nsec int64) (fd int, mode int, err error) {
81 var t *syscall.Timespec
82 for len(p.events) == 0 {
85 t = new(syscall.Timespec)
87 *t = syscall.NsecToTimespec(nsec)
91 n, err := syscall.Kevent(p.kq, nil, p.eventbuf[:], t)
95 if err == syscall.EINTR {
98 return -1, 0, os.NewSyscallError("kevent", err)
103 p.events = p.eventbuf[:n]
106 p.events = p.events[1:]
108 if ev.Filter == syscall.EVFILT_READ {
116 func (p *pollster) Close() error { return os.NewSyscallError("close", syscall.Close(p.kq)) }