os: OS-dependent bits to support NetBSD.

R=golang-dev, jsing
CC=golang-dev
http://codereview.appspot.com/5482068

Committer: Russ Cox <rsc@golang.org>

1 files changed, 115 insertions, 0 deletions

diff --git a/src/pkg/net/fd_netbsd.go b/src/pkg/net/fd_netbsd.go
new file mode 100644
index 000000000..e52ac356b
--- /dev/null
+++ b/src/pkg/net/fd_netbsd.go
@@ -0,0 +1,115 @@
+// Copyright 2009 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.
+
+// Waiting for FDs via kqueue/kevent.
+
+package net
+
+import (
+	"os"
+	"syscall"
+)
+
+type pollster struct {
+	kq       int
+	eventbuf [10]syscall.Kevent_t
+	events   []syscall.Kevent_t
+
+	// An event buffer for AddFD/DelFD.
+	// Must hold pollServer lock.
+	kbuf [1]syscall.Kevent_t
+}
+
+func newpollster() (p *pollster, err error) {
+	p = new(pollster)
+	if p.kq, err = syscall.Kqueue(); err != nil {
+		return nil, os.NewSyscallError("kqueue", err)
+	}
+	p.events = p.eventbuf[0:0]
+	return p, nil
+}
+
+func (p *pollster) AddFD(fd int, mode int, repeat bool) (bool, error) {
+	// pollServer is locked.
+
+	var kmode int
+	if mode == 'r' {
+		kmode = syscall.EVFILT_READ
+	} else {
+		kmode = syscall.EVFILT_WRITE
+	}
+	ev := &p.kbuf[0]
+	// EV_ADD - add event to kqueue list
+	// EV_ONESHOT - delete the event the first time it triggers
+	flags := syscall.EV_ADD
+	if !repeat {
+		flags |= syscall.EV_ONESHOT
+	}
+	syscall.SetKevent(ev, fd, kmode, flags)
+
+	n, e := syscall.Kevent(p.kq, p.kbuf[:], nil, nil)
+	if e != nil {
+		return false, os.NewSyscallError("kevent", e)
+	}
+	if n != 1 || (ev.Flags&syscall.EV_ERROR) == 0 || int(ev.Ident) != fd || int(ev.Filter) != kmode {
+		return false, os.NewSyscallError("kqueue phase error", e)
+	}
+	if ev.Data != 0 {
+		return false, syscall.Errno(int(ev.Data))
+	}
+	return false, nil
+}
+
+func (p *pollster) DelFD(fd int, mode int) {
+	// pollServer is locked.
+
+	var kmode int
+	if mode == 'r' {
+		kmode = syscall.EVFILT_READ
+	} else {
+		kmode = syscall.EVFILT_WRITE
+	}
+	ev := &p.kbuf[0]
+	// EV_DELETE - delete event from kqueue list
+	syscall.SetKevent(ev, fd, kmode, syscall.EV_DELETE)
+	syscall.Kevent(p.kq, p.kbuf[:], nil, nil)
+}
+
+func (p *pollster) WaitFD(s *pollServer, nsec int64) (fd int, mode int, err error) {
+	var t *syscall.Timespec
+	for len(p.events) == 0 {
+		if nsec > 0 {
+			if t == nil {
+				t = new(syscall.Timespec)
+			}
+			*t = syscall.NsecToTimespec(nsec)
+		}
+
+		s.Unlock()
+		nn, e := syscall.Kevent(p.kq, nil, p.eventbuf[:], t)
+		s.Lock()
+
+		if e != nil {
+			if e == syscall.EINTR {
+				continue
+			}
+			return -1, 0, os.NewSyscallError("kevent", e)
+		}
+		if nn == 0 {
+			return -1, 0, nil
+		}
+		p.events = p.eventbuf[0:nn]
+	}
+	ev := &p.events[0]
+	p.events = p.events[1:]
+	fd = int(ev.Ident)
+	if ev.Filter == syscall.EVFILT_READ {
+		mode = 'r'
+	} else {
+		mode = 'w'
+	}
+	return fd, mode, nil
+}
+
+func (p *pollster) Close() error { return os.NewSyscallError("close", syscall.Close(p.kq)) }