Retro68/gcc/libgo/go/net/fd_plan9.go
2017-10-07 02:16:47 +02:00

305 lines
6.0 KiB
Go

// 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.
package net
import (
"io"
"os"
"sync/atomic"
"syscall"
"time"
)
type atomicBool int32
func (b *atomicBool) isSet() bool { return atomic.LoadInt32((*int32)(b)) != 0 }
func (b *atomicBool) setFalse() { atomic.StoreInt32((*int32)(b), 0) }
func (b *atomicBool) setTrue() { atomic.StoreInt32((*int32)(b), 1) }
// Network file descriptor.
type netFD struct {
// locking/lifetime of sysfd + serialize access to Read and Write methods
fdmu fdMutex
// immutable until Close
net string
n string
dir string
listen, ctl, data *os.File
laddr, raddr Addr
isStream bool
// deadlines
raio *asyncIO
waio *asyncIO
rtimer *time.Timer
wtimer *time.Timer
rtimedout atomicBool // set true when read deadline has been reached
wtimedout atomicBool // set true when write deadline has been reached
}
var (
netdir string // default network
)
func sysInit() {
netdir = "/net"
}
func newFD(net, name string, listen, ctl, data *os.File, laddr, raddr Addr) (*netFD, error) {
return &netFD{
net: net,
n: name,
dir: netdir + "/" + net + "/" + name,
listen: listen,
ctl: ctl, data: data,
laddr: laddr,
raddr: raddr,
}, nil
}
func (fd *netFD) init() error {
// stub for future fd.pd.Init(fd)
return nil
}
func (fd *netFD) name() string {
var ls, rs string
if fd.laddr != nil {
ls = fd.laddr.String()
}
if fd.raddr != nil {
rs = fd.raddr.String()
}
return fd.net + ":" + ls + "->" + rs
}
func (fd *netFD) ok() bool { return fd != nil && fd.ctl != nil }
func (fd *netFD) destroy() {
if !fd.ok() {
return
}
err := fd.ctl.Close()
if fd.data != nil {
if err1 := fd.data.Close(); err1 != nil && err == nil {
err = err1
}
}
if fd.listen != nil {
if err1 := fd.listen.Close(); err1 != nil && err == nil {
err = err1
}
}
fd.ctl = nil
fd.data = nil
fd.listen = nil
}
func (fd *netFD) Read(b []byte) (n int, err error) {
if fd.rtimedout.isSet() {
return 0, errTimeout
}
if !fd.ok() || fd.data == nil {
return 0, syscall.EINVAL
}
if err := fd.readLock(); err != nil {
return 0, err
}
defer fd.readUnlock()
if len(b) == 0 {
return 0, nil
}
fd.raio = newAsyncIO(fd.data.Read, b)
n, err = fd.raio.Wait()
fd.raio = nil
if isHangup(err) {
err = io.EOF
}
if isInterrupted(err) {
err = errTimeout
}
if fd.net == "udp" && err == io.EOF {
n = 0
err = nil
}
return
}
func (fd *netFD) Write(b []byte) (n int, err error) {
if fd.wtimedout.isSet() {
return 0, errTimeout
}
if !fd.ok() || fd.data == nil {
return 0, syscall.EINVAL
}
if err := fd.writeLock(); err != nil {
return 0, err
}
defer fd.writeUnlock()
fd.waio = newAsyncIO(fd.data.Write, b)
n, err = fd.waio.Wait()
fd.waio = nil
if isInterrupted(err) {
err = errTimeout
}
return
}
func (fd *netFD) closeRead() error {
if !fd.ok() {
return syscall.EINVAL
}
return syscall.EPLAN9
}
func (fd *netFD) closeWrite() error {
if !fd.ok() {
return syscall.EINVAL
}
return syscall.EPLAN9
}
func (fd *netFD) Close() error {
if !fd.fdmu.increfAndClose() {
return errClosing
}
if !fd.ok() {
return syscall.EINVAL
}
if fd.net == "tcp" {
// The following line is required to unblock Reads.
_, err := fd.ctl.WriteString("close")
if err != nil {
return err
}
}
err := fd.ctl.Close()
if fd.data != nil {
if err1 := fd.data.Close(); err1 != nil && err == nil {
err = err1
}
}
if fd.listen != nil {
if err1 := fd.listen.Close(); err1 != nil && err == nil {
err = err1
}
}
fd.ctl = nil
fd.data = nil
fd.listen = nil
return err
}
// This method is only called via Conn.
func (fd *netFD) dup() (*os.File, error) {
if !fd.ok() || fd.data == nil {
return nil, syscall.EINVAL
}
return fd.file(fd.data, fd.dir+"/data")
}
func (l *TCPListener) dup() (*os.File, error) {
if !l.fd.ok() {
return nil, syscall.EINVAL
}
return l.fd.file(l.fd.ctl, l.fd.dir+"/ctl")
}
func (fd *netFD) file(f *os.File, s string) (*os.File, error) {
dfd, err := syscall.Dup(int(f.Fd()), -1)
if err != nil {
return nil, os.NewSyscallError("dup", err)
}
return os.NewFile(uintptr(dfd), s), nil
}
func (fd *netFD) setDeadline(t time.Time) error {
return setDeadlineImpl(fd, t, 'r'+'w')
}
func (fd *netFD) setReadDeadline(t time.Time) error {
return setDeadlineImpl(fd, t, 'r')
}
func (fd *netFD) setWriteDeadline(t time.Time) error {
return setDeadlineImpl(fd, t, 'w')
}
func setDeadlineImpl(fd *netFD, t time.Time, mode int) error {
d := t.Sub(time.Now())
if mode == 'r' || mode == 'r'+'w' {
fd.rtimedout.setFalse()
}
if mode == 'w' || mode == 'r'+'w' {
fd.wtimedout.setFalse()
}
if t.IsZero() || d < 0 {
// Stop timer
if mode == 'r' || mode == 'r'+'w' {
if fd.rtimer != nil {
fd.rtimer.Stop()
}
fd.rtimer = nil
}
if mode == 'w' || mode == 'r'+'w' {
if fd.wtimer != nil {
fd.wtimer.Stop()
}
fd.wtimer = nil
}
} else {
// Interrupt I/O operation once timer has expired
if mode == 'r' || mode == 'r'+'w' {
fd.rtimer = time.AfterFunc(d, func() {
fd.rtimedout.setTrue()
if fd.raio != nil {
fd.raio.Cancel()
}
})
}
if mode == 'w' || mode == 'r'+'w' {
fd.wtimer = time.AfterFunc(d, func() {
fd.wtimedout.setTrue()
if fd.waio != nil {
fd.waio.Cancel()
}
})
}
}
if !t.IsZero() && d < 0 {
// Interrupt current I/O operation
if mode == 'r' || mode == 'r'+'w' {
fd.rtimedout.setTrue()
if fd.raio != nil {
fd.raio.Cancel()
}
}
if mode == 'w' || mode == 'r'+'w' {
fd.wtimedout.setTrue()
if fd.waio != nil {
fd.waio.Cancel()
}
}
}
return nil
}
func setReadBuffer(fd *netFD, bytes int) error {
return syscall.EPLAN9
}
func setWriteBuffer(fd *netFD, bytes int) error {
return syscall.EPLAN9
}
func isHangup(err error) bool {
return err != nil && stringsHasSuffix(err.Error(), "Hangup")
}
func isInterrupted(err error) bool {
return err != nil && stringsHasSuffix(err.Error(), "interrupted")
}