Golang syscall.SetNonblock函数代码示例

func newPollServer() (s *pollServer, err error) {
	s = new(pollServer)
	if s.pr, s.pw, err = os.Pipe(); err != nil {
		return nil, err
	}
	if err = syscall.SetNonblock(int(s.pr.Fd()), true); err != nil {
		goto Errno
	}
	if err = syscall.SetNonblock(int(s.pw.Fd()), true); err != nil {
		goto Errno
	}
	if s.poll, err = newpollster(); err != nil {
		goto Error
	}
	if _, err = s.poll.AddFD(int(s.pr.Fd()), 'r', true); err != nil {
		s.poll.Close()
		goto Error
	}
	s.pending = make(map[int]*pollDesc)
	go s.Run()
	return s, nil

Errno:
	err = &os.PathError{
		Op:   "setnonblock",
		Path: s.pr.Name(),
		Err:  err,
	}
Error:
	s.pr.Close()
	s.pw.Close()
	return nil, err
}

func (sc *selectCtx) Init() error {
	sc.rset.Zero()
	sc.wset.Zero()
	sc.fdmax = -1
	// Create and configure the pipe-ends.
	b := make([]int, 2)
	err := syscall.Pipe(b)
	if err != nil {
		return err
	}
	sc.pfdr, sc.pfdw = b[0], b[1]
	syscall.CloseOnExec(sc.pfdr)
	syscall.CloseOnExec(sc.pfdw)
	err = syscall.SetNonblock(sc.pfdr, true)
	if err != nil {
		syscall.Close(sc.pfdr)
		syscall.Close(sc.pfdw)
		return err
	}
	err = syscall.SetNonblock(sc.pfdw, true)
	if err != nil {
		syscall.Close(sc.pfdr)
		syscall.Close(sc.pfdw)
		return err
	}
	// pfdr (read-end of pipe) is set (and remains set forever) on
	// rset.
	sc.rset.Set(sc.pfdr)
	sc.fdmax = sc.pfdr
	// allocate dummy selectCtx.{b,b1} buffers.
	sc.b = make([]byte, 1)
	sc.b1 = make([]byte, 128)
	return nil
}

func (t *pty) open(cols, rows int) error {
	var winp = new(C.struct_winsize)
	winp.ws_col = C.ushort(cols)
	winp.ws_row = C.ushort(rows)
	winp.ws_xpixel = 0
	winp.ws_ypixel = 0

	var master, slave C.int
	var name = make([]C.char, 40)

	if ret := int(C.GoOpenpty(&master, &slave, &name[0], winp)); ret == -1 {
		return errors.New("openpty(3) failed")
	}

	t.master = int(master)
	t.slave = int(slave)
	t.pty = C.GoString(&name[0])

	if err := syscall.SetNonblock(t.master, true); err != nil {
		return err
	}

	if err := syscall.SetNonblock(t.slave, true); err != nil {
		return err
	}
	return nil
}

func newPollServer() (s *pollServer, err os.Error) {
	s = new(pollServer)
	s.cr = make(chan *netFD, 1)
	s.cw = make(chan *netFD, 1)
	if s.pr, s.pw, err = os.Pipe(); err != nil {
		return nil, err
	}
	var e int
	if e = syscall.SetNonblock(s.pr.Fd(), true); e != 0 {
		goto Errno
	}
	if e = syscall.SetNonblock(s.pw.Fd(), true); e != 0 {
		goto Errno
	}
	if s.poll, err = newpollster(); err != nil {
		goto Error
	}
	if _, err = s.poll.AddFD(s.pr.Fd(), 'r', true); err != nil {
		s.poll.Close()
		goto Error
	}
	s.pending = make(map[int]*netFD)
	go s.Run()
	return s, nil

Errno:
	err = &os.PathError{"setnonblock", s.pr.Name(), os.Errno(e)}
Error:
	s.pr.Close()
	s.pw.Close()
	return nil, err
}

func (io *NetIOManager) ProxyNetAccept(serverinfo syscall.Sockaddr) (sa syscall.Sockaddr, err error) {
	var clientfd, serverfd int
	// accpet mongodb client connection request
	clientfd, clientinfo, err := syscall.Accept(io.proxy_server_fd)
	if err != nil {
		goto ClientError
	}

	err = syscall.SetNonblock(clientfd, true)
	if err != nil {
		goto ClientCleanup
	}

	err = syscall.EpollCtl(io.epoll_fd, syscall.EPOLL_CTL_ADD, clientfd,
		&syscall.EpollEvent{Events: syscall.EPOLLIN | syscall.EPOLLOUT |
			syscall.EPOLLRDHUP, Fd: int32(clientfd)})
	if err != nil {
		goto ClientCleanup
	}

	// establish connection with mongodb server
	serverfd, err = syscall.Socket(syscall.AF_INET, syscall.SOCK_STREAM,
		syscall.IPPROTO_TCP)
	if err != nil {
		goto ServerError
	}

	err = syscall.Connect(serverfd, serverinfo)
	if err != nil {
		goto ServerCleanup
	}

	err = syscall.SetNonblock(serverfd, true)
	if err != nil {
		goto ServerCleanup
	}

	err = syscall.EpollCtl(io.epoll_fd, syscall.EPOLL_CTL_ADD, serverfd,
		&syscall.EpollEvent{Events: syscall.EPOLLIN | syscall.EPOLLOUT |
			syscall.EPOLLRDHUP, Fd: int32(serverfd)})
	if err != nil {
		goto ServerCleanup
	}

	// now proxy server becomes a bridge between client <-> server
	add_sock_peer(io, clientfd, clientinfo, serverfd, serverinfo)
	return clientinfo, nil

ServerCleanup:
	syscall.Close(serverfd)
ServerError:
	syscall.EpollCtl(io.epoll_fd, syscall.EPOLL_CTL_DEL, clientfd,
		&syscall.EpollEvent{Events: syscall.EPOLLIN | syscall.EPOLLOUT |
			syscall.EPOLLRDHUP, Fd: int32(clientfd)})
ClientCleanup:
	syscall.Close(clientfd)
ClientError:
	return nil, err
}

func (p *pin) BeginWatch(edge Edge, callback IRQEvent) error {
	p.SetMode(ModeInput)
	if err := write([]byte(edge), p.edgePath); err != nil {
		return err
	}

	var event syscall.EpollEvent
	event.Events = syscall.EPOLLIN | (syscall.EPOLLET & 0xffffffff) | syscall.EPOLLPRI

	fd := int(p.valueFile.Fd())

	p.callback = callback
	watchEventCallbacks[fd] = p

	if err := syscall.SetNonblock(fd, true); err != nil {
		return err
	}

	event.Fd = int32(fd)

	if err := syscall.EpollCtl(epollFD, syscall.EPOLL_CTL_ADD, fd, &event); err != nil {
		return err
	}

	return nil

}

func newPollServer() (s *pollServer, err os.Error) {
	s = new(pollServer)
	s.cr = make(chan *netFD, 1)
	s.cw = make(chan *netFD, 1)
	// s.pr and s.pw are indistinguishable.
	if s.pr, s.pw, err = selfConnectedTCPSocket(); err != nil {
		return nil, err
	}
	var e int
	if e = syscall.SetNonblock(s.pr.Fd(), true); e != 0 {
	Errno:
		err = &os.PathError{"setnonblock", s.pr.Name(), os.Errno(e)}
	Error:
		s.pr.Close()
		return nil, err
	}
	if s.poll, err = newpollster(); err != nil {
		goto Error
	}
	if _, err = s.poll.AddFD(s.pr.Fd(), 'r', true); err != nil {
		s.poll.Close()
		goto Error
	}
	s.pending = make(map[int]*netFD)
	go s.Run()
	return s, nil
}

// Wrapper around the accept system call that marks the returned file
// descriptor as nonblocking and close-on-exec.
func accept(fd int) (int, syscall.Sockaddr, error) {
	nfd, sa, err := syscall.Accept4(fd, syscall.SOCK_NONBLOCK|syscall.SOCK_CLOEXEC)
	// The accept4 system call was introduced in Linux 2.6.28.  If
	// we get an ENOSYS error, fall back to using accept.
	if err == nil || err != syscall.ENOSYS {
		return nfd, sa, err
	}

	// See ../syscall/exec_unix.go for description of ForkLock.
	// It is okay to hold the lock across syscall.Accept
	// because we have put fd.sysfd into non-blocking mode.
	syscall.ForkLock.RLock()
	nfd, sa, err = syscall.Accept(fd)
	if err == nil {
		syscall.CloseOnExec(nfd)
	}
	syscall.ForkLock.RUnlock()
	if err != nil {
		return -1, nil, err
	}
	if err = syscall.SetNonblock(nfd, true); err != nil {
		syscall.Close(nfd)
		return -1, nil, err
	}
	return nfd, sa, nil
}

// Open opens an asynchronous communications port.
func Open(name string, options ...func(*Term) error) (*Term, error) {
	fd, e := syscall.Open(name, syscall.O_NOCTTY|syscall.O_CLOEXEC|syscall.O_NDELAY|syscall.O_RDWR, 0666)
	if e != nil {
		return nil, &os.PathError{"open", name, e}
	}

	modules := [2]string{"ptem", "ldterm"}
	for _, mod := range modules {
		err := unix.IoctlSetInt(fd, C.I_PUSH, int(uintptr(unsafe.Pointer(syscall.StringBytePtr(mod)))))
		if err != nil {
			return nil, err
		}
	}

	t := Term{name: name, fd: fd}
	termios.Tcgetattr(uintptr(t.fd), &t.orig)
	if err := termios.Tcgetattr(uintptr(t.fd), &t.orig); err != nil {
		return nil, err
	}

	if err := t.SetOption(options...); err != nil {
		return nil, err
	}

	return &t, syscall.SetNonblock(t.fd, false)
}

// Remove a reference to this FD and close if we've been asked to do so (and
// there are no references left.
func (fd *netFD) decref() {
	fd.sysmu.Lock()
	fd.sysref--
	// NOTE(rsc): On Unix we check fd.sysref == 0 here before closing,
	// but on Windows we have no way to wake up the blocked I/O other
	// than closing the socket (or calling Shutdown, which breaks other
	// programs that might have a reference to the socket).  So there is
	// a small race here that we might close fd.sysfd and then some other
	// goroutine might start a read of fd.sysfd (having read it before we
	// write InvalidHandle to it), which might refer to some other file
	// if the specific handle value gets reused.  I think handle values on
	// Windows are not reused as aggressively as file descriptors on Unix,
	// so this might be tolerable.
	if fd.closing && fd.sysfd != syscall.InvalidHandle {
		// In case the user has set linger, switch to blocking mode so
		// the close blocks.  As long as this doesn't happen often, we
		// can handle the extra OS processes.  Otherwise we'll need to
		// use the resultsrv for Close too.  Sigh.
		syscall.SetNonblock(fd.sysfd, false)
		closesocket(fd.sysfd)
		fd.sysfd = syscall.InvalidHandle
		// no need for a finalizer anymore
		runtime.SetFinalizer(fd, nil)
	}
	fd.sysmu.Unlock()
}

func newFD(sysfd int) (*FD, error) {
	// Set sysfd to non-blocking mode
	err := syscall.SetNonblock(sysfd, true)
	if err != nil {
		debugf("FD %03d: NF: SetNonBlock: %s", sysfd, err.Error())
		return nil, err
	}
	// Check if sysfd is select-able
	// NOTE(npat): Is this useful? Can it ever fail?
	var rs fdSet
	var tv syscall.Timeval
	rs.Zero()
	rs.Set(sysfd)
	_, err = uxSelect(sysfd+1, &rs, nil, nil, &tv)
	if err != nil {
		debugf("FD %03d: NF: select(2): %s", sysfd, err.Error())
		return nil, err
	}
	// Initialize FD. We don't generate arbitrary ids, instead we
	// use sysfd as the fdMap id. In effect, fd.id is alays ==
	// fd.sysfd. Remember that sysfd's can be reused; we must be
	// carefull not to allow this to mess things up.
	fd := &FD{id: sysfd, sysfd: sysfd}
	fd.r.cond = sync.NewCond(&fd.r.mu)
	fd.w.cond = sync.NewCond(&fd.w.mu)
	// Add to fdMap
	fdM.AddFD(fd)
	debugf("FD %03d: NF: Ok", fd.id)
	return fd, nil
}

// Wrapper around the socket system call that marks the returned file
// descriptor as nonblocking and close-on-exec.
func sysSocket(family, sotype, proto int) (int, error) { // 创建socket套接字
	s, err := socketFunc(family, sotype|syscall.SOCK_NONBLOCK|syscall.SOCK_CLOEXEC, proto)
	// On Linux the SOCK_NONBLOCK and SOCK_CLOEXEC flags were
	// introduced in 2.6.27 kernel and on FreeBSD both flags were
	// introduced in 10 kernel. If we get an EINVAL error on Linux
	// or EPROTONOSUPPORT error on FreeBSD, fall back to using
	// socket without them.
	switch err {
	case nil:
		return s, nil
	default:
		return -1, os.NewSyscallError("socket", err)
	case syscall.EPROTONOSUPPORT, syscall.EINVAL:
	}

	// See ../syscall/exec_unix.go for description of ForkLock.
	syscall.ForkLock.RLock()
	s, err = socketFunc(family, sotype, proto)
	if err == nil {
		syscall.CloseOnExec(s)
	}
	syscall.ForkLock.RUnlock()
	if err != nil {
		return -1, os.NewSyscallError("socket", err)
	}
	if err = syscall.SetNonblock(s, true); err != nil {
		closeFunc(s)
		return -1, os.NewSyscallError("setnonblock", err)
	}
	return s, nil
}

func newFD(sysfd int) (*FD, error) {
	// Set sysfd to non-blocking mode
	err := syscall.SetNonblock(sysfd, true)
	if err != nil {
		debugf("FD xxx: NF: sysfd=%d, err=%v", sysfd, err)
		return nil, err
	}
	// Initialize FD
	fd := &FD{sysfd: sysfd}
	fd.id = fdM.GetID()
	fd.r.cond = sync.NewCond(&fd.r.mu)
	fd.w.cond = sync.NewCond(&fd.w.mu)
	// Add to Epoll set. We may imediatelly start receiving events
	// after this. They will be dropped since the FD is not yet in
	// fdMap. It's ok. Nobody is waiting on this FD yet, anyway.
	ev := syscall.EpollEvent{
		Events: syscall.EPOLLIN |
			syscall.EPOLLOUT |
			syscall.EPOLLRDHUP |
			(syscall.EPOLLET & 0xffffffff),
		Fd: int32(fd.id)}
	err = syscall.EpollCtl(epfd, syscall.EPOLL_CTL_ADD, fd.sysfd, &ev)
	if err != nil {
		debugf("FD %03d: NF: sysfd=%d, err=%v", fd.id, fd.sysfd, err)
		return nil, err
	}
	// Add to fdMap
	fdM.AddFD(fd)
	debugf("FD %03d: NF: sysfd=%d", fd.id, fd.sysfd)
	return fd, nil
}

func (c *Connection) setBaudRate(rate uint32) error {
	// Create the term IO settings structure
	term := syscall.Termios{
		Iflag:  syscall.IGNPAR,
		Cflag:  syscall.CS8 | syscall.CREAD | syscall.CLOCAL | rate,
		Cc:     [32]uint8{syscall.VMIN: 0, syscall.VTIME: getVtime(connectionTimeout)},
		Ispeed: rate,
		Ospeed: rate,
	}

	// Make the IOCTL system call to configure the term
	if _, _, errno := syscall.Syscall(
		syscall.SYS_IOCTL,
		uintptr(c.file.Fd()),
		uintptr(syscall.TCSETS),
		uintptr(unsafe.Pointer(&term)),
	); errno != 0 {
		// TODO: include errno in this
		return errors.New("Encountered error doing IOCTL syscall")
	}

	if err := syscall.SetNonblock(int(c.file.Fd()), false); err != nil {
		return err
	}

	return nil
}

func newFakeVTYServer() (*fakeVTYServer, error) {
	fds, err := syscall.Socketpair(syscall.AF_UNIX, syscall.SOCK_STREAM, 0)
	if err != nil {
		return nil, err
	}

	vtyClientFile := os.NewFile(uintptr(fds[1]), "vty-client")
	vtyClientConn, err := net.FileConn(vtyClientFile)
	if err != nil {
		return nil, err
	}

	vtyServerFile := os.NewFile(uintptr(fds[0]), "vty-server")
	vtyServerConn, err := net.FileConn(vtyServerFile)
	if err != nil {
		return nil, err
	}
	syscall.SetNonblock(fds[0], false)

	vs := &fakeVTYServer{
		clientConn: vtyClientConn,
		serverConn: vtyServerConn,
		clientFile: vtyClientFile,
		serverFile: vtyServerFile,

		send:     make(chan []byte),
		received: make(chan []byte),
	}

	go vs.read()
	go vs.write()

	return vs, nil
}