Golang syscall.Pipe函数代码示例

// epollinit opens an epoll file descriptor and creates a pipe which will be
// used to wake up the epoll_wait(2) function. Then, file descriptor associated
// with inotify event queue and the read end of the pipe are added to epoll set.
// Note that `fd` member must be set before this function is called.
func (i *inotify) epollinit() (err error) {
	if i.epfd, err = syscall.EpollCreate1(0); err != nil {
		return
	}
	if err = syscall.Pipe(i.pipefd); err != nil {
		return
	}
	i.epes = []syscall.EpollEvent{
		{Events: syscall.EPOLLIN, Fd: i.fd},
		{Events: syscall.EPOLLIN, Fd: int32(i.pipefd[0])},
	}
	if err = syscall.EpollCtl(i.epfd, syscall.EPOLL_CTL_ADD, int(i.fd), &i.epes[0]); err != nil {
		return
	}
	return syscall.EpollCtl(i.epfd, syscall.EPOLL_CTL_ADD, i.pipefd[0], &i.epes[1])
}

func TestSelect(t *testing.T) {
	var p1, p2 [2]int
	mustNil(syscall.Pipe(p1[:]))
	mustNil(syscall.Pipe(p2[:]))
	fs := NewFdSet(p1[0], p2[0])
	var maxfd int
	if p1[0] > p2[0] {
		maxfd = p1[0] + 1
	} else {
		maxfd = p2[0] + 1
	}
	go func() {
		syscall.Write(p1[1], []byte("to p1"))
		syscall.Write(p2[1], []byte("to p2"))
		syscall.Close(p1[1])
		syscall.Close(p2[1])
	}()
	e := Select(maxfd+1, fs, nil, nil, nil)
	if e != nil {
		t.Errorf("Select(%v, %v, nil, nil, nil) => %v, want <nil>",
			maxfd+1, fs, e)
	}
	syscall.Close(p1[0])
	syscall.Close(p2[0])
}

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 NewGTKUI() *GTKUI {
	gtk.Init(nil)
	window := gtk.Window(gtk.GTK_WINDOW_TOPLEVEL)
	window.SetPosition(gtk.GTK_WIN_POS_CENTER)
	window.SetTitle("Pond")
	window.SetDefaultSize(1000, 800)

	ui := &GTKUI{
		window:  window,
		actions: make(chan interface{}, uiActionsQueueLen),
		events:  make(chan interface{}, 8),
	}
	window.Connect("destroy", func(ctx *glib.CallbackContext) {
		close(ui.events)
		for {
			if _, ok := <-ui.actions; !ok {
				break
			}
		}
		gtk.MainQuit()
	})
	if err := syscall.Pipe(ui.pipe[:]); err != nil {
		panic(err)
	}
	syscall.SetNonblock(ui.pipe[0], true)

	glib.FdWatchAdd(ui.pipe[0], glib.IOIn, func(conditions int) bool {
		ui.onAction()
		return true
	})

	return ui
}

func main() {
	fd := make([]int, 2)
	if err := syscall.Pipe(fd); err != nil {
		log.Fatal("Socketpair:", err)
	}
	defer syscall.Close(fd[0])
	defer syscall.Close(fd[1])
	name := fmt.Sprintf("/proc/%d/fd/%d", os.Getpid(), fd[1])
	fmt.Println(name)

	cmd := exec.Command("ubertooth-btle", "-f", "-d", name)
	if err := cmd.Start(); err != nil {
		log.Fatal(err)
	}

	f := os.NewFile(uintptr(fd[0]), "server")
	buf := make([]byte, 1024)
	for {
		n, err := f.Read(buf)
		if err == io.EOF {
			break
		}
		if err != nil {
			log.Fatal(err)
		}
		fmt.Printf("%q\n", buf[:n])
	}
}

func makeTestFd(t *testing.T) testFd {
	var tfd testFd
	errno := syscall.Pipe(tfd[:])
	if errno != nil {
		t.Fatalf("Failed to create pipe: %v", errno)
	}
	return tfd
}

// Pipe returns a connected pair of Files; reads from r return bytes
// written to w. It returns the files and an error, if any.
func Pipe() (r *File, w *File, err error) {
	var p [2]int

	if e := syscall.Pipe(p[0:]); e != nil {
		return nil, nil, NewSyscallError("pipe", e)
	}

	return NewFile(uintptr(p[0]), "|0"), NewFile(uintptr(p[1]), "|1"), nil
}

// Try to open a pipe with O_CLOEXEC set on both file descriptors.
func forkExecPipe(p []int) error {
	err := syscall.Pipe(p)
	if err != nil {
		return err
	}
	_, err = fcntl(p[0], syscall.F_SETFD, syscall.FD_CLOEXEC)
	if err != nil {
		return err
	}
	_, err = fcntl(p[1], syscall.F_SETFD, syscall.FD_CLOEXEC)
	return err
}

// Pipe returns a connected pair of Files; reads from r return bytes
// written to w. It returns the files and an error, if any.
func Pipe() (r *File, w *File, err error) {
	var p [2]int

	syscall.ForkLock.RLock()
	if e := syscall.Pipe(p[0:]); e != nil {
		syscall.ForkLock.RUnlock()
		return nil, nil, NewSyscallError("pipe", e)
	}
	syscall.ForkLock.RUnlock()

	return NewFile(uintptr(p[0]), "|0"), NewFile(uintptr(p[1]), "|1"), nil
}

func Pipe() (r *File, w *File, err Error) {
	var p [2]int

	syscall.ForkLock.RLock()
	if e := syscall.Pipe(p[0:]); iserror(e) {
		syscall.ForkLock.RUnlock()
		return nil, nil, NewSyscallError("pipe", e)
	}
	syscall.ForkLock.RUnlock()

	return NewFile(p[0], "|0"), NewFile(p[1], "|1"), nil
}

// launchQemu run qemu and wait it's quit, includes
func launchQemu(ctx *VmContext) {
	qemu, err := exec.LookPath("qemu-system-x86_64")
	if err != nil {
		ctx.hub <- &QemuExitEvent{message: "can not find qemu executable"}
		return
	}

	args := ctx.QemuArguments()

	if glog.V(1) {
		glog.Info("cmdline arguments: ", strings.Join(args, " "))
	}

	go waitConsoleOutput(ctx)

	pipe := make([]int, 2)
	err = syscall.Pipe(pipe)
	if err != nil {
		glog.Error("fail to create pipe")
		ctx.hub <- &QemuExitEvent{message: "fail to create pipe"}
		return
	}

	err = daemon(qemu, append([]string{"qemu-system-x86_64"}, args...), pipe[1])
	if err != nil {
		//fail to daemonize
		glog.Error("try to start qemu failed")
		ctx.hub <- &QemuExitEvent{message: "try to start qemu failed"}
		return
	}

	buf := make([]byte, 4)
	nr, err := syscall.Read(pipe[0], buf)
	if err != nil || nr != 4 {
		glog.Error("try to start qemu failed")
		ctx.hub <- &QemuExitEvent{message: "try to start qemu failed"}
		return
	}
	syscall.Close(pipe[1])
	syscall.Close(pipe[0])

	pid := binary.BigEndian.Uint32(buf[:nr])
	glog.V(1).Infof("starting daemon with pid: %d", pid)

	err = ctx.watchPid(int(pid))
	if err != nil {
		glog.Error("watch qemu process failed")
		ctx.hub <- &QemuExitEvent{message: "watch qemu process failed"}
		return
	}
}

func (s *Splicer) splice(direction string, inFD, outFD int, wg *sync.WaitGroup) {
	// Signal to the caller that we're done
	defer func() {
		// If a reliable delivery socket has data associated with it when a close takes place, the system continues to attempt data transfer.
		if err := syscall.Shutdown(inFD, SHUT_RDWR); err != nil {
			log.Printf("Shutdown err %v", err)
		}
		if err := syscall.Shutdown(outFD, SHUT_RDWR); err != nil {
			log.Printf("Shutdown err %v", err)
		}
		if wg != nil {
			wg.Done()
		}
	}()

	pipe := make([]int, 2)
	if err := syscall.Pipe(pipe); err != nil {
		log.Fatal(err)
	}
	defer func() {
		syscall.Close(pipe[0])
		syscall.Close(pipe[1])
	}()

	var netWrittenBytes, netReadBytes int64
	log.Printf("[%v] Splicing pipe %+v, tcpfds %+v", direction, s.pipe, s.tcpFD)
	for {
		// SPLICE_F_NONBLOCK: don't block if TCP buffer is empty
		// SPLICE_F_MOVE: directly move pages into splice buffer in kernel memory
		// SPLICE_F_MORE: just makes mysql connections slow
		log.Printf("[input (%v)] Entering input", direction)
		inBytes, err := syscall.Splice(inFD, nil, pipe[1], nil, s.bufferSize, SPLICE_F_NONBLOCK)
		if err := s.checkSpliceErr(inBytes, err, fmt.Sprintf("input (%v)", direction)); err != nil {
			log.Printf("ERROR [input (%v)] error: %v", direction, err)
			return
		}
		netReadBytes += inBytes
		log.Printf("[input (%v)] %d bytes read", direction, inBytes)

		log.Printf("[input (%v)] Entering output", direction)
		outBytes, err := syscall.Splice(pipe[0], nil, outFD, nil, s.bufferSize, SPLICE_F_NONBLOCK)
		if err := s.checkSpliceErr(inBytes, err, fmt.Sprintf("output (%v)", direction)); err != nil {
			log.Printf("ERROR [output (%v)] error: %v", direction, err)
			return
		}
		log.Printf("[output (%v)] %d bytes written, out of given input %d", direction, outBytes, inBytes)
		netWrittenBytes += outBytes
	}
	log.Printf("[%v] Spliced %d bytes read %d bytes written", direction, netWrittenBytes, netReadBytes)
}

// init initializes kqueue.
func (k *kqueue) init() (err error) {
	if k.fd, err = syscall.Kqueue(); err != nil {
		return
	}
	// Creates pipe used to stop `Kevent` call by registering it,
	// watching read end and writing to other end of it.
	if err = syscall.Pipe(k.pipefds[:]); err != nil {
		return
	}
	var kevn [1]syscall.Kevent_t
	syscall.SetKevent(&kevn[0], k.pipefds[0], syscall.EVFILT_READ, syscall.EV_ADD)
	_, err = syscall.Kevent(k.fd, kevn[:], nil, nil)
	return
}

// launchQemu run qemu and wait it's quit, includes
func launchQemu(qc *QemuContext, ctx *hypervisor.VmContext) {
	qemu := qc.driver.executable
	if qemu == "" {
		ctx.Hub <- &hypervisor.VmStartFailEvent{Message: "can not find qemu executable"}
		return
	}

	args := qc.arguments(ctx)

	if glog.V(1) {
		glog.Info("cmdline arguments: ", strings.Join(args, " "))
	}

	pipe := make([]int, 2)
	err := syscall.Pipe(pipe)
	if err != nil {
		glog.Error("fail to create pipe")
		ctx.Hub <- &hypervisor.VmStartFailEvent{Message: "fail to create pipe"}
		return
	}

	err = daemon(qemu, append([]string{"qemu-system-x86_64"}, args...), pipe[1])
	if err != nil {
		//fail to daemonize
		glog.Error("try to start qemu failed")
		ctx.Hub <- &hypervisor.VmStartFailEvent{Message: "try to start qemu failed"}
		return
	}

	buf := make([]byte, 4)
	nr, err := syscall.Read(pipe[0], buf)
	if err != nil || nr != 4 {
		glog.Error("try to start qemu failed")
		ctx.Hub <- &hypervisor.VmStartFailEvent{Message: "try to start qemu failed"}
		return
	}
	syscall.Close(pipe[1])
	syscall.Close(pipe[0])

	pid := binary.BigEndian.Uint32(buf[:nr])
	glog.V(1).Infof("starting daemon with pid: %d", pid)

	err = ctx.DCtx.(*QemuContext).watchPid(int(pid), ctx.Hub)
	if err != nil {
		glog.Error("watch qemu process failed")
		ctx.Hub <- &hypervisor.VmStartFailEvent{Message: "watch qemu process failed"}
		return
	}
}

func ext۰os۰Pipe(fr *frame, args []value) value {
	// func os.Pipe() (r *File, w *File, err error)

	// The portable POSIX pipe(2) call is good enough for our needs.
	var p [2]int
	if err := syscall.Pipe(p[:]); err != nil {
		// TODO(adonovan): fix: return an *os.SyscallError.
		return tuple{nil, nil, wrapError(err)}
	}

	NewFile := fr.i.prog.ImportedPackage("os").Func("NewFile")
	r := call(fr.i, fr, 0, NewFile, []value{uintptr(p[0]), "|0"})
	w := call(fr.i, fr, 0, NewFile, []value{uintptr(p[1]), "|1"})
	return tuple{r, w, wrapError(nil)}
}