Golang syscall.Close函數代碼示例

func childMain() error {
	var err error

	pipe := os.NewFile(uintptr(3), "pipe")
	if pipe != nil {
		defer pipe.Close()
		if err == nil {
			pipe.Write([]byte{DaemonSuccess})
		} else {
			pipe.Write([]byte{DaemonFailure})
		}
	}

	signal.Ignore(syscall.SIGCHLD)

	syscall.Close(0)
	syscall.Close(1)
	syscall.Close(2)

	syscall.Setsid()
	syscall.Umask(022)

	// syscall.Chdir("/")

	return nil
}

func listenStream(netw, addr string) (l net.Listener, err error) {
	var (
		file *os.File
	)

	fd, err := listen(netw, addr)
	if err != nil {
		return nil, err
	}

	// Set backlog size to the maximum
	if err = syscall.Listen(fd, syscall.SOMAXCONN); err != nil {
		syscall.Close(fd)
		return nil, err
	}

	file = os.NewFile(uintptr(fd), filePrefix+strconv.Itoa(os.Getpid()))
	if l, err = net.FileListener(file); err != nil {
		syscall.Close(fd)
		return nil, err
	}

	if err = file.Close(); err != nil {
		syscall.Close(fd)
		l.Close()
		return nil, err
	}

	return l, err
}

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 CaptureStream(file *os.File) (*os.File, func(), error) {
	pipeR, pipeW, err := os.Pipe()
	if err != nil {
		return nil, nil, err
	}

	bkupFD, err := syscall.Dup(int(file.Fd()))
	if err != nil {
		pipeW.Close()
		pipeR.Close()
		return nil, nil, err
	}

	err = syscall.Dup2(int(pipeW.Fd()), int(file.Fd()))
	if err != nil {
		syscall.Close(bkupFD)
		pipeW.Close()
		pipeR.Close()
	}

	cleanFunc := func() {
		syscall.Dup2(bkupFD, int(file.Fd()))
		syscall.Close(bkupFD)
		pipeW.Close()
		pipeR.Close()
	}

	return pipeR, cleanFunc, nil
}

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
}

// Close wraps syscall.Close.
func (sw *Switch) Close(s int) (err error) {
	so := sw.sockso(s)
	if so == nil {
		return syscall.Close(s)
	}
	sw.fmu.RLock()
	f, _ := sw.fltab[FilterClose]
	sw.fmu.RUnlock()

	af, err := f.apply(so)
	if err != nil {
		return err
	}
	so.Err = syscall.Close(s)
	if err = af.apply(so); err != nil {
		return err
	}

	if so.Err != nil {
		return so.Err
	}
	sw.smu.Lock()
	delete(sw.sotab, s)
	sw.stats.getLocked(so.Cookie).Closed++
	sw.smu.Unlock()
	return nil
}

func main() {
	args := Arguments()

	infile, args, err := args.String("in-file", nil)
	Check(err)
	outfile, args, err := args.String("out-file", nil)
	Check(err)

	infd, err := syscall.Open(infile, int(ReadOnly), 0)
	Check(err)
	defer func() { Check(syscall.Close(infd)) }()

	flags := Create | WriteOnly | Truncate
	perms := 0 |
		UserRead | UserWrite |
		GroupRead | GroupWrite |
		OtherRead | OtherWrite
	outfd, err := syscall.Open(outfile, int(flags), uint32(perms))
	Check(err)
	defer func() { Check(syscall.Close(outfd)) }()

	bufSize := 1024
	buf := make([]byte, bufSize)
	var n int
	for {
		n, err = syscall.Read(infd, buf)
		Check(err)
		if n == 0 {
			break
		}
		_, err = syscall.Write(outfd, buf[:n])
		Check(err)
	}
}

func (s *Splicer) CopyBytes(in, out *net.TCPConn) {
	// Close the tcp connection given to us.
	defer func() {
		// TODO: Double close problems?
		out.Close()
		in.Close()
	}()

	// Invoking File() on the connection will duplicate the socket fd, setting
	// the original (socket fd) to block.
	inFile, err := in.File()
	if err != nil {
		log.Fatal(err)
	}
	inFD := int(inFile.Fd())
	defer syscall.Close(inFD)

	outFile, err := out.File()
	if err != nil {
		log.Fatal(err)
	}
	outFD := int(outFile.Fd())
	defer syscall.Close(outFD)

	var wg sync.WaitGroup
	wg.Add(2)
	go s.splice(fmt.Sprintf("from backend: %v -> %v", in.RemoteAddr(), out.RemoteAddr()), inFD, outFD, &wg)
	go s.splice(fmt.Sprintf("to backend: %v -> %v", out.RemoteAddr(), in.RemoteAddr()), outFD, inFD, &wg)
	wg.Wait()
}

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])
	}
}

/*
	c.sa = new(syscall.SockaddrInet4)
	c.sa.Addr = [4]byte{10, 1, 1, 131}
	c.sa.Port = port
*/
func (c *Worker) socket() {
	begin := time.Now()
	s, err := syscall.Socket(syscall.AF_INET, syscall.SOCK_STREAM, 0)
	if err != nil {
		syscall.Close(s)
		return
	}

	err = syscall.Connect(s, nil) //TODO
	if err != nil {
		lg(err)
		syscall.Close(s)
		return
	}

	_, err = syscall.Write(s, message.content)
	if err != nil {
		syscall.Close(s)
		return
	}

	_, err = syscall.Read(s, c.data)
	if err != nil {
		syscall.Close(s)
		return
	}

	syscall.Close(s)
	time.Now().Sub(begin)
}

func ListenPipe(path, sddl string) (net.Listener, error) {
	var (
		sd  []byte
		err error
	)
	if sddl != "" {
		sd, err = sddlToSecurityDescriptor(sddl)
		if err != nil {
			return nil, err
		}
	}
	h, err := makeServerPipeHandle(path, sd, true)
	if err != nil {
		return nil, err
	}
	// Immediately open and then close a client handle so that the named pipe is
	// created but not currently accepting connections.
	h2, err := createFile(path, 0, 0, nil, syscall.OPEN_EXISTING, cSECURITY_SQOS_PRESENT|cSECURITY_ANONYMOUS, 0)
	if err != nil {
		syscall.Close(h)
		return nil, err
	}
	syscall.Close(h2)
	l := &win32PipeListener{
		firstHandle:        h,
		path:               path,
		securityDescriptor: sd,
		acceptCh:           make(chan (chan acceptResponse)),
		closeCh:            make(chan int),
		doneCh:             make(chan int),
	}
	go l.listenerRoutine()
	return l, nil
}

func afterDaemonize(err error) {
	// Ignore SIGCHLD signal
	signal.Ignore(syscall.SIGCHLD)

	// Close STDOUT, STDIN, STDERR
	syscall.Close(0)
	syscall.Close(1)
	syscall.Close(2)

	// Become the process group leader
	syscall.Setsid()

	// // Clear umask
	syscall.Umask(022)

	// // chdir for root directory
	syscall.Chdir("/")

	// Notify that the child process started successfuly
	pipe := os.NewFile(uintptr(3), "pipe")
	if pipe != nil {
		defer pipe.Close()
		if err == nil {
			pipe.Write([]byte{DAEMONIZE_SUCCESS})
		} else {
			pipe.Write([]byte{DAEMONIZE_FAIL})
		}
	}
}

func (w *Watcher) readEvent() {
	var (
		buf   [syscall.SizeofInotifyEvent * 4096]byte // Buffer for a maximum of 4096 raw events
		n     int                                     // Number of bytes read with read()
		errno error                                   // Syscall errno
	)

	for {

		select {
		case <-w.done:
			syscall.Close(w.fd)
			close(w.acceptEvent)
			close(w.Error)
			return
		default:
		}

		n, errno = syscall.Read(w.fd, buf[0:])

		if n == 0 {
			syscall.Close(w.fd)
			close(w.acceptEvent)
			close(w.Error)
			return
		}

		if n < syscall.SizeofInotifyEvent {
			log.Fatal("size of InotifyEvent error", errno)
		}

		var offset uint32 = 0

		for offset <= uint32(n-syscall.SizeofInotifyEvent) {
			raw := (*syscall.InotifyEvent)(unsafe.Pointer(&buf[offset]))
			event := new(FileEvent)
			event.wd = raw.Wd
			event.nameLen = raw.Len
			event.mask = raw.Mask
			event.cookie = raw.Cookie
			path := w.wm.paths[int(raw.Wd)]
			if raw.Len > 0 {
				// Point "bytes" at the first byte of the filename
				bytes := (*[syscall.PathMax]byte)(unsafe.Pointer(&buf[offset+syscall.SizeofInotifyEvent]))
				// The filename is padded with NUL bytes. TrimRight() gets rid of those.
				event.fileName = path + "/" + strings.TrimRight(string(bytes[0:raw.Len]), "\000")
			}

			if _, found := w.skipExt[filepath.Ext(event.fileName)]; !found {
				fmt.Println("--->", w.skipExt, "--->", filepath.Ext(event.fileName), "--->", found)
				//發送事件acceptEvent通道
				w.acceptEvent <- event
			} else {
				fmt.Println("過濾文件:", event.fileName)
			}

			offset += syscall.SizeofInotifyEvent + raw.Len
		}
	}
}

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 initJob() {
	// Create Job object and assign current process to it.
	jobObject, err := createJobObject(nil, nil)
	if err != nil {
		log.Printf("CreateJobObject failed: %v", err)
		return
	}
	if err = assignProcessToJobObject(jobObject, currentProcess); err != nil {
		log.Printf("AssignProcessToJobObject failed: %v", err)
		syscall.Close(jobObject)
		return
	}
	iocp, err := syscall.CreateIoCompletionPort(syscall.InvalidHandle, 0, 0, 1)
	if err != nil {
		log.Printf("CreateIoCompletionPort failed: %v", err)
		syscall.Close(jobObject)
		return
	}
	port := JOBOBJECT_ASSOCIATE_COMPLETION_PORT{
		CompletionKey:  uintptr(jobObject),
		CompletionPort: iocp,
	}
	err = setInformationJobObject(jobObject, JobObjectAssociateCompletionPortInformation, uintptr(unsafe.Pointer(&port)), uint32(unsafe.Sizeof(port)))
	if err != nil {
		log.Printf("SetInformationJobObject failed: %v", err)
		syscall.Close(jobObject)
		syscall.Close(iocp)
		return
	}
	// Read Job notifications about new "child" processes and collect them in childProcesses.
	go func() {
		var code, key uint32
		var o *syscall.Overlapped
		for {
			err := syscall.GetQueuedCompletionStatus(iocp, &code, &key, &o, syscall.INFINITE)
			if err != nil {
				log.Printf("GetQueuedCompletionStatus failed: %v", err)
				return
			}
			if key != uint32(jobObject) {
				panic("Invalid GetQueuedCompletionStatus key parameter")
			}
			if code == JOB_OBJECT_MSG_NEW_PROCESS {
				pid := int(uintptr(unsafe.Pointer(o)))
				if pid == syscall.Getpid() {
					continue
				}
				c, err := syscall.OpenProcess(syscall.PROCESS_QUERY_INFORMATION, false, uint32(pid))
				if err != nil {
					log.Printf("OpenProcess failed: %v", err)
					continue
				}
				childMu.Lock()
				childProcesses = append(childProcesses, c)
				childMu.Unlock()
			}
		}
	}()
}