Golang syscall.SetKevent函数代码示例

func (this *watcher) doDel(path string) error {
	info, found := this.watchedByPath[path]
	if !found {
		return errors.Newf("can't remove non-existent kevent watch for: %s", path)
	}

	var kbuf [1]syscall.Kevent_t
	watchEntry := &kbuf[0]
	syscall.SetKevent(watchEntry, info.fd, syscall.EVFILT_VNODE, syscall.EV_DELETE)
	entryFlags := watchEntry.Flags
	success, errno := syscall.Kevent(this.kq, kbuf[:], nil, nil)
	if success == sysCallFailed {
		return os.NewSyscallError("kevent_rm_watch", errno)
	} else if entryFlags&syscall.EV_ERROR == syscall.EV_ERROR {
		return errors.New("kevent rm error")
	}
	syscall.Close(info.fd)

	//Remove childs if it's directory
	for _, child := range info.childes {
		this.doDel(child)
	}

	delete(this.watchedByPath, path)
	delete(this.watchedByFD, info.fd)

	return nil
}

// unwatch stops watching p file/directory.
func (k *kqueue) singleunwatch(p string, direct bool) error {
	w := k.pthLkp[p]
	if w == nil {
		return errNotWatched
	}
	if direct {
		w.eDir = 0
	} else {
		w.eNonDir = 0
	}
	var kevn [1]syscall.Kevent_t
	syscall.SetKevent(&kevn[0], w.fd, syscall.EVFILT_VNODE, syscall.EV_DELETE)
	if _, err := syscall.Kevent(k.fd, kevn[:], nil, nil); err != nil {
		return err
	}
	if w.eNonDir&w.eDir != 0 {
		if err := k.singlewatch(p, w.eNonDir|w.eDir, w.eNonDir == 0,
			w.fi); err != nil {
			return err
		}
	} else {
		k.del(*w)
	}
	return nil
}

// AddWatch adds path to the watched file set.
// The flags are interpreted as described in kevent(2).
func (w *Watcher) addWatch(path string, flags uint32) error {
	if w.isClosed {
		return errors.New("kevent instance already closed")
	}

	watchEntry := &w.kbuf[0]
	watchEntry.Fflags = flags

	watchfd, found := w.watches[path]
	if !found {
		fd, errno := syscall.Open(path, syscall.O_NONBLOCK|syscall.O_RDONLY, 0700)
		if fd == -1 {
			return &os.PathError{"kevent_add_watch", path, errno}
		}
		watchfd = fd

		w.watches[path] = watchfd
		w.paths[watchfd] = path

		fi, _ := os.Stat(path)
		w.finfo[watchfd] = &fi
	}
	syscall.SetKevent(watchEntry, watchfd, syscall.EVFILT_VNODE, syscall.EV_ADD|syscall.EV_CLEAR)

	wd, errno := syscall.Kevent(w.kq, w.kbuf[:], nil, nil)
	if wd == -1 {
		return &os.PathError{"kevent_add_watch", path, errno}
	} else if (watchEntry.Flags & syscall.EV_ERROR) == syscall.EV_ERROR {
		return &os.PathError{"kevent_add_watch", path, errors.New(fmt.Sprintf("%v", watchEntry.Data))}
	}

	return nil
}

// Unwatch implements trigger.
func (k *kq) Unwatch(w *watched) (err error) {
	var kevn [1]syscall.Kevent_t
	syscall.SetKevent(&kevn[0], w.fd, syscall.EVFILT_VNODE, syscall.EV_DELETE)

	_, err = syscall.Kevent(k.fd, kevn[:], nil, nil)
	return
}

// RemoveWatch removes path from the watched file set.
func (w *Watcher) removeWatch(path string) error {
	w.wmut.Lock()
	watchfd, ok := w.watches[path]
	w.wmut.Unlock()
	if !ok {
		return errors.New(fmt.Sprintf("can't remove non-existent kevent watch for: %s", path))
	}
	w.bufmut.Lock()
	defer w.bufmut.Unlock()
	watchEntry := &w.kbuf[0]
	syscall.SetKevent(watchEntry, watchfd, syscall.EVFILT_VNODE, syscall.EV_DELETE)
	success, errno := syscall.Kevent(w.kq, w.kbuf[:], nil, nil)
	if success == -1 {
		return os.NewSyscallError("kevent_rm_watch", errno)
	} else if (watchEntry.Flags & syscall.EV_ERROR) == syscall.EV_ERROR {
		return errors.New("kevent rm error")
	}
	syscall.Close(watchfd)
	w.wmut.Lock()
	delete(w.watches, path)
	w.wmut.Unlock()
	w.enmut.Lock()
	delete(w.enFlags, path)
	w.enmut.Unlock()
	w.pmut.Lock()
	delete(w.paths, watchfd)
	delete(w.finfo, watchfd)
	w.pmut.Unlock()
	return nil
}

// First return value is whether the pollServer should be woken up.
// This version always returns false.
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, err := syscall.Kevent(p.kq, p.kbuf[:], nil, nil)
	if err != nil {
		return false, os.NewSyscallError("kevent", err)
	}
	if n != 1 || (ev.Flags&syscall.EV_ERROR) == 0 || int(ev.Ident) != fd || int(ev.Filter) != kmode {
		return false, os.NewSyscallError("kqueue phase error", err)
	}
	if ev.Data != 0 {
		return false, syscall.Errno(int(ev.Data))
	}
	return false, nil
}

// watch starts to watch given p file/directory.
func (k *kqueue) singlewatch(p string, e Event, direct bool,
	fi os.FileInfo) error {
	w, ok := k.pthLkp[p]
	if !ok {
		fd, err := syscall.Open(p, syscall.O_NONBLOCK|syscall.O_RDONLY, 0)
		if err != nil {
			return err
		}
		w = &watched{fd: fd, p: p, fi: fi}
	}
	if direct {
		w.eDir |= e
	} else {
		w.eNonDir |= e
	}
	var kevn [1]syscall.Kevent_t
	syscall.SetKevent(&kevn[0], w.fd, syscall.EVFILT_VNODE,
		syscall.EV_ADD|syscall.EV_CLEAR)
	kevn[0].Fflags = encode(w.eDir | w.eNonDir)
	if _, err := syscall.Kevent(k.fd, kevn[:], nil, nil); err != nil {
		return err
	}
	if !ok {
		k.idLkp[w.fd], k.pthLkp[w.p] = w, w
		return nil
	}
	return errAlreadyWatched
}

func (p *pollster) AddFD(fd int, mode int, repeat bool) os.Error {
	var kmode int
	if mode == 'r' {
		kmode = syscall.EVFILT_READ
	} else {
		kmode = syscall.EVFILT_WRITE
	}
	var events [1]syscall.Kevent_t
	ev := &events[0]
	// EV_ADD - add event to kqueue list
	// EV_RECEIPT - generate fake EV_ERROR as result of add,
	//	rather than waiting for real event
	// EV_ONESHOT - delete the event the first time it triggers
	flags := syscall.EV_ADD | syscall.EV_RECEIPT
	if !repeat {
		flags |= syscall.EV_ONESHOT
	}
	syscall.SetKevent(ev, fd, kmode, flags)

	n, e := syscall.Kevent(p.kq, &events, &events, nil)
	if e != 0 {
		return os.NewSyscallError("kevent", e)
	}
	if n != 1 || (ev.Flags&syscall.EV_ERROR) == 0 || int(ev.Ident) != fd || int(ev.Filter) != kmode {
		return os.ErrorString("kqueue phase error")
	}
	if ev.Data != 0 {
		return os.Errno(int(ev.Data))
	}
	return nil
}

// Watch implements trigger.
func (k *kq) Watch(fi os.FileInfo, w *watched, e int64) (err error) {
	var kevn [1]syscall.Kevent_t
	syscall.SetKevent(&kevn[0], w.fd, syscall.EVFILT_VNODE,
		syscall.EV_ADD|syscall.EV_CLEAR)
	kevn[0].Fflags = uint32(e)

	_, err = syscall.Kevent(k.fd, kevn[:], nil, nil)
	return
}

// Remove stops watching the the named file or directory (non-recursively).
func (w *Watcher) Remove(name string) error {
	name = filepath.Clean(name)
	w.wmut.Lock()
	watchfd, ok := w.watches[name]
	w.wmut.Unlock()
	if !ok {
		return fmt.Errorf("can't remove non-existent kevent watch for: %s", name)
	}
	var kbuf [1]syscall.Kevent_t
	watchEntry := &kbuf[0]
	syscall.SetKevent(watchEntry, watchfd, syscall.EVFILT_VNODE, syscall.EV_DELETE)
	entryFlags := watchEntry.Flags
	success, errno := syscall.Kevent(w.kq, kbuf[:], nil, nil)
	if success == -1 {
		return os.NewSyscallError("kevent_rm_watch", errno)
	} else if (entryFlags & syscall.EV_ERROR) == syscall.EV_ERROR {
		return errors.New("kevent rm error")
	}
	syscall.Close(watchfd)
	w.wmut.Lock()
	delete(w.watches, name)
	w.wmut.Unlock()
	w.enmut.Lock()
	delete(w.enFlags, name)
	w.enmut.Unlock()
	w.pmut.Lock()
	delete(w.paths, watchfd)
	fInfo := w.finfo[watchfd]
	delete(w.finfo, watchfd)
	w.pmut.Unlock()

	// Find all watched paths that are in this directory that are not external.
	if fInfo.IsDir() {
		var pathsToRemove []string
		w.pmut.Lock()
		for _, wpath := range w.paths {
			wdir, _ := filepath.Split(wpath)
			if filepath.Clean(wdir) == filepath.Clean(name) {
				w.ewmut.Lock()
				if !w.externalWatches[wpath] {
					pathsToRemove = append(pathsToRemove, wpath)
				}
				w.ewmut.Unlock()
			}
		}
		w.pmut.Unlock()
		for _, name := range pathsToRemove {
			// Since these are internal, not much sense in propagating error
			// to the user, as that will just confuse them with an error about
			// a path they did not explicitly watch themselves.
			w.Remove(name)
		}
	}

	return nil
}

// RemoveWatch removes path from the watched file set.
func (w *Watcher) removeWatch(path string) error {
	w.wmut.Lock()
	watchfd, ok := w.watches[path]
	w.wmut.Unlock()
	if !ok {
		return errors.New(fmt.Sprintf("can't remove non-existent kevent watch for: %s", path))
	}
	w.bufmut.Lock()
	watchEntry := &w.kbuf[0]
	syscall.SetKevent(watchEntry, watchfd, syscall.EVFILT_VNODE, syscall.EV_DELETE)
	success, errno := syscall.Kevent(w.kq, w.kbuf[:], nil, nil)
	w.bufmut.Unlock()
	if success == -1 {
		return os.NewSyscallError("kevent_rm_watch", errno)
	} else if (watchEntry.Flags & syscall.EV_ERROR) == syscall.EV_ERROR {
		return errors.New("kevent rm error")
	}
	syscall.Close(watchfd)
	w.wmut.Lock()
	delete(w.watches, path)
	w.wmut.Unlock()
	w.enmut.Lock()
	delete(w.enFlags, path)
	w.enmut.Unlock()
	w.pmut.Lock()
	delete(w.paths, watchfd)
	fInfo := w.finfo[watchfd]
	delete(w.finfo, watchfd)
	w.pmut.Unlock()

	// Find all watched paths that are in this directory that are not external.
	if fInfo.IsDir() {
		pathsToRemove := make([]string, 0)
		w.pmut.Lock()
		for _, wpath := range w.paths {
			wdir, _ := filepath.Split(wpath)
			if filepath.Clean(wdir) == filepath.Clean(path) {
				w.ewmut.Lock()
				if _, extern := w.externalWatches[wpath]; !extern {
					pathsToRemove = append(pathsToRemove, wpath)
				}
				w.ewmut.Unlock()
			}
		}
		w.pmut.Unlock()
		for idx := 0; idx < len(pathsToRemove); idx++ {
			// Since these are internal, not much sense in propogating error
			// to the user, as that will just confuse them with an error about
			// a path they did not explicitly watch themselves.
			w.removeWatch(pathsToRemove[idx])
		}
	}

	return nil
}

// Initialize Kevent_t fields and propagate changelist for the given pid
func (w *Watcher) kevent(pid int, fflags uint32, flags int) error {
	listener, _ := w.listener.(*kqueueListener)
	event := &listener.buf[0]

	syscall.SetKevent(event, pid, syscall.EVFILT_PROC, flags)
	event.Fflags = fflags

	_, err := syscall.Kevent(listener.kq, listener.buf[:], nil, nil)

	return err
}

func (p *pollster) DelFD(fd int, mode int) {
	var kmode int
	if mode == 'r' {
		kmode = syscall.EVFILT_READ
	} else {
		kmode = syscall.EVFILT_WRITE
	}
	var events [1]syscall.Kevent_t
	ev := &events[0]
	// EV_DELETE - delete event from kqueue list
	syscall.SetKevent(ev, fd, kmode, syscall.EV_DELETE)
	syscall.Kevent(p.kq, &events, nil, nil)
}

// 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
}

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)
}