// Store fd here as os.File.Read() will no longer return on close after
// calling Fd(). See: https://github.com/golang/go/issues/26439
fd int
- mu sync.Mutex // Map access
inotifyFile *os.File
- watches map[string]*watch // Map of inotify watches (path → watch)
- paths map[int]string // Map of watched paths (watch descriptor → path)
- done chan struct{} // Channel for sending a "quit message" to the reader goroutine
- doneResp chan struct{} // Channel to respond to Close
+ watches *watches
+ done chan struct{} // Channel for sending a "quit message" to the reader goroutine
+ closeMu sync.Mutex
+ doneResp chan struct{} // Channel to respond to Close
+}
+
+type (
+ watches struct {
+ mu sync.RWMutex
+ wd map[uint32]*watch // wd → watch
+ path map[string]uint32 // pathname → wd
+ }
+ watch struct {
+ wd uint32 // Watch descriptor (as returned by the inotify_add_watch() syscall)
+ flags uint32 // inotify flags of this watch (see inotify(7) for the list of valid flags)
+ path string // Watch path.
+ }
+)
+
+func newWatches() *watches {
+ return &watches{
+ wd: make(map[uint32]*watch),
+ path: make(map[string]uint32),
+ }
+}
+
+func (w *watches) len() int {
+ w.mu.RLock()
+ defer w.mu.RUnlock()
+ return len(w.wd)
+}
+
+func (w *watches) add(ww *watch) {
+ w.mu.Lock()
+ defer w.mu.Unlock()
+ w.wd[ww.wd] = ww
+ w.path[ww.path] = ww.wd
+}
+
+func (w *watches) remove(wd uint32) {
+ w.mu.Lock()
+ defer w.mu.Unlock()
+ delete(w.path, w.wd[wd].path)
+ delete(w.wd, wd)
+}
+
+func (w *watches) removePath(path string) (uint32, bool) {
+ w.mu.Lock()
+ defer w.mu.Unlock()
+
+ wd, ok := w.path[path]
+ if !ok {
+ return 0, false
+ }
+
+ delete(w.path, path)
+ delete(w.wd, wd)
+
+ return wd, true
+}
+
+func (w *watches) byPath(path string) *watch {
+ w.mu.RLock()
+ defer w.mu.RUnlock()
+ return w.wd[w.path[path]]
+}
+
+func (w *watches) byWd(wd uint32) *watch {
+ w.mu.RLock()
+ defer w.mu.RUnlock()
+ return w.wd[wd]
+}
+
+func (w *watches) updatePath(path string, f func(*watch) (*watch, error)) error {
+ w.mu.Lock()
+ defer w.mu.Unlock()
+
+ var existing *watch
+ wd, ok := w.path[path]
+ if ok {
+ existing = w.wd[wd]
+ }
+
+ upd, err := f(existing)
+ if err != nil {
+ return err
+ }
+ if upd != nil {
+ w.wd[upd.wd] = upd
+ w.path[upd.path] = upd.wd
+
+ if upd.wd != wd {
+ delete(w.wd, wd)
+ }
+ }
+
+ return nil
}
// NewWatcher creates a new Watcher.
func NewWatcher() (*Watcher, error) {
- // Create inotify fd
- // Need to set the FD to nonblocking mode in order for SetDeadline methods to work
- // Otherwise, blocking i/o operations won't terminate on close
+ // Need to set nonblocking mode for SetDeadline to work, otherwise blocking
+ // I/O operations won't terminate on close.
fd, errno := unix.InotifyInit1(unix.IN_CLOEXEC | unix.IN_NONBLOCK)
if fd == -1 {
return nil, errno
w := &Watcher{
fd: fd,
inotifyFile: os.NewFile(uintptr(fd), ""),
- watches: make(map[string]*watch),
- paths: make(map[int]string),
+ watches: newWatches(),
Events: make(chan Event),
Errors: make(chan error),
done: make(chan struct{}),
case w.Events <- e:
return true
case <-w.done:
+ return false
}
- return false
}
// Returns true if the error was sent, or false if watcher is closed.
// Close removes all watches and closes the events channel.
func (w *Watcher) Close() error {
- w.mu.Lock()
+ w.closeMu.Lock()
if w.isClosed() {
- w.mu.Unlock()
+ w.closeMu.Unlock()
return nil
}
-
- // Send 'close' signal to goroutine, and set the Watcher to closed.
close(w.done)
- w.mu.Unlock()
+ w.closeMu.Unlock()
// Causes any blocking reads to return with an error, provided the file
// still supports deadline operations.
unix.IN_CREATE | unix.IN_ATTRIB | unix.IN_MODIFY |
unix.IN_MOVE_SELF | unix.IN_DELETE | unix.IN_DELETE_SELF
- w.mu.Lock()
- defer w.mu.Unlock()
- watchEntry := w.watches[name]
- if watchEntry != nil {
- flags |= watchEntry.flags | unix.IN_MASK_ADD
- }
- wd, errno := unix.InotifyAddWatch(w.fd, name, flags)
- if wd == -1 {
- return errno
- }
+ return w.watches.updatePath(name, func(existing *watch) (*watch, error) {
+ if existing != nil {
+ flags |= existing.flags | unix.IN_MASK_ADD
+ }
- if watchEntry == nil {
- w.watches[name] = &watch{wd: uint32(wd), flags: flags}
- w.paths[wd] = name
- } else {
- watchEntry.wd = uint32(wd)
- watchEntry.flags = flags
- }
+ wd, err := unix.InotifyAddWatch(w.fd, name, flags)
+ if wd == -1 {
+ return nil, err
+ }
- return nil
+ if existing == nil {
+ return &watch{
+ wd: uint32(wd),
+ path: name,
+ flags: flags,
+ }, nil
+ }
+
+ existing.wd = uint32(wd)
+ existing.flags = flags
+ return existing, nil
+ })
}
// Remove stops monitoring the path for changes.
if w.isClosed() {
return nil
}
+ return w.remove(filepath.Clean(name))
+}
- name = filepath.Clean(name)
-
- // Fetch the watch.
- w.mu.Lock()
- defer w.mu.Unlock()
-
- watch, ok := w.watches[name]
+func (w *Watcher) remove(name string) error {
+ wd, ok := w.watches.removePath(name)
if !ok {
return fmt.Errorf("%w: %s", ErrNonExistentWatch, name)
}
- return w.remove(name, watch)
-}
-
-// Unlocked!
-func (w *Watcher) remove(name string, watch *watch) error {
- delete(w.paths, int(watch.wd))
- delete(w.watches, name)
-
- success, errno := unix.InotifyRmWatch(w.fd, watch.wd)
+ success, errno := unix.InotifyRmWatch(w.fd, wd)
if success == -1 {
// TODO: Perhaps it's not helpful to return an error here in every case;
// The only two possible errors are:
return nil
}
- w.mu.Lock()
- defer w.mu.Unlock()
-
- entries := make([]string, 0, len(w.watches))
- for pathname := range w.watches {
+ entries := make([]string, 0, w.watches.len())
+ w.watches.mu.RLock()
+ for pathname := range w.watches.path {
entries = append(entries, pathname)
}
+ w.watches.mu.RUnlock()
return entries
}
-type watch struct {
- wd uint32 // Watch descriptor (as returned by the inotify_add_watch() syscall)
- flags uint32 // inotify flags of this watch (see inotify(7) for the list of valid flags)
-}
-
// readEvents reads from the inotify file descriptor, converts the
// received events into Event objects and sends them via the Events channel
func (w *Watcher) readEvents() {
// doesn't append the filename to the event, but we would like to always fill the
// the "Name" field with a valid filename. We retrieve the path of the watch from
// the "paths" map.
- w.mu.Lock()
- name, ok := w.paths[int(raw.Wd)]
+ watch := w.watches.byWd(uint32(raw.Wd))
+
// inotify will automatically remove the watch on deletes; just need
// to clean our state here.
- if ok && mask&unix.IN_DELETE_SELF == unix.IN_DELETE_SELF {
- delete(w.paths, int(raw.Wd))
- delete(w.watches, name)
+ if watch != nil && mask&unix.IN_DELETE_SELF == unix.IN_DELETE_SELF {
+ w.watches.remove(watch.wd)
}
// We can't really update the state when a watched path is moved;
// only IN_MOVE_SELF is sent and not IN_MOVED_{FROM,TO}. So remove
// the watch.
- if ok && mask&unix.IN_MOVE_SELF == unix.IN_MOVE_SELF {
- err := w.remove(name, w.watches[name])
- if err != nil {
+ if watch != nil && mask&unix.IN_MOVE_SELF == unix.IN_MOVE_SELF {
+ err := w.remove(watch.path)
+ if err != nil && !errors.Is(err, ErrNonExistentWatch) {
if !w.sendError(err) {
return
}
}
}
- w.mu.Unlock()
+ var name string
+ if watch != nil {
+ name = watch.path
+ }
if nameLen > 0 {
// Point "bytes" at the first byte of the filename
bytes := (*[unix.PathMax]byte)(unsafe.Pointer(&buf[offset+unix.SizeofInotifyEvent]))[:nameLen:nameLen]
projects / fsnotify.git / commitdiff