// Must run within the I/O thread.
func (w *Watcher) startRead(watch *watch) error {
if e := syscall.CancelIo(watch.ino.handle); e != nil {
w.Error <- os.NewSyscallError("CancelIo", e)
w.deleteWatch(watch)
}
mask := toWindowsFlags(watch.mask)
for _, m := range watch.names {
mask |= toWindowsFlags(m)
}
if mask == 0 {
if e := syscall.CloseHandle(watch.ino.handle); e != nil {
w.Error <- os.NewSyscallError("CloseHandle", e)
}
delete(w.watches[watch.ino.volume], watch.ino.index)
return nil
}
e := syscall.ReadDirectoryChanges(watch.ino.handle, &watch.buf[0],
uint32(unsafe.Sizeof(watch.buf)), false, mask, nil, &watch.ov, 0)
if e != nil {
err := os.NewSyscallError("ReadDirectoryChanges", e)
if e == syscall.ERROR_ACCESS_DENIED && watch.mask&provisional == 0 {
// Watched directory was probably removed
if w.sendEvent(watch.path, watch.mask&FS_DELETE_SELF) {
if watch.mask&FS_ONESHOT != 0 {
watch.mask = 0
}
}
err = nil
}
w.deleteWatch(watch)
w.startRead(watch)
return err
}
return nil
}
// readDirChanges tells the system to store file change information in grip's
// buffer. Directory changes that occur between calls to this function are added
// to the buffer and then, returned with the next call.
func (g *grip) readDirChanges() error {
return syscall.ReadDirectoryChanges(
g.handle,
&g.buffer[0],
uint32(unsafe.Sizeof(g.buffer)),
g.recursive,
encode(g.filter),
nil,
(*syscall.Overlapped)(unsafe.Pointer(g.ovlapped)),
0,
)
}