- proj, err := fs.getProject(id)
- if os.IsNotExist(err) {
- return nil, nil
- } else if err != nil {
- return nil, err
+ fs.byIDLock.Lock()
+ node := fs.byID[id]
+ fs.byIDLock.Unlock()
+ if node == nil {
+ // Look up the project synchronously before
+ // calling projectSingleton (otherwise we
+ // wouldn't detect a nonexistent project until
+ // it's too late to return ErrNotExist).
+ proj, err := fs.getProject(id)
+ if os.IsNotExist(err) {
+ return nil, nil
+ } else if err != nil {
+ return nil, err
+ }
+ node = fs.projectSingleton(id, proj)