D1457: workers: don't use backgroundfilecloser in threads

[durin42 (Augie Fackler)]

durin42 added inline comments.

INLINE COMMENTS

> vfs.py:420
>  
> -        if backgroundclose:
> +        if backgroundclose and \
> +                isinstance(threading.currentThread(), threading._MainThread):

nit: wrap lines using () instead of \, eg

if (backgroundclose and

  isinstance(...)):

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D1457

To: wlis, #hg-reviewers, indygreg
Cc: durin42, indygreg, mercurial-devel