问题
The issue of PFUser deadlocking from thread contention via parse background calls has been raised numerous times by the Parse community, but Parse has chosen not to deal with this giant bug in the framework. Does anyone know of a work around for this issue?
Other apparent reports of this issue:
https://developers.facebook.com/bugs/649920188390439/
https://www.parse.com/questions/ios-api-apparent-deadlock-in-main-thread-v1213
https://www.parse.com/questions/occasional-freezing-at-pfuser-currentuser
https://www.parse.com/questions/deadlock-on-pfuser-currentuser-ios-sdk-1219
来源：https://stackoverflow.com/questions/25443279/major-bug-in-parse-pfuser-currentuser-deadlocks