[GHC] #15193: QSem makes nonsense claim

[GHC]

#15193: QSem makes nonsense claim
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        Reporter:  dfeuer            |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:  8.6.1
       Component:  Core Libraries    |              Version:  8.2.2
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Documentation     |  Unknown/Multiple
  bug                                |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by dfeuer):

 `TSem` was not what I meant to write. The trouble with "first in" is that
 it's hard to say what happens "first" in a concurrent setting. If I create
 ten threads, each of which immediately waits on an empty `QSem`, then
 later signal that `QSem` several times, it's totally arbitrary which
 threads get serviced when. It seems the guarantee must have to do with
 consecutive requests by the same thread, with some guarantees about thread
 creation. Or something...

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15193#comment:4>
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