[GHC] #8684: hWaitForInput cannot be interrupted by async exceptions on unix

[GHC]

#8684: hWaitForInput cannot be interrupted by async exceptions on unix
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        Reporter:  nh2               |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Core Libraries    |              Version:  7.6.3
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:  13497, 13525      |             Blocking:
 Related Tickets:  #12912, #13525    |  Differential Rev(s):  Phab:D42
       Wiki Page:                    |
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Comment (by nh2):

 I think I've got it!

 Inserting a `yield`
 [https://github.com/nh2/ghc/blob/49a5e9ce7062da7594bfd86ca7af92796b84b52a/libraries/base/GHC/IO/FD.hs#L422
 here] after `fdReady()` returns back into Haskell makes `delay over`
 appear and my example code terminate after the 1 second `timeout`.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8684#comment:20>
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