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

[GHC]

#8684: hWaitForInput cannot be interrupted by async exceptions on unix
-------------------------------------+-------------------------------------
        Reporter:  nh2               |                Owner:  snoyberg
            Type:  bug               |               Status:  patch
        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:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D42
       Wiki Page:                    |
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Comment (by nh2):

 Ai, it seems that ghc 8.0.2 changed some behaviour here:


 {{{
 import System.IO
 import System.Timeout

 main = hWaitForInput stdin (5 * 1000)
 }}}


 On ghc 8.0.2, this crashes with `fdReady: msecs != 0, this shouldn't
 happen`.

 On ghc 8.0.1, this works as expected (doing nothing, terminating after 5
 seconds).

 Probably this commit:

 https://github.com/ghc/ghc/commit/f46369b8a1bf90a3bdc30f2b566c3a7e03672518
 #diff-f727d72230bd33b0e218d47df4738565R28

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8684#comment:8>
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