[GHC] #13497: GHC does not use select()/poll() correctly on non-Linux platforms

[GHC]

#13497: GHC does not use select()/poll() correctly on non-Linux platforms
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        Reporter:  nh2               |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Runtime System    |              Version:  8.0.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #8684, #12912     |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by nh2):

 Hmm, this seems to happen on purpose:

 Commit
 [https://github.com/ghc/ghc/commit/0b79d5cd4687dacf7efd430df7fba9d9a5a5ce32
 Another overhaul of the recent_activity / idle GC handling] (#5991)
 mentions

 {{{
  - we now turn off the timer signal after idleGCDelay even if the
    idle GC is disabled with +RTS -I0.
 }}}

 I personally find that very confusing, using a setting called
 `idleGCDelay` even when the user explicitly turned that off.

 Further, doing it this way, there's no way of actually setting what the
 value of `idleGCDelay` is, because if you use `-I0`, well, then it's the
 default (0.3 seconds), and if you use `-I` with any other value, then that
 actually turns idle GC on (as I found above). So there's no way to change
 away from the default 0.3 seconds when idle GC is set to off.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13497#comment:10>
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