[GHC] #7653: incorrect handling of StackOverflow exception in the event manager

[GHC]

#7653: incorrect handling of StackOverflow exception in the event manager
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    Reporter:  nus               |       Owner:  tibbe        
        Type:  bug               |      Status:  patch        
    Priority:  normal            |   Milestone:               
   Component:  libraries/base    |     Version:  7.7          
    Keywords:                    |          Os:  Linux        
Architecture:  Unknown/Multiple  |     Failure:  Runtime crash
  Difficulty:  Unknown           |    Testcase:               
   Blockedby:                    |    Blocking:               
     Related:                    |  
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Comment(by nus):

 Replying to [comment:6 kazu-yamamoto]:
 > First of all, I would like to discuss what is the best behavior when the
 stack of IO manager overflows.
 Perhaps the best would be not to cause stack overflows in the manager at
 all. At least the shutdown should be as gracious as possible.
 >
 > Note that in the current parallel IO manager, timer manager and IO
 managers are separated. We should apply this discussion to the timer
 manager.
 Sure, the bug report and the patches were made before the new I/O manager
 merge. The code excerpts above that show how the thunk is accumulated are
 now only pertinent to 7.4 and 7.6 branches.
 While I'm not sure how (and if) the situation like this could be
 reproduced on the current HEAD, the concerns might still be applicable:
    1. There're no counterparts for `c_setIOManagerControlFd` and
 `c_setIOManagerWakeupFd` of `newControl` in `closeControl`;
    2. A situation might emerge (again, I'm not sure how, but still) when
 `wakeManager` would be passed an `EventManager` in the `Finished` state.

 >
 > A comment to the first patch: even if we set manager's FD to -1, nobody
 refers to it. What is the purpose of this patch?
 The RTS does, please have a look at `ioManagerWakeup` in
 `rts/posix/Signals.c` (and `wakeUpRts` in `rts/Schedule.c`).

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Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7653#comment:7>
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