[GHC] #1081: HGL indefinite pause with "thread blocked indefinitely" message

[GHC]

#1081: HGL indefinite pause with "thread blocked indefinitely" message
---------------------------------+------------------------------------------
 Reporter:  calvins              |          Owner:          
     Type:  bug                  |         Status:  new     
 Priority:  normal               |      Milestone:  Not GHC 
Component:  libraries (other)    |        Version:  6.6     
 Severity:  normal               |     Resolution:          
 Keywords:  hgl thread deadlock  |     Difficulty:  Unknown 
 Testcase:                       |   Architecture:  Multiple
       Os:  Multiple             |  
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Changes (by simonmar):

  * component:  Compiler => libraries (other)
  * milestone:  => Not GHC

Comment:

 I believe I've fixed some of the issues here, but there may be more.

  * The X11 library didn't provide a way to call XInitThreads, required for
    multithreaded clients.  (now added, and called from `HGL.runGraphics`
    if necessary).

  * The XNextEvent function wasn't imported ''safe'', so it blocked the
 other
    threads.

 However, with these fixes, the program still hangs on startup until the
 first event is received.  I'm not sure why - the two active threads both
 appear to be waiting in `XNextEvent`, so the program really is waiting for
 an event.  Maybe an HGL expert is needed here (is there one?).

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/1081>
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