[GHC] #15363: Do some cleaning up of the testsuite driver

[GHC]

#15363: Do some cleaning up of the testsuite driver
-------------------------------------+-------------------------------------
        Reporter:  lantti            |                Owner:  lantti
            Type:  task              |               Status:  new
        Priority:  low               |            Milestone:  8.6.1
       Component:  Test Suite        |              Version:  8.4.3
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by Phyx-):

 timeout.hs goes through great lengths to be able to reliably detect when
 all child processes exit using job groups. replacing this with the
 standard python process api will re-introduce threading issues we spent a
 great deal of time debugging so be careful with that. It also deals with
 quite a few corner cases with regards to how msys implements pipes.

 You would essentially have to rewrite it using ctypes because python's
 `os` package only provides process grouping for posix OSes.

 Before such a patch is accepted I'd like to see some evidence that it
 works correctly when the system is under heavy load.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15363#comment:10>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler