[GHC] #9052: Support a "stable heap" which doesn't get garbage collected

[GHC]

#9052: Support a "stable heap" which doesn't get garbage collected
----------------------------+----------------------------------------------
        Reporter:  ezyang   |            Owner:  simonmar
            Type:  feature  |           Status:  new
  request                   |        Milestone:
        Priority:  normal   |          Version:  7.9
       Component:  Runtime  |         Keywords:
  System                    |     Architecture:  Unknown/Multiple
      Resolution:           |       Difficulty:  Moderate (less than a day)
Operating System:           |       Blocked By:
  Unknown/Multiple          |  Related Tickets:
 Type of failure:           |
  None/Unknown              |
       Test Case:           |
        Blocking:           |
----------------------------+----------------------------------------------

Comment (by ezyang):

 A little musing about implementation: we could go about representing the
 stable generation in two ways. One is that the stable generation is an
 extra generation which is always present (e.g. we always allocate a field
 for it when initializing the storage manager), but the GC ignores it; the
 other is the stable generation is "just another generation" (i.e. to have
 g0, g1 and a stable gen, the user needs to pass -G3) but specially flagged
 to behave differently. I think the first option is more user-friendly, but
 the latter option makes for cleaner implementation, because we don't have
 to +1 the value of the 'generations' configuration flag.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9052#comment:3>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler