[GHC] #15665: Break up the stable pointer table

[GHC]

#15665: Break up the stable pointer table
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        Reporter:  dfeuer            |                Owner:  (none)
            Type:  feature request   |               Status:  new
        Priority:  normal            |            Milestone:  8.6.1
       Component:  Compiler          |              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:  #7670             |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by dfeuer):

 Deletion marking in the doubly linked regime:

 1. Set the key pointer to the head of the maintenance list for this block.
 The garbage collector can realize this as within-block and thus not a heap
 pointer.

 2. Use CAS to set the head of the maintenance list. On failure, go back to
 1.

 If the thread marking deletion pauses between these steps, then a
 concurrent maintenance pass may fail to delete the entry. That's okay;
 it'll be cleaned up on the next pass. Even if the thread fails altogether,
 that just means the entry can never be reused.

 Note: the maintenance routine doesn't risk ABA problems because it's the
 only one popping.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15665#comment:11>
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