Re: Hash Tables and GC

[Michael Greenwald <Greenwald@STONY-BROOK.SCRC.Symbolics.COM>]

    Date: Wed, 7 Sep 88 11:52 PDT
    From: DDYER@RIVERSIDE.SCRC.Symbolics.COM


    Just to throw a little light into this discussion:   On Symbolics systems there
    is a list of forms to be evaluated before any gc flip (ephemeral or dynamic).
    It's possible to implement whatever kind of weak pointers strategy you want by 
    explicitly clearing whatever pointers are "weak" before the flip occurs.  The
    list is called SI:GC-EVERY-FLIP-LIST

How does this tell you whether there *are* any non-weak pointers to the
object in question?