From: Charles Thornton <ceo@...>
Date: 2008-01-20T14:01:16+09:00
Subject: [Fwd: IRHG - GC_MARK Question]

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Message-ID: <4792D72C.7050007@hawthorne-press.com>
Date: Sat, 19 Jan 2008 23:07:56 -0600
From: Charles Thornton <bad-mail@hawthorne-press.com>
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To:  ruby-core@ruby-lang.org
Subject: IRHG - GC_MARK Question
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OK

  I am documenting GC_MARK in GC.C

  gc_mark(ptr,lev) ....

  It seems that 'lev' is being used to limit the Depth of the trace?   
Correct?

  NOW:  If  'lev' > GC_LEVEL_MAX, the obj pointer is pushed onto
a secondary stack (mark_stack_overflow).
  
       If this happens I assume that at some point the ptr's are pulled
off the mark_stack and mark tracing continue's at this point?    Correct?

   If the 'mark_stack' get's to deep I assume that mark tracing stops here.
      ( It should not be a failure --- Just a "MORE" conservative  pass?
        that is some objects won't be collected that COULD have been??).

  Now  'lev' == 0 && ruby_stack_check() seems to imply that the
  ruby stack  can get to full??    Something about this does not seem right?

   Can someone explain any errors of mine.

    Thanks.

      Ruby Hackers Guide Translating

             Chuck T.


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