[parrot/parrot] d3ef71: [GH #880/#875] Try to fix some GC thread bugs

[GitHub]

  Branch: refs/heads/rurban/fix-gc-thr-gh880+gh875
  Home:   https://github.com/parrot/parrot
  Commit: d3ef71d29e1b166a020eae63dc4a7ca8351c22d8
      https://github.com/parrot/parrot/commit/d3ef71d29e1b166a020eae63dc4a7ca8351c22d8
  Author: Reini Urban <rurban at cpanel.net>
  Date:   2012-12-18 (Tue, 18 Dec 2012)

  Changed paths:
    M include/parrot/gc_api.h
    M src/gc/api.c
    M src/gc/mark_sweep.c

  Log Message:
  -----------
  [GH #880/#875] Try to fix some GC thread bugs

Do not ascent into parent_interpreter with a threaded interp. (No influence)
Do not mark PMCs when threaded interp is different to the current interp
(Parrot_gc_mark_PMC_alive)