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| author | Tim Peters <tim.peters@gmail.com> | 2002-07-02 00:52:30 (GMT) |
|---|---|---|
| committer | Tim Peters <tim.peters@gmail.com> | 2002-07-02 00:52:30 (GMT) |
| commit | ea405639bff00b4c177026b474a9d75207c0bf1b (patch) | |
| tree | 60c5deaa5a010c28c3784cbf93f9add8af42ad7d /Include | |
| parent | 7c75bf2090c58ac0d2bb57220c41327285bf7c1a (diff) | |
| download | cpython-ea405639bff00b4c177026b474a9d75207c0bf1b.zip cpython-ea405639bff00b4c177026b474a9d75207c0bf1b.tar.gz cpython-ea405639bff00b4c177026b474a9d75207c0bf1b.tar.bz2 | |
Reserved another gc_refs value for untracked objects. Every live gc
object should now have a well-defined gc_refs value, with clear transitions
among gc_refs states. As a result, none of the visit_XYZ traversal
callbacks need to check IS_TRACKED() anymore, and those tests were removed.
(They were already looking for objects with specific gc_refs states, and
the gc_refs state of an untracked object can no longer match any other
gc_refs state by accident.)
Added more asserts.
I expect that the gc_next == NULL indicator for an untracked object is
now redundant and can also be removed, but I ran out of time for this.
Diffstat (limited to 'Include')
| -rw-r--r-- | Include/objimpl.h | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/Include/objimpl.h b/Include/objimpl.h index e037322..28f3661 100644 --- a/Include/objimpl.h +++ b/Include/objimpl.h @@ -262,12 +262,18 @@ extern PyGC_Head *_PyGC_generation0; #define _Py_AS_GC(o) ((PyGC_Head *)(o)-1) +#define _PyGC_REFS_UNTRACKED (-2) +#define _PyGC_REFS_REACHABLE (-3) +#define _PyGC_REFS_TENTATIVELY_UNREACHABLE (-4) + /* Tell the GC to track this object. NB: While the object is tracked the * collector it must be safe to call the ob_traverse method. */ #define _PyObject_GC_TRACK(o) do { \ PyGC_Head *g = _Py_AS_GC(o); \ - if (g->gc.gc_next != NULL) \ - Py_FatalError("GC object already in linked list"); \ + if (g->gc.gc_refs != _PyGC_REFS_UNTRACKED) \ + Py_FatalError("GC object already tracked"); \ + assert(g->gc.gc_refs == _PyGC_REFS_UNTRACKED); \ + g->gc.gc_refs = _PyGC_REFS_REACHABLE; \ g->gc.gc_next = _PyGC_generation0; \ g->gc.gc_prev = _PyGC_generation0->gc.gc_prev; \ g->gc.gc_prev->gc.gc_next = g; \ @@ -277,6 +283,8 @@ extern PyGC_Head *_PyGC_generation0; /* Tell the GC to stop tracking this object. */ #define _PyObject_GC_UNTRACK(o) do { \ PyGC_Head *g = _Py_AS_GC(o); \ + assert(g->gc.gc_refs != _PyGC_REFS_UNTRACKED); \ + g->gc.gc_refs = _PyGC_REFS_UNTRACKED; \ g->gc.gc_prev->gc.gc_next = g->gc.gc_next; \ g->gc.gc_next->gc.gc_prev = g->gc.gc_prev; \ g->gc.gc_next = NULL; \ |