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| author | Antoine Pitrou <solipsis@pitrou.net> | 2013-07-30 17:59:21 (GMT) |
|---|---|---|
| committer | Antoine Pitrou <solipsis@pitrou.net> | 2013-07-30 17:59:21 (GMT) |
| commit | 796564c27b8f2e32b9fbc034bbdda75f9507ca43 (patch) | |
| tree | 52db4985f7fe10db48703103a156ff3fd2011d8d /Include/objimpl.h | |
| parent | c5d95b17acfdf2d01569bd32d67cadbd5f5cd4a3 (diff) | |
| download | cpython-796564c27b8f2e32b9fbc034bbdda75f9507ca43.zip cpython-796564c27b8f2e32b9fbc034bbdda75f9507ca43.tar.gz cpython-796564c27b8f2e32b9fbc034bbdda75f9507ca43.tar.bz2 | |
Issue #18112: PEP 442 implementation (safe object finalization).
Diffstat (limited to 'Include/objimpl.h')
| -rw-r--r-- | Include/objimpl.h | 34 |
1 files changed, 29 insertions, 5 deletions
diff --git a/Include/objimpl.h b/Include/objimpl.h index 4e72a46..264c120 100644 --- a/Include/objimpl.h +++ b/Include/objimpl.h @@ -256,6 +256,30 @@ extern PyGC_Head *_PyGC_generation0; #define _Py_AS_GC(o) ((PyGC_Head *)(o)-1) +/* Bit 0 is set when tp_finalize is called */ +#define _PyGC_REFS_MASK_FINALIZED (1 << 0) +/* The (N-1) most significant bits contain the gc state / refcount */ +#define _PyGC_REFS_SHIFT (1) +#define _PyGC_REFS_MASK (((size_t) -1) << _PyGC_REFS_SHIFT) + +#define _PyGCHead_REFS(g) ((g)->gc.gc_refs >> _PyGC_REFS_SHIFT) +#define _PyGCHead_SET_REFS(g, v) do { \ + (g)->gc.gc_refs = ((g)->gc.gc_refs & ~_PyGC_REFS_MASK) \ + | (v << _PyGC_REFS_SHIFT); \ + } while (0) +#define _PyGCHead_DECREF(g) ((g)->gc.gc_refs -= 1 << _PyGC_REFS_SHIFT) + +#define _PyGCHead_FINALIZED(g) (((g)->gc.gc_refs & _PyGC_REFS_MASK_FINALIZED) != 0) +#define _PyGCHead_SET_FINALIZED(g, v) do { \ + (g)->gc.gc_refs = ((g)->gc.gc_refs & ~_PyGC_REFS_MASK_FINALIZED) \ + | (v != 0); \ + } while (0) + +#define _PyGC_FINALIZED(o) _PyGCHead_FINALIZED(_Py_AS_GC(o)) +#define _PyGC_SET_FINALIZED(o, v) _PyGCHead_SET_FINALIZED(_Py_AS_GC(o), v) + +#define _PyGC_REFS(o) _PyGCHead_REFS(_Py_AS_GC(o)) + #define _PyGC_REFS_UNTRACKED (-2) #define _PyGC_REFS_REACHABLE (-3) #define _PyGC_REFS_TENTATIVELY_UNREACHABLE (-4) @@ -264,9 +288,9 @@ extern PyGC_Head *_PyGC_generation0; * 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_refs != _PyGC_REFS_UNTRACKED) \ + if (_PyGCHead_REFS(g) != _PyGC_REFS_UNTRACKED) \ Py_FatalError("GC object already tracked"); \ - g->gc.gc_refs = _PyGC_REFS_REACHABLE; \ + _PyGCHead_SET_REFS(g, _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; \ @@ -279,8 +303,8 @@ extern PyGC_Head *_PyGC_generation0; */ #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; \ + assert(_PyGCHead_REFS(g) != _PyGC_REFS_UNTRACKED); \ + _PyGCHead_SET_REFS(g, _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; \ @@ -288,7 +312,7 @@ extern PyGC_Head *_PyGC_generation0; /* True if the object is currently tracked by the GC. */ #define _PyObject_GC_IS_TRACKED(o) \ - ((_Py_AS_GC(o))->gc.gc_refs != _PyGC_REFS_UNTRACKED) + (_PyGC_REFS(o) != _PyGC_REFS_UNTRACKED) /* True if the object may be tracked by the GC in the future, or already is. This can be useful to implement some optimizations. */ |