mirrors/cpython
1
0
Fork 0
mirror of https://github.com/python/cpython.git synced 2025-11-02 03:01:58 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 15

object.h special-build macro minefield: renamed all the new lexical

Browse source 
helper macros to something saner, and used them appropriately in other
files too, to reduce #ifdef blocks.

classobject.c, instance_dealloc():  One of my worst Python Memories is
trying to fix this routine a few years ago when COUNT_ALLOCS was defined
but Py_TRACE_REFS wasn't.  The special-build code here is way too
complicated.  Now it's much simpler.  Difference:  in a Py_TRACE_REFS
build, the instance is no longer in the doubly-linked list of live
objects while its __del__ method is executing, and that may be visible
via sys.getobjects() called from a __del__ method.  Tough -- the object
is presumed dead while its __del__ is executing anyway, and not calling
_Py_NewReference() at the start allows enormous code simplification.

typeobject.c, call_finalizer():  The special-build instance_dealloc()
pain apparently spread to here too via cut-'n-paste, and this is much
simpler now too.  In addition, I didn't understand why this routine
was calling _PyObject_GC_TRACK() after a resurrection, since there's no
plausible way _PyObject_GC_UNTRACK() could have been called on the
object by this point.  I suspect it was left over from pasting the
instance_delloc() code.  Instead asserted that the object is still
tracked.  Caution:  I suspect we don't have a test that actually
exercises the subtype_dealloc() __del__-resurrected-me code.
This commit is contained in:
Tim Peters 2002-07-11 06:23:50 +00:00
parent dc1e70987f
commit 3459251d5a
6 changed files with 114 additions and 159 deletions
Download patch file Download diff file Expand all files Collapse all files

70
Objects/typeobject.c
View file

@ -365,22 +365,8 @@ call_finalizer(PyObject *self)
PyObject *error_type, *error_value, *error_traceback;
/* Temporarily resurrect the object. */
#ifdef Py_TRACE_REFS
#ifndef Py_REF_DEBUG
# error "Py_TRACE_REFS defined but Py_REF_DEBUG not."
#endif
/* much too complicated if Py_TRACE_REFS defined */
_Py_NewReference((PyObject *)self);
#ifdef COUNT_ALLOCS
/* compensate for boost in _Py_NewReference; note that
* _Py_RefTotal was also boosted; we'll knock that down later.
*/
self->ob_type->tp_allocs--;
#endif
#else /* !Py_TRACE_REFS */
/* Py_INCREF boosts _Py_RefTotal if Py_REF_DEBUG is defined */
Py_INCREF(self);
#endif /* !Py_TRACE_REFS */
assert(self->ob_refcnt == 0);
self->ob_refcnt = 1;
/* Save the current exception, if any. */
PyErr_Fetch(&error_type, &error_value, &error_traceback);
@ -402,28 +388,32 @@ call_finalizer(PyObject *self)
/* Undo the temporary resurrection; can't use DECREF here, it would
* cause a recursive call.
*/
#ifdef Py_REF_DEBUG
/* _Py_RefTotal was boosted either by _Py_NewReference or
* Py_INCREF above.
*/
_Py_RefTotal--;
#endif
if (--self->ob_refcnt > 0) {
#ifdef COUNT_ALLOCS
self->ob_type->tp_frees--;
#endif
_PyObject_GC_TRACK(self);
return -1; /* __del__ added a reference; don't delete now */
}
#ifdef Py_TRACE_REFS
_Py_ForgetReference((PyObject *)self);
#ifdef COUNT_ALLOCS
/* compensate for increment in _Py_ForgetReference */
self->ob_type->tp_frees--;
#endif
#endif
assert(self->ob_refcnt > 0);
if (--self->ob_refcnt == 0)
return 0; /* this is the normal path out */
return 0;
/* __del__ resurrected it! Make it look like the original Py_DECREF
* never happened.
*/
{
int refcnt = self->ob_refcnt;
_Py_NewReference(self);
self->ob_refcnt = refcnt;
}
assert(_Py_AS_GC(self)->gc.gc_refs != _PyGC_REFS_UNTRACKED);
/* If Py_REF_DEBUG, the original decref dropped _Py_RefTotal, but
* _Py_NewReference bumped it again, so that's a wash.
* If Py_TRACE_REFS, _Py_NewReference re-added self to the object
* chain, so no more to do there either.
* If COUNT_ALLOCS, the original decref bumped tp_frees, and
* _Py_NewReference bumped tp_allocs: both of those need to be
* undone.
*/
#ifdef COUNT_ALLOCS
--self->ob_type->tp_frees;
--self->ob_type->tp_allocs;
#endif
return -1; /* __del__ added a reference; don't delete now */
}
static void
@ -1387,13 +1377,13 @@ type_getattro(PyTypeObject *type, PyObject *name)
/* No readable descriptor found yet */
meta_get = NULL;
/* Look for the attribute in the metatype */
meta_attribute = _PyType_Lookup(metatype, name);
if (meta_attribute != NULL) {
meta_get = meta_attribute->ob_type->tp_descr_get;
if (meta_get != NULL && PyDescr_IsData(meta_attribute)) {
/* Data descriptors implement tp_descr_set to intercept
* writes. Assume the attribute is not overridden in
@ -1416,7 +1406,7 @@ type_getattro(PyTypeObject *type, PyObject *name)
return local_get(attribute, (PyObject *)NULL,
(PyObject *)type);
}
Py_INCREF(attribute);
return attribute;
}