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Remove the freelist scheme for setobjects. 

The setobject freelist was consuming memory but not providing much value.
Even when a freelisted setobject was available, most of the setobject
fields still needed to be initialized and the small table still required
a memset().  This meant that the custom freelisting scheme for sets was
providing almost no incremental benefit over the default Python freelist
scheme used by _PyObject_Malloc() in Objects/obmalloc.c.
This commit is contained in:
Raymond Hettinger 2013-09-07 20:26:50 -07:00
parent ff6382b40d
commit 8f8839e10a
3 changed files with 8 additions and 49 deletions
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1
Include/setobject.h
View File

@ -105,7 +105,6 @@ PyAPI_FUNC(PyObject *) PySet_Pop(PyObject *set);
PyAPI_FUNC(int) _PySet_Update(PyObject *set, PyObject *iterable);
PyAPI_FUNC(int) PySet_ClearFreeList(void);
PyAPI_FUNC(void) _PySet_DebugMallocStats(FILE *out);
#endif
#ifdef __cplusplus

1
Objects/object.c
View File

@ -1955,7 +1955,6 @@ _PyObject_DebugTypeStats(FILE *out)
_PyFrame_DebugMallocStats(out);
_PyList_DebugMallocStats(out);
_PyMethod_DebugMallocStats(out);
_PySet_DebugMallocStats(out);
_PyTuple_DebugMallocStats(out);
}

55
Objects/setobject.c
View File

@ -57,13 +57,6 @@ PyObject *_PySet_Dummy = dummy;
INIT_NONZERO_SET_SLOTS(so); \
} while(0)
/* Reuse scheme to save calls to malloc, free, and memset */
#ifndef PySet_MAXFREELIST
#define PySet_MAXFREELIST 80
#endif
static PySetObject *free_list[PySet_MAXFREELIST];
static int numfree = 0;
/* ======================================================================== */
/* ======= Begin logic for probing the hash table ========================= */
@ -565,10 +558,7 @@ set_dealloc(PySetObject *so)
}
if (so->table != so->smalltable)
PyMem_DEL(so->table);
if (numfree < PySet_MAXFREELIST && PyAnySet_CheckExact(so))
free_list[numfree++] = so;
else
Py_TYPE(so)->tp_free(so);
Py_TYPE(so)->tp_free(so);
Py_TRASHCAN_SAFE_END(so)
}
@ -1023,22 +1013,12 @@ make_new_set(PyTypeObject *type, PyObject *iterable)
PySetObject *so = NULL;
/* create PySetObject structure */
if (numfree &&
(type == &PySet_Type || type == &PyFrozenSet_Type)) {
so = free_list[--numfree];
assert (so != NULL && PyAnySet_CheckExact(so));
Py_TYPE(so) = type;
_Py_NewReference((PyObject *)so);
EMPTY_TO_MINSIZE(so);
PyObject_GC_Track(so);
} else {
so = (PySetObject *)type->tp_alloc(type, 0);
if (so == NULL)
return NULL;
/* tp_alloc has already zeroed the structure */
assert(so->table == NULL && so->fill == 0 && so->used == 0);
INIT_NONZERO_SET_SLOTS(so);
}
so = (PySetObject *)type->tp_alloc(type, 0);
if (so == NULL)
return NULL;
/* tp_alloc has already zeroed the structure */
assert(so->table == NULL && so->fill == 0 && so->used == 0);
INIT_NONZERO_SET_SLOTS(so);
so->lookup = set_lookkey_unicode;
so->weakreflist = NULL;
@ -1103,34 +1083,15 @@ frozenset_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
int
PySet_ClearFreeList(void)
{
int freelist_size = numfree;
PySetObject *so;
while (numfree) {
numfree--;
so = free_list[numfree];
PyObject_GC_Del(so);
}
return freelist_size;
return 0;
}
void
PySet_Fini(void)
{
PySet_ClearFreeList();
Py_CLEAR(emptyfrozenset);
}
/* Print summary info about the state of the optimized allocator */
void
_PySet_DebugMallocStats(FILE *out)
{
_PyDebugAllocatorStats(out,
"free PySetObject",
numfree, sizeof(PySetObject));
}
static PyObject *
set_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
{