[Python-checkins] r60646 - python/trunk/Objects/dictobject.c python/trunk/Objects/listobject.c
christian.heimes
python-checkins at python.org
Thu Feb 7 18:15:30 CET 2008
Author: christian.heimes
Date: Thu Feb 7 18:15:30 2008
New Revision: 60646
Modified:
python/trunk/Objects/dictobject.c
python/trunk/Objects/listobject.c
Log:
Added some statistics code to dict and list object code. I wanted to test how a larger freelist affects the reusage of freed objects. Contrary to my gut feelings 80 objects is more than fine for small apps. I haven't profiled a large app yet.
Modified: python/trunk/Objects/dictobject.c
==============================================================================
--- python/trunk/Objects/dictobject.c (original)
+++ python/trunk/Objects/dictobject.c Thu Feb 7 18:15:30 2008
@@ -162,6 +162,22 @@
}
#endif
+/* Debug statistic to compare allocations with reuse through the free list */
+#undef SHOW_ALLOC_COUNT
+#ifdef SHOW_ALLOC_COUNT
+static size_t count_alloc = 0;
+static size_t count_reuse = 0;
+
+static void
+show_alloc(void)
+{
+ fprintf(stderr, "Dict allocations: %zd\n", count_alloc);
+ fprintf(stderr, "Dict reuse through freelist: %zd\n", count_reuse);
+ fprintf(stderr, "%.2f%% reuse rate\n\n",
+ (100.0*count_reuse/(count_alloc+count_reuse)));
+}
+#endif
+
/* Initialization macros.
There are two ways to create a dict: PyDict_New() is the main C API
function, and the tp_new slot maps to dict_new(). In the latter case we
@@ -200,6 +216,9 @@
#ifdef SHOW_CONVERSION_COUNTS
Py_AtExit(show_counts);
#endif
+#ifdef SHOW_ALLOC_COUNT
+ Py_AtExit(show_alloc);
+#endif
}
if (numfree) {
mp = free_list[--numfree];
@@ -212,11 +231,17 @@
assert (mp->ma_used == 0);
assert (mp->ma_table == mp->ma_smalltable);
assert (mp->ma_mask == PyDict_MINSIZE - 1);
+#ifdef SHOW_ALLOC_COUNT
+ count_reuse++;
+#endif
} else {
mp = PyObject_GC_New(PyDictObject, &PyDict_Type);
if (mp == NULL)
return NULL;
EMPTY_TO_MINSIZE(mp);
+#ifdef SHOW_ALLOC_COUNT
+ count_alloc++;
+#endif
}
mp->ma_lookup = lookdict_string;
#ifdef SHOW_CONVERSION_COUNTS
Modified: python/trunk/Objects/listobject.c
==============================================================================
--- python/trunk/Objects/listobject.c (original)
+++ python/trunk/Objects/listobject.c Thu Feb 7 18:15:30 2008
@@ -63,6 +63,22 @@
return 0;
}
+/* Debug statistic to compare allocations with reuse through the free list */
+#undef SHOW_ALLOC_COUNT
+#ifdef SHOW_ALLOC_COUNT
+static size_t count_alloc = 0;
+static size_t count_reuse = 0;
+
+static void
+show_alloc(void)
+{
+ fprintf(stderr, "List allocations: %zd\n", count_alloc);
+ fprintf(stderr, "List reuse through freelist: %zd\n", count_reuse);
+ fprintf(stderr, "%.2f%% reuse rate\n\n",
+ (100.0*count_reuse/(count_alloc+count_reuse)));
+}
+#endif
+
/* Empty list reuse scheme to save calls to malloc and free */
#ifndef PyList_MAXFREELIST
#define PyList_MAXFREELIST 80
@@ -88,6 +104,13 @@
{
PyListObject *op;
size_t nbytes;
+#ifdef SHOW_ALLOC_COUNT
+ static int initialized = 0;
+ if (!initialized) {
+ Py_AtExit(show_alloc);
+ initialized = 1;
+ }
+#endif
if (size < 0) {
PyErr_BadInternalCall();
@@ -101,10 +124,16 @@
numfree--;
op = free_list[numfree];
_Py_NewReference((PyObject *)op);
+#ifdef SHOW_ALLOC_COUNT
+ count_reuse++;
+#endif
} else {
op = PyObject_GC_New(PyListObject, &PyList_Type);
if (op == NULL)
return NULL;
+#ifdef SHOW_ALLOC_COUNT
+ count_alloc++;
+#endif
}
if (size <= 0)
op->ob_item = NULL;
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