[Python-checkins] Move stats for the method cache into the `Py_STAT` machinery (GH-100255)

[markshannon]

https://github.com/python/cpython/commit/48e352a2410b6e962d40359939a0d43aaba5ece9
commit: 48e352a2410b6e962d40359939a0d43aaba5ece9
branch: main
author: Mark Shannon <mark at hotpy.org>
committer: markshannon <mark at hotpy.org>
date: 2022-12-15T09:45:03Z
summary:

Move stats for the method cache into the `Py_STAT` machinery (GH-100255)

files:
M Include/internal/pycore_typeobject.h
M Include/pystats.h
M Objects/typeobject.c
M Python/specialize.c

diff --git a/Include/internal/pycore_typeobject.h b/Include/internal/pycore_typeobject.h
index 71f3068900da..c207ce615c6f 100644
--- a/Include/internal/pycore_typeobject.h
+++ b/Include/internal/pycore_typeobject.h
@@ -36,15 +36,9 @@ struct type_cache_entry {
 };
 
 #define MCACHE_SIZE_EXP 12
-#define MCACHE_STATS 0
 
 struct type_cache {
     struct type_cache_entry hashtable[1 << MCACHE_SIZE_EXP];
-#if MCACHE_STATS
-    size_t hits;
-    size_t misses;
-    size_t collisions;
-#endif
 };
 
 /* For now we hard-code this to a value for which we are confident
diff --git a/Include/pystats.h b/Include/pystats.h
index 87e92aa4f05f..04630c9e0f92 100644
--- a/Include/pystats.h
+++ b/Include/pystats.h
@@ -65,8 +65,15 @@ typedef struct _object_stats {
     uint64_t dict_materialized_new_key;
     uint64_t dict_materialized_too_big;
     uint64_t dict_materialized_str_subclass;
+    uint64_t type_cache_hits;
+    uint64_t type_cache_misses;
+    uint64_t type_cache_dunder_hits;
+    uint64_t type_cache_dunder_misses;
+    uint64_t type_cache_collisions;
 } ObjectStats;
 
+#
+
 typedef struct _stats {
     OpcodeStats opcode_stats[256];
     CallStats call_stats;
diff --git a/Objects/typeobject.c b/Objects/typeobject.c
index 2c3b39521a6d..a96f993e99dd 100644
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -327,18 +327,6 @@ static unsigned int
 _PyType_ClearCache(PyInterpreterState *interp)
 {
     struct type_cache *cache = &interp->types.type_cache;
-#if MCACHE_STATS
-    size_t total = cache->hits + cache->collisions + cache->misses;
-    fprintf(stderr, "-- Method cache hits        = %zd (%d%%)\n",
-            cache->hits, (int) (100.0 * cache->hits / total));
-    fprintf(stderr, "-- Method cache true misses = %zd (%d%%)\n",
-            cache->misses, (int) (100.0 * cache->misses / total));
-    fprintf(stderr, "-- Method cache collisions  = %zd (%d%%)\n",
-            cache->collisions, (int) (100.0 * cache->collisions / total));
-    fprintf(stderr, "-- Method cache size        = %zd KiB\n",
-            sizeof(cache->hashtable) / 1024);
-#endif
-
     // Set to None, rather than NULL, so _PyType_Lookup() can
     // use Py_SETREF() rather than using slower Py_XSETREF().
     type_cache_clear(cache, Py_None);
@@ -4148,6 +4136,24 @@ find_name_in_mro(PyTypeObject *type, PyObject *name, int *error)
     return res;
 }
 
+/* Check if the "readied" PyUnicode name
+   is a double-underscore special name. */
+static int
+is_dunder_name(PyObject *name)
+{
+    Py_ssize_t length = PyUnicode_GET_LENGTH(name);
+    int kind = PyUnicode_KIND(name);
+    /* Special names contain at least "__x__" and are always ASCII. */
+    if (length > 4 && kind == PyUnicode_1BYTE_KIND) {
+        const Py_UCS1 *characters = PyUnicode_1BYTE_DATA(name);
+        return (
+            ((characters[length-2] == '_') && (characters[length-1] == '_')) &&
+            ((characters[0] == '_') && (characters[1] == '_'))
+        );
+    }
+    return 0;
+}
+
 /* Internal API to look for a name through the MRO.
    This returns a borrowed reference, and doesn't set an exception! */
 PyObject *
@@ -4161,12 +4167,13 @@ _PyType_Lookup(PyTypeObject *type, PyObject *name)
     struct type_cache_entry *entry = &cache->hashtable[h];
     if (entry->version == type->tp_version_tag &&
         entry->name == name) {
-#if MCACHE_STATS
-        cache->hits++;
-#endif
         assert(_PyType_HasFeature(type, Py_TPFLAGS_VALID_VERSION_TAG));
+        OBJECT_STAT_INC_COND(type_cache_hits, !is_dunder_name(name));
+        OBJECT_STAT_INC_COND(type_cache_dunder_hits, is_dunder_name(name));
         return entry->value;
     }
+    OBJECT_STAT_INC_COND(type_cache_misses, !is_dunder_name(name));
+    OBJECT_STAT_INC_COND(type_cache_dunder_misses, is_dunder_name(name));
 
     /* We may end up clearing live exceptions below, so make sure it's ours. */
     assert(!PyErr_Occurred());
@@ -4194,14 +4201,7 @@ _PyType_Lookup(PyTypeObject *type, PyObject *name)
         entry->version = type->tp_version_tag;
         entry->value = res;  /* borrowed */
         assert(_PyASCIIObject_CAST(name)->hash != -1);
-#if MCACHE_STATS
-        if (entry->name != Py_None && entry->name != name) {
-            cache->collisions++;
-        }
-        else {
-            cache->misses++;
-        }
-#endif
+        OBJECT_STAT_INC_COND(type_cache_collisions, entry->name != Py_None && entry->name != name);
         assert(_PyType_HasFeature(type, Py_TPFLAGS_VALID_VERSION_TAG));
         Py_SETREF(entry->name, Py_NewRef(name));
     }
@@ -4218,24 +4218,6 @@ _PyType_LookupId(PyTypeObject *type, _Py_Identifier *name)
     return _PyType_Lookup(type, oname);
 }
 
-/* Check if the "readied" PyUnicode name
-   is a double-underscore special name. */
-static int
-is_dunder_name(PyObject *name)
-{
-    Py_ssize_t length = PyUnicode_GET_LENGTH(name);
-    int kind = PyUnicode_KIND(name);
-    /* Special names contain at least "__x__" and are always ASCII. */
-    if (length > 4 && kind == PyUnicode_1BYTE_KIND) {
-        const Py_UCS1 *characters = PyUnicode_1BYTE_DATA(name);
-        return (
-            ((characters[length-2] == '_') && (characters[length-1] == '_')) &&
-            ((characters[0] == '_') && (characters[1] == '_'))
-        );
-    }
-    return 0;
-}
-
 /* This is similar to PyObject_GenericGetAttr(),
    but uses _PyType_Lookup() instead of just looking in type->tp_dict. */
 static PyObject *
diff --git a/Python/specialize.c b/Python/specialize.c
index e88fdde79a67..d1a38450fff0 100644
--- a/Python/specialize.c
+++ b/Python/specialize.c
@@ -187,6 +187,11 @@ print_object_stats(FILE *out, ObjectStats *stats)
     fprintf(out, "Object materialize dict (new key): %" PRIu64 "\n", stats->dict_materialized_new_key);
     fprintf(out, "Object materialize dict (too big): %" PRIu64 "\n", stats->dict_materialized_too_big);
     fprintf(out, "Object materialize dict (str subclass): %" PRIu64 "\n", stats->dict_materialized_str_subclass);
+    fprintf(out, "Object method cache hits: %" PRIu64 "\n", stats->type_cache_hits);
+    fprintf(out, "Object method cache misses: %" PRIu64 "\n", stats->type_cache_misses);
+    fprintf(out, "Object method cache collisions: %" PRIu64 "\n", stats->type_cache_collisions);
+    fprintf(out, "Object method cache dunder hits: %" PRIu64 "\n", stats->type_cache_dunder_hits);
+    fprintf(out, "Object method cache dunder misses: %" PRIu64 "\n", stats->type_cache_dunder_misses);
 }
 
 static void