Experimental visit stats by type

Author: markshannon

Include/cpython/pystats.h

@@ -91,6 +91,12 @@ typedef struct _object_stats {
     uint64_t type_cache_dunder_hits;
     uint64_t type_cache_dunder_misses;
     uint64_t type_cache_collisions;
+    uint64_t dict_visits;
+    uint64_t list_visits;
+    uint64_t tuple_visits;
+    uint64_t immortal_object_visits;
+    uint64_t gc_object_visits;
+    uint64_t non_gc_object_visits;
     /* Temporary value used during GC */
     uint64_t object_visits;
 } ObjectStats;

Include/internal/pycore_code.h

@@ -389,13 +389,17 @@ extern void _Py_Specialize_ContainsOp(_PyStackRef value, _Py_CODEUNIT *instr);
 // Export for '_opcode' shared extension
 PyAPI_FUNC(PyObject*) _Py_GetSpecializationStats(void);
 
+extern void _PyStats_ObjectVisit(PyObject *op);
+#define OBJECT_VISIT(op) _PyStats_ObjectVisit(op)
+
 #else
 #define STAT_INC(opname, name) ((void)0)
 #define STAT_DEC(opname, name) ((void)0)
 #define OPCODE_EXE_INC(opname) ((void)0)
 #define CALL_STAT_INC(name) ((void)0)
 #define OBJECT_STAT_INC(name) ((void)0)
 #define OBJECT_STAT_INC_COND(name, cond) ((void)0)
+#define OBJECT_VISIT(op) ((void)0)
 #define EVAL_CALL_STAT_INC(name) ((void)0)
 #define EVAL_CALL_STAT_INC_IF_FUNCTION(name, callable) ((void)0)
 #define GC_STAT_ADD(gen, name, n) ((void)0)

Python/gc.c

@@ -514,11 +514,36 @@ update_refs(PyGC_Head *containers)
     }
 }
 
+#ifdef Py_STATS
+void _PyStats_ObjectVisit(PyObject *op)
+{
+    OBJECT_STAT_INC(object_visits);
+    if (_Py_IsImmortal(op)) {
+        OBJECT_STAT_INC(immortal_object_visits);
+    }
+    else if (PyDict_CheckExact(op)) {
+        OBJECT_STAT_INC(dict_visits);
+    }
+    else if (PyList_CheckExact(op)) {
+        OBJECT_STAT_INC(list_visits);
+    }
+    else if (PyTuple_CheckExact(op)) {
+        OBJECT_STAT_INC(tuple_visits);
+    }
+    else if (_PyObject_IS_GC(op)) {
+        OBJECT_STAT_INC(gc_object_visits);
+    }
+    else {
+        OBJECT_STAT_INC(non_gc_object_visits);
+    }
+}
+#endif
+
 /* A traversal callback for subtract_refs. */
 static int
 visit_decref(PyObject *op, void *parent)
 {
-    OBJECT_STAT_INC(object_visits);
+    OBJECT_VISIT(op);
     _PyObject_ASSERT(_PyObject_CAST(parent), !_PyObject_IsFreed(op));
 
     if (_PyObject_IS_GC(op)) {
@@ -576,7 +601,7 @@ static int
 visit_reachable(PyObject *op, void *arg)
 {
     PyGC_Head *reachable = arg;
-    OBJECT_STAT_INC(object_visits);
+    OBJECT_VISIT(op);
     if (!_PyObject_IS_GC(op)) {
         return 0;
     }
@@ -816,7 +841,7 @@ static int
 visit_move(PyObject *op, void *arg)
 {
     PyGC_Head *tolist = arg;
-    OBJECT_STAT_INC(object_visits);
+    OBJECT_VISIT(op);
     if (_PyObject_IS_GC(op)) {
         PyGC_Head *gc = AS_GC(op);
         if (gc_is_collecting(gc)) {
@@ -1367,7 +1392,7 @@ struct container_and_flag {
 static int
 visit_add_to_container(PyObject *op, void *arg)
 {
-    OBJECT_STAT_INC(object_visits);
+    OBJECT_VISIT(op);
     struct container_and_flag *cf = (struct container_and_flag *)arg;
     int visited = cf->visited_space;
     assert(visited == get_gc_state()->visited_space);

Python/specialize.c

@@ -222,6 +222,13 @@ print_object_stats(FILE *out, ObjectStats *stats)
     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);
+    fprintf(out, "Object tuple visits: %" PRIu64 "\n", stats->tuple_visits);
+    fprintf(out, "Object dict visits: %" PRIu64 "\n", stats->dict_visits);
+    fprintf(out, "Object list visits: %" PRIu64 "\n", stats->list_visits);
+    fprintf(out, "Object tuple visits: %" PRIu64 "\n", stats->tuple_visits);
+    fprintf(out, "Object immortal object visits: %" PRIu64 "\n", stats->immortal_object_visits);
+    fprintf(out, "Object GC object visits: %" PRIu64 "\n", stats->gc_object_visits);
+    fprintf(out, "Object non-GC object visits: %" PRIu64 "\n", stats->non_gc_object_visits);
 }
 
 static void