gh-94673: More Per-Interpreter Fields for Builtin Static Types (gh-103912)

his involves moving tp_dict, tp_bases, and tp_mro to PyInterpreterState, in the same way we did for tp_subclasses.  Those three fields are effectively const for builtin static types (unlike tp_subclasses).  In theory we only need to make their values immortal, along with their contents.  However, that isn't such a simple proposition.  (See gh-103823.)  In the meantime the simplest solution is to move the fields into the interpreter.

One alternative is to statically allocate the values, but that's its own can of worms.
This commit is contained in:
Eric Snow 2023-05-02 21:30:03 -06:00 committed by GitHub
parent 872cbc6132
commit de64e75616
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
5 changed files with 185 additions and 86 deletions

View File

@ -44,6 +44,13 @@ struct type_cache {
typedef struct {
PyTypeObject *type;
int readying;
int ready;
// XXX tp_dict, tp_bases, and tp_mro can probably be statically
// allocated, instead of dynamically and stored on the interpreter.
PyObject *tp_dict;
PyObject *tp_bases;
PyObject *tp_mro;
PyObject *tp_subclasses;
/* We never clean up weakrefs for static builtin types since
they will effectively never get triggered. However, there

View File

@ -7,6 +7,7 @@
#include "pycore_moduleobject.h" // _PyModule_GetState()
#include "pycore_object.h" // _PyType_GetSubclasses()
#include "pycore_runtime.h" // _Py_ID()
#include "pycore_typeobject.h" // _PyType_GetMRO()
#include "clinic/_abc.c.h"
/*[clinic input]

View File

@ -2174,23 +2174,6 @@ _PyGC_DumpShutdownStats(PyInterpreterState *interp)
}
static void
gc_fini_untrack(PyGC_Head *list)
{
PyGC_Head *gc;
for (gc = GC_NEXT(list); gc != list; gc = GC_NEXT(list)) {
PyObject *op = FROM_GC(gc);
_PyObject_GC_UNTRACK(op);
// gh-92036: If a deallocator function expect the object to be tracked
// by the GC (ex: func_dealloc()), it can crash if called on an object
// which is no longer tracked by the GC. Leak one strong reference on
// purpose so the object is never deleted and its deallocator is not
// called.
Py_INCREF(op);
}
}
void
_PyGC_Fini(PyInterpreterState *interp)
{
@ -2198,17 +2181,9 @@ _PyGC_Fini(PyInterpreterState *interp)
Py_CLEAR(gcstate->garbage);
Py_CLEAR(gcstate->callbacks);
if (!_Py_IsMainInterpreter(interp)) {
// bpo-46070: Explicitly untrack all objects currently tracked by the
// GC. Otherwise, if an object is used later by another interpreter,
// calling PyObject_GC_UnTrack() on the object crashs if the previous
// or the next object of the PyGC_Head structure became a dangling
// pointer.
for (int i = 0; i < NUM_GENERATIONS; i++) {
PyGC_Head *gen = GEN_HEAD(gcstate, i);
gc_fini_untrack(gen);
}
}
/* We expect that none of this interpreters objects are shared
with other interpreters.
See https://github.com/python/cpython/issues/90228. */
}
/* for debugging */

View File

@ -511,7 +511,6 @@ _PyStructSequence_InitBuiltinWithFlags(PyInterpreterState *interp,
Py_ssize_t n_members = count_members(desc, &n_unnamed_members);
PyMemberDef *members = NULL;
int initialized = 1;
if ((type->tp_flags & Py_TPFLAGS_READY) == 0) {
assert(type->tp_name == NULL);
assert(type->tp_members == NULL);
@ -524,7 +523,6 @@ _PyStructSequence_InitBuiltinWithFlags(PyInterpreterState *interp,
initialize_static_fields(type, desc, members, tp_flags);
_Py_SetImmortal(type);
initialized = 0;
}
#ifndef NDEBUG
else {
@ -543,13 +541,10 @@ _PyStructSequence_InitBuiltinWithFlags(PyInterpreterState *interp,
desc->name);
goto error;
}
// This should be dropped if tp_dict is made per-interpreter.
if (initialized) {
return 0;
}
if (initialize_structseq_dict(
desc, _PyType_GetDict(type), n_members, n_unnamed_members) < 0) {
desc, _PyType_GetDict(type), n_members, n_unnamed_members) < 0)
{
goto error;
}

View File

@ -167,29 +167,93 @@ static_builtin_state_clear(PyInterpreterState *interp, PyTypeObject *self)
/* end static builtin helpers */
static inline void
start_readying(PyTypeObject *type)
{
if (type->tp_flags & _Py_TPFLAGS_STATIC_BUILTIN) {
PyInterpreterState *interp = _PyInterpreterState_GET();
static_builtin_state *state = static_builtin_state_get(interp, type);
assert(state != NULL);
assert(!state->readying);
state->readying = 1;
return;
}
assert((type->tp_flags & Py_TPFLAGS_READYING) == 0);
type->tp_flags |= Py_TPFLAGS_READYING;
}
static inline void
stop_readying(PyTypeObject *type)
{
if (type->tp_flags & _Py_TPFLAGS_STATIC_BUILTIN) {
PyInterpreterState *interp = _PyInterpreterState_GET();
static_builtin_state *state = static_builtin_state_get(interp, type);
assert(state != NULL);
assert(state->readying);
state->readying = 0;
return;
}
assert(type->tp_flags & Py_TPFLAGS_READYING);
type->tp_flags &= ~Py_TPFLAGS_READYING;
}
static inline int
is_readying(PyTypeObject *type)
{
if (type->tp_flags & _Py_TPFLAGS_STATIC_BUILTIN) {
PyInterpreterState *interp = _PyInterpreterState_GET();
static_builtin_state *state = static_builtin_state_get(interp, type);
assert(state != NULL);
return state->readying;
}
return (type->tp_flags & Py_TPFLAGS_READYING) != 0;
}
/* accessors for objects stored on PyTypeObject */
static inline PyObject *
lookup_tp_dict(PyTypeObject *self)
{
if (self->tp_flags & _Py_TPFLAGS_STATIC_BUILTIN) {
PyInterpreterState *interp = _PyInterpreterState_GET();
static_builtin_state *state = _PyStaticType_GetState(interp, self);
assert(state != NULL);
return state->tp_dict;
}
return self->tp_dict;
}
PyObject *
_PyType_GetDict(PyTypeObject *self)
{
/* It returns a borrowed reference. */
return lookup_tp_dict(self);
}
static inline void
set_tp_dict(PyTypeObject *self, PyObject *dict)
{
if (self->tp_flags & _Py_TPFLAGS_STATIC_BUILTIN) {
PyInterpreterState *interp = _PyInterpreterState_GET();
static_builtin_state *state = _PyStaticType_GetState(interp, self);
assert(state != NULL);
state->tp_dict = dict;
return;
}
self->tp_dict = dict;
}
static inline void
clear_tp_dict(PyTypeObject *self)
{
if (self->tp_flags & _Py_TPFLAGS_STATIC_BUILTIN) {
PyInterpreterState *interp = _PyInterpreterState_GET();
static_builtin_state *state = _PyStaticType_GetState(interp, self);
assert(state != NULL);
Py_CLEAR(state->tp_dict);
return;
}
Py_CLEAR(self->tp_dict);
}
@ -197,24 +261,45 @@ clear_tp_dict(PyTypeObject *self)
static inline PyObject *
lookup_tp_bases(PyTypeObject *self)
{
if (self->tp_flags & _Py_TPFLAGS_STATIC_BUILTIN) {
PyInterpreterState *interp = _PyInterpreterState_GET();
static_builtin_state *state = _PyStaticType_GetState(interp, self);
assert(state != NULL);
return state->tp_bases;
}
return self->tp_bases;
}
PyObject *
_PyType_GetBases(PyTypeObject *self)
{
/* It returns a borrowed reference. */
return lookup_tp_bases(self);
}
static inline void
set_tp_bases(PyTypeObject *self, PyObject *bases)
{
if (self->tp_flags & _Py_TPFLAGS_STATIC_BUILTIN) {
PyInterpreterState *interp = _PyInterpreterState_GET();
static_builtin_state *state = _PyStaticType_GetState(interp, self);
assert(state != NULL);
state->tp_bases = bases;
return;
}
self->tp_bases = bases;
}
static inline void
clear_tp_bases(PyTypeObject *self)
{
if (self->tp_flags & _Py_TPFLAGS_STATIC_BUILTIN) {
PyInterpreterState *interp = _PyInterpreterState_GET();
static_builtin_state *state = _PyStaticType_GetState(interp, self);
assert(state != NULL);
Py_CLEAR(state->tp_bases);
return;
}
Py_CLEAR(self->tp_bases);
}
@ -222,24 +307,45 @@ clear_tp_bases(PyTypeObject *self)
static inline PyObject *
lookup_tp_mro(PyTypeObject *self)
{
if (self->tp_flags & _Py_TPFLAGS_STATIC_BUILTIN) {
PyInterpreterState *interp = _PyInterpreterState_GET();
static_builtin_state *state = _PyStaticType_GetState(interp, self);
assert(state != NULL);
return state->tp_mro;
}
return self->tp_mro;
}
PyObject *
_PyType_GetMRO(PyTypeObject *self)
{
/* It returns a borrowed reference. */
return lookup_tp_mro(self);
}
static inline void
set_tp_mro(PyTypeObject *self, PyObject *mro)
{
if (self->tp_flags & _Py_TPFLAGS_STATIC_BUILTIN) {
PyInterpreterState *interp = _PyInterpreterState_GET();
static_builtin_state *state = _PyStaticType_GetState(interp, self);
assert(state != NULL);
state->tp_mro = mro;
return;
}
self->tp_mro = mro;
}
static inline void
clear_tp_mro(PyTypeObject *self)
{
if (self->tp_flags & _Py_TPFLAGS_STATIC_BUILTIN) {
PyInterpreterState *interp = _PyInterpreterState_GET();
static_builtin_state *state = _PyStaticType_GetState(interp, self);
assert(state != NULL);
Py_CLEAR(state->tp_mro);
return;
}
Py_CLEAR(self->tp_mro);
}
@ -408,7 +514,7 @@ _PyType_CheckConsistency(PyTypeObject *type)
CHECK(Py_REFCNT(type) >= 1);
CHECK(PyType_Check(type));
CHECK(!(type->tp_flags & Py_TPFLAGS_READYING));
CHECK(!is_readying(type));
CHECK(lookup_tp_dict(type) != NULL);
if (type->tp_flags & Py_TPFLAGS_HAVE_GC) {
@ -809,7 +915,6 @@ static PyMemberDef type_members[] = {
{"__base__", T_OBJECT, offsetof(PyTypeObject, tp_base), READONLY},
{"__dictoffset__", T_PYSSIZET,
offsetof(PyTypeObject, tp_dictoffset), READONLY},
{"__mro__", T_OBJECT, offsetof(PyTypeObject, tp_mro), READONLY},
{0}
};
@ -1023,7 +1128,21 @@ type_set_abstractmethods(PyTypeObject *type, PyObject *value, void *context)
static PyObject *
type_get_bases(PyTypeObject *type, void *context)
{
return Py_NewRef(lookup_tp_bases(type));
PyObject *bases = lookup_tp_bases(type);
if (bases == NULL) {
Py_RETURN_NONE;
}
return Py_NewRef(bases);
}
static PyObject *
type_get_mro(PyTypeObject *type, void *context)
{
PyObject *mro = lookup_tp_mro(type);
if (mro == NULL) {
Py_RETURN_NONE;
}
return Py_NewRef(mro);
}
static PyTypeObject *best_base(PyObject *);
@ -1402,6 +1521,7 @@ static PyGetSetDef type_getsets[] = {
{"__name__", (getter)type_name, (setter)type_set_name, NULL},
{"__qualname__", (getter)type_qualname, (setter)type_set_qualname, NULL},
{"__bases__", (getter)type_get_bases, (setter)type_set_bases, NULL},
{"__mro__", (getter)type_get_mro, NULL, NULL},
{"__module__", (getter)type_module, (setter)type_set_module, NULL},
{"__abstractmethods__", (getter)type_abstractmethods,
(setter)type_set_abstractmethods, NULL},
@ -4342,7 +4462,7 @@ find_name_in_mro(PyTypeObject *type, PyObject *name, int *error)
/* Look in tp_dict of types in MRO */
PyObject *mro = lookup_tp_mro(type);
if (mro == NULL) {
if ((type->tp_flags & Py_TPFLAGS_READYING) == 0) {
if (!is_readying(type)) {
if (PyType_Ready(type) < 0) {
*error = -1;
return NULL;
@ -4692,11 +4812,11 @@ static void
clear_static_type_objects(PyInterpreterState *interp, PyTypeObject *type)
{
if (_Py_IsMainInterpreter(interp)) {
Py_CLEAR(type->tp_cache);
}
clear_tp_dict(type);
clear_tp_bases(type);
clear_tp_mro(type);
Py_CLEAR(type->tp_cache);
}
clear_static_tp_subclasses(type);
}
@ -6684,6 +6804,10 @@ type_ready_pre_checks(PyTypeObject *type)
static int
type_ready_set_bases(PyTypeObject *type)
{
if (lookup_tp_bases(type) != NULL) {
return 0;
}
/* Initialize tp_base (defaults to BaseObject unless that's us) */
PyTypeObject *base = type->tp_base;
if (base == NULL && type != &PyBaseObject_Type) {
@ -6997,7 +7121,7 @@ type_ready_add_subclasses(PyTypeObject *type)
// Set tp_new and the "__new__" key in the type dictionary.
// Use the Py_TPFLAGS_DISALLOW_INSTANTIATION flag.
static int
type_ready_set_new(PyTypeObject *type)
type_ready_set_new(PyTypeObject *type, int rerunbuiltin)
{
PyTypeObject *base = type->tp_base;
/* The condition below could use some explanation.
@ -7019,12 +7143,14 @@ type_ready_set_new(PyTypeObject *type)
if (!(type->tp_flags & Py_TPFLAGS_DISALLOW_INSTANTIATION)) {
if (type->tp_new != NULL) {
if (!rerunbuiltin || base == NULL || type->tp_new != base->tp_new) {
// If "__new__" key does not exists in the type dictionary,
// set it to tp_new_wrapper().
if (add_tp_new_wrapper(type) < 0) {
return -1;
}
}
}
else {
// tp_new is NULL: inherit tp_new from base
type->tp_new = base->tp_new;
@ -7096,11 +7222,10 @@ type_ready_post_checks(PyTypeObject *type)
static int
type_ready(PyTypeObject *type)
type_ready(PyTypeObject *type, int rerunbuiltin)
{
_PyObject_ASSERT((PyObject *)type,
(type->tp_flags & Py_TPFLAGS_READYING) == 0);
type->tp_flags |= Py_TPFLAGS_READYING;
_PyObject_ASSERT((PyObject *)type, !is_readying(type));
start_readying(type);
if (type_ready_pre_checks(type) < 0) {
goto error;
@ -7125,39 +7250,44 @@ type_ready(PyTypeObject *type)
if (type_ready_mro(type) < 0) {
goto error;
}
if (type_ready_set_new(type) < 0) {
if (type_ready_set_new(type, rerunbuiltin) < 0) {
goto error;
}
if (type_ready_fill_dict(type) < 0) {
goto error;
}
if (!rerunbuiltin) {
if (type_ready_inherit(type) < 0) {
goto error;
}
if (type_ready_preheader(type) < 0) {
goto error;
}
}
if (type_ready_set_hash(type) < 0) {
goto error;
}
if (type_ready_add_subclasses(type) < 0) {
goto error;
}
if (!rerunbuiltin) {
if (type_ready_managed_dict(type) < 0) {
goto error;
}
if (type_ready_post_checks(type) < 0) {
goto error;
}
}
/* All done -- set the ready flag */
type->tp_flags = (type->tp_flags & ~Py_TPFLAGS_READYING) | Py_TPFLAGS_READY;
type->tp_flags = type->tp_flags | Py_TPFLAGS_READY;
stop_readying(type);
assert(_PyType_CheckConsistency(type));
return 0;
error:
type->tp_flags &= ~Py_TPFLAGS_READYING;
stop_readying(type);
return -1;
}
@ -7175,7 +7305,7 @@ PyType_Ready(PyTypeObject *type)
type->tp_flags |= Py_TPFLAGS_IMMUTABLETYPE;
}
return type_ready(type);
return type_ready(type, 0);
}
int
@ -7186,23 +7316,8 @@ _PyStaticType_InitBuiltin(PyInterpreterState *interp, PyTypeObject *self)
assert(!(self->tp_flags & Py_TPFLAGS_MANAGED_DICT));
assert(!(self->tp_flags & Py_TPFLAGS_MANAGED_WEAKREF));
#ifndef NDEBUG
int ismain = _Py_IsMainInterpreter(interp);
#endif
if (self->tp_flags & Py_TPFLAGS_READY) {
assert(!ismain);
assert(self->tp_flags & _Py_TPFLAGS_STATIC_BUILTIN);
assert(self->tp_flags & Py_TPFLAGS_VALID_VERSION_TAG);
static_builtin_state_init(interp, self);
/* Per-interpreter tp_subclasses is done lazily.
Otherwise we would initialize it here. */
assert(_PyType_CheckConsistency(self));
return 0;
}
if ((self->tp_flags & Py_TPFLAGS_READY) == 0) {
assert(ismain);
self->tp_flags |= _Py_TPFLAGS_STATIC_BUILTIN;
@ -7211,10 +7326,16 @@ _PyStaticType_InitBuiltin(PyInterpreterState *interp, PyTypeObject *self)
assert(NEXT_GLOBAL_VERSION_TAG <= _Py_MAX_GLOBAL_TYPE_VERSION_TAG);
self->tp_version_tag = NEXT_GLOBAL_VERSION_TAG++;
self->tp_flags |= Py_TPFLAGS_VALID_VERSION_TAG;
}
else {
assert(!ismain);
assert(self->tp_flags & _Py_TPFLAGS_STATIC_BUILTIN);
assert(self->tp_flags & Py_TPFLAGS_VALID_VERSION_TAG);
}
static_builtin_state_init(interp, self);
int res = type_ready(self);
int res = type_ready(self, !ismain);
if (res < 0) {
static_builtin_state_clear(interp, self);
}