diff options
Diffstat (limited to 'Python/specialize.c')
| -rw-r--r-- | Python/specialize.c | 229 |
1 files changed, 139 insertions, 90 deletions
diff --git a/Python/specialize.c b/Python/specialize.c index 897005c4f10..8d9f19c8895 100644 --- a/Python/specialize.c +++ b/Python/specialize.c @@ -3,6 +3,7 @@ #include "opcode.h" #include "pycore_code.h" +#include "pycore_critical_section.h" #include "pycore_descrobject.h" // _PyMethodWrapper_Type #include "pycore_dict.h" // DICT_KEYS_UNICODE #include "pycore_function.h" // _PyFunction_GetVersionForCurrentState() @@ -537,6 +538,7 @@ _PyCode_Quicken(_Py_CODEUNIT *instructions, Py_ssize_t size, PyObject *consts, #define SPEC_FAIL_ATTR_BUILTIN_CLASS_METHOD_OBJ 33 #define SPEC_FAIL_ATTR_METACLASS_OVERRIDDEN 34 #define SPEC_FAIL_ATTR_SPLIT_DICT 35 +#define SPEC_FAIL_ATTR_DESCR_NOT_DEFERRED 36 /* Binary subscr and store subscr */ @@ -729,11 +731,8 @@ unspecialize(_Py_CODEUNIT *instr) } static int function_kind(PyCodeObject *code); -#ifndef Py_GIL_DISABLED static bool function_check_args(PyObject *o, int expected_argcount, int opcode); static uint32_t function_get_version(PyObject *o, int opcode); -static uint32_t type_get_version(PyTypeObject *t, int opcode); -#endif static int specialize_module_load_attr_lock_held(PyDictObject *dict, _Py_CODEUNIT *instr, PyObject *name) @@ -879,10 +878,11 @@ descriptor_is_class(PyObject *descriptor, PyObject *name) (descriptor == _PyType_Lookup(&PyBaseObject_Type, name))); } -#ifndef Py_GIL_DISABLED static DescriptorClassification -analyze_descriptor_load(PyTypeObject *type, PyObject *name, PyObject **descr) { +analyze_descriptor_load(PyTypeObject *type, PyObject *name, PyObject **descr, unsigned int *tp_version) { bool has_getattr = false; + bool have_ga_version = false; + unsigned int ga_version; getattrofunc getattro_slot = type->tp_getattro; if (getattro_slot == PyObject_GenericGetAttr) { /* Normal attribute lookup; */ @@ -892,24 +892,27 @@ analyze_descriptor_load(PyTypeObject *type, PyObject *name, PyObject **descr) { getattro_slot == _Py_slot_tp_getattro) { /* One or both of __getattribute__ or __getattr__ may have been overridden See typeobject.c for why these functions are special. */ - PyObject *getattribute = _PyType_LookupRef(type, &_Py_ID(__getattribute__)); + PyObject *getattribute = _PyType_LookupRefAndVersion(type, + &_Py_ID(__getattribute__), &ga_version); + have_ga_version = true; PyInterpreterState *interp = _PyInterpreterState_GET(); bool has_custom_getattribute = getattribute != NULL && getattribute != interp->callable_cache.object__getattribute__; - PyObject *getattr = _PyType_LookupRef(type, &_Py_ID(__getattr__)); + PyObject *getattr = _PyType_Lookup(type, &_Py_ID(__getattr__)); has_getattr = getattr != NULL; - Py_XDECREF(getattr); if (has_custom_getattribute) { if (getattro_slot == _Py_slot_tp_getattro && !has_getattr && Py_IS_TYPE(getattribute, &PyFunction_Type)) { *descr = getattribute; + *tp_version = ga_version; return GETATTRIBUTE_IS_PYTHON_FUNCTION; } /* Potentially both __getattr__ and __getattribute__ are set. Too complicated */ Py_DECREF(getattribute); *descr = NULL; + *tp_version = ga_version; return GETSET_OVERRIDDEN; } /* Potentially has __getattr__ but no custom __getattribute__. @@ -923,16 +926,18 @@ analyze_descriptor_load(PyTypeObject *type, PyObject *name, PyObject **descr) { } else { *descr = NULL; + *tp_version = FT_ATOMIC_LOAD_UINT_RELAXED(type->tp_version_tag); return GETSET_OVERRIDDEN; } - PyObject *descriptor = _PyType_LookupRef(type, name); + unsigned int descr_version; + PyObject *descriptor = _PyType_LookupRefAndVersion(type, name, &descr_version); *descr = descriptor; + *tp_version = have_ga_version ? ga_version : descr_version; if (descriptor_is_class(descriptor, name)) { return DUNDER_CLASS; } return classify_descriptor(descriptor, has_getattr); } -#endif //!Py_GIL_DISABLED static DescriptorClassification analyze_descriptor_store(PyTypeObject *type, PyObject *name, PyObject **descr, unsigned int *tp_version) @@ -952,12 +957,13 @@ analyze_descriptor_store(PyTypeObject *type, PyObject *name, PyObject **descr, u static int specialize_dict_access_inline( PyObject *owner, _Py_CODEUNIT *instr, PyTypeObject *type, - DescriptorClassification kind, PyObject *name, unsigned int tp_version, + PyObject *name, unsigned int tp_version, int base_op, int values_op) { _PyAttrCache *cache = (_PyAttrCache *)(instr + 1); PyDictKeysObject *keys = ((PyHeapTypeObject *)type)->ht_cached_keys; assert(PyUnicode_CheckExact(name)); + _Py_CRITICAL_SECTION_ASSERT_OBJECT_LOCKED(owner); Py_ssize_t index = _PyDictKeys_StringLookupSplit(keys, name); assert (index != DKIX_ERROR); if (index == DKIX_EMPTY) { @@ -965,6 +971,7 @@ specialize_dict_access_inline( return 0; } assert(index >= 0); + assert(_PyObject_InlineValues(owner)->valid); char *value_addr = (char *)&_PyObject_InlineValues(owner)->values[index]; Py_ssize_t offset = value_addr - (char *)owner; if (offset != (uint16_t)offset) { @@ -980,10 +987,13 @@ specialize_dict_access_inline( static int specialize_dict_access_hint( PyDictObject *dict, _Py_CODEUNIT *instr, PyTypeObject *type, - DescriptorClassification kind, PyObject *name, unsigned int tp_version, + PyObject *name, unsigned int tp_version, int base_op, int hint_op) { _PyAttrCache *cache = (_PyAttrCache *)(instr + 1); + + _Py_CRITICAL_SECTION_ASSERT_OBJECT_LOCKED(dict); + // We found an instance with a __dict__. if (_PyDict_HasSplitTable(dict)) { SPECIALIZATION_FAIL(base_op, SPEC_FAIL_ATTR_SPLIT_DICT); @@ -1027,7 +1037,7 @@ specialize_dict_access( PyDictObject *dict = _PyObject_GetManagedDict(owner); if (dict == NULL) { // managed dict, not materialized, inline values valid - res = specialize_dict_access_inline(owner, instr, type, kind, name, + res = specialize_dict_access_inline(owner, instr, type, name, tp_version, base_op, values_op); } else { @@ -1047,16 +1057,19 @@ specialize_dict_access( int res; Py_BEGIN_CRITICAL_SECTION(dict); // materialized managed dict - res = specialize_dict_access_hint(dict, instr, type, kind, name, + res = specialize_dict_access_hint(dict, instr, type, name, tp_version, base_op, hint_op); Py_END_CRITICAL_SECTION(); return res; } } -#ifndef Py_GIL_DISABLED -static int specialize_attr_loadclassattr(PyObject* owner, _Py_CODEUNIT* instr, PyObject* name, - PyObject* descr, DescriptorClassification kind, bool is_method); +static int +specialize_attr_loadclassattr(PyObject *owner, _Py_CODEUNIT *instr, + PyObject *name, PyObject *descr, + unsigned int tp_version, + DescriptorClassification kind, bool is_method, + uint32_t shared_keys_version); static int specialize_class_load_attr(PyObject* owner, _Py_CODEUNIT* instr, PyObject* name); /* Returns true if instances of obj's class are @@ -1065,7 +1078,7 @@ static int specialize_class_load_attr(PyObject* owner, _Py_CODEUNIT* instr, PyOb * For other objects, we check their actual dictionary. */ static bool -instance_has_key(PyObject *obj, PyObject* name) +instance_has_key(PyObject *obj, PyObject *name, uint32_t *shared_keys_version) { PyTypeObject *cls = Py_TYPE(obj); if ((cls->tp_flags & Py_TPFLAGS_MANAGED_DICT) == 0) { @@ -1073,36 +1086,38 @@ instance_has_key(PyObject *obj, PyObject* name) } if (cls->tp_flags & Py_TPFLAGS_INLINE_VALUES) { PyDictKeysObject *keys = ((PyHeapTypeObject *)cls)->ht_cached_keys; - Py_ssize_t index = _PyDictKeys_StringLookup(keys, name); + Py_ssize_t index = + _PyDictKeys_StringLookupAndVersion(keys, name, shared_keys_version); return index >= 0; } PyDictObject *dict = _PyObject_GetManagedDict(obj); if (dict == NULL || !PyDict_CheckExact(dict)) { return false; } + bool result; + Py_BEGIN_CRITICAL_SECTION(dict); if (dict->ma_values) { - return false; + result = false; } - Py_ssize_t index = _PyDict_LookupIndex(dict, name); - if (index < 0) { - return false; + else { + result = (_PyDict_LookupIndex(dict, name) >= 0); } - return true; + Py_END_CRITICAL_SECTION(); + return result; } static int -specialize_instance_load_attr(PyObject* owner, _Py_CODEUNIT* instr, PyObject* name) +do_specialize_instance_load_attr(PyObject* owner, _Py_CODEUNIT* instr, PyObject* name, + bool shadow, uint32_t shared_keys_version, + DescriptorClassification kind, PyObject *descr, unsigned int tp_version) { _PyAttrCache *cache = (_PyAttrCache *)(instr + 1); PyTypeObject *type = Py_TYPE(owner); - bool shadow = instance_has_key(owner, name); - PyObject *descr = NULL; - DescriptorClassification kind = analyze_descriptor_load(type, name, &descr); - Py_XDECREF(descr); // turn strong ref into a borrowed ref - assert(descr != NULL || kind == ABSENT || kind == GETSET_OVERRIDDEN); - if (type_get_version(type, LOAD_ATTR) == 0) { + if (tp_version == 0) { + SPECIALIZATION_FAIL(LOAD_ATTR, SPEC_FAIL_OUT_OF_VERSIONS); return -1; } + uint8_t oparg = FT_ATOMIC_LOAD_UINT8_RELAXED(instr->op.arg); switch(kind) { case OVERRIDING: SPECIALIZATION_FAIL(LOAD_ATTR, SPEC_FAIL_ATTR_OVERRIDING_DESCRIPTOR); @@ -1112,9 +1127,10 @@ specialize_instance_load_attr(PyObject* owner, _Py_CODEUNIT* instr, PyObject* na if (shadow) { goto try_instance; } - int oparg = instr->op.arg; if (oparg & 1) { - if (specialize_attr_loadclassattr(owner, instr, name, descr, kind, true)) { + if (specialize_attr_loadclassattr(owner, instr, name, descr, + tp_version, kind, true, + shared_keys_version)) { return 0; } else { @@ -1140,7 +1156,7 @@ specialize_instance_load_attr(PyObject* owner, _Py_CODEUNIT* instr, PyObject* na if (!function_check_args(fget, 1, LOAD_ATTR)) { return -1; } - if (instr->op.arg & 1) { + if (oparg & 1) { SPECIALIZATION_FAIL(LOAD_ATTR, SPEC_FAIL_ATTR_METHOD); return -1; } @@ -1149,8 +1165,14 @@ specialize_instance_load_attr(PyObject* owner, _Py_CODEUNIT* instr, PyObject* na SPECIALIZATION_FAIL(LOAD_ATTR, SPEC_FAIL_OTHER); return -1; } - assert(type->tp_version_tag != 0); - write_u32(lm_cache->type_version, type->tp_version_tag); + #ifdef Py_GIL_DISABLED + if (!_PyObject_HasDeferredRefcount(fget)) { + SPECIALIZATION_FAIL(LOAD_ATTR, SPEC_FAIL_ATTR_DESCR_NOT_DEFERRED); + return -1; + } + #endif + assert(tp_version != 0); + write_u32(lm_cache->type_version, tp_version); /* borrowed */ write_obj(lm_cache->descr, fget); specialize(instr, LOAD_ATTR_PROPERTY); @@ -1176,7 +1198,7 @@ specialize_instance_load_attr(PyObject* owner, _Py_CODEUNIT* instr, PyObject* na assert(dmem->type == Py_T_OBJECT_EX || dmem->type == _Py_T_OBJECT); assert(offset > 0); cache->index = (uint16_t)offset; - write_u32(cache->version, type->tp_version_tag); + write_u32(cache->version, tp_version); specialize(instr, LOAD_ATTR_SLOT); return 0; } @@ -1185,7 +1207,7 @@ specialize_instance_load_attr(PyObject* owner, _Py_CODEUNIT* instr, PyObject* na Py_ssize_t offset = offsetof(PyObject, ob_type); assert(offset == (uint16_t)offset); cache->index = (uint16_t)offset; - write_u32(cache->version, type->tp_version_tag); + write_u32(cache->version, tp_version); specialize(instr, LOAD_ATTR_SLOT); return 0; } @@ -1200,13 +1222,18 @@ specialize_instance_load_attr(PyObject* owner, _Py_CODEUNIT* instr, PyObject* na return -1; case GETATTRIBUTE_IS_PYTHON_FUNCTION: { + #ifndef Py_GIL_DISABLED + // In free-threaded builds it's possible for tp_getattro to change + // after the call to analyze_descriptor. That is fine: the version + // guard will fail. assert(type->tp_getattro == _Py_slot_tp_getattro); + #endif assert(Py_IS_TYPE(descr, &PyFunction_Type)); _PyLoadMethodCache *lm_cache = (_PyLoadMethodCache *)(instr + 1); if (!function_check_args(descr, 2, LOAD_ATTR)) { return -1; } - if (instr->op.arg & 1) { + if (oparg & 1) { SPECIALIZATION_FAIL(LOAD_ATTR, SPEC_FAIL_ATTR_METHOD); return -1; } @@ -1219,10 +1246,16 @@ specialize_instance_load_attr(PyObject* owner, _Py_CODEUNIT* instr, PyObject* na SPECIALIZATION_FAIL(LOAD_ATTR, SPEC_FAIL_OTHER); return -1; } + #ifdef Py_GIL_DISABLED + if (!_PyObject_HasDeferredRefcount(descr)) { + SPECIALIZATION_FAIL(LOAD_ATTR, SPEC_FAIL_ATTR_DESCR_NOT_DEFERRED); + return -1; + } + #endif write_u32(lm_cache->keys_version, version); /* borrowed */ write_obj(lm_cache->descr, descr); - write_u32(lm_cache->type_version, type->tp_version_tag); + write_u32(lm_cache->type_version, tp_version); specialize(instr, LOAD_ATTR_GETATTRIBUTE_OVERRIDDEN); return 0; } @@ -1237,8 +1270,10 @@ specialize_instance_load_attr(PyObject* owner, _Py_CODEUNIT* instr, PyObject* na if (shadow) { goto try_instance; } - if ((instr->op.arg & 1) == 0) { - if (specialize_attr_loadclassattr(owner, instr, name, descr, kind, false)) { + if ((oparg & 1) == 0) { + if (specialize_attr_loadclassattr(owner, instr, name, descr, + tp_version, kind, false, + shared_keys_version)) { return 0; } } @@ -1252,14 +1287,28 @@ specialize_instance_load_attr(PyObject* owner, _Py_CODEUNIT* instr, PyObject* na } Py_UNREACHABLE(); try_instance: - if (specialize_dict_access(owner, instr, type, kind, name, type->tp_version_tag, + if (specialize_dict_access(owner, instr, type, kind, name, tp_version, LOAD_ATTR, LOAD_ATTR_INSTANCE_VALUE, LOAD_ATTR_WITH_HINT)) { return 0; } return -1; } -#endif // Py_GIL_DISABLED + +static int +specialize_instance_load_attr(PyObject* owner, _Py_CODEUNIT* instr, PyObject* name) +{ + // 0 is not a valid version + uint32_t shared_keys_version = 0; + bool shadow = instance_has_key(owner, name, &shared_keys_version); + PyObject *descr = NULL; + unsigned int tp_version = 0; + PyTypeObject *type = Py_TYPE(owner); + DescriptorClassification kind = analyze_descriptor_load(type, name, &descr, &tp_version); + int result = do_specialize_instance_load_attr(owner, instr, name, shadow, shared_keys_version, kind, descr, tp_version); + Py_XDECREF(descr); + return result; +} void _Py_Specialize_LoadAttr(_PyStackRef owner_st, _Py_CODEUNIT *instr, PyObject *name) @@ -1281,20 +1330,10 @@ _Py_Specialize_LoadAttr(_PyStackRef owner_st, _Py_CODEUNIT *instr, PyObject *nam fail = specialize_module_load_attr(owner, instr, name); } else if (PyType_Check(owner)) { - #ifdef Py_GIL_DISABLED - SPECIALIZATION_FAIL(LOAD_ATTR, SPEC_FAIL_EXPECTED_ERROR); - fail = true; - #else fail = specialize_class_load_attr(owner, instr, name); - #endif } else { - #ifdef Py_GIL_DISABLED - SPECIALIZATION_FAIL(LOAD_ATTR, SPEC_FAIL_EXPECTED_ERROR); - fail = true; - #else fail = specialize_instance_load_attr(owner, instr, name); - #endif } if (fail) { @@ -1402,8 +1441,6 @@ success: return; } -#ifndef Py_GIL_DISABLED - #ifdef Py_STATS static int load_attr_fail_kind(DescriptorClassification kind) @@ -1452,8 +1489,10 @@ specialize_class_load_attr(PyObject *owner, _Py_CODEUNIT *instr, SPECIALIZATION_FAIL(LOAD_ATTR, SPEC_FAIL_ATTR_METACLASS_OVERRIDDEN); return -1; } - PyObject *metadescriptor = _PyType_Lookup(Py_TYPE(cls), name); + unsigned int meta_version = 0; + PyObject *metadescriptor = _PyType_LookupRefAndVersion(Py_TYPE(cls), name, &meta_version); DescriptorClassification metakind = classify_descriptor(metadescriptor, false); + Py_XDECREF(metadescriptor); switch (metakind) { case METHOD: case NON_DESCRIPTOR: @@ -1468,38 +1507,52 @@ specialize_class_load_attr(PyObject *owner, _Py_CODEUNIT *instr, } PyObject *descr = NULL; DescriptorClassification kind = 0; - kind = analyze_descriptor_load(cls, name, &descr); - Py_XDECREF(descr); // turn strong ref into a borrowed ref - if (type_get_version(cls, LOAD_ATTR) == 0) { + unsigned int tp_version = 0; + kind = analyze_descriptor_load(cls, name, &descr, &tp_version); + if (tp_version == 0) { + SPECIALIZATION_FAIL(LOAD_ATTR, SPEC_FAIL_OUT_OF_VERSIONS); + Py_XDECREF(descr); return -1; } bool metaclass_check = false; if ((Py_TYPE(cls)->tp_flags & Py_TPFLAGS_IMMUTABLETYPE) == 0) { metaclass_check = true; - if (type_get_version(Py_TYPE(cls), LOAD_ATTR) == 0) { + if (meta_version == 0) { + SPECIALIZATION_FAIL(LOAD_ATTR, SPEC_FAIL_OUT_OF_VERSIONS); + Py_XDECREF(descr); return -1; } } switch (kind) { case METHOD: case NON_DESCRIPTOR: - write_u32(cache->type_version, cls->tp_version_tag); + #ifdef Py_GIL_DISABLED + if (!_PyObject_HasDeferredRefcount(descr)) { + SPECIALIZATION_FAIL(LOAD_ATTR, SPEC_FAIL_ATTR_DESCR_NOT_DEFERRED); + Py_XDECREF(descr); + return -1; + } + #endif + write_u32(cache->type_version, tp_version); write_obj(cache->descr, descr); if (metaclass_check) { - write_u32(cache->keys_version, Py_TYPE(cls)->tp_version_tag); + write_u32(cache->keys_version, meta_version); specialize(instr, LOAD_ATTR_CLASS_WITH_METACLASS_CHECK); } else { specialize(instr, LOAD_ATTR_CLASS); } + Py_XDECREF(descr); return 0; #ifdef Py_STATS case ABSENT: SPECIALIZATION_FAIL(LOAD_ATTR, SPEC_FAIL_EXPECTED_ERROR); + Py_XDECREF(descr); return -1; #endif default: SPECIALIZATION_FAIL(LOAD_ATTR, load_attr_fail_kind(kind)); + Py_XDECREF(descr); return -1; } } @@ -1508,29 +1561,41 @@ specialize_class_load_attr(PyObject *owner, _Py_CODEUNIT *instr, // can cause a significant drop in cache hits. A possible test is // python.exe -m test_typing test_re test_dis test_zlib. static int -specialize_attr_loadclassattr(PyObject *owner, _Py_CODEUNIT *instr, PyObject *name, -PyObject *descr, DescriptorClassification kind, bool is_method) +specialize_attr_loadclassattr(PyObject *owner, _Py_CODEUNIT *instr, + PyObject *name, PyObject *descr, + unsigned int tp_version, + DescriptorClassification kind, bool is_method, + uint32_t shared_keys_version) { _PyLoadMethodCache *cache = (_PyLoadMethodCache *)(instr + 1); PyTypeObject *owner_cls = Py_TYPE(owner); assert(descr != NULL); assert((is_method && kind == METHOD) || (!is_method && kind == NON_DESCRIPTOR)); - if (owner_cls->tp_flags & Py_TPFLAGS_INLINE_VALUES) { - PyDictKeysObject *keys = ((PyHeapTypeObject *)owner_cls)->ht_cached_keys; - assert(_PyDictKeys_StringLookup(keys, name) < 0); - uint32_t keys_version = _PyDictKeys_GetVersionForCurrentState( - _PyInterpreterState_GET(), keys); - if (keys_version == 0) { + + #ifdef Py_GIL_DISABLED + if (!_PyObject_HasDeferredRefcount(descr)) { + SPECIALIZATION_FAIL(LOAD_ATTR, SPEC_FAIL_ATTR_DESCR_NOT_DEFERRED); + return 0; + } + #endif + + unsigned long tp_flags = PyType_GetFlags(owner_cls); + if (tp_flags & Py_TPFLAGS_INLINE_VALUES) { + #ifndef Py_GIL_DISABLED + assert(_PyDictKeys_StringLookup( + ((PyHeapTypeObject *)owner_cls)->ht_cached_keys, name) < 0); + #endif + if (shared_keys_version == 0) { SPECIALIZATION_FAIL(LOAD_ATTR, SPEC_FAIL_OUT_OF_VERSIONS); return 0; } - write_u32(cache->keys_version, keys_version); + write_u32(cache->keys_version, shared_keys_version); specialize(instr, is_method ? LOAD_ATTR_METHOD_WITH_VALUES : LOAD_ATTR_NONDESCRIPTOR_WITH_VALUES); } else { Py_ssize_t dictoffset; - if (owner_cls->tp_flags & Py_TPFLAGS_MANAGED_DICT) { + if (tp_flags & Py_TPFLAGS_MANAGED_DICT) { dictoffset = MANAGED_DICT_OFFSET; } else { @@ -1576,13 +1641,11 @@ PyObject *descr, DescriptorClassification kind, bool is_method) * PyType_Modified usages in typeobject.c). The MCACHE has been * working since Python 2.6 and it's battle-tested. */ - write_u32(cache->type_version, owner_cls->tp_version_tag); + write_u32(cache->type_version, tp_version); write_obj(cache->descr, descr); return 1; } -#endif // Py_GIL_DISABLED - static void specialize_load_global_lock_held( @@ -1729,7 +1792,6 @@ function_kind(PyCodeObject *code) { return SIMPLE_FUNCTION; } -#ifndef Py_GIL_DISABLED /* Returning false indicates a failure. */ static bool function_check_args(PyObject *o, int expected_argcount, int opcode) @@ -1763,19 +1825,6 @@ function_get_version(PyObject *o, int opcode) return version; } -/* Returning 0 indicates a failure. */ -static uint32_t -type_get_version(PyTypeObject *t, int opcode) -{ - uint32_t version = t->tp_version_tag; - if (version == 0) { - SPECIALIZATION_FAIL(opcode, SPEC_FAIL_OUT_OF_VERSIONS); - return 0; - } - return version; -} -#endif // Py_GIL_DISABLED - void _Py_Specialize_BinarySubscr( _PyStackRef container_st, _PyStackRef sub_st, _Py_CODEUNIT *instr) |