https://github.com/python/cpython/commit/3f9118f1d17ae2ff0e25bd07fce9940ba13afdff commit: 3f9118f1d17ae2ff0e25bd07fce9940ba13afdff branch: main author: Pieter Eendebak <[email protected]> committer: eendebakpt <[email protected]> date: 2026-10-05T18:44:28Z summary:
gh-151157: Speed up PyObject_CallMethod via _PyObject_GetMethod (#151158) * Speed up PyObject_CallMethod via _PyObject_GetMethod PyObject_CallMethod (and _PyObject_CallMethod, PyEval_CallMethod, _PyObject_CallMethodId and the _SizeT variant) resolved the method with PyObject_GetAttr, which builds a temporary bound-method object on every call, then called it. Resolve the method with _PyObject_GetMethod instead (the same lookup the interpreter uses for obj.name(...)) and call it directly via _PyObject_VectorcallPrepend, skipping the bound-method allocation. Behaviour is unchanged: same attribute semantics, same "attribute of type ... is not callable" error, and the historical PyObject_CallMethod(o, m, "O", tuple) -> o.m(*tuple) unpacking. The shared helper callmethod() and _PyObject_CallMethodFormat() are no longer needed: their only caller (traceback.c) now uses PyObject_CallFunction, so both are removed. Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]> * Use _PyObject_GetMethodStackRef so method calls scale in free-threading Resolve the method in callmethod_va() via _PyObject_GetMethodStackRef() instead of _PyObject_GetMethod(). The StackRef variant returns the method as a deferred reference, avoiding the per-call atomic refcount on the shared method object that otherwise serializes threads in the free-threaded build. Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]> * rename to callmethod * review comments * review comments --------- Co-authored-by: Claude Opus 4.8 (1M context) <[email protected]> Co-authored-by: Kumar Aditya <[email protected]> Co-authored-by: Inada Naoki <[email protected]> files: M Include/internal/pycore_call.h M Objects/call.c M Python/traceback.c diff --git a/Include/internal/pycore_call.h b/Include/internal/pycore_call.h index 477b3c20e53f6e..824bb7f9499a9a 100644 --- a/Include/internal/pycore_call.h +++ b/Include/internal/pycore_call.h @@ -57,12 +57,6 @@ extern PyObject* _PyObject_Call( PyObject *args, PyObject *kwargs); -extern PyObject * _PyObject_CallMethodFormat( - PyThreadState *tstate, - PyObject *callable, - const char *format, - ...); - // Export for 'array' shared extension PyAPI_FUNC(PyObject*) _PyObject_CallMethod( PyObject *obj, diff --git a/Objects/call.c b/Objects/call.c index 9718642473103c..a79f167aacc8c0 100644 --- a/Objects/call.c +++ b/Objects/call.c @@ -612,18 +612,70 @@ _PyObject_CallFunction_SizeT(PyObject *callable, const char *format, ...) } -static PyObject* -callmethod(PyThreadState *tstate, PyObject* callable, const char *format, va_list va) +static PyObject * +callmethod(PyThreadState *tstate, PyObject *obj, PyObject *name, + const char *format, va_list va) { - assert(callable != NULL); + PyObject *result = NULL; + + _PyCStackRef self, method; + _PyThreadState_PushCStackRef(tstate, &self); + _PyThreadState_PushCStackRef(tstate, &method); + self.ref = PyStackRef_FromPyObjectBorrow(obj); + + int res = _PyObject_GetMethodStackRef(tstate, &self.ref, name, &method.ref); + if (res < 0) { + goto exit; + } + + PyObject *callable = PyStackRef_AsPyObjectBorrow(method.ref); + PyObject *self_obj = PyStackRef_AsPyObjectBorrow(self.ref); + if (!PyCallable_Check(callable)) { _PyErr_Format(tstate, PyExc_TypeError, "attribute of type '%.200s' is not callable", Py_TYPE(callable)->tp_name); - return NULL; + goto exit; } - return _PyObject_CallFunctionVa(tstate, callable, format, va); + /* Build the positional arguments from the format string. */ + PyObject *small_stack[_PY_FASTCALL_SMALL_STACK]; + Py_ssize_t nargs = 0; + PyObject **built = NULL; + if (format != NULL && *format != '\0') { + built = _Py_VaBuildStack(small_stack, _PY_FASTCALL_SMALL_STACK, + format, va, &nargs); + if (built == NULL) { + goto exit; + } + } + + /* Backward compat: a single tuple from "O" is unpacked. */ + PyObject *const *args = built; + Py_ssize_t n = nargs; + if (nargs == 1 && PyTuple_Check(built[0])) { + args = _PyTuple_ITEMS(built[0]); + n = PyTuple_GET_SIZE(built[0]); + } + + if (self_obj != NULL) { + result = _PyObject_VectorcallPrepend(tstate, callable, self_obj, args, n, NULL); + } + else { + result = _PyObject_VectorcallTstate(tstate, callable, args, n, NULL); + } + + for (Py_ssize_t i = 0; i < nargs; i++) { + Py_DECREF(built[i]); + } + if (built != small_stack) { + PyMem_Free(built); + } + +exit: + _PyThreadState_PopCStackRef(tstate, &method); + _PyThreadState_PopCStackRef(tstate, &self); + return result; } PyObject * @@ -635,17 +687,17 @@ PyObject_CallMethod(PyObject *obj, const char *name, const char *format, ...) return null_error(tstate); } - PyObject *callable = PyObject_GetAttrString(obj, name); - if (callable == NULL) { + PyObject *name_obj = PyUnicode_FromString(name); + if (name_obj == NULL) { return NULL; } va_list va; va_start(va, format); - PyObject *retval = callmethod(tstate, callable, format, va); + PyObject *retval = callmethod(tstate, obj, name_obj, format, va); va_end(va); - Py_DECREF(callable); + Py_DECREF(name_obj); return retval; } @@ -660,17 +712,17 @@ PyEval_CallMethod(PyObject *obj, const char *name, const char *format, ...) return null_error(tstate); } - PyObject *callable = PyObject_GetAttrString(obj, name); - if (callable == NULL) { + PyObject *name_obj = PyUnicode_FromString(name); + if (name_obj == NULL) { return NULL; } va_list va; va_start(va, format); - PyObject *retval = callmethod(tstate, callable, format, va); + PyObject *retval = callmethod(tstate, obj, name_obj, format, va); va_end(va); - Py_DECREF(callable); + Py_DECREF(name_obj); return retval; } @@ -684,17 +736,11 @@ _PyObject_CallMethod(PyObject *obj, PyObject *name, return null_error(tstate); } - PyObject *callable = PyObject_GetAttr(obj, name); - if (callable == NULL) { - return NULL; - } - va_list va; va_start(va, format); - PyObject *retval = callmethod(tstate, callable, format, va); + PyObject *retval = callmethod(tstate, obj, name, format, va); va_end(va); - Py_DECREF(callable); return retval; } @@ -710,30 +756,17 @@ _PyObject_CallMethodId(PyObject *obj, _Py_Identifier *name, _Py_COMP_DIAG_PUSH _Py_COMP_DIAG_IGNORE_DEPR_DECLS - PyObject *callable = _PyObject_GetAttrId(obj, name); + PyObject *name_obj = _PyUnicode_FromId(name); /* borrowed */ _Py_COMP_DIAG_POP - if (callable == NULL) { + if (name_obj == NULL) { return NULL; } va_list va; va_start(va, format); - PyObject *retval = callmethod(tstate, callable, format, va); + PyObject *retval = callmethod(tstate, obj, name_obj, format, va); va_end(va); - Py_DECREF(callable); - return retval; -} - - -PyObject * _PyObject_CallMethodFormat(PyThreadState *tstate, PyObject *callable, - const char *format, ...) -{ - assert(callable != NULL); - va_list va; - va_start(va, format); - PyObject *retval = callmethod(tstate, callable, format, va); - va_end(va); return retval; } @@ -749,17 +782,17 @@ _PyObject_CallMethod_SizeT(PyObject *obj, const char *name, return null_error(tstate); } - PyObject *callable = PyObject_GetAttrString(obj, name); - if (callable == NULL) { + PyObject *name_obj = PyUnicode_FromString(name); + if (name_obj == NULL) { return NULL; } va_list va; va_start(va, format); - PyObject *retval = callmethod(tstate, callable, format, va); + PyObject *retval = callmethod(tstate, obj, name_obj, format, va); va_end(va); - Py_DECREF(callable); + Py_DECREF(name_obj); return retval; } diff --git a/Python/traceback.c b/Python/traceback.c index ca94a735db5b8f..7dc72d48274567 100644 --- a/Python/traceback.c +++ b/Python/traceback.c @@ -2,7 +2,7 @@ /* Traceback implementation */ #include "Python.h" -#include "pycore_call.h" // _PyObject_CallMethodFormat() +#include "pycore_call.h" // _PyObject_CallMethod() #include "pycore_fileutils.h" // _Py_BEGIN_SUPPRESS_IPH #include "pycore_frame.h" // PyFrameObject #include "pycore_interp.h" // PyInterpreterState.gc @@ -397,7 +397,6 @@ _Py_FindSourceFile(PyObject *filename, char* namebuf, size_t namelen, PyObject * tail++; taillen = strlen(tail); - PyThreadState *tstate = _PyThreadState_GET(); if (PySys_GetOptionalAttr(&_Py_ID(path), &syspath) < 0) { PyErr_Clear(); goto error; @@ -437,7 +436,7 @@ _Py_FindSourceFile(PyObject *filename, char* namebuf, size_t namelen, PyObject * namebuf[len++] = SEP; strcpy(namebuf+len, tail); - binary = _PyObject_CallMethodFormat(tstate, open, "ss", namebuf, "rb"); + binary = PyObject_CallFunction(open, "ss", namebuf, "rb"); if (binary != NULL) { result = binary; goto finally; _______________________________________________ Python-checkins mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3//lists/python-checkins.python.org Member address: [email protected]
