https://github.com/python/cpython/commit/0706bab1c0985761cdbc07ab448f98c7172... commit: 0706bab1c0985761cdbc07ab448f98c717276b36 branch: main author: Abhijeet <abhijeetsharma2002@gmail.com> committer: kumaraditya303 <kumaraditya@python.org> date: 2025-01-03T13:50:56+05:30 summary: gh-128133: use relaxed atomics for hash of bytes (#128412) files: M Objects/bytesobject.c diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c index 533089d25cd73a..90e8a9af88b4a3 100644 --- a/Objects/bytesobject.c +++ b/Objects/bytesobject.c @@ -51,6 +51,33 @@ static inline PyObject* bytes_get_empty(void) } +static inline void +set_ob_shash(PyBytesObject *a, Py_hash_t hash) +{ +_Py_COMP_DIAG_PUSH +_Py_COMP_DIAG_IGNORE_DEPR_DECLS +#ifdef Py_GIL_DISABLED + _Py_atomic_store_ssize_relaxed(&a->ob_shash, hash); +#else + a->ob_shash = hash; +#endif +_Py_COMP_DIAG_POP +} + +static inline Py_hash_t +get_ob_shash(PyBytesObject *a) +{ +_Py_COMP_DIAG_PUSH +_Py_COMP_DIAG_IGNORE_DEPR_DECLS +#ifdef Py_GIL_DISABLED + return _Py_atomic_load_ssize_relaxed(&a->ob_shash); +#else + return a->ob_shash; +#endif +_Py_COMP_DIAG_POP +} + + /* For PyBytes_FromString(), the parameter 'str' points to a null-terminated string containing exactly 'size' bytes. @@ -98,10 +125,7 @@ _PyBytes_FromSize(Py_ssize_t size, int use_calloc) return PyErr_NoMemory(); } _PyObject_InitVar((PyVarObject*)op, &PyBytes_Type, size); -_Py_COMP_DIAG_PUSH -_Py_COMP_DIAG_IGNORE_DEPR_DECLS - op->ob_shash = -1; -_Py_COMP_DIAG_POP + set_ob_shash(op, -1); if (!use_calloc) { op->ob_sval[size] = '\0'; } @@ -165,10 +189,7 @@ PyBytes_FromString(const char *str) return PyErr_NoMemory(); } _PyObject_InitVar((PyVarObject*)op, &PyBytes_Type, size); -_Py_COMP_DIAG_PUSH -_Py_COMP_DIAG_IGNORE_DEPR_DECLS - op->ob_shash = -1; -_Py_COMP_DIAG_POP + set_ob_shash(op, -1); memcpy(op->ob_sval, str, size+1); return (PyObject *) op; } @@ -1485,10 +1506,7 @@ bytes_repeat(PyObject *self, Py_ssize_t n) return PyErr_NoMemory(); } _PyObject_InitVar((PyVarObject*)op, &PyBytes_Type, size); -_Py_COMP_DIAG_PUSH -_Py_COMP_DIAG_IGNORE_DEPR_DECLS - op->ob_shash = -1; -_Py_COMP_DIAG_POP + set_ob_shash(op, -1); op->ob_sval[size] = '\0'; _PyBytes_Repeat(op->ob_sval, size, a->ob_sval, Py_SIZE(a)); @@ -1597,14 +1615,13 @@ static Py_hash_t bytes_hash(PyObject *self) { PyBytesObject *a = _PyBytes_CAST(self); -_Py_COMP_DIAG_PUSH -_Py_COMP_DIAG_IGNORE_DEPR_DECLS - if (a->ob_shash == -1) { + Py_hash_t hash = get_ob_shash(a); + if (hash == -1) { /* Can't fail */ - a->ob_shash = Py_HashBuffer(a->ob_sval, Py_SIZE(a)); + hash = Py_HashBuffer(a->ob_sval, Py_SIZE(a)); + set_ob_shash(a, hash); } - return a->ob_shash; -_Py_COMP_DIAG_POP + return hash; } static PyObject* @@ -3004,10 +3021,7 @@ bytes_alloc(PyTypeObject *self, Py_ssize_t nitems) if (obj == NULL) { return NULL; } -_Py_COMP_DIAG_PUSH -_Py_COMP_DIAG_IGNORE_DEPR_DECLS - obj->ob_shash = -1; -_Py_COMP_DIAG_POP + set_ob_shash(obj, -1); return (PyObject*)obj; } @@ -3024,11 +3038,8 @@ bytes_subtype_new(PyTypeObject *type, PyObject *tmp) if (pnew != NULL) { memcpy(PyBytes_AS_STRING(pnew), PyBytes_AS_STRING(tmp), n+1); -_Py_COMP_DIAG_PUSH -_Py_COMP_DIAG_IGNORE_DEPR_DECLS - ((PyBytesObject *)pnew)->ob_shash = - ((PyBytesObject *)tmp)->ob_shash; -_Py_COMP_DIAG_POP + set_ob_shash((PyBytesObject *)pnew, + get_ob_shash((PyBytesObject *)tmp)); } return pnew; } @@ -3221,10 +3232,7 @@ _PyBytes_Resize(PyObject **pv, Py_ssize_t newsize) sv = (PyBytesObject *) *pv; Py_SET_SIZE(sv, newsize); sv->ob_sval[newsize] = '\0'; -_Py_COMP_DIAG_PUSH -_Py_COMP_DIAG_IGNORE_DEPR_DECLS - sv->ob_shash = -1; /* invalidate cached hash value */ -_Py_COMP_DIAG_POP + set_ob_shash(sv, -1); /* invalidate cached hash value */ return 0; }