diff options
Diffstat (limited to 'Python/context.c')
| -rw-r--r-- | Python/context.c | 1321 |
1 files changed, 0 insertions, 1321 deletions
diff --git a/Python/context.c b/Python/context.c deleted file mode 100644 index e0338c9..0000000 --- a/Python/context.c +++ /dev/null @@ -1,1321 +0,0 @@ -#include "Python.h" - -#include "pycore_context.h" -#include "pycore_hamt.h" -#include "pycore_object.h" -#include "pycore_pyerrors.h" -#include "pycore_pystate.h" -#include "structmember.h" - - -#define CONTEXT_FREELIST_MAXLEN 255 -static PyContext *ctx_freelist = NULL; -static int ctx_freelist_len = 0; - - -#include "clinic/context.c.h" -/*[clinic input] -module _contextvars -[clinic start generated code]*/ -/*[clinic end generated code: output=da39a3ee5e6b4b0d input=a0955718c8b8cea6]*/ - - -#define ENSURE_Context(o, err_ret) \ - if (!PyContext_CheckExact(o)) { \ - PyErr_SetString(PyExc_TypeError, \ - "an instance of Context was expected"); \ - return err_ret; \ - } - -#define ENSURE_ContextVar(o, err_ret) \ - if (!PyContextVar_CheckExact(o)) { \ - PyErr_SetString(PyExc_TypeError, \ - "an instance of ContextVar was expected"); \ - return err_ret; \ - } - -#define ENSURE_ContextToken(o, err_ret) \ - if (!PyContextToken_CheckExact(o)) { \ - PyErr_SetString(PyExc_TypeError, \ - "an instance of Token was expected"); \ - return err_ret; \ - } - - -/////////////////////////// Context API - - -static PyContext * -context_new_empty(void); - -static PyContext * -context_new_from_vars(PyHamtObject *vars); - -static inline PyContext * -context_get(void); - -static PyContextToken * -token_new(PyContext *ctx, PyContextVar *var, PyObject *val); - -static PyContextVar * -contextvar_new(PyObject *name, PyObject *def); - -static int -contextvar_set(PyContextVar *var, PyObject *val); - -static int -contextvar_del(PyContextVar *var); - - -PyObject * -_PyContext_NewHamtForTests(void) -{ - return (PyObject *)_PyHamt_New(); -} - - -PyObject * -PyContext_New(void) -{ - return (PyObject *)context_new_empty(); -} - - -PyObject * -PyContext_Copy(PyObject * octx) -{ - ENSURE_Context(octx, NULL) - PyContext *ctx = (PyContext *)octx; - return (PyObject *)context_new_from_vars(ctx->ctx_vars); -} - - -PyObject * -PyContext_CopyCurrent(void) -{ - PyContext *ctx = context_get(); - if (ctx == NULL) { - return NULL; - } - - return (PyObject *)context_new_from_vars(ctx->ctx_vars); -} - - -static int -_PyContext_Enter(PyThreadState *ts, PyObject *octx) -{ - ENSURE_Context(octx, -1) - PyContext *ctx = (PyContext *)octx; - - if (ctx->ctx_entered) { - _PyErr_Format(ts, PyExc_RuntimeError, - "cannot enter context: %R is already entered", ctx); - return -1; - } - - ctx->ctx_prev = (PyContext *)ts->context; /* borrow */ - ctx->ctx_entered = 1; - - Py_INCREF(ctx); - ts->context = (PyObject *)ctx; - ts->context_ver++; - - return 0; -} - - -int -PyContext_Enter(PyObject *octx) -{ - PyThreadState *ts = _PyThreadState_GET(); - assert(ts != NULL); - return _PyContext_Enter(ts, octx); -} - - -static int -_PyContext_Exit(PyThreadState *ts, PyObject *octx) -{ - ENSURE_Context(octx, -1) - PyContext *ctx = (PyContext *)octx; - - if (!ctx->ctx_entered) { - PyErr_Format(PyExc_RuntimeError, - "cannot exit context: %R has not been entered", ctx); - return -1; - } - - if (ts->context != (PyObject *)ctx) { - /* Can only happen if someone misuses the C API */ - PyErr_SetString(PyExc_RuntimeError, - "cannot exit context: thread state references " - "a different context object"); - return -1; - } - - Py_SETREF(ts->context, (PyObject *)ctx->ctx_prev); - ts->context_ver++; - - ctx->ctx_prev = NULL; - ctx->ctx_entered = 0; - - return 0; -} - -int -PyContext_Exit(PyObject *octx) -{ - PyThreadState *ts = _PyThreadState_GET(); - assert(ts != NULL); - return _PyContext_Exit(ts, octx); -} - - -PyObject * -PyContextVar_New(const char *name, PyObject *def) -{ - PyObject *pyname = PyUnicode_FromString(name); - if (pyname == NULL) { - return NULL; - } - PyContextVar *var = contextvar_new(pyname, def); - Py_DECREF(pyname); - return (PyObject *)var; -} - - -int -PyContextVar_Get(PyObject *ovar, PyObject *def, PyObject **val) -{ - ENSURE_ContextVar(ovar, -1) - PyContextVar *var = (PyContextVar *)ovar; - - PyThreadState *ts = _PyThreadState_GET(); - assert(ts != NULL); - if (ts->context == NULL) { - goto not_found; - } - - if (var->var_cached != NULL && - var->var_cached_tsid == ts->id && - var->var_cached_tsver == ts->context_ver) - { - *val = var->var_cached; - goto found; - } - - assert(PyContext_CheckExact(ts->context)); - PyHamtObject *vars = ((PyContext *)ts->context)->ctx_vars; - - PyObject *found = NULL; - int res = _PyHamt_Find(vars, (PyObject*)var, &found); - if (res < 0) { - goto error; - } - if (res == 1) { - assert(found != NULL); - var->var_cached = found; /* borrow */ - var->var_cached_tsid = ts->id; - var->var_cached_tsver = ts->context_ver; - - *val = found; - goto found; - } - -not_found: - if (def == NULL) { - if (var->var_default != NULL) { - *val = var->var_default; - goto found; - } - - *val = NULL; - goto found; - } - else { - *val = def; - goto found; - } - -found: - Py_XINCREF(*val); - return 0; - -error: - *val = NULL; - return -1; -} - - -PyObject * -PyContextVar_Set(PyObject *ovar, PyObject *val) -{ - ENSURE_ContextVar(ovar, NULL) - PyContextVar *var = (PyContextVar *)ovar; - - if (!PyContextVar_CheckExact(var)) { - PyErr_SetString( - PyExc_TypeError, "an instance of ContextVar was expected"); - return NULL; - } - - PyContext *ctx = context_get(); - if (ctx == NULL) { - return NULL; - } - - PyObject *old_val = NULL; - int found = _PyHamt_Find(ctx->ctx_vars, (PyObject *)var, &old_val); - if (found < 0) { - return NULL; - } - - Py_XINCREF(old_val); - PyContextToken *tok = token_new(ctx, var, old_val); - Py_XDECREF(old_val); - - if (contextvar_set(var, val)) { - Py_DECREF(tok); - return NULL; - } - - return (PyObject *)tok; -} - - -int -PyContextVar_Reset(PyObject *ovar, PyObject *otok) -{ - ENSURE_ContextVar(ovar, -1) - ENSURE_ContextToken(otok, -1) - PyContextVar *var = (PyContextVar *)ovar; - PyContextToken *tok = (PyContextToken *)otok; - - if (tok->tok_used) { - PyErr_Format(PyExc_RuntimeError, - "%R has already been used once", tok); - return -1; - } - - if (var != tok->tok_var) { - PyErr_Format(PyExc_ValueError, - "%R was created by a different ContextVar", tok); - return -1; - } - - PyContext *ctx = context_get(); - if (ctx != tok->tok_ctx) { - PyErr_Format(PyExc_ValueError, - "%R was created in a different Context", tok); - return -1; - } - - tok->tok_used = 1; - - if (tok->tok_oldval == NULL) { - return contextvar_del(var); - } - else { - return contextvar_set(var, tok->tok_oldval); - } -} - - -/////////////////////////// PyContext - -/*[clinic input] -class _contextvars.Context "PyContext *" "&PyContext_Type" -[clinic start generated code]*/ -/*[clinic end generated code: output=da39a3ee5e6b4b0d input=bdf87f8e0cb580e8]*/ - - -static inline PyContext * -_context_alloc(void) -{ - PyContext *ctx; - if (ctx_freelist_len) { - ctx_freelist_len--; - ctx = ctx_freelist; - ctx_freelist = (PyContext *)ctx->ctx_weakreflist; - ctx->ctx_weakreflist = NULL; - _Py_NewReference((PyObject *)ctx); - } - else { - ctx = PyObject_GC_New(PyContext, &PyContext_Type); - if (ctx == NULL) { - return NULL; - } - } - - ctx->ctx_vars = NULL; - ctx->ctx_prev = NULL; - ctx->ctx_entered = 0; - ctx->ctx_weakreflist = NULL; - - return ctx; -} - - -static PyContext * -context_new_empty(void) -{ - PyContext *ctx = _context_alloc(); - if (ctx == NULL) { - return NULL; - } - - ctx->ctx_vars = _PyHamt_New(); - if (ctx->ctx_vars == NULL) { - Py_DECREF(ctx); - return NULL; - } - - _PyObject_GC_TRACK(ctx); - return ctx; -} - - -static PyContext * -context_new_from_vars(PyHamtObject *vars) -{ - PyContext *ctx = _context_alloc(); - if (ctx == NULL) { - return NULL; - } - - Py_INCREF(vars); - ctx->ctx_vars = vars; - - _PyObject_GC_TRACK(ctx); - return ctx; -} - - -static inline PyContext * -context_get(void) -{ - PyThreadState *ts = _PyThreadState_GET(); - assert(ts != NULL); - PyContext *current_ctx = (PyContext *)ts->context; - if (current_ctx == NULL) { - current_ctx = context_new_empty(); - if (current_ctx == NULL) { - return NULL; - } - ts->context = (PyObject *)current_ctx; - } - return current_ctx; -} - -static int -context_check_key_type(PyObject *key) -{ - if (!PyContextVar_CheckExact(key)) { - // abort(); - PyErr_Format(PyExc_TypeError, - "a ContextVar key was expected, got %R", key); - return -1; - } - return 0; -} - -static PyObject * -context_tp_new(PyTypeObject *type, PyObject *args, PyObject *kwds) -{ - if (PyTuple_Size(args) || (kwds != NULL && PyDict_Size(kwds))) { - PyErr_SetString( - PyExc_TypeError, "Context() does not accept any arguments"); - return NULL; - } - return PyContext_New(); -} - -static int -context_tp_clear(PyContext *self) -{ - Py_CLEAR(self->ctx_prev); - Py_CLEAR(self->ctx_vars); - return 0; -} - -static int -context_tp_traverse(PyContext *self, visitproc visit, void *arg) -{ - Py_VISIT(self->ctx_prev); - Py_VISIT(self->ctx_vars); - return 0; -} - -static void -context_tp_dealloc(PyContext *self) -{ - _PyObject_GC_UNTRACK(self); - - if (self->ctx_weakreflist != NULL) { - PyObject_ClearWeakRefs((PyObject*)self); - } - (void)context_tp_clear(self); - - if (ctx_freelist_len < CONTEXT_FREELIST_MAXLEN) { - ctx_freelist_len++; - self->ctx_weakreflist = (PyObject *)ctx_freelist; - ctx_freelist = self; - } - else { - Py_TYPE(self)->tp_free(self); - } -} - -static PyObject * -context_tp_iter(PyContext *self) -{ - return _PyHamt_NewIterKeys(self->ctx_vars); -} - -static PyObject * -context_tp_richcompare(PyObject *v, PyObject *w, int op) -{ - if (!PyContext_CheckExact(v) || !PyContext_CheckExact(w) || - (op != Py_EQ && op != Py_NE)) - { - Py_RETURN_NOTIMPLEMENTED; - } - - int res = _PyHamt_Eq( - ((PyContext *)v)->ctx_vars, ((PyContext *)w)->ctx_vars); - if (res < 0) { - return NULL; - } - - if (op == Py_NE) { - res = !res; - } - - if (res) { - Py_RETURN_TRUE; - } - else { - Py_RETURN_FALSE; - } -} - -static Py_ssize_t -context_tp_len(PyContext *self) -{ - return _PyHamt_Len(self->ctx_vars); -} - -static PyObject * -context_tp_subscript(PyContext *self, PyObject *key) -{ - if (context_check_key_type(key)) { - return NULL; - } - PyObject *val = NULL; - int found = _PyHamt_Find(self->ctx_vars, key, &val); - if (found < 0) { - return NULL; - } - if (found == 0) { - PyErr_SetObject(PyExc_KeyError, key); - return NULL; - } - Py_INCREF(val); - return val; -} - -static int -context_tp_contains(PyContext *self, PyObject *key) -{ - if (context_check_key_type(key)) { - return -1; - } - PyObject *val = NULL; - return _PyHamt_Find(self->ctx_vars, key, &val); -} - - -/*[clinic input] -_contextvars.Context.get - key: object - default: object = None - / - -Return the value for `key` if `key` has the value in the context object. - -If `key` does not exist, return `default`. If `default` is not given, -return None. -[clinic start generated code]*/ - -static PyObject * -_contextvars_Context_get_impl(PyContext *self, PyObject *key, - PyObject *default_value) -/*[clinic end generated code: output=0c54aa7664268189 input=c8eeb81505023995]*/ -{ - if (context_check_key_type(key)) { - return NULL; - } - - PyObject *val = NULL; - int found = _PyHamt_Find(self->ctx_vars, key, &val); - if (found < 0) { - return NULL; - } - if (found == 0) { - Py_INCREF(default_value); - return default_value; - } - Py_INCREF(val); - return val; -} - - -/*[clinic input] -_contextvars.Context.items - -Return all variables and their values in the context object. - -The result is returned as a list of 2-tuples (variable, value). -[clinic start generated code]*/ - -static PyObject * -_contextvars_Context_items_impl(PyContext *self) -/*[clinic end generated code: output=fa1655c8a08502af input=00db64ae379f9f42]*/ -{ - return _PyHamt_NewIterItems(self->ctx_vars); -} - - -/*[clinic input] -_contextvars.Context.keys - -Return a list of all variables in the context object. -[clinic start generated code]*/ - -static PyObject * -_contextvars_Context_keys_impl(PyContext *self) -/*[clinic end generated code: output=177227c6b63ec0e2 input=114b53aebca3449c]*/ -{ - return _PyHamt_NewIterKeys(self->ctx_vars); -} - - -/*[clinic input] -_contextvars.Context.values - -Return a list of all variables' values in the context object. -[clinic start generated code]*/ - -static PyObject * -_contextvars_Context_values_impl(PyContext *self) -/*[clinic end generated code: output=d286dabfc8db6dde input=ce8075d04a6ea526]*/ -{ - return _PyHamt_NewIterValues(self->ctx_vars); -} - - -/*[clinic input] -_contextvars.Context.copy - -Return a shallow copy of the context object. -[clinic start generated code]*/ - -static PyObject * -_contextvars_Context_copy_impl(PyContext *self) -/*[clinic end generated code: output=30ba8896c4707a15 input=ebafdbdd9c72d592]*/ -{ - return (PyObject *)context_new_from_vars(self->ctx_vars); -} - - -static PyObject * -context_run(PyContext *self, PyObject *const *args, - Py_ssize_t nargs, PyObject *kwnames) -{ - PyThreadState *ts = _PyThreadState_GET(); - - if (nargs < 1) { - _PyErr_SetString(ts, PyExc_TypeError, - "run() missing 1 required positional argument"); - return NULL; - } - - if (_PyContext_Enter(ts, (PyObject *)self)) { - return NULL; - } - - PyObject *call_result = _PyObject_VectorcallTstate( - ts, args[0], args + 1, nargs - 1, kwnames); - - if (_PyContext_Exit(ts, (PyObject *)self)) { - return NULL; - } - - return call_result; -} - - -static PyMethodDef PyContext_methods[] = { - _CONTEXTVARS_CONTEXT_GET_METHODDEF - _CONTEXTVARS_CONTEXT_ITEMS_METHODDEF - _CONTEXTVARS_CONTEXT_KEYS_METHODDEF - _CONTEXTVARS_CONTEXT_VALUES_METHODDEF - _CONTEXTVARS_CONTEXT_COPY_METHODDEF - {"run", (PyCFunction)(void(*)(void))context_run, METH_FASTCALL | METH_KEYWORDS, NULL}, - {NULL, NULL} -}; - -static PySequenceMethods PyContext_as_sequence = { - 0, /* sq_length */ - 0, /* sq_concat */ - 0, /* sq_repeat */ - 0, /* sq_item */ - 0, /* sq_slice */ - 0, /* sq_ass_item */ - 0, /* sq_ass_slice */ - (objobjproc)context_tp_contains, /* sq_contains */ - 0, /* sq_inplace_concat */ - 0, /* sq_inplace_repeat */ -}; - -static PyMappingMethods PyContext_as_mapping = { - (lenfunc)context_tp_len, /* mp_length */ - (binaryfunc)context_tp_subscript, /* mp_subscript */ -}; - -PyTypeObject PyContext_Type = { - PyVarObject_HEAD_INIT(&PyType_Type, 0) - "Context", - sizeof(PyContext), - .tp_methods = PyContext_methods, - .tp_as_mapping = &PyContext_as_mapping, - .tp_as_sequence = &PyContext_as_sequence, - .tp_iter = (getiterfunc)context_tp_iter, - .tp_dealloc = (destructor)context_tp_dealloc, - .tp_getattro = PyObject_GenericGetAttr, - .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC, - .tp_richcompare = context_tp_richcompare, - .tp_traverse = (traverseproc)context_tp_traverse, - .tp_clear = (inquiry)context_tp_clear, - .tp_new = context_tp_new, - .tp_weaklistoffset = offsetof(PyContext, ctx_weakreflist), - .tp_hash = PyObject_HashNotImplemented, -}; - - -/////////////////////////// ContextVar - - -static int -contextvar_set(PyContextVar *var, PyObject *val) -{ - var->var_cached = NULL; - PyThreadState *ts = PyThreadState_Get(); - - PyContext *ctx = context_get(); - if (ctx == NULL) { - return -1; - } - - PyHamtObject *new_vars = _PyHamt_Assoc( - ctx->ctx_vars, (PyObject *)var, val); - if (new_vars == NULL) { - return -1; - } - - Py_SETREF(ctx->ctx_vars, new_vars); - - var->var_cached = val; /* borrow */ - var->var_cached_tsid = ts->id; - var->var_cached_tsver = ts->context_ver; - return 0; -} - -static int -contextvar_del(PyContextVar *var) -{ - var->var_cached = NULL; - - PyContext *ctx = context_get(); - if (ctx == NULL) { - return -1; - } - - PyHamtObject *vars = ctx->ctx_vars; - PyHamtObject *new_vars = _PyHamt_Without(vars, (PyObject *)var); - if (new_vars == NULL) { - return -1; - } - - if (vars == new_vars) { - Py_DECREF(new_vars); - PyErr_SetObject(PyExc_LookupError, (PyObject *)var); - return -1; - } - - Py_SETREF(ctx->ctx_vars, new_vars); - return 0; -} - -static Py_hash_t -contextvar_generate_hash(void *addr, PyObject *name) -{ - /* Take hash of `name` and XOR it with the object's addr. - - The structure of the tree is encoded in objects' hashes, which - means that sufficiently similar hashes would result in tall trees - with many Collision nodes. Which would, in turn, result in slower - get and set operations. - - The XORing helps to ensure that: - - (1) sequentially allocated ContextVar objects have - different hashes; - - (2) context variables with equal names have - different hashes. - */ - - Py_hash_t name_hash = PyObject_Hash(name); - if (name_hash == -1) { - return -1; - } - - Py_hash_t res = _Py_HashPointer(addr) ^ name_hash; - return res == -1 ? -2 : res; -} - -static PyContextVar * -contextvar_new(PyObject *name, PyObject *def) -{ - if (!PyUnicode_Check(name)) { - PyErr_SetString(PyExc_TypeError, - "context variable name must be a str"); - return NULL; - } - - PyContextVar *var = PyObject_GC_New(PyContextVar, &PyContextVar_Type); - if (var == NULL) { - return NULL; - } - - var->var_hash = contextvar_generate_hash(var, name); - if (var->var_hash == -1) { - Py_DECREF(var); - return NULL; - } - - Py_INCREF(name); - var->var_name = name; - - Py_XINCREF(def); - var->var_default = def; - - var->var_cached = NULL; - var->var_cached_tsid = 0; - var->var_cached_tsver = 0; - - if (_PyObject_GC_MAY_BE_TRACKED(name) || - (def != NULL && _PyObject_GC_MAY_BE_TRACKED(def))) - { - PyObject_GC_Track(var); - } - return var; -} - - -/*[clinic input] -class _contextvars.ContextVar "PyContextVar *" "&PyContextVar_Type" -[clinic start generated code]*/ -/*[clinic end generated code: output=da39a3ee5e6b4b0d input=445da935fa8883c3]*/ - - -static PyObject * -contextvar_tp_new(PyTypeObject *type, PyObject *args, PyObject *kwds) -{ - static char *kwlist[] = {"", "default", NULL}; - PyObject *name; - PyObject *def = NULL; - - if (!PyArg_ParseTupleAndKeywords( - args, kwds, "O|$O:ContextVar", kwlist, &name, &def)) - { - return NULL; - } - - return (PyObject *)contextvar_new(name, def); -} - -static int -contextvar_tp_clear(PyContextVar *self) -{ - Py_CLEAR(self->var_name); - Py_CLEAR(self->var_default); - self->var_cached = NULL; - self->var_cached_tsid = 0; - self->var_cached_tsver = 0; - return 0; -} - -static int -contextvar_tp_traverse(PyContextVar *self, visitproc visit, void *arg) -{ - Py_VISIT(self->var_name); - Py_VISIT(self->var_default); - return 0; -} - -static void -contextvar_tp_dealloc(PyContextVar *self) -{ - PyObject_GC_UnTrack(self); - (void)contextvar_tp_clear(self); - Py_TYPE(self)->tp_free(self); -} - -static Py_hash_t -contextvar_tp_hash(PyContextVar *self) -{ - return self->var_hash; -} - -static PyObject * -contextvar_tp_repr(PyContextVar *self) -{ - _PyUnicodeWriter writer; - - _PyUnicodeWriter_Init(&writer); - - if (_PyUnicodeWriter_WriteASCIIString( - &writer, "<ContextVar name=", 17) < 0) - { - goto error; - } - - PyObject *name = PyObject_Repr(self->var_name); - if (name == NULL) { - goto error; - } - if (_PyUnicodeWriter_WriteStr(&writer, name) < 0) { - Py_DECREF(name); - goto error; - } - Py_DECREF(name); - - if (self->var_default != NULL) { - if (_PyUnicodeWriter_WriteASCIIString(&writer, " default=", 9) < 0) { - goto error; - } - - PyObject *def = PyObject_Repr(self->var_default); - if (def == NULL) { - goto error; - } - if (_PyUnicodeWriter_WriteStr(&writer, def) < 0) { - Py_DECREF(def); - goto error; - } - Py_DECREF(def); - } - - PyObject *addr = PyUnicode_FromFormat(" at %p>", self); - if (addr == NULL) { - goto error; - } - if (_PyUnicodeWriter_WriteStr(&writer, addr) < 0) { - Py_DECREF(addr); - goto error; - } - Py_DECREF(addr); - - return _PyUnicodeWriter_Finish(&writer); - -error: - _PyUnicodeWriter_Dealloc(&writer); - return NULL; -} - - -/*[clinic input] -_contextvars.ContextVar.get - default: object = NULL - / - -Return a value for the context variable for the current context. - -If there is no value for the variable in the current context, the method will: - * return the value of the default argument of the method, if provided; or - * return the default value for the context variable, if it was created - with one; or - * raise a LookupError. -[clinic start generated code]*/ - -static PyObject * -_contextvars_ContextVar_get_impl(PyContextVar *self, PyObject *default_value) -/*[clinic end generated code: output=0746bd0aa2ced7bf input=30aa2ab9e433e401]*/ -{ - if (!PyContextVar_CheckExact(self)) { - PyErr_SetString( - PyExc_TypeError, "an instance of ContextVar was expected"); - return NULL; - } - - PyObject *val; - if (PyContextVar_Get((PyObject *)self, default_value, &val) < 0) { - return NULL; - } - - if (val == NULL) { - PyErr_SetObject(PyExc_LookupError, (PyObject *)self); - return NULL; - } - - return val; -} - -/*[clinic input] -_contextvars.ContextVar.set - value: object - / - -Call to set a new value for the context variable in the current context. - -The required value argument is the new value for the context variable. - -Returns a Token object that can be used to restore the variable to its previous -value via the `ContextVar.reset()` method. -[clinic start generated code]*/ - -static PyObject * -_contextvars_ContextVar_set(PyContextVar *self, PyObject *value) -/*[clinic end generated code: output=446ed5e820d6d60b input=c0a6887154227453]*/ -{ - return PyContextVar_Set((PyObject *)self, value); -} - -/*[clinic input] -_contextvars.ContextVar.reset - token: object - / - -Reset the context variable. - -The variable is reset to the value it had before the `ContextVar.set()` that -created the token was used. -[clinic start generated code]*/ - -static PyObject * -_contextvars_ContextVar_reset(PyContextVar *self, PyObject *token) -/*[clinic end generated code: output=d4ee34d0742d62ee input=ebe2881e5af4ffda]*/ -{ - if (!PyContextToken_CheckExact(token)) { - PyErr_Format(PyExc_TypeError, - "expected an instance of Token, got %R", token); - return NULL; - } - - if (PyContextVar_Reset((PyObject *)self, token)) { - return NULL; - } - - Py_RETURN_NONE; -} - - -static PyObject * -contextvar_cls_getitem(PyObject *self, PyObject *arg) -{ - Py_INCREF(self); - return self; -} - -static PyMemberDef PyContextVar_members[] = { - {"name", T_OBJECT, offsetof(PyContextVar, var_name), READONLY}, - {NULL} -}; - -static PyMethodDef PyContextVar_methods[] = { - _CONTEXTVARS_CONTEXTVAR_GET_METHODDEF - _CONTEXTVARS_CONTEXTVAR_SET_METHODDEF - _CONTEXTVARS_CONTEXTVAR_RESET_METHODDEF - {"__class_getitem__", contextvar_cls_getitem, - METH_O | METH_CLASS, NULL}, - {NULL, NULL} -}; - -PyTypeObject PyContextVar_Type = { - PyVarObject_HEAD_INIT(&PyType_Type, 0) - "ContextVar", - sizeof(PyContextVar), - .tp_methods = PyContextVar_methods, - .tp_members = PyContextVar_members, - .tp_dealloc = (destructor)contextvar_tp_dealloc, - .tp_getattro = PyObject_GenericGetAttr, - .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC, - .tp_traverse = (traverseproc)contextvar_tp_traverse, - .tp_clear = (inquiry)contextvar_tp_clear, - .tp_new = contextvar_tp_new, - .tp_free = PyObject_GC_Del, - .tp_hash = (hashfunc)contextvar_tp_hash, - .tp_repr = (reprfunc)contextvar_tp_repr, -}; - - -/////////////////////////// Token - -static PyObject * get_token_missing(void); - - -/*[clinic input] -class _contextvars.Token "PyContextToken *" "&PyContextToken_Type" -[clinic start generated code]*/ -/*[clinic end generated code: output=da39a3ee5e6b4b0d input=338a5e2db13d3f5b]*/ - - -static PyObject * -token_tp_new(PyTypeObject *type, PyObject *args, PyObject *kwds) -{ - PyErr_SetString(PyExc_RuntimeError, - "Tokens can only be created by ContextVars"); - return NULL; -} - -static int -token_tp_clear(PyContextToken *self) -{ - Py_CLEAR(self->tok_ctx); - Py_CLEAR(self->tok_var); - Py_CLEAR(self->tok_oldval); - return 0; -} - -static int -token_tp_traverse(PyContextToken *self, visitproc visit, void *arg) -{ - Py_VISIT(self->tok_ctx); - Py_VISIT(self->tok_var); - Py_VISIT(self->tok_oldval); - return 0; -} - -static void -token_tp_dealloc(PyContextToken *self) -{ - PyObject_GC_UnTrack(self); - (void)token_tp_clear(self); - Py_TYPE(self)->tp_free(self); -} - -static PyObject * -token_tp_repr(PyContextToken *self) -{ - _PyUnicodeWriter writer; - - _PyUnicodeWriter_Init(&writer); - - if (_PyUnicodeWriter_WriteASCIIString(&writer, "<Token", 6) < 0) { - goto error; - } - - if (self->tok_used) { - if (_PyUnicodeWriter_WriteASCIIString(&writer, " used", 5) < 0) { - goto error; - } - } - - if (_PyUnicodeWriter_WriteASCIIString(&writer, " var=", 5) < 0) { - goto error; - } - - PyObject *var = PyObject_Repr((PyObject *)self->tok_var); - if (var == NULL) { - goto error; - } - if (_PyUnicodeWriter_WriteStr(&writer, var) < 0) { - Py_DECREF(var); - goto error; - } - Py_DECREF(var); - - PyObject *addr = PyUnicode_FromFormat(" at %p>", self); - if (addr == NULL) { - goto error; - } - if (_PyUnicodeWriter_WriteStr(&writer, addr) < 0) { - Py_DECREF(addr); - goto error; - } - Py_DECREF(addr); - - return _PyUnicodeWriter_Finish(&writer); - -error: - _PyUnicodeWriter_Dealloc(&writer); - return NULL; -} - -static PyObject * -token_get_var(PyContextToken *self, void *Py_UNUSED(ignored)) -{ - Py_INCREF(self->tok_var); - return (PyObject *)self->tok_var; -} - -static PyObject * -token_get_old_value(PyContextToken *self, void *Py_UNUSED(ignored)) -{ - if (self->tok_oldval == NULL) { - return get_token_missing(); - } - - Py_INCREF(self->tok_oldval); - return self->tok_oldval; -} - -static PyGetSetDef PyContextTokenType_getsetlist[] = { - {"var", (getter)token_get_var, NULL, NULL}, - {"old_value", (getter)token_get_old_value, NULL, NULL}, - {NULL} -}; - -PyTypeObject PyContextToken_Type = { - PyVarObject_HEAD_INIT(&PyType_Type, 0) - "Token", - sizeof(PyContextToken), - .tp_getset = PyContextTokenType_getsetlist, - .tp_dealloc = (destructor)token_tp_dealloc, - .tp_getattro = PyObject_GenericGetAttr, - .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC, - .tp_traverse = (traverseproc)token_tp_traverse, - .tp_clear = (inquiry)token_tp_clear, - .tp_new = token_tp_new, - .tp_free = PyObject_GC_Del, - .tp_hash = PyObject_HashNotImplemented, - .tp_repr = (reprfunc)token_tp_repr, -}; - -static PyContextToken * -token_new(PyContext *ctx, PyContextVar *var, PyObject *val) -{ - PyContextToken *tok = PyObject_GC_New(PyContextToken, &PyContextToken_Type); - if (tok == NULL) { - return NULL; - } - - Py_INCREF(ctx); - tok->tok_ctx = ctx; - - Py_INCREF(var); - tok->tok_var = var; - - Py_XINCREF(val); - tok->tok_oldval = val; - - tok->tok_used = 0; - - PyObject_GC_Track(tok); - return tok; -} - - -/////////////////////////// Token.MISSING - - -static PyObject *_token_missing; - - -typedef struct { - PyObject_HEAD -} PyContextTokenMissing; - - -static PyObject * -context_token_missing_tp_repr(PyObject *self) -{ - return PyUnicode_FromString("<Token.MISSING>"); -} - - -PyTypeObject PyContextTokenMissing_Type = { - PyVarObject_HEAD_INIT(&PyType_Type, 0) - "Token.MISSING", - sizeof(PyContextTokenMissing), - .tp_getattro = PyObject_GenericGetAttr, - .tp_flags = Py_TPFLAGS_DEFAULT, - .tp_repr = context_token_missing_tp_repr, -}; - - -static PyObject * -get_token_missing(void) -{ - if (_token_missing != NULL) { - Py_INCREF(_token_missing); - return _token_missing; - } - - _token_missing = (PyObject *)PyObject_New( - PyContextTokenMissing, &PyContextTokenMissing_Type); - if (_token_missing == NULL) { - return NULL; - } - - Py_INCREF(_token_missing); - return _token_missing; -} - - -/////////////////////////// - - -int -PyContext_ClearFreeList(void) -{ - int size = ctx_freelist_len; - while (ctx_freelist_len) { - PyContext *ctx = ctx_freelist; - ctx_freelist = (PyContext *)ctx->ctx_weakreflist; - ctx->ctx_weakreflist = NULL; - PyObject_GC_Del(ctx); - ctx_freelist_len--; - } - return size; -} - - -void -_PyContext_Fini(void) -{ - Py_CLEAR(_token_missing); - (void)PyContext_ClearFreeList(); - (void)_PyHamt_Fini(); -} - - -int -_PyContext_Init(void) -{ - if (!_PyHamt_Init()) { - return 0; - } - - if ((PyType_Ready(&PyContext_Type) < 0) || - (PyType_Ready(&PyContextVar_Type) < 0) || - (PyType_Ready(&PyContextToken_Type) < 0) || - (PyType_Ready(&PyContextTokenMissing_Type) < 0)) - { - return 0; - } - - PyObject *missing = get_token_missing(); - if (PyDict_SetItemString( - PyContextToken_Type.tp_dict, "MISSING", missing)) - { - Py_DECREF(missing); - return 0; - } - Py_DECREF(missing); - - return 1; -} |