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#include "Python.h"

#include "pycore_call.h" // _PyObject_VectorcallTstate()

#include "pycore_context.h"

#include "pycore_critical_section.h" // Py_BEGIN_CRITICAL_SECTION()

#include "pycore_freelist.h" // _Py_FREELIST_FREE(), _Py_FREELIST_POP()

#include "pycore_gc.h" // _PyObject_GC_MAY_BE_TRACKED()

#include "pycore_hamt.h"

#include "pycore_initconfig.h" // _PyStatus_OK()

#include "pycore_object.h"

#include "pycore_pyatomic_ft_wrappers.h" // FT_ATOMIC_LOAD_INT_RELAXED()

#include "pycore_pyerrors.h"

#include "pycore_pystate.h" // _PyThreadState_GET()

#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);

static inline PyHamtObject *

context_get_vars(PyContext *ctx)

{

PyHamtObject *vars;

Py_BEGIN_CRITICAL_SECTION(ctx);

vars = ctx->ctx_vars;

assert(vars != NULL);

Py_INCREF(vars);

Py_END_CRITICAL_SECTION();

return vars;

}

static inline PyHamtObject *

context_get_current_vars(PyContext *ctx)

{

// ctx_vars written only by the owning thread, and read by other threads

// only under the context's lock, a plain (non-atomic) load is okay

PyHamtObject *vars = ctx->ctx_vars;

assert(vars != NULL);

return vars;

}

// Note: steals a reference to new_vars and must only be called by the thread

// that has `ctx` as its current context.

static inline void

context_set_vars(PyContext *ctx, PyHamtObject *new_vars)

{

PyHamtObject *old_vars;

Py_BEGIN_CRITICAL_SECTION(ctx);

old_vars = ctx->ctx_vars;

ctx->ctx_vars = new_vars;

Py_END_CRITICAL_SECTION();

Py_XDECREF(old_vars);

}

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;

PyHamtObject *vars = context_get_vars(ctx);

PyObject *res = (PyObject *)context_new_from_vars(vars);

Py_DECREF(vars);

return res;

}

PyObject *

PyContext_CopyCurrent(void)

{

PyContext *ctx = context_get();

if (ctx == NULL) {

return NULL;

}

return (PyObject *)context_new_from_vars(context_get_current_vars(ctx));

}

static const char *

context_event_name(PyContextEvent event) {

switch (event) {

case Py_CONTEXT_SWITCHED:

return "Py_CONTEXT_SWITCHED";

default:

return "?";

}

Py_UNREACHABLE();

}

static void

notify_context_watchers(PyThreadState *ts, PyContextEvent event, PyObject *ctx)

{

if (ctx == NULL) {

// This will happen after exiting the last context in the stack, which

// can occur if context_get was never called before entering a context

// (e.g., called `contextvars.Context().run()` on a fresh thread, as

// PyContext_Enter doesn't call context_get).

ctx = Py_None;

}

assert(Py_REFCNT(ctx) > 0);

PyInterpreterState *interp = ts->interp;

assert(interp->_initialized);

uint8_t bits = interp->active_context_watchers;

int i = 0;

while (bits) {

assert(i < CONTEXT_MAX_WATCHERS);

if (bits & 1) {

PyContext_WatchCallback cb = interp->context_watchers[i];

assert(cb != NULL);

if (cb(event, ctx) < 0) {

PyErr_FormatUnraisable(

"Exception ignored in %s watcher callback for %R",

context_event_name(event), ctx);

}

i++;

bits >>= 1;

}

int

PyContext_AddWatcher(PyContext_WatchCallback callback)

{

PyInterpreterState *interp = _PyInterpreterState_GET();

assert(interp->_initialized);

for (int i = 0; i < CONTEXT_MAX_WATCHERS; i++) {

if (!interp->context_watchers[i]) {

interp->context_watchers[i] = callback;

interp->active_context_watchers |= (1 << i);

return i;

}

PyErr_SetString(PyExc_RuntimeError, "no more context watcher IDs available");

return -1;

}

int

PyContext_ClearWatcher(int watcher_id)

{

PyInterpreterState *interp = _PyInterpreterState_GET();

assert(interp->_initialized);

if (watcher_id < 0 || watcher_id >= CONTEXT_MAX_WATCHERS) {

PyErr_Format(PyExc_ValueError, "Invalid context watcher ID %d", watcher_id);

return -1;

}

if (!interp->context_watchers[watcher_id]) {

PyErr_Format(PyExc_ValueError, "No context watcher set for ID %d", watcher_id);

return -1;

}

interp->context_watchers[watcher_id] = NULL;

interp->active_context_watchers &= ~(1 << watcher_id);

return 0;

}

static inline void

context_switched(PyThreadState *ts)

{

ts->context_ver++;

// ts->context is used instead of context_get() because context_get() might

// throw if ts->context is NULL.

notify_context_watchers(ts, Py_CONTEXT_SWITCHED, ts->context);

}

int

_PyContext_Enter(PyThreadState *ts, PyObject *octx)

{

ENSURE_Context(octx, -1)

PyContext *ctx = (PyContext *)octx;

#ifdef Py_GIL_DISABLED

int already_entered = _Py_atomic_exchange_int(&ctx->ctx_entered, 1);

#else

int already_entered = ctx->ctx_entered;

ctx->ctx_entered = 1;

#endif

if (already_entered) {

_PyErr_Format(ts, PyExc_RuntimeError,

"cannot enter context: %R is already entered", ctx);

return -1;

}

ctx->ctx_prev = (PyContext *)ts->context; /* borrow */

ts->context = Py_NewRef(ctx);

context_switched(ts);

return 0;

}

int

PyContext_Enter(PyObject *octx)

{

PyThreadState *ts = _PyThreadState_GET();

assert(ts != NULL);

return _PyContext_Enter(ts, octx);

}

int

_PyContext_Exit(PyThreadState *ts, PyObject *octx)

{

ENSURE_Context(octx, -1)

PyContext *ctx = (PyContext *)octx;

int already_entered = FT_ATOMIC_LOAD_INT_RELAXED(ctx->ctx_entered);

if (!already_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);

ctx->ctx_prev = NULL;

FT_ATOMIC_STORE_INT(ctx->ctx_entered, 0);

context_switched(ts);

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;

}

#ifndef Py_GIL_DISABLED

if (var->var_cached != NULL &&

var->var_cached_tsid == ts->id &&

var->var_cached_tsver == ts->context_ver)

{

*val = var->var_cached;

goto found;

}

#endif

assert(PyContext_CheckExact(ts->context));

PyHamtObject *vars = context_get_current_vars((PyContext *)ts->context);

PyObject *found = NULL;

int res = _PyHamt_Find(vars, (PyObject*)var, &found);

if (res < 0) {

goto error;

}

if (res == 1) {

assert(found != NULL);

#ifndef Py_GIL_DISABLED

var->var_cached = found; /* borrow */

var->var_cached_tsid = ts->id;

var->var_cached_tsver = ts->context_ver;

#endif

*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;

PyContext *ctx = context_get();

if (ctx == NULL) {

return NULL;

}

PyObject *old_val = NULL;

int found = _PyHamt_Find(context_get_current_vars(ctx), (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 (tok == NULL) {

return NULL;

}

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]*/

#define _PyContext_CAST(op) ((PyContext *)(op))

static inline PyContext *

_context_alloc(void)

{

PyContext *ctx = _Py_FREELIST_POP(PyContext, contexts);

if (ctx == NULL) {

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;

}

ctx->ctx_vars = (PyHamtObject*)Py_NewRef(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(PyObject *op)

{

PyContext *self = _PyContext_CAST(op);

Py_CLEAR(self->ctx_prev);

Py_CLEAR(self->ctx_vars);

return 0;

}

static int

context_tp_traverse(PyObject *op, visitproc visit, void *arg)

{

PyContext *self = _PyContext_CAST(op);

Py_VISIT(self->ctx_prev);

Py_VISIT(self->ctx_vars);

return 0;

}

static void

context_tp_dealloc(PyObject *self)

{

_PyObject_GC_UNTRACK(self);

PyContext *ctx = _PyContext_CAST(self);

if (ctx->ctx_weakreflist != NULL) {

PyObject_ClearWeakRefs(self);

}

(void)context_tp_clear(self);

_Py_FREELIST_FREE(contexts, self, Py_TYPE(self)->tp_free);

}

static PyObject *

context_tp_iter(PyObject *op)

{

PyContext *self = _PyContext_CAST(op);

PyHamtObject *vars = context_get_vars(self);

PyObject *res = _PyHamt_NewIterKeys(vars);

Py_DECREF(vars);

return res;

}

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;

}

PyHamtObject *v_vars = context_get_vars((PyContext *)v);

PyHamtObject *w_vars = context_get_vars((PyContext *)w);

int res = _PyHamt_Eq(v_vars, w_vars);

Py_DECREF(v_vars);

Py_DECREF(w_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(PyObject *op)

{

PyContext *self = _PyContext_CAST(op);

PyHamtObject *vars = context_get_vars(self);

Py_ssize_t res = _PyHamt_Len(vars);

Py_DECREF(vars);

return res;

}

static PyObject *

context_tp_subscript(PyObject *op, PyObject *key)

{

if (context_check_key_type(key)) {

return NULL;

}

PyObject *val = NULL;

PyContext *self = _PyContext_CAST(op);

PyHamtObject *vars = context_get_vars(self);

int found = _PyHamt_Find(vars, key, &val);

Py_XINCREF(val);

Py_DECREF(vars);

if (found < 0) {

return NULL;

}

if (found == 0) {

PyErr_SetObject(PyExc_KeyError, key);

return NULL;

}

return val;

}

static int

context_tp_contains(PyObject *op, PyObject *key)

{

if (context_check_key_type(key)) {

return -1;

}

PyObject *val = NULL;

PyContext *self = _PyContext_CAST(op);

PyHamtObject *vars = context_get_vars(self);

int res = _PyHamt_Find(vars, key, &val);

Py_DECREF(vars);

return res;

}

/*[clinic input]

@permit_long_summary

_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=d669a0d56fabb0a5]*/

{

if (context_check_key_type(key)) {

return NULL;

}

PyObject *val = NULL;

PyHamtObject *vars = context_get_vars(self);

int found = _PyHamt_Find(vars, key, &val);

Py_XINCREF(val);

Py_DECREF(vars);

if (found < 0) {

return NULL;

}

if (found == 0) {

return Py_NewRef(default_value);

}

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]*/

{

PyHamtObject *vars = context_get_vars(self);

PyObject *res = _PyHamt_NewIterItems(vars);

Py_DECREF(vars);

return res;

}

/*[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]*/

{

PyHamtObject *vars = context_get_vars(self);

PyObject *res = _PyHamt_NewIterKeys(vars);

Py_DECREF(vars);

return res;

}

/*[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]*/

{

PyHamtObject *vars = context_get_vars(self);

PyObject *res = _PyHamt_NewIterValues(vars);

Py_DECREF(vars);

return res;

}

/*[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]*/

{

PyHamtObject *vars = context_get_vars(self);

PyObject *res = (PyObject *)context_new_from_vars(vars);

Py_DECREF(vars);

return res;

}

static PyObject *

context_run(PyObject *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, self)) {

return NULL;

}

PyObject *call_result = _PyObject_VectorcallTstate(

ts, args[0], args + 1, nargs - 1, kwnames);

if (_PyContext_Exit(ts, self)) {

Py_XDECREF(call_result);

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_CAST(context_run), METH_FASTCALL | METH_KEYWORDS, NULL},

{NULL, NULL}

};

static PySequenceMethods PyContext_as_sequence = {

.sq_contains = context_tp_contains

};

static PyMappingMethods PyContext_as_mapping = {

.mp_length = context_tp_len,

.mp_subscript = context_tp_subscript

};

PyTypeObject PyContext_Type = {

PyVarObject_HEAD_INIT(&PyType_Type, 0)

"_contextvars.Context",

sizeof(PyContext),

.tp_methods = PyContext_methods,

.tp_as_mapping = &PyContext_as_mapping,

.tp_as_sequence = &PyContext_as_sequence,

.tp_iter = context_tp_iter,

.tp_dealloc = context_tp_dealloc,

.tp_getattro = PyObject_GenericGetAttr,

.tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,

.tp_richcompare = context_tp_richcompare,

.tp_traverse = context_tp_traverse,

.tp_clear = 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)

{

#ifndef Py_GIL_DISABLED

var->var_cached = NULL;

PyThreadState *ts = _PyThreadState_GET();

#endif

PyContext *ctx = context_get();

if (ctx == NULL) {

return -1;

}

PyHamtObject *new_vars = _PyHamt_Assoc(

context_get_current_vars(ctx), (PyObject *)var, val);

if (new_vars == NULL) {

return -1;

}

context_set_vars(ctx, new_vars);

#ifndef Py_GIL_DISABLED

var->var_cached = val; /* borrow */

var->var_cached_tsid = ts->id;

var->var_cached_tsver = ts->context_ver;

#endif

return 0;

}

static int

contextvar_del(PyContextVar *var)

{

#ifndef Py_GIL_DISABLED

var->var_cached = NULL;

#endif

PyContext *ctx = context_get();

if (ctx == NULL) {

return -1;

}

PyHamtObject *vars = context_get_current_vars(ctx);

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;

}

context_set_vars(ctx, 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_name = Py_NewRef(name);

var->var_default = Py_XNewRef(def);

#ifndef Py_GIL_DISABLED

var->var_cached = NULL;

var->var_cached_tsid = 0;

var->var_cached_tsver = 0;

#endif

var->var_hash = contextvar_generate_hash(var, name);

if (var->var_hash == -1) {

Py_DECREF(var);

return NULL;

}

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]*/

#define _PyContextVar_CAST(op) ((PyContextVar *)(op))

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;

}

View remainder of file in raw view

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