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1 /* Generator object implementation */
2 
3 #include "Python.h"
4 #include "internal/pystate.h"
5 #include "frameobject.h"
6 #include "structmember.h"
7 #include "opcode.h"
8 
9 static PyObject *gen_close(PyGenObject *, PyObject *);
10 static PyObject *async_gen_asend_new(PyAsyncGenObject *, PyObject *);
11 static PyObject *async_gen_athrow_new(PyAsyncGenObject *, PyObject *);
12 
13 static char *NON_INIT_CORO_MSG = "can't send non-None value to a "
14                                  "just-started coroutine";
15 
16 static char *ASYNC_GEN_IGNORED_EXIT_MSG =
17                                  "async generator ignored GeneratorExit";
18 
19 static inline int
exc_state_traverse(_PyErr_StackItem * exc_state,visitproc visit,void * arg)20 exc_state_traverse(_PyErr_StackItem *exc_state, visitproc visit, void *arg)
21 {
22     Py_VISIT(exc_state->exc_type);
23     Py_VISIT(exc_state->exc_value);
24     Py_VISIT(exc_state->exc_traceback);
25     return 0;
26 }
27 
28 static int
gen_traverse(PyGenObject * gen,visitproc visit,void * arg)29 gen_traverse(PyGenObject *gen, visitproc visit, void *arg)
30 {
31     Py_VISIT((PyObject *)gen->gi_frame);
32     Py_VISIT(gen->gi_code);
33     Py_VISIT(gen->gi_name);
34     Py_VISIT(gen->gi_qualname);
35     /* No need to visit cr_origin, because it's just tuples/str/int, so can't
36        participate in a reference cycle. */
37     return exc_state_traverse(&gen->gi_exc_state, visit, arg);
38 }
39 
40 void
_PyGen_Finalize(PyObject * self)41 _PyGen_Finalize(PyObject *self)
42 {
43     PyGenObject *gen = (PyGenObject *)self;
44     PyObject *res = NULL;
45     PyObject *error_type, *error_value, *error_traceback;
46 
47     if (gen->gi_frame == NULL || gen->gi_frame->f_stacktop == NULL) {
48         /* Generator isn't paused, so no need to close */
49         return;
50     }
51 
52     if (PyAsyncGen_CheckExact(self)) {
53         PyAsyncGenObject *agen = (PyAsyncGenObject*)self;
54         PyObject *finalizer = agen->ag_finalizer;
55         if (finalizer && !agen->ag_closed) {
56             /* Save the current exception, if any. */
57             PyErr_Fetch(&error_type, &error_value, &error_traceback);
58 
59             res = PyObject_CallFunctionObjArgs(finalizer, self, NULL);
60 
61             if (res == NULL) {
62                 PyErr_WriteUnraisable(self);
63             } else {
64                 Py_DECREF(res);
65             }
66             /* Restore the saved exception. */
67             PyErr_Restore(error_type, error_value, error_traceback);
68             return;
69         }
70     }
71 
72     /* Save the current exception, if any. */
73     PyErr_Fetch(&error_type, &error_value, &error_traceback);
74 
75     /* If `gen` is a coroutine, and if it was never awaited on,
76        issue a RuntimeWarning. */
77     if (gen->gi_code != NULL &&
78         ((PyCodeObject *)gen->gi_code)->co_flags & CO_COROUTINE &&
79         gen->gi_frame->f_lasti == -1)
80     {
81         _PyErr_WarnUnawaitedCoroutine((PyObject *)gen);
82     }
83     else {
84         res = gen_close(gen, NULL);
85     }
86 
87     if (res == NULL) {
88         if (PyErr_Occurred()) {
89             PyErr_WriteUnraisable(self);
90         }
91     }
92     else {
93         Py_DECREF(res);
94     }
95 
96     /* Restore the saved exception. */
97     PyErr_Restore(error_type, error_value, error_traceback);
98 }
99 
100 static inline void
exc_state_clear(_PyErr_StackItem * exc_state)101 exc_state_clear(_PyErr_StackItem *exc_state)
102 {
103     PyObject *t, *v, *tb;
104     t = exc_state->exc_type;
105     v = exc_state->exc_value;
106     tb = exc_state->exc_traceback;
107     exc_state->exc_type = NULL;
108     exc_state->exc_value = NULL;
109     exc_state->exc_traceback = NULL;
110     Py_XDECREF(t);
111     Py_XDECREF(v);
112     Py_XDECREF(tb);
113 }
114 
115 static void
gen_dealloc(PyGenObject * gen)116 gen_dealloc(PyGenObject *gen)
117 {
118     PyObject *self = (PyObject *) gen;
119 
120     _PyObject_GC_UNTRACK(gen);
121 
122     if (gen->gi_weakreflist != NULL)
123         PyObject_ClearWeakRefs(self);
124 
125     _PyObject_GC_TRACK(self);
126 
127     if (PyObject_CallFinalizerFromDealloc(self))
128         return;                     /* resurrected.  :( */
129 
130     _PyObject_GC_UNTRACK(self);
131     if (PyAsyncGen_CheckExact(gen)) {
132         /* We have to handle this case for asynchronous generators
133            right here, because this code has to be between UNTRACK
134            and GC_Del. */
135         Py_CLEAR(((PyAsyncGenObject*)gen)->ag_finalizer);
136     }
137     if (gen->gi_frame != NULL) {
138         gen->gi_frame->f_gen = NULL;
139         Py_CLEAR(gen->gi_frame);
140     }
141     if (((PyCodeObject *)gen->gi_code)->co_flags & CO_COROUTINE) {
142         Py_CLEAR(((PyCoroObject *)gen)->cr_origin);
143     }
144     Py_CLEAR(gen->gi_code);
145     Py_CLEAR(gen->gi_name);
146     Py_CLEAR(gen->gi_qualname);
147     exc_state_clear(&gen->gi_exc_state);
148     PyObject_GC_Del(gen);
149 }
150 
151 static PyObject *
gen_send_ex(PyGenObject * gen,PyObject * arg,int exc,int closing)152 gen_send_ex(PyGenObject *gen, PyObject *arg, int exc, int closing)
153 {
154     PyThreadState *tstate = PyThreadState_GET();
155     PyFrameObject *f = gen->gi_frame;
156     PyObject *result;
157 
158     if (gen->gi_running) {
159         const char *msg = "generator already executing";
160         if (PyCoro_CheckExact(gen)) {
161             msg = "coroutine already executing";
162         }
163         else if (PyAsyncGen_CheckExact(gen)) {
164             msg = "async generator already executing";
165         }
166         PyErr_SetString(PyExc_ValueError, msg);
167         return NULL;
168     }
169     if (f == NULL || f->f_stacktop == NULL) {
170         if (PyCoro_CheckExact(gen) && !closing) {
171             /* `gen` is an exhausted coroutine: raise an error,
172                except when called from gen_close(), which should
173                always be a silent method. */
174             PyErr_SetString(
175                 PyExc_RuntimeError,
176                 "cannot reuse already awaited coroutine");
177         }
178         else if (arg && !exc) {
179             /* `gen` is an exhausted generator:
180                only set exception if called from send(). */
181             if (PyAsyncGen_CheckExact(gen)) {
182                 PyErr_SetNone(PyExc_StopAsyncIteration);
183             }
184             else {
185                 PyErr_SetNone(PyExc_StopIteration);
186             }
187         }
188         return NULL;
189     }
190 
191     if (f->f_lasti == -1) {
192         if (arg && arg != Py_None) {
193             const char *msg = "can't send non-None value to a "
194                               "just-started generator";
195             if (PyCoro_CheckExact(gen)) {
196                 msg = NON_INIT_CORO_MSG;
197             }
198             else if (PyAsyncGen_CheckExact(gen)) {
199                 msg = "can't send non-None value to a "
200                       "just-started async generator";
201             }
202             PyErr_SetString(PyExc_TypeError, msg);
203             return NULL;
204         }
205     } else {
206         /* Push arg onto the frame's value stack */
207         result = arg ? arg : Py_None;
208         Py_INCREF(result);
209         *(f->f_stacktop++) = result;
210     }
211 
212     /* Generators always return to their most recent caller, not
213      * necessarily their creator. */
214     Py_XINCREF(tstate->frame);
215     assert(f->f_back == NULL);
216     f->f_back = tstate->frame;
217 
218     gen->gi_running = 1;
219     gen->gi_exc_state.previous_item = tstate->exc_info;
220     tstate->exc_info = &gen->gi_exc_state;
221     result = PyEval_EvalFrameEx(f, exc);
222     tstate->exc_info = gen->gi_exc_state.previous_item;
223     gen->gi_exc_state.previous_item = NULL;
224     gen->gi_running = 0;
225 
226     /* Don't keep the reference to f_back any longer than necessary.  It
227      * may keep a chain of frames alive or it could create a reference
228      * cycle. */
229     assert(f->f_back == tstate->frame);
230     Py_CLEAR(f->f_back);
231 
232     /* If the generator just returned (as opposed to yielding), signal
233      * that the generator is exhausted. */
234     if (result && f->f_stacktop == NULL) {
235         if (result == Py_None) {
236             /* Delay exception instantiation if we can */
237             if (PyAsyncGen_CheckExact(gen)) {
238                 PyErr_SetNone(PyExc_StopAsyncIteration);
239             }
240             else {
241                 PyErr_SetNone(PyExc_StopIteration);
242             }
243         }
244         else {
245             /* Async generators cannot return anything but None */
246             assert(!PyAsyncGen_CheckExact(gen));
247             _PyGen_SetStopIterationValue(result);
248         }
249         Py_CLEAR(result);
250     }
251     else if (!result && PyErr_ExceptionMatches(PyExc_StopIteration)) {
252         const char *msg = "generator raised StopIteration";
253         if (PyCoro_CheckExact(gen)) {
254             msg = "coroutine raised StopIteration";
255         }
256         else if PyAsyncGen_CheckExact(gen) {
257             msg = "async generator raised StopIteration";
258         }
259         _PyErr_FormatFromCause(PyExc_RuntimeError, "%s", msg);
260 
261     }
262     else if (!result && PyAsyncGen_CheckExact(gen) &&
263              PyErr_ExceptionMatches(PyExc_StopAsyncIteration))
264     {
265         /* code in `gen` raised a StopAsyncIteration error:
266            raise a RuntimeError.
267         */
268         const char *msg = "async generator raised StopAsyncIteration";
269         _PyErr_FormatFromCause(PyExc_RuntimeError, "%s", msg);
270     }
271 
272     if (!result || f->f_stacktop == NULL) {
273         /* generator can't be rerun, so release the frame */
274         /* first clean reference cycle through stored exception traceback */
275         exc_state_clear(&gen->gi_exc_state);
276         gen->gi_frame->f_gen = NULL;
277         gen->gi_frame = NULL;
278         Py_DECREF(f);
279     }
280 
281     return result;
282 }
283 
284 PyDoc_STRVAR(send_doc,
285 "send(arg) -> send 'arg' into generator,\n\
286 return next yielded value or raise StopIteration.");
287 
288 PyObject *
_PyGen_Send(PyGenObject * gen,PyObject * arg)289 _PyGen_Send(PyGenObject *gen, PyObject *arg)
290 {
291     return gen_send_ex(gen, arg, 0, 0);
292 }
293 
294 PyDoc_STRVAR(close_doc,
295 "close() -> raise GeneratorExit inside generator.");
296 
297 /*
298  *   This helper function is used by gen_close and gen_throw to
299  *   close a subiterator being delegated to by yield-from.
300  */
301 
302 static int
gen_close_iter(PyObject * yf)303 gen_close_iter(PyObject *yf)
304 {
305     PyObject *retval = NULL;
306     _Py_IDENTIFIER(close);
307 
308     if (PyGen_CheckExact(yf) || PyCoro_CheckExact(yf)) {
309         retval = gen_close((PyGenObject *)yf, NULL);
310         if (retval == NULL)
311             return -1;
312     }
313     else {
314         PyObject *meth;
315         if (_PyObject_LookupAttrId(yf, &PyId_close, &meth) < 0) {
316             PyErr_WriteUnraisable(yf);
317         }
318         if (meth) {
319             retval = _PyObject_CallNoArg(meth);
320             Py_DECREF(meth);
321             if (retval == NULL)
322                 return -1;
323         }
324     }
325     Py_XDECREF(retval);
326     return 0;
327 }
328 
329 PyObject *
_PyGen_yf(PyGenObject * gen)330 _PyGen_yf(PyGenObject *gen)
331 {
332     PyObject *yf = NULL;
333     PyFrameObject *f = gen->gi_frame;
334 
335     if (f && f->f_stacktop) {
336         PyObject *bytecode = f->f_code->co_code;
337         unsigned char *code = (unsigned char *)PyBytes_AS_STRING(bytecode);
338 
339         if (f->f_lasti < 0) {
340             /* Return immediately if the frame didn't start yet. YIELD_FROM
341                always come after LOAD_CONST: a code object should not start
342                with YIELD_FROM */
343             assert(code[0] != YIELD_FROM);
344             return NULL;
345         }
346 
347         if (code[f->f_lasti + sizeof(_Py_CODEUNIT)] != YIELD_FROM)
348             return NULL;
349         yf = f->f_stacktop[-1];
350         Py_INCREF(yf);
351     }
352 
353     return yf;
354 }
355 
356 static PyObject *
gen_close(PyGenObject * gen,PyObject * args)357 gen_close(PyGenObject *gen, PyObject *args)
358 {
359     PyObject *retval;
360     PyObject *yf = _PyGen_yf(gen);
361     int err = 0;
362 
363     if (yf) {
364         gen->gi_running = 1;
365         err = gen_close_iter(yf);
366         gen->gi_running = 0;
367         Py_DECREF(yf);
368     }
369     if (err == 0)
370         PyErr_SetNone(PyExc_GeneratorExit);
371     retval = gen_send_ex(gen, Py_None, 1, 1);
372     if (retval) {
373         const char *msg = "generator ignored GeneratorExit";
374         if (PyCoro_CheckExact(gen)) {
375             msg = "coroutine ignored GeneratorExit";
376         } else if (PyAsyncGen_CheckExact(gen)) {
377             msg = ASYNC_GEN_IGNORED_EXIT_MSG;
378         }
379         Py_DECREF(retval);
380         PyErr_SetString(PyExc_RuntimeError, msg);
381         return NULL;
382     }
383     if (PyErr_ExceptionMatches(PyExc_StopIteration)
384         || PyErr_ExceptionMatches(PyExc_GeneratorExit)) {
385         PyErr_Clear();          /* ignore these errors */
386         Py_RETURN_NONE;
387     }
388     return NULL;
389 }
390 
391 
392 PyDoc_STRVAR(throw_doc,
393 "throw(typ[,val[,tb]]) -> raise exception in generator,\n\
394 return next yielded value or raise StopIteration.");
395 
396 static PyObject *
_gen_throw(PyGenObject * gen,int close_on_genexit,PyObject * typ,PyObject * val,PyObject * tb)397 _gen_throw(PyGenObject *gen, int close_on_genexit,
398            PyObject *typ, PyObject *val, PyObject *tb)
399 {
400     PyObject *yf = _PyGen_yf(gen);
401     _Py_IDENTIFIER(throw);
402 
403     if (yf) {
404         PyObject *ret;
405         int err;
406         if (PyErr_GivenExceptionMatches(typ, PyExc_GeneratorExit) &&
407             close_on_genexit
408         ) {
409             /* Asynchronous generators *should not* be closed right away.
410                We have to allow some awaits to work it through, hence the
411                `close_on_genexit` parameter here.
412             */
413             gen->gi_running = 1;
414             err = gen_close_iter(yf);
415             gen->gi_running = 0;
416             Py_DECREF(yf);
417             if (err < 0)
418                 return gen_send_ex(gen, Py_None, 1, 0);
419             goto throw_here;
420         }
421         if (PyGen_CheckExact(yf) || PyCoro_CheckExact(yf)) {
422             /* `yf` is a generator or a coroutine. */
423             gen->gi_running = 1;
424             /* Close the generator that we are currently iterating with
425                'yield from' or awaiting on with 'await'. */
426             ret = _gen_throw((PyGenObject *)yf, close_on_genexit,
427                              typ, val, tb);
428             gen->gi_running = 0;
429         } else {
430             /* `yf` is an iterator or a coroutine-like object. */
431             PyObject *meth;
432             if (_PyObject_LookupAttrId(yf, &PyId_throw, &meth) < 0) {
433                 Py_DECREF(yf);
434                 return NULL;
435             }
436             if (meth == NULL) {
437                 Py_DECREF(yf);
438                 goto throw_here;
439             }
440             gen->gi_running = 1;
441             ret = PyObject_CallFunctionObjArgs(meth, typ, val, tb, NULL);
442             gen->gi_running = 0;
443             Py_DECREF(meth);
444         }
445         Py_DECREF(yf);
446         if (!ret) {
447             PyObject *val;
448             /* Pop subiterator from stack */
449             ret = *(--gen->gi_frame->f_stacktop);
450             assert(ret == yf);
451             Py_DECREF(ret);
452             /* Termination repetition of YIELD_FROM */
453             assert(gen->gi_frame->f_lasti >= 0);
454             gen->gi_frame->f_lasti += sizeof(_Py_CODEUNIT);
455             if (_PyGen_FetchStopIterationValue(&val) == 0) {
456                 ret = gen_send_ex(gen, val, 0, 0);
457                 Py_DECREF(val);
458             } else {
459                 ret = gen_send_ex(gen, Py_None, 1, 0);
460             }
461         }
462         return ret;
463     }
464 
465 throw_here:
466     /* First, check the traceback argument, replacing None with
467        NULL. */
468     if (tb == Py_None) {
469         tb = NULL;
470     }
471     else if (tb != NULL && !PyTraceBack_Check(tb)) {
472         PyErr_SetString(PyExc_TypeError,
473             "throw() third argument must be a traceback object");
474         return NULL;
475     }
476 
477     Py_INCREF(typ);
478     Py_XINCREF(val);
479     Py_XINCREF(tb);
480 
481     if (PyExceptionClass_Check(typ))
482         PyErr_NormalizeException(&typ, &val, &tb);
483 
484     else if (PyExceptionInstance_Check(typ)) {
485         /* Raising an instance.  The value should be a dummy. */
486         if (val && val != Py_None) {
487             PyErr_SetString(PyExc_TypeError,
488               "instance exception may not have a separate value");
489             goto failed_throw;
490         }
491         else {
492             /* Normalize to raise <class>, <instance> */
493             Py_XDECREF(val);
494             val = typ;
495             typ = PyExceptionInstance_Class(typ);
496             Py_INCREF(typ);
497 
498             if (tb == NULL)
499                 /* Returns NULL if there's no traceback */
500                 tb = PyException_GetTraceback(val);
501         }
502     }
503     else {
504         /* Not something you can raise.  throw() fails. */
505         PyErr_Format(PyExc_TypeError,
506                      "exceptions must be classes or instances "
507                      "deriving from BaseException, not %s",
508                      Py_TYPE(typ)->tp_name);
509             goto failed_throw;
510     }
511 
512     PyErr_Restore(typ, val, tb);
513     return gen_send_ex(gen, Py_None, 1, 0);
514 
515 failed_throw:
516     /* Didn't use our arguments, so restore their original refcounts */
517     Py_DECREF(typ);
518     Py_XDECREF(val);
519     Py_XDECREF(tb);
520     return NULL;
521 }
522 
523 
524 static PyObject *
gen_throw(PyGenObject * gen,PyObject * args)525 gen_throw(PyGenObject *gen, PyObject *args)
526 {
527     PyObject *typ;
528     PyObject *tb = NULL;
529     PyObject *val = NULL;
530 
531     if (!PyArg_UnpackTuple(args, "throw", 1, 3, &typ, &val, &tb)) {
532         return NULL;
533     }
534 
535     return _gen_throw(gen, 1, typ, val, tb);
536 }
537 
538 
539 static PyObject *
gen_iternext(PyGenObject * gen)540 gen_iternext(PyGenObject *gen)
541 {
542     return gen_send_ex(gen, NULL, 0, 0);
543 }
544 
545 /*
546  * Set StopIteration with specified value.  Value can be arbitrary object
547  * or NULL.
548  *
549  * Returns 0 if StopIteration is set and -1 if any other exception is set.
550  */
551 int
_PyGen_SetStopIterationValue(PyObject * value)552 _PyGen_SetStopIterationValue(PyObject *value)
553 {
554     PyObject *e;
555 
556     if (value == NULL ||
557         (!PyTuple_Check(value) && !PyExceptionInstance_Check(value)))
558     {
559         /* Delay exception instantiation if we can */
560         PyErr_SetObject(PyExc_StopIteration, value);
561         return 0;
562     }
563     /* Construct an exception instance manually with
564      * PyObject_CallFunctionObjArgs and pass it to PyErr_SetObject.
565      *
566      * We do this to handle a situation when "value" is a tuple, in which
567      * case PyErr_SetObject would set the value of StopIteration to
568      * the first element of the tuple.
569      *
570      * (See PyErr_SetObject/_PyErr_CreateException code for details.)
571      */
572     e = PyObject_CallFunctionObjArgs(PyExc_StopIteration, value, NULL);
573     if (e == NULL) {
574         return -1;
575     }
576     PyErr_SetObject(PyExc_StopIteration, e);
577     Py_DECREF(e);
578     return 0;
579 }
580 
581 /*
582  *   If StopIteration exception is set, fetches its 'value'
583  *   attribute if any, otherwise sets pvalue to None.
584  *
585  *   Returns 0 if no exception or StopIteration is set.
586  *   If any other exception is set, returns -1 and leaves
587  *   pvalue unchanged.
588  */
589 
590 int
_PyGen_FetchStopIterationValue(PyObject ** pvalue)591 _PyGen_FetchStopIterationValue(PyObject **pvalue)
592 {
593     PyObject *et, *ev, *tb;
594     PyObject *value = NULL;
595 
596     if (PyErr_ExceptionMatches(PyExc_StopIteration)) {
597         PyErr_Fetch(&et, &ev, &tb);
598         if (ev) {
599             /* exception will usually be normalised already */
600             if (PyObject_TypeCheck(ev, (PyTypeObject *) et)) {
601                 value = ((PyStopIterationObject *)ev)->value;
602                 Py_INCREF(value);
603                 Py_DECREF(ev);
604             } else if (et == PyExc_StopIteration && !PyTuple_Check(ev)) {
605                 /* Avoid normalisation and take ev as value.
606                  *
607                  * Normalization is required if the value is a tuple, in
608                  * that case the value of StopIteration would be set to
609                  * the first element of the tuple.
610                  *
611                  * (See _PyErr_CreateException code for details.)
612                  */
613                 value = ev;
614             } else {
615                 /* normalisation required */
616                 PyErr_NormalizeException(&et, &ev, &tb);
617                 if (!PyObject_TypeCheck(ev, (PyTypeObject *)PyExc_StopIteration)) {
618                     PyErr_Restore(et, ev, tb);
619                     return -1;
620                 }
621                 value = ((PyStopIterationObject *)ev)->value;
622                 Py_INCREF(value);
623                 Py_DECREF(ev);
624             }
625         }
626         Py_XDECREF(et);
627         Py_XDECREF(tb);
628     } else if (PyErr_Occurred()) {
629         return -1;
630     }
631     if (value == NULL) {
632         value = Py_None;
633         Py_INCREF(value);
634     }
635     *pvalue = value;
636     return 0;
637 }
638 
639 static PyObject *
gen_repr(PyGenObject * gen)640 gen_repr(PyGenObject *gen)
641 {
642     return PyUnicode_FromFormat("<generator object %S at %p>",
643                                 gen->gi_qualname, gen);
644 }
645 
646 static PyObject *
gen_get_name(PyGenObject * op,void * Py_UNUSED (ignored))647 gen_get_name(PyGenObject *op, void *Py_UNUSED(ignored))
648 {
649     Py_INCREF(op->gi_name);
650     return op->gi_name;
651 }
652 
653 static int
gen_set_name(PyGenObject * op,PyObject * value,void * Py_UNUSED (ignored))654 gen_set_name(PyGenObject *op, PyObject *value, void *Py_UNUSED(ignored))
655 {
656     /* Not legal to del gen.gi_name or to set it to anything
657      * other than a string object. */
658     if (value == NULL || !PyUnicode_Check(value)) {
659         PyErr_SetString(PyExc_TypeError,
660                         "__name__ must be set to a string object");
661         return -1;
662     }
663     Py_INCREF(value);
664     Py_XSETREF(op->gi_name, value);
665     return 0;
666 }
667 
668 static PyObject *
gen_get_qualname(PyGenObject * op,void * Py_UNUSED (ignored))669 gen_get_qualname(PyGenObject *op, void *Py_UNUSED(ignored))
670 {
671     Py_INCREF(op->gi_qualname);
672     return op->gi_qualname;
673 }
674 
675 static int
gen_set_qualname(PyGenObject * op,PyObject * value,void * Py_UNUSED (ignored))676 gen_set_qualname(PyGenObject *op, PyObject *value, void *Py_UNUSED(ignored))
677 {
678     /* Not legal to del gen.__qualname__ or to set it to anything
679      * other than a string object. */
680     if (value == NULL || !PyUnicode_Check(value)) {
681         PyErr_SetString(PyExc_TypeError,
682                         "__qualname__ must be set to a string object");
683         return -1;
684     }
685     Py_INCREF(value);
686     Py_XSETREF(op->gi_qualname, value);
687     return 0;
688 }
689 
690 static PyObject *
gen_getyieldfrom(PyGenObject * gen,void * Py_UNUSED (ignored))691 gen_getyieldfrom(PyGenObject *gen, void *Py_UNUSED(ignored))
692 {
693     PyObject *yf = _PyGen_yf(gen);
694     if (yf == NULL)
695         Py_RETURN_NONE;
696     return yf;
697 }
698 
699 static PyGetSetDef gen_getsetlist[] = {
700     {"__name__", (getter)gen_get_name, (setter)gen_set_name,
701      PyDoc_STR("name of the generator")},
702     {"__qualname__", (getter)gen_get_qualname, (setter)gen_set_qualname,
703      PyDoc_STR("qualified name of the generator")},
704     {"gi_yieldfrom", (getter)gen_getyieldfrom, NULL,
705      PyDoc_STR("object being iterated by yield from, or None")},
706     {NULL} /* Sentinel */
707 };
708 
709 static PyMemberDef gen_memberlist[] = {
710     {"gi_frame",     T_OBJECT, offsetof(PyGenObject, gi_frame),    READONLY},
711     {"gi_running",   T_BOOL,   offsetof(PyGenObject, gi_running),  READONLY},
712     {"gi_code",      T_OBJECT, offsetof(PyGenObject, gi_code),     READONLY},
713     {NULL}      /* Sentinel */
714 };
715 
716 static PyMethodDef gen_methods[] = {
717     {"send",(PyCFunction)_PyGen_Send, METH_O, send_doc},
718     {"throw",(PyCFunction)gen_throw, METH_VARARGS, throw_doc},
719     {"close",(PyCFunction)gen_close, METH_NOARGS, close_doc},
720     {NULL, NULL}        /* Sentinel */
721 };
722 
723 PyTypeObject PyGen_Type = {
724     PyVarObject_HEAD_INIT(&PyType_Type, 0)
725     "generator",                                /* tp_name */
726     sizeof(PyGenObject),                        /* tp_basicsize */
727     0,                                          /* tp_itemsize */
728     /* methods */
729     (destructor)gen_dealloc,                    /* tp_dealloc */
730     0,                                          /* tp_print */
731     0,                                          /* tp_getattr */
732     0,                                          /* tp_setattr */
733     0,                                          /* tp_as_async */
734     (reprfunc)gen_repr,                         /* tp_repr */
735     0,                                          /* tp_as_number */
736     0,                                          /* tp_as_sequence */
737     0,                                          /* tp_as_mapping */
738     0,                                          /* tp_hash */
739     0,                                          /* tp_call */
740     0,                                          /* tp_str */
741     PyObject_GenericGetAttr,                    /* tp_getattro */
742     0,                                          /* tp_setattro */
743     0,                                          /* tp_as_buffer */
744     Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
745         Py_TPFLAGS_HAVE_FINALIZE,               /* tp_flags */
746     0,                                          /* tp_doc */
747     (traverseproc)gen_traverse,                 /* tp_traverse */
748     0,                                          /* tp_clear */
749     0,                                          /* tp_richcompare */
750     offsetof(PyGenObject, gi_weakreflist),      /* tp_weaklistoffset */
751     PyObject_SelfIter,                          /* tp_iter */
752     (iternextfunc)gen_iternext,                 /* tp_iternext */
753     gen_methods,                                /* tp_methods */
754     gen_memberlist,                             /* tp_members */
755     gen_getsetlist,                             /* tp_getset */
756     0,                                          /* tp_base */
757     0,                                          /* tp_dict */
758 
759     0,                                          /* tp_descr_get */
760     0,                                          /* tp_descr_set */
761     0,                                          /* tp_dictoffset */
762     0,                                          /* tp_init */
763     0,                                          /* tp_alloc */
764     0,                                          /* tp_new */
765     0,                                          /* tp_free */
766     0,                                          /* tp_is_gc */
767     0,                                          /* tp_bases */
768     0,                                          /* tp_mro */
769     0,                                          /* tp_cache */
770     0,                                          /* tp_subclasses */
771     0,                                          /* tp_weaklist */
772     0,                                          /* tp_del */
773     0,                                          /* tp_version_tag */
774     _PyGen_Finalize,                            /* tp_finalize */
775 };
776 
777 static PyObject *
gen_new_with_qualname(PyTypeObject * type,PyFrameObject * f,PyObject * name,PyObject * qualname)778 gen_new_with_qualname(PyTypeObject *type, PyFrameObject *f,
779                       PyObject *name, PyObject *qualname)
780 {
781     PyGenObject *gen = PyObject_GC_New(PyGenObject, type);
782     if (gen == NULL) {
783         Py_DECREF(f);
784         return NULL;
785     }
786     gen->gi_frame = f;
787     f->f_gen = (PyObject *) gen;
788     Py_INCREF(f->f_code);
789     gen->gi_code = (PyObject *)(f->f_code);
790     gen->gi_running = 0;
791     gen->gi_weakreflist = NULL;
792     gen->gi_exc_state.exc_type = NULL;
793     gen->gi_exc_state.exc_value = NULL;
794     gen->gi_exc_state.exc_traceback = NULL;
795     gen->gi_exc_state.previous_item = NULL;
796     if (name != NULL)
797         gen->gi_name = name;
798     else
799         gen->gi_name = ((PyCodeObject *)gen->gi_code)->co_name;
800     Py_INCREF(gen->gi_name);
801     if (qualname != NULL)
802         gen->gi_qualname = qualname;
803     else
804         gen->gi_qualname = gen->gi_name;
805     Py_INCREF(gen->gi_qualname);
806     _PyObject_GC_TRACK(gen);
807     return (PyObject *)gen;
808 }
809 
810 PyObject *
PyGen_NewWithQualName(PyFrameObject * f,PyObject * name,PyObject * qualname)811 PyGen_NewWithQualName(PyFrameObject *f, PyObject *name, PyObject *qualname)
812 {
813     return gen_new_with_qualname(&PyGen_Type, f, name, qualname);
814 }
815 
816 PyObject *
PyGen_New(PyFrameObject * f)817 PyGen_New(PyFrameObject *f)
818 {
819     return gen_new_with_qualname(&PyGen_Type, f, NULL, NULL);
820 }
821 
822 int
PyGen_NeedsFinalizing(PyGenObject * gen)823 PyGen_NeedsFinalizing(PyGenObject *gen)
824 {
825     int i;
826     PyFrameObject *f = gen->gi_frame;
827 
828     if (f == NULL || f->f_stacktop == NULL)
829         return 0; /* no frame or empty blockstack == no finalization */
830 
831     /* Any block type besides a loop requires cleanup. */
832     for (i = 0; i < f->f_iblock; i++)
833         if (f->f_blockstack[i].b_type != SETUP_LOOP)
834             return 1;
835 
836     /* No blocks except loops, it's safe to skip finalization. */
837     return 0;
838 }
839 
840 /* Coroutine Object */
841 
842 typedef struct {
843     PyObject_HEAD
844     PyCoroObject *cw_coroutine;
845 } PyCoroWrapper;
846 
847 static int
gen_is_coroutine(PyObject * o)848 gen_is_coroutine(PyObject *o)
849 {
850     if (PyGen_CheckExact(o)) {
851         PyCodeObject *code = (PyCodeObject *)((PyGenObject*)o)->gi_code;
852         if (code->co_flags & CO_ITERABLE_COROUTINE) {
853             return 1;
854         }
855     }
856     return 0;
857 }
858 
859 /*
860  *   This helper function returns an awaitable for `o`:
861  *     - `o` if `o` is a coroutine-object;
862  *     - `type(o)->tp_as_async->am_await(o)`
863  *
864  *   Raises a TypeError if it's not possible to return
865  *   an awaitable and returns NULL.
866  */
867 PyObject *
_PyCoro_GetAwaitableIter(PyObject * o)868 _PyCoro_GetAwaitableIter(PyObject *o)
869 {
870     unaryfunc getter = NULL;
871     PyTypeObject *ot;
872 
873     if (PyCoro_CheckExact(o) || gen_is_coroutine(o)) {
874         /* 'o' is a coroutine. */
875         Py_INCREF(o);
876         return o;
877     }
878 
879     ot = Py_TYPE(o);
880     if (ot->tp_as_async != NULL) {
881         getter = ot->tp_as_async->am_await;
882     }
883     if (getter != NULL) {
884         PyObject *res = (*getter)(o);
885         if (res != NULL) {
886             if (PyCoro_CheckExact(res) || gen_is_coroutine(res)) {
887                 /* __await__ must return an *iterator*, not
888                    a coroutine or another awaitable (see PEP 492) */
889                 PyErr_SetString(PyExc_TypeError,
890                                 "__await__() returned a coroutine");
891                 Py_CLEAR(res);
892             } else if (!PyIter_Check(res)) {
893                 PyErr_Format(PyExc_TypeError,
894                              "__await__() returned non-iterator "
895                              "of type '%.100s'",
896                              Py_TYPE(res)->tp_name);
897                 Py_CLEAR(res);
898             }
899         }
900         return res;
901     }
902 
903     PyErr_Format(PyExc_TypeError,
904                  "object %.100s can't be used in 'await' expression",
905                  ot->tp_name);
906     return NULL;
907 }
908 
909 static PyObject *
coro_repr(PyCoroObject * coro)910 coro_repr(PyCoroObject *coro)
911 {
912     return PyUnicode_FromFormat("<coroutine object %S at %p>",
913                                 coro->cr_qualname, coro);
914 }
915 
916 static PyObject *
coro_await(PyCoroObject * coro)917 coro_await(PyCoroObject *coro)
918 {
919     PyCoroWrapper *cw = PyObject_GC_New(PyCoroWrapper, &_PyCoroWrapper_Type);
920     if (cw == NULL) {
921         return NULL;
922     }
923     Py_INCREF(coro);
924     cw->cw_coroutine = coro;
925     _PyObject_GC_TRACK(cw);
926     return (PyObject *)cw;
927 }
928 
929 static PyObject *
coro_get_cr_await(PyCoroObject * coro,void * Py_UNUSED (ignored))930 coro_get_cr_await(PyCoroObject *coro, void *Py_UNUSED(ignored))
931 {
932     PyObject *yf = _PyGen_yf((PyGenObject *) coro);
933     if (yf == NULL)
934         Py_RETURN_NONE;
935     return yf;
936 }
937 
938 static PyGetSetDef coro_getsetlist[] = {
939     {"__name__", (getter)gen_get_name, (setter)gen_set_name,
940      PyDoc_STR("name of the coroutine")},
941     {"__qualname__", (getter)gen_get_qualname, (setter)gen_set_qualname,
942      PyDoc_STR("qualified name of the coroutine")},
943     {"cr_await", (getter)coro_get_cr_await, NULL,
944      PyDoc_STR("object being awaited on, or None")},
945     {NULL} /* Sentinel */
946 };
947 
948 static PyMemberDef coro_memberlist[] = {
949     {"cr_frame",     T_OBJECT, offsetof(PyCoroObject, cr_frame),    READONLY},
950     {"cr_running",   T_BOOL,   offsetof(PyCoroObject, cr_running),  READONLY},
951     {"cr_code",      T_OBJECT, offsetof(PyCoroObject, cr_code),     READONLY},
952     {"cr_origin",    T_OBJECT, offsetof(PyCoroObject, cr_origin),   READONLY},
953     {NULL}      /* Sentinel */
954 };
955 
956 PyDoc_STRVAR(coro_send_doc,
957 "send(arg) -> send 'arg' into coroutine,\n\
958 return next iterated value or raise StopIteration.");
959 
960 PyDoc_STRVAR(coro_throw_doc,
961 "throw(typ[,val[,tb]]) -> raise exception in coroutine,\n\
962 return next iterated value or raise StopIteration.");
963 
964 PyDoc_STRVAR(coro_close_doc,
965 "close() -> raise GeneratorExit inside coroutine.");
966 
967 static PyMethodDef coro_methods[] = {
968     {"send",(PyCFunction)_PyGen_Send, METH_O, coro_send_doc},
969     {"throw",(PyCFunction)gen_throw, METH_VARARGS, coro_throw_doc},
970     {"close",(PyCFunction)gen_close, METH_NOARGS, coro_close_doc},
971     {NULL, NULL}        /* Sentinel */
972 };
973 
974 static PyAsyncMethods coro_as_async = {
975     (unaryfunc)coro_await,                      /* am_await */
976     0,                                          /* am_aiter */
977     0                                           /* am_anext */
978 };
979 
980 PyTypeObject PyCoro_Type = {
981     PyVarObject_HEAD_INIT(&PyType_Type, 0)
982     "coroutine",                                /* tp_name */
983     sizeof(PyCoroObject),                       /* tp_basicsize */
984     0,                                          /* tp_itemsize */
985     /* methods */
986     (destructor)gen_dealloc,                    /* tp_dealloc */
987     0,                                          /* tp_print */
988     0,                                          /* tp_getattr */
989     0,                                          /* tp_setattr */
990     &coro_as_async,                             /* tp_as_async */
991     (reprfunc)coro_repr,                        /* tp_repr */
992     0,                                          /* tp_as_number */
993     0,                                          /* tp_as_sequence */
994     0,                                          /* tp_as_mapping */
995     0,                                          /* tp_hash */
996     0,                                          /* tp_call */
997     0,                                          /* tp_str */
998     PyObject_GenericGetAttr,                    /* tp_getattro */
999     0,                                          /* tp_setattro */
1000     0,                                          /* tp_as_buffer */
1001     Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
1002         Py_TPFLAGS_HAVE_FINALIZE,               /* tp_flags */
1003     0,                                          /* tp_doc */
1004     (traverseproc)gen_traverse,                 /* tp_traverse */
1005     0,                                          /* tp_clear */
1006     0,                                          /* tp_richcompare */
1007     offsetof(PyCoroObject, cr_weakreflist),     /* tp_weaklistoffset */
1008     0,                                          /* tp_iter */
1009     0,                                          /* tp_iternext */
1010     coro_methods,                               /* tp_methods */
1011     coro_memberlist,                            /* tp_members */
1012     coro_getsetlist,                            /* tp_getset */
1013     0,                                          /* tp_base */
1014     0,                                          /* tp_dict */
1015     0,                                          /* tp_descr_get */
1016     0,                                          /* tp_descr_set */
1017     0,                                          /* tp_dictoffset */
1018     0,                                          /* tp_init */
1019     0,                                          /* tp_alloc */
1020     0,                                          /* tp_new */
1021     0,                                          /* tp_free */
1022     0,                                          /* tp_is_gc */
1023     0,                                          /* tp_bases */
1024     0,                                          /* tp_mro */
1025     0,                                          /* tp_cache */
1026     0,                                          /* tp_subclasses */
1027     0,                                          /* tp_weaklist */
1028     0,                                          /* tp_del */
1029     0,                                          /* tp_version_tag */
1030     _PyGen_Finalize,                            /* tp_finalize */
1031 };
1032 
1033 static void
coro_wrapper_dealloc(PyCoroWrapper * cw)1034 coro_wrapper_dealloc(PyCoroWrapper *cw)
1035 {
1036     _PyObject_GC_UNTRACK((PyObject *)cw);
1037     Py_CLEAR(cw->cw_coroutine);
1038     PyObject_GC_Del(cw);
1039 }
1040 
1041 static PyObject *
coro_wrapper_iternext(PyCoroWrapper * cw)1042 coro_wrapper_iternext(PyCoroWrapper *cw)
1043 {
1044     return gen_send_ex((PyGenObject *)cw->cw_coroutine, NULL, 0, 0);
1045 }
1046 
1047 static PyObject *
coro_wrapper_send(PyCoroWrapper * cw,PyObject * arg)1048 coro_wrapper_send(PyCoroWrapper *cw, PyObject *arg)
1049 {
1050     return gen_send_ex((PyGenObject *)cw->cw_coroutine, arg, 0, 0);
1051 }
1052 
1053 static PyObject *
coro_wrapper_throw(PyCoroWrapper * cw,PyObject * args)1054 coro_wrapper_throw(PyCoroWrapper *cw, PyObject *args)
1055 {
1056     return gen_throw((PyGenObject *)cw->cw_coroutine, args);
1057 }
1058 
1059 static PyObject *
coro_wrapper_close(PyCoroWrapper * cw,PyObject * args)1060 coro_wrapper_close(PyCoroWrapper *cw, PyObject *args)
1061 {
1062     return gen_close((PyGenObject *)cw->cw_coroutine, args);
1063 }
1064 
1065 static int
coro_wrapper_traverse(PyCoroWrapper * cw,visitproc visit,void * arg)1066 coro_wrapper_traverse(PyCoroWrapper *cw, visitproc visit, void *arg)
1067 {
1068     Py_VISIT((PyObject *)cw->cw_coroutine);
1069     return 0;
1070 }
1071 
1072 static PyMethodDef coro_wrapper_methods[] = {
1073     {"send",(PyCFunction)coro_wrapper_send, METH_O, coro_send_doc},
1074     {"throw",(PyCFunction)coro_wrapper_throw, METH_VARARGS, coro_throw_doc},
1075     {"close",(PyCFunction)coro_wrapper_close, METH_NOARGS, coro_close_doc},
1076     {NULL, NULL}        /* Sentinel */
1077 };
1078 
1079 PyTypeObject _PyCoroWrapper_Type = {
1080     PyVarObject_HEAD_INIT(&PyType_Type, 0)
1081     "coroutine_wrapper",
1082     sizeof(PyCoroWrapper),                      /* tp_basicsize */
1083     0,                                          /* tp_itemsize */
1084     (destructor)coro_wrapper_dealloc,           /* destructor tp_dealloc */
1085     0,                                          /* tp_print */
1086     0,                                          /* tp_getattr */
1087     0,                                          /* tp_setattr */
1088     0,                                          /* tp_as_async */
1089     0,                                          /* tp_repr */
1090     0,                                          /* tp_as_number */
1091     0,                                          /* tp_as_sequence */
1092     0,                                          /* tp_as_mapping */
1093     0,                                          /* tp_hash */
1094     0,                                          /* tp_call */
1095     0,                                          /* tp_str */
1096     PyObject_GenericGetAttr,                    /* tp_getattro */
1097     0,                                          /* tp_setattro */
1098     0,                                          /* tp_as_buffer */
1099     Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,    /* tp_flags */
1100     "A wrapper object implementing __await__ for coroutines.",
1101     (traverseproc)coro_wrapper_traverse,        /* tp_traverse */
1102     0,                                          /* tp_clear */
1103     0,                                          /* tp_richcompare */
1104     0,                                          /* tp_weaklistoffset */
1105     PyObject_SelfIter,                          /* tp_iter */
1106     (iternextfunc)coro_wrapper_iternext,        /* tp_iternext */
1107     coro_wrapper_methods,                       /* tp_methods */
1108     0,                                          /* tp_members */
1109     0,                                          /* tp_getset */
1110     0,                                          /* tp_base */
1111     0,                                          /* tp_dict */
1112     0,                                          /* tp_descr_get */
1113     0,                                          /* tp_descr_set */
1114     0,                                          /* tp_dictoffset */
1115     0,                                          /* tp_init */
1116     0,                                          /* tp_alloc */
1117     0,                                          /* tp_new */
1118     0,                                          /* tp_free */
1119 };
1120 
1121 static PyObject *
compute_cr_origin(int origin_depth)1122 compute_cr_origin(int origin_depth)
1123 {
1124     PyFrameObject *frame = PyEval_GetFrame();
1125     /* First count how many frames we have */
1126     int frame_count = 0;
1127     for (; frame && frame_count < origin_depth; ++frame_count) {
1128         frame = frame->f_back;
1129     }
1130 
1131     /* Now collect them */
1132     PyObject *cr_origin = PyTuple_New(frame_count);
1133     if (cr_origin == NULL) {
1134         return NULL;
1135     }
1136     frame = PyEval_GetFrame();
1137     for (int i = 0; i < frame_count; ++i) {
1138         PyObject *frameinfo = Py_BuildValue(
1139             "OiO",
1140             frame->f_code->co_filename,
1141             PyFrame_GetLineNumber(frame),
1142             frame->f_code->co_name);
1143         if (!frameinfo) {
1144             Py_DECREF(cr_origin);
1145             return NULL;
1146         }
1147         PyTuple_SET_ITEM(cr_origin, i, frameinfo);
1148         frame = frame->f_back;
1149     }
1150 
1151     return cr_origin;
1152 }
1153 
1154 PyObject *
PyCoro_New(PyFrameObject * f,PyObject * name,PyObject * qualname)1155 PyCoro_New(PyFrameObject *f, PyObject *name, PyObject *qualname)
1156 {
1157     PyObject *coro = gen_new_with_qualname(&PyCoro_Type, f, name, qualname);
1158     if (!coro) {
1159         return NULL;
1160     }
1161 
1162     PyThreadState *tstate = PyThreadState_GET();
1163     int origin_depth = tstate->coroutine_origin_tracking_depth;
1164 
1165     if (origin_depth == 0) {
1166         ((PyCoroObject *)coro)->cr_origin = NULL;
1167     } else {
1168         PyObject *cr_origin = compute_cr_origin(origin_depth);
1169         ((PyCoroObject *)coro)->cr_origin = cr_origin;
1170         if (!cr_origin) {
1171             Py_DECREF(coro);
1172             return NULL;
1173         }
1174     }
1175 
1176     return coro;
1177 }
1178 
1179 
1180 /* ========= Asynchronous Generators ========= */
1181 
1182 
1183 typedef enum {
1184     AWAITABLE_STATE_INIT,   /* new awaitable, has not yet been iterated */
1185     AWAITABLE_STATE_ITER,   /* being iterated */
1186     AWAITABLE_STATE_CLOSED, /* closed */
1187 } AwaitableState;
1188 
1189 
1190 typedef struct {
1191     PyObject_HEAD
1192     PyAsyncGenObject *ags_gen;
1193 
1194     /* Can be NULL, when in the __anext__() mode
1195        (equivalent of "asend(None)") */
1196     PyObject *ags_sendval;
1197 
1198     AwaitableState ags_state;
1199 } PyAsyncGenASend;
1200 
1201 
1202 typedef struct {
1203     PyObject_HEAD
1204     PyAsyncGenObject *agt_gen;
1205 
1206     /* Can be NULL, when in the "aclose()" mode
1207        (equivalent of "athrow(GeneratorExit)") */
1208     PyObject *agt_args;
1209 
1210     AwaitableState agt_state;
1211 } PyAsyncGenAThrow;
1212 
1213 
1214 typedef struct {
1215     PyObject_HEAD
1216     PyObject *agw_val;
1217 } _PyAsyncGenWrappedValue;
1218 
1219 
1220 #ifndef _PyAsyncGen_MAXFREELIST
1221 #define _PyAsyncGen_MAXFREELIST 80
1222 #endif
1223 
1224 /* Freelists boost performance 6-10%; they also reduce memory
1225    fragmentation, as _PyAsyncGenWrappedValue and PyAsyncGenASend
1226    are short-living objects that are instantiated for every
1227    __anext__ call.
1228 */
1229 
1230 static _PyAsyncGenWrappedValue *ag_value_freelist[_PyAsyncGen_MAXFREELIST];
1231 static int ag_value_freelist_free = 0;
1232 
1233 static PyAsyncGenASend *ag_asend_freelist[_PyAsyncGen_MAXFREELIST];
1234 static int ag_asend_freelist_free = 0;
1235 
1236 #define _PyAsyncGenWrappedValue_CheckExact(o) \
1237                     (Py_TYPE(o) == &_PyAsyncGenWrappedValue_Type)
1238 
1239 #define PyAsyncGenASend_CheckExact(o) \
1240                     (Py_TYPE(o) == &_PyAsyncGenASend_Type)
1241 
1242 
1243 static int
async_gen_traverse(PyAsyncGenObject * gen,visitproc visit,void * arg)1244 async_gen_traverse(PyAsyncGenObject *gen, visitproc visit, void *arg)
1245 {
1246     Py_VISIT(gen->ag_finalizer);
1247     return gen_traverse((PyGenObject*)gen, visit, arg);
1248 }
1249 
1250 
1251 static PyObject *
async_gen_repr(PyAsyncGenObject * o)1252 async_gen_repr(PyAsyncGenObject *o)
1253 {
1254     return PyUnicode_FromFormat("<async_generator object %S at %p>",
1255                                 o->ag_qualname, o);
1256 }
1257 
1258 
1259 static int
async_gen_init_hooks(PyAsyncGenObject * o)1260 async_gen_init_hooks(PyAsyncGenObject *o)
1261 {
1262     PyThreadState *tstate;
1263     PyObject *finalizer;
1264     PyObject *firstiter;
1265 
1266     if (o->ag_hooks_inited) {
1267         return 0;
1268     }
1269 
1270     o->ag_hooks_inited = 1;
1271 
1272     tstate = PyThreadState_GET();
1273 
1274     finalizer = tstate->async_gen_finalizer;
1275     if (finalizer) {
1276         Py_INCREF(finalizer);
1277         o->ag_finalizer = finalizer;
1278     }
1279 
1280     firstiter = tstate->async_gen_firstiter;
1281     if (firstiter) {
1282         PyObject *res;
1283 
1284         Py_INCREF(firstiter);
1285         res = PyObject_CallFunctionObjArgs(firstiter, o, NULL);
1286         Py_DECREF(firstiter);
1287         if (res == NULL) {
1288             return 1;
1289         }
1290         Py_DECREF(res);
1291     }
1292 
1293     return 0;
1294 }
1295 
1296 
1297 static PyObject *
async_gen_anext(PyAsyncGenObject * o)1298 async_gen_anext(PyAsyncGenObject *o)
1299 {
1300     if (async_gen_init_hooks(o)) {
1301         return NULL;
1302     }
1303     return async_gen_asend_new(o, NULL);
1304 }
1305 
1306 
1307 static PyObject *
async_gen_asend(PyAsyncGenObject * o,PyObject * arg)1308 async_gen_asend(PyAsyncGenObject *o, PyObject *arg)
1309 {
1310     if (async_gen_init_hooks(o)) {
1311         return NULL;
1312     }
1313     return async_gen_asend_new(o, arg);
1314 }
1315 
1316 
1317 static PyObject *
async_gen_aclose(PyAsyncGenObject * o,PyObject * arg)1318 async_gen_aclose(PyAsyncGenObject *o, PyObject *arg)
1319 {
1320     if (async_gen_init_hooks(o)) {
1321         return NULL;
1322     }
1323     return async_gen_athrow_new(o, NULL);
1324 }
1325 
1326 static PyObject *
async_gen_athrow(PyAsyncGenObject * o,PyObject * args)1327 async_gen_athrow(PyAsyncGenObject *o, PyObject *args)
1328 {
1329     if (async_gen_init_hooks(o)) {
1330         return NULL;
1331     }
1332     return async_gen_athrow_new(o, args);
1333 }
1334 
1335 
1336 static PyGetSetDef async_gen_getsetlist[] = {
1337     {"__name__", (getter)gen_get_name, (setter)gen_set_name,
1338      PyDoc_STR("name of the async generator")},
1339     {"__qualname__", (getter)gen_get_qualname, (setter)gen_set_qualname,
1340      PyDoc_STR("qualified name of the async generator")},
1341     {"ag_await", (getter)coro_get_cr_await, NULL,
1342      PyDoc_STR("object being awaited on, or None")},
1343     {NULL} /* Sentinel */
1344 };
1345 
1346 static PyMemberDef async_gen_memberlist[] = {
1347     {"ag_frame",   T_OBJECT, offsetof(PyAsyncGenObject, ag_frame),   READONLY},
1348     {"ag_running", T_BOOL,   offsetof(PyAsyncGenObject, ag_running), READONLY},
1349     {"ag_code",    T_OBJECT, offsetof(PyAsyncGenObject, ag_code),    READONLY},
1350     {NULL}      /* Sentinel */
1351 };
1352 
1353 PyDoc_STRVAR(async_aclose_doc,
1354 "aclose() -> raise GeneratorExit inside generator.");
1355 
1356 PyDoc_STRVAR(async_asend_doc,
1357 "asend(v) -> send 'v' in generator.");
1358 
1359 PyDoc_STRVAR(async_athrow_doc,
1360 "athrow(typ[,val[,tb]]) -> raise exception in generator.");
1361 
1362 static PyMethodDef async_gen_methods[] = {
1363     {"asend", (PyCFunction)async_gen_asend, METH_O, async_asend_doc},
1364     {"athrow",(PyCFunction)async_gen_athrow, METH_VARARGS, async_athrow_doc},
1365     {"aclose", (PyCFunction)async_gen_aclose, METH_NOARGS, async_aclose_doc},
1366     {NULL, NULL}        /* Sentinel */
1367 };
1368 
1369 
1370 static PyAsyncMethods async_gen_as_async = {
1371     0,                                          /* am_await */
1372     PyObject_SelfIter,                          /* am_aiter */
1373     (unaryfunc)async_gen_anext                  /* am_anext */
1374 };
1375 
1376 
1377 PyTypeObject PyAsyncGen_Type = {
1378     PyVarObject_HEAD_INIT(&PyType_Type, 0)
1379     "async_generator",                          /* tp_name */
1380     sizeof(PyAsyncGenObject),                   /* tp_basicsize */
1381     0,                                          /* tp_itemsize */
1382     /* methods */
1383     (destructor)gen_dealloc,                    /* tp_dealloc */
1384     0,                                          /* tp_print */
1385     0,                                          /* tp_getattr */
1386     0,                                          /* tp_setattr */
1387     &async_gen_as_async,                        /* tp_as_async */
1388     (reprfunc)async_gen_repr,                   /* tp_repr */
1389     0,                                          /* tp_as_number */
1390     0,                                          /* tp_as_sequence */
1391     0,                                          /* tp_as_mapping */
1392     0,                                          /* tp_hash */
1393     0,                                          /* tp_call */
1394     0,                                          /* tp_str */
1395     PyObject_GenericGetAttr,                    /* tp_getattro */
1396     0,                                          /* tp_setattro */
1397     0,                                          /* tp_as_buffer */
1398     Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
1399         Py_TPFLAGS_HAVE_FINALIZE,               /* tp_flags */
1400     0,                                          /* tp_doc */
1401     (traverseproc)async_gen_traverse,           /* tp_traverse */
1402     0,                                          /* tp_clear */
1403     0,                                          /* tp_richcompare */
1404     offsetof(PyAsyncGenObject, ag_weakreflist), /* tp_weaklistoffset */
1405     0,                                          /* tp_iter */
1406     0,                                          /* tp_iternext */
1407     async_gen_methods,                          /* tp_methods */
1408     async_gen_memberlist,                       /* tp_members */
1409     async_gen_getsetlist,                       /* tp_getset */
1410     0,                                          /* tp_base */
1411     0,                                          /* tp_dict */
1412     0,                                          /* tp_descr_get */
1413     0,                                          /* tp_descr_set */
1414     0,                                          /* tp_dictoffset */
1415     0,                                          /* tp_init */
1416     0,                                          /* tp_alloc */
1417     0,                                          /* tp_new */
1418     0,                                          /* tp_free */
1419     0,                                          /* tp_is_gc */
1420     0,                                          /* tp_bases */
1421     0,                                          /* tp_mro */
1422     0,                                          /* tp_cache */
1423     0,                                          /* tp_subclasses */
1424     0,                                          /* tp_weaklist */
1425     0,                                          /* tp_del */
1426     0,                                          /* tp_version_tag */
1427     _PyGen_Finalize,                            /* tp_finalize */
1428 };
1429 
1430 
1431 PyObject *
PyAsyncGen_New(PyFrameObject * f,PyObject * name,PyObject * qualname)1432 PyAsyncGen_New(PyFrameObject *f, PyObject *name, PyObject *qualname)
1433 {
1434     PyAsyncGenObject *o;
1435     o = (PyAsyncGenObject *)gen_new_with_qualname(
1436         &PyAsyncGen_Type, f, name, qualname);
1437     if (o == NULL) {
1438         return NULL;
1439     }
1440     o->ag_finalizer = NULL;
1441     o->ag_closed = 0;
1442     o->ag_hooks_inited = 0;
1443     return (PyObject*)o;
1444 }
1445 
1446 
1447 int
PyAsyncGen_ClearFreeLists(void)1448 PyAsyncGen_ClearFreeLists(void)
1449 {
1450     int ret = ag_value_freelist_free + ag_asend_freelist_free;
1451 
1452     while (ag_value_freelist_free) {
1453         _PyAsyncGenWrappedValue *o;
1454         o = ag_value_freelist[--ag_value_freelist_free];
1455         assert(_PyAsyncGenWrappedValue_CheckExact(o));
1456         PyObject_GC_Del(o);
1457     }
1458 
1459     while (ag_asend_freelist_free) {
1460         PyAsyncGenASend *o;
1461         o = ag_asend_freelist[--ag_asend_freelist_free];
1462         assert(Py_TYPE(o) == &_PyAsyncGenASend_Type);
1463         PyObject_GC_Del(o);
1464     }
1465 
1466     return ret;
1467 }
1468 
1469 void
PyAsyncGen_Fini(void)1470 PyAsyncGen_Fini(void)
1471 {
1472     PyAsyncGen_ClearFreeLists();
1473 }
1474 
1475 
1476 static PyObject *
async_gen_unwrap_value(PyAsyncGenObject * gen,PyObject * result)1477 async_gen_unwrap_value(PyAsyncGenObject *gen, PyObject *result)
1478 {
1479     if (result == NULL) {
1480         if (!PyErr_Occurred()) {
1481             PyErr_SetNone(PyExc_StopAsyncIteration);
1482         }
1483 
1484         if (PyErr_ExceptionMatches(PyExc_StopAsyncIteration)
1485             || PyErr_ExceptionMatches(PyExc_GeneratorExit)
1486         ) {
1487             gen->ag_closed = 1;
1488         }
1489 
1490         return NULL;
1491     }
1492 
1493     if (_PyAsyncGenWrappedValue_CheckExact(result)) {
1494         /* async yield */
1495         _PyGen_SetStopIterationValue(((_PyAsyncGenWrappedValue*)result)->agw_val);
1496         Py_DECREF(result);
1497         return NULL;
1498     }
1499 
1500     return result;
1501 }
1502 
1503 
1504 /* ---------- Async Generator ASend Awaitable ------------ */
1505 
1506 
1507 static void
async_gen_asend_dealloc(PyAsyncGenASend * o)1508 async_gen_asend_dealloc(PyAsyncGenASend *o)
1509 {
1510     _PyObject_GC_UNTRACK((PyObject *)o);
1511     Py_CLEAR(o->ags_gen);
1512     Py_CLEAR(o->ags_sendval);
1513     if (ag_asend_freelist_free < _PyAsyncGen_MAXFREELIST) {
1514         assert(PyAsyncGenASend_CheckExact(o));
1515         ag_asend_freelist[ag_asend_freelist_free++] = o;
1516     } else {
1517         PyObject_GC_Del(o);
1518     }
1519 }
1520 
1521 static int
async_gen_asend_traverse(PyAsyncGenASend * o,visitproc visit,void * arg)1522 async_gen_asend_traverse(PyAsyncGenASend *o, visitproc visit, void *arg)
1523 {
1524     Py_VISIT(o->ags_gen);
1525     Py_VISIT(o->ags_sendval);
1526     return 0;
1527 }
1528 
1529 
1530 static PyObject *
async_gen_asend_send(PyAsyncGenASend * o,PyObject * arg)1531 async_gen_asend_send(PyAsyncGenASend *o, PyObject *arg)
1532 {
1533     PyObject *result;
1534 
1535     if (o->ags_state == AWAITABLE_STATE_CLOSED) {
1536         PyErr_SetNone(PyExc_StopIteration);
1537         return NULL;
1538     }
1539 
1540     if (o->ags_state == AWAITABLE_STATE_INIT) {
1541         if (arg == NULL || arg == Py_None) {
1542             arg = o->ags_sendval;
1543         }
1544         o->ags_state = AWAITABLE_STATE_ITER;
1545     }
1546 
1547     result = gen_send_ex((PyGenObject*)o->ags_gen, arg, 0, 0);
1548     result = async_gen_unwrap_value(o->ags_gen, result);
1549 
1550     if (result == NULL) {
1551         o->ags_state = AWAITABLE_STATE_CLOSED;
1552     }
1553 
1554     return result;
1555 }
1556 
1557 
1558 static PyObject *
async_gen_asend_iternext(PyAsyncGenASend * o)1559 async_gen_asend_iternext(PyAsyncGenASend *o)
1560 {
1561     return async_gen_asend_send(o, NULL);
1562 }
1563 
1564 
1565 static PyObject *
async_gen_asend_throw(PyAsyncGenASend * o,PyObject * args)1566 async_gen_asend_throw(PyAsyncGenASend *o, PyObject *args)
1567 {
1568     PyObject *result;
1569 
1570     if (o->ags_state == AWAITABLE_STATE_CLOSED) {
1571         PyErr_SetNone(PyExc_StopIteration);
1572         return NULL;
1573     }
1574 
1575     result = gen_throw((PyGenObject*)o->ags_gen, args);
1576     result = async_gen_unwrap_value(o->ags_gen, result);
1577 
1578     if (result == NULL) {
1579         o->ags_state = AWAITABLE_STATE_CLOSED;
1580     }
1581 
1582     return result;
1583 }
1584 
1585 
1586 static PyObject *
async_gen_asend_close(PyAsyncGenASend * o,PyObject * args)1587 async_gen_asend_close(PyAsyncGenASend *o, PyObject *args)
1588 {
1589     o->ags_state = AWAITABLE_STATE_CLOSED;
1590     Py_RETURN_NONE;
1591 }
1592 
1593 
1594 static PyMethodDef async_gen_asend_methods[] = {
1595     {"send", (PyCFunction)async_gen_asend_send, METH_O, send_doc},
1596     {"throw", (PyCFunction)async_gen_asend_throw, METH_VARARGS, throw_doc},
1597     {"close", (PyCFunction)async_gen_asend_close, METH_NOARGS, close_doc},
1598     {NULL, NULL}        /* Sentinel */
1599 };
1600 
1601 
1602 static PyAsyncMethods async_gen_asend_as_async = {
1603     PyObject_SelfIter,                          /* am_await */
1604     0,                                          /* am_aiter */
1605     0                                           /* am_anext */
1606 };
1607 
1608 
1609 PyTypeObject _PyAsyncGenASend_Type = {
1610     PyVarObject_HEAD_INIT(&PyType_Type, 0)
1611     "async_generator_asend",                    /* tp_name */
1612     sizeof(PyAsyncGenASend),                    /* tp_basicsize */
1613     0,                                          /* tp_itemsize */
1614     /* methods */
1615     (destructor)async_gen_asend_dealloc,        /* tp_dealloc */
1616     0,                                          /* tp_print */
1617     0,                                          /* tp_getattr */
1618     0,                                          /* tp_setattr */
1619     &async_gen_asend_as_async,                  /* tp_as_async */
1620     0,                                          /* tp_repr */
1621     0,                                          /* tp_as_number */
1622     0,                                          /* tp_as_sequence */
1623     0,                                          /* tp_as_mapping */
1624     0,                                          /* tp_hash */
1625     0,                                          /* tp_call */
1626     0,                                          /* tp_str */
1627     PyObject_GenericGetAttr,                    /* tp_getattro */
1628     0,                                          /* tp_setattro */
1629     0,                                          /* tp_as_buffer */
1630     Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,    /* tp_flags */
1631     0,                                          /* tp_doc */
1632     (traverseproc)async_gen_asend_traverse,     /* tp_traverse */
1633     0,                                          /* tp_clear */
1634     0,                                          /* tp_richcompare */
1635     0,                                          /* tp_weaklistoffset */
1636     PyObject_SelfIter,                          /* tp_iter */
1637     (iternextfunc)async_gen_asend_iternext,     /* tp_iternext */
1638     async_gen_asend_methods,                    /* tp_methods */
1639     0,                                          /* tp_members */
1640     0,                                          /* tp_getset */
1641     0,                                          /* tp_base */
1642     0,                                          /* tp_dict */
1643     0,                                          /* tp_descr_get */
1644     0,                                          /* tp_descr_set */
1645     0,                                          /* tp_dictoffset */
1646     0,                                          /* tp_init */
1647     0,                                          /* tp_alloc */
1648     0,                                          /* tp_new */
1649 };
1650 
1651 
1652 static PyObject *
async_gen_asend_new(PyAsyncGenObject * gen,PyObject * sendval)1653 async_gen_asend_new(PyAsyncGenObject *gen, PyObject *sendval)
1654 {
1655     PyAsyncGenASend *o;
1656     if (ag_asend_freelist_free) {
1657         ag_asend_freelist_free--;
1658         o = ag_asend_freelist[ag_asend_freelist_free];
1659         _Py_NewReference((PyObject *)o);
1660     } else {
1661         o = PyObject_GC_New(PyAsyncGenASend, &_PyAsyncGenASend_Type);
1662         if (o == NULL) {
1663             return NULL;
1664         }
1665     }
1666 
1667     Py_INCREF(gen);
1668     o->ags_gen = gen;
1669 
1670     Py_XINCREF(sendval);
1671     o->ags_sendval = sendval;
1672 
1673     o->ags_state = AWAITABLE_STATE_INIT;
1674 
1675     _PyObject_GC_TRACK((PyObject*)o);
1676     return (PyObject*)o;
1677 }
1678 
1679 
1680 /* ---------- Async Generator Value Wrapper ------------ */
1681 
1682 
1683 static void
async_gen_wrapped_val_dealloc(_PyAsyncGenWrappedValue * o)1684 async_gen_wrapped_val_dealloc(_PyAsyncGenWrappedValue *o)
1685 {
1686     _PyObject_GC_UNTRACK((PyObject *)o);
1687     Py_CLEAR(o->agw_val);
1688     if (ag_value_freelist_free < _PyAsyncGen_MAXFREELIST) {
1689         assert(_PyAsyncGenWrappedValue_CheckExact(o));
1690         ag_value_freelist[ag_value_freelist_free++] = o;
1691     } else {
1692         PyObject_GC_Del(o);
1693     }
1694 }
1695 
1696 
1697 static int
async_gen_wrapped_val_traverse(_PyAsyncGenWrappedValue * o,visitproc visit,void * arg)1698 async_gen_wrapped_val_traverse(_PyAsyncGenWrappedValue *o,
1699                                visitproc visit, void *arg)
1700 {
1701     Py_VISIT(o->agw_val);
1702     return 0;
1703 }
1704 
1705 
1706 PyTypeObject _PyAsyncGenWrappedValue_Type = {
1707     PyVarObject_HEAD_INIT(&PyType_Type, 0)
1708     "async_generator_wrapped_value",            /* tp_name */
1709     sizeof(_PyAsyncGenWrappedValue),            /* tp_basicsize */
1710     0,                                          /* tp_itemsize */
1711     /* methods */
1712     (destructor)async_gen_wrapped_val_dealloc,  /* tp_dealloc */
1713     0,                                          /* tp_print */
1714     0,                                          /* tp_getattr */
1715     0,                                          /* tp_setattr */
1716     0,                                          /* tp_as_async */
1717     0,                                          /* tp_repr */
1718     0,                                          /* tp_as_number */
1719     0,                                          /* tp_as_sequence */
1720     0,                                          /* tp_as_mapping */
1721     0,                                          /* tp_hash */
1722     0,                                          /* tp_call */
1723     0,                                          /* tp_str */
1724     PyObject_GenericGetAttr,                    /* tp_getattro */
1725     0,                                          /* tp_setattro */
1726     0,                                          /* tp_as_buffer */
1727     Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,    /* tp_flags */
1728     0,                                          /* tp_doc */
1729     (traverseproc)async_gen_wrapped_val_traverse, /* tp_traverse */
1730     0,                                          /* tp_clear */
1731     0,                                          /* tp_richcompare */
1732     0,                                          /* tp_weaklistoffset */
1733     0,                                          /* tp_iter */
1734     0,                                          /* tp_iternext */
1735     0,                                          /* tp_methods */
1736     0,                                          /* tp_members */
1737     0,                                          /* tp_getset */
1738     0,                                          /* tp_base */
1739     0,                                          /* tp_dict */
1740     0,                                          /* tp_descr_get */
1741     0,                                          /* tp_descr_set */
1742     0,                                          /* tp_dictoffset */
1743     0,                                          /* tp_init */
1744     0,                                          /* tp_alloc */
1745     0,                                          /* tp_new */
1746 };
1747 
1748 
1749 PyObject *
_PyAsyncGenValueWrapperNew(PyObject * val)1750 _PyAsyncGenValueWrapperNew(PyObject *val)
1751 {
1752     _PyAsyncGenWrappedValue *o;
1753     assert(val);
1754 
1755     if (ag_value_freelist_free) {
1756         ag_value_freelist_free--;
1757         o = ag_value_freelist[ag_value_freelist_free];
1758         assert(_PyAsyncGenWrappedValue_CheckExact(o));
1759         _Py_NewReference((PyObject*)o);
1760     } else {
1761         o = PyObject_GC_New(_PyAsyncGenWrappedValue,
1762                             &_PyAsyncGenWrappedValue_Type);
1763         if (o == NULL) {
1764             return NULL;
1765         }
1766     }
1767     o->agw_val = val;
1768     Py_INCREF(val);
1769     _PyObject_GC_TRACK((PyObject*)o);
1770     return (PyObject*)o;
1771 }
1772 
1773 
1774 /* ---------- Async Generator AThrow awaitable ------------ */
1775 
1776 
1777 static void
async_gen_athrow_dealloc(PyAsyncGenAThrow * o)1778 async_gen_athrow_dealloc(PyAsyncGenAThrow *o)
1779 {
1780     _PyObject_GC_UNTRACK((PyObject *)o);
1781     Py_CLEAR(o->agt_gen);
1782     Py_CLEAR(o->agt_args);
1783     PyObject_GC_Del(o);
1784 }
1785 
1786 
1787 static int
async_gen_athrow_traverse(PyAsyncGenAThrow * o,visitproc visit,void * arg)1788 async_gen_athrow_traverse(PyAsyncGenAThrow *o, visitproc visit, void *arg)
1789 {
1790     Py_VISIT(o->agt_gen);
1791     Py_VISIT(o->agt_args);
1792     return 0;
1793 }
1794 
1795 
1796 static PyObject *
async_gen_athrow_send(PyAsyncGenAThrow * o,PyObject * arg)1797 async_gen_athrow_send(PyAsyncGenAThrow *o, PyObject *arg)
1798 {
1799     PyGenObject *gen = (PyGenObject*)o->agt_gen;
1800     PyFrameObject *f = gen->gi_frame;
1801     PyObject *retval;
1802 
1803     if (f == NULL || f->f_stacktop == NULL ||
1804             o->agt_state == AWAITABLE_STATE_CLOSED) {
1805         PyErr_SetNone(PyExc_StopIteration);
1806         return NULL;
1807     }
1808 
1809     if (o->agt_state == AWAITABLE_STATE_INIT) {
1810         if (o->agt_gen->ag_closed) {
1811             PyErr_SetNone(PyExc_StopIteration);
1812             return NULL;
1813         }
1814 
1815         if (arg != Py_None) {
1816             PyErr_SetString(PyExc_RuntimeError, NON_INIT_CORO_MSG);
1817             return NULL;
1818         }
1819 
1820         o->agt_state = AWAITABLE_STATE_ITER;
1821 
1822         if (o->agt_args == NULL) {
1823             /* aclose() mode */
1824             o->agt_gen->ag_closed = 1;
1825 
1826             retval = _gen_throw((PyGenObject *)gen,
1827                                 0,  /* Do not close generator when
1828                                        PyExc_GeneratorExit is passed */
1829                                 PyExc_GeneratorExit, NULL, NULL);
1830 
1831             if (retval && _PyAsyncGenWrappedValue_CheckExact(retval)) {
1832                 Py_DECREF(retval);
1833                 goto yield_close;
1834             }
1835         } else {
1836             PyObject *typ;
1837             PyObject *tb = NULL;
1838             PyObject *val = NULL;
1839 
1840             if (!PyArg_UnpackTuple(o->agt_args, "athrow", 1, 3,
1841                                    &typ, &val, &tb)) {
1842                 return NULL;
1843             }
1844 
1845             retval = _gen_throw((PyGenObject *)gen,
1846                                 0,  /* Do not close generator when
1847                                        PyExc_GeneratorExit is passed */
1848                                 typ, val, tb);
1849             retval = async_gen_unwrap_value(o->agt_gen, retval);
1850         }
1851         if (retval == NULL) {
1852             goto check_error;
1853         }
1854         return retval;
1855     }
1856 
1857     assert(o->agt_state == AWAITABLE_STATE_ITER);
1858 
1859     retval = gen_send_ex((PyGenObject *)gen, arg, 0, 0);
1860     if (o->agt_args) {
1861         return async_gen_unwrap_value(o->agt_gen, retval);
1862     } else {
1863         /* aclose() mode */
1864         if (retval) {
1865             if (_PyAsyncGenWrappedValue_CheckExact(retval)) {
1866                 Py_DECREF(retval);
1867                 goto yield_close;
1868             }
1869             else {
1870                 return retval;
1871             }
1872         }
1873         else {
1874             goto check_error;
1875         }
1876     }
1877 
1878 yield_close:
1879     PyErr_SetString(
1880         PyExc_RuntimeError, ASYNC_GEN_IGNORED_EXIT_MSG);
1881     return NULL;
1882 
1883 check_error:
1884     if (PyErr_ExceptionMatches(PyExc_StopAsyncIteration)) {
1885         o->agt_state = AWAITABLE_STATE_CLOSED;
1886         if (o->agt_args == NULL) {
1887             /* when aclose() is called we don't want to propagate
1888                StopAsyncIteration; just raise StopIteration, signalling
1889                that 'aclose()' is done. */
1890             PyErr_Clear();
1891             PyErr_SetNone(PyExc_StopIteration);
1892         }
1893     }
1894     else if (PyErr_ExceptionMatches(PyExc_GeneratorExit)) {
1895         o->agt_state = AWAITABLE_STATE_CLOSED;
1896         PyErr_Clear();          /* ignore these errors */
1897         PyErr_SetNone(PyExc_StopIteration);
1898     }
1899     return NULL;
1900 }
1901 
1902 
1903 static PyObject *
async_gen_athrow_throw(PyAsyncGenAThrow * o,PyObject * args)1904 async_gen_athrow_throw(PyAsyncGenAThrow *o, PyObject *args)
1905 {
1906     PyObject *retval;
1907 
1908     if (o->agt_state == AWAITABLE_STATE_INIT) {
1909         PyErr_SetString(PyExc_RuntimeError, NON_INIT_CORO_MSG);
1910         return NULL;
1911     }
1912 
1913     if (o->agt_state == AWAITABLE_STATE_CLOSED) {
1914         PyErr_SetNone(PyExc_StopIteration);
1915         return NULL;
1916     }
1917 
1918     retval = gen_throw((PyGenObject*)o->agt_gen, args);
1919     if (o->agt_args) {
1920         return async_gen_unwrap_value(o->agt_gen, retval);
1921     } else {
1922         /* aclose() mode */
1923         if (retval && _PyAsyncGenWrappedValue_CheckExact(retval)) {
1924             Py_DECREF(retval);
1925             PyErr_SetString(PyExc_RuntimeError, ASYNC_GEN_IGNORED_EXIT_MSG);
1926             return NULL;
1927         }
1928         return retval;
1929     }
1930 }
1931 
1932 
1933 static PyObject *
async_gen_athrow_iternext(PyAsyncGenAThrow * o)1934 async_gen_athrow_iternext(PyAsyncGenAThrow *o)
1935 {
1936     return async_gen_athrow_send(o, Py_None);
1937 }
1938 
1939 
1940 static PyObject *
async_gen_athrow_close(PyAsyncGenAThrow * o,PyObject * args)1941 async_gen_athrow_close(PyAsyncGenAThrow *o, PyObject *args)
1942 {
1943     o->agt_state = AWAITABLE_STATE_CLOSED;
1944     Py_RETURN_NONE;
1945 }
1946 
1947 
1948 static PyMethodDef async_gen_athrow_methods[] = {
1949     {"send", (PyCFunction)async_gen_athrow_send, METH_O, send_doc},
1950     {"throw", (PyCFunction)async_gen_athrow_throw, METH_VARARGS, throw_doc},
1951     {"close", (PyCFunction)async_gen_athrow_close, METH_NOARGS, close_doc},
1952     {NULL, NULL}        /* Sentinel */
1953 };
1954 
1955 
1956 static PyAsyncMethods async_gen_athrow_as_async = {
1957     PyObject_SelfIter,                          /* am_await */
1958     0,                                          /* am_aiter */
1959     0                                           /* am_anext */
1960 };
1961 
1962 
1963 PyTypeObject _PyAsyncGenAThrow_Type = {
1964     PyVarObject_HEAD_INIT(&PyType_Type, 0)
1965     "async_generator_athrow",                   /* tp_name */
1966     sizeof(PyAsyncGenAThrow),                   /* tp_basicsize */
1967     0,                                          /* tp_itemsize */
1968     /* methods */
1969     (destructor)async_gen_athrow_dealloc,       /* tp_dealloc */
1970     0,                                          /* tp_print */
1971     0,                                          /* tp_getattr */
1972     0,                                          /* tp_setattr */
1973     &async_gen_athrow_as_async,                 /* tp_as_async */
1974     0,                                          /* tp_repr */
1975     0,                                          /* tp_as_number */
1976     0,                                          /* tp_as_sequence */
1977     0,                                          /* tp_as_mapping */
1978     0,                                          /* tp_hash */
1979     0,                                          /* tp_call */
1980     0,                                          /* tp_str */
1981     PyObject_GenericGetAttr,                    /* tp_getattro */
1982     0,                                          /* tp_setattro */
1983     0,                                          /* tp_as_buffer */
1984     Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,    /* tp_flags */
1985     0,                                          /* tp_doc */
1986     (traverseproc)async_gen_athrow_traverse,    /* tp_traverse */
1987     0,                                          /* tp_clear */
1988     0,                                          /* tp_richcompare */
1989     0,                                          /* tp_weaklistoffset */
1990     PyObject_SelfIter,                          /* tp_iter */
1991     (iternextfunc)async_gen_athrow_iternext,    /* tp_iternext */
1992     async_gen_athrow_methods,                   /* tp_methods */
1993     0,                                          /* tp_members */
1994     0,                                          /* tp_getset */
1995     0,                                          /* tp_base */
1996     0,                                          /* tp_dict */
1997     0,                                          /* tp_descr_get */
1998     0,                                          /* tp_descr_set */
1999     0,                                          /* tp_dictoffset */
2000     0,                                          /* tp_init */
2001     0,                                          /* tp_alloc */
2002     0,                                          /* tp_new */
2003 };
2004 
2005 
2006 static PyObject *
async_gen_athrow_new(PyAsyncGenObject * gen,PyObject * args)2007 async_gen_athrow_new(PyAsyncGenObject *gen, PyObject *args)
2008 {
2009     PyAsyncGenAThrow *o;
2010     o = PyObject_GC_New(PyAsyncGenAThrow, &_PyAsyncGenAThrow_Type);
2011     if (o == NULL) {
2012         return NULL;
2013     }
2014     o->agt_gen = gen;
2015     o->agt_args = args;
2016     o->agt_state = AWAITABLE_STATE_INIT;
2017     Py_INCREF(gen);
2018     Py_XINCREF(args);
2019     _PyObject_GC_TRACK((PyObject*)o);
2020     return (PyObject*)o;
2021 }
2022