Issue #28003: Implement PEP 525 -- Asynchronous Generators.
diff --git a/Python/ceval.c b/Python/ceval.c
index a52ee8a..f737a2f 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -1204,7 +1204,7 @@
f->f_stacktop = NULL; /* remains NULL unless yield suspends frame */
f->f_executing = 1;
- if (co->co_flags & (CO_GENERATOR | CO_COROUTINE)) {
+ if (co->co_flags & (CO_GENERATOR | CO_COROUTINE | CO_ASYNC_GENERATOR)) {
if (!throwflag && f->f_exc_type != NULL && f->f_exc_type != Py_None) {
/* We were in an except handler when we left,
restore the exception state which was put aside
@@ -2083,36 +2083,45 @@
PyObject *aiter = TOP();
PyTypeObject *type = Py_TYPE(aiter);
- if (type->tp_as_async != NULL)
- getter = type->tp_as_async->am_anext;
-
- if (getter != NULL) {
- next_iter = (*getter)(aiter);
- if (next_iter == NULL) {
+ if (PyAsyncGen_CheckExact(aiter)) {
+ awaitable = type->tp_as_async->am_anext(aiter);
+ if (awaitable == NULL) {
goto error;
}
- }
- else {
- PyErr_Format(
- PyExc_TypeError,
- "'async for' requires an iterator with "
- "__anext__ method, got %.100s",
- type->tp_name);
- goto error;
- }
+ } else {
+ if (type->tp_as_async != NULL){
+ getter = type->tp_as_async->am_anext;
+ }
- awaitable = _PyCoro_GetAwaitableIter(next_iter);
- if (awaitable == NULL) {
- PyErr_Format(
- PyExc_TypeError,
- "'async for' received an invalid object "
- "from __anext__: %.100s",
- Py_TYPE(next_iter)->tp_name);
+ if (getter != NULL) {
+ next_iter = (*getter)(aiter);
+ if (next_iter == NULL) {
+ goto error;
+ }
+ }
+ else {
+ PyErr_Format(
+ PyExc_TypeError,
+ "'async for' requires an iterator with "
+ "__anext__ method, got %.100s",
+ type->tp_name);
+ goto error;
+ }
- Py_DECREF(next_iter);
- goto error;
- } else
- Py_DECREF(next_iter);
+ awaitable = _PyCoro_GetAwaitableIter(next_iter);
+ if (awaitable == NULL) {
+ PyErr_Format(
+ PyExc_TypeError,
+ "'async for' received an invalid object "
+ "from __anext__: %.100s",
+ Py_TYPE(next_iter)->tp_name);
+
+ Py_DECREF(next_iter);
+ goto error;
+ } else {
+ Py_DECREF(next_iter);
+ }
+ }
PUSH(awaitable);
PREDICT(LOAD_CONST);
@@ -2187,6 +2196,17 @@
TARGET(YIELD_VALUE) {
retval = POP();
+
+ if (co->co_flags & CO_ASYNC_GENERATOR) {
+ PyObject *w = _PyAsyncGenValueWrapperNew(retval);
+ Py_DECREF(retval);
+ if (w == NULL) {
+ retval = NULL;
+ goto error;
+ }
+ retval = w;
+ }
+
f->f_stacktop = stack_pointer;
why = WHY_YIELD;
goto fast_yield;
@@ -3712,7 +3732,7 @@
assert((retval != NULL) ^ (PyErr_Occurred() != NULL));
fast_yield:
- if (co->co_flags & (CO_GENERATOR | CO_COROUTINE)) {
+ if (co->co_flags & (CO_GENERATOR | CO_COROUTINE | CO_ASYNC_GENERATOR)) {
/* The purpose of this block is to put aside the generator's exception
state and restore that of the calling frame. If the current
@@ -4156,8 +4176,8 @@
freevars[PyTuple_GET_SIZE(co->co_cellvars) + i] = o;
}
- /* Handle generator/coroutine */
- if (co->co_flags & (CO_GENERATOR | CO_COROUTINE)) {
+ /* Handle generator/coroutine/asynchronous generator */
+ if (co->co_flags & (CO_GENERATOR | CO_COROUTINE | CO_ASYNC_GENERATOR)) {
PyObject *gen;
PyObject *coro_wrapper = tstate->coroutine_wrapper;
int is_coro = co->co_flags & CO_COROUTINE;
@@ -4182,6 +4202,8 @@
* and return that as the value. */
if (is_coro) {
gen = PyCoro_New(f, name, qualname);
+ } else if (co->co_flags & CO_ASYNC_GENERATOR) {
+ gen = PyAsyncGen_New(f, name, qualname);
} else {
gen = PyGen_NewWithQualName(f, name, qualname);
}
@@ -4660,6 +4682,38 @@
return tstate->coroutine_wrapper;
}
+void
+_PyEval_SetAsyncGenFirstiter(PyObject *firstiter)
+{
+ PyThreadState *tstate = PyThreadState_GET();
+
+ Py_XINCREF(firstiter);
+ Py_XSETREF(tstate->async_gen_firstiter, firstiter);
+}
+
+PyObject *
+_PyEval_GetAsyncGenFirstiter(void)
+{
+ PyThreadState *tstate = PyThreadState_GET();
+ return tstate->async_gen_firstiter;
+}
+
+void
+_PyEval_SetAsyncGenFinalizer(PyObject *finalizer)
+{
+ PyThreadState *tstate = PyThreadState_GET();
+
+ Py_XINCREF(finalizer);
+ Py_XSETREF(tstate->async_gen_finalizer, finalizer);
+}
+
+PyObject *
+_PyEval_GetAsyncGenFinalizer(void)
+{
+ PyThreadState *tstate = PyThreadState_GET();
+ return tstate->async_gen_finalizer;
+}
+
PyObject *
PyEval_GetBuiltins(void)
{
diff --git a/Python/compile.c b/Python/compile.c
index b46edd4..faae4f5 100644
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -1886,8 +1886,6 @@
return 0;
}
- if (is_async)
- co->co_flags |= CO_COROUTINE;
compiler_make_closure(c, co, funcflags, qualname);
Py_DECREF(qualname);
Py_DECREF(co);
@@ -2801,6 +2799,9 @@
if (c->u->u_ste->ste_type != FunctionBlock)
return compiler_error(c, "'return' outside function");
if (s->v.Return.value) {
+ if (c->u->u_ste->ste_coroutine && c->u->u_ste->ste_generator)
+ return compiler_error(
+ c, "'return' with value in async generator");
VISIT(c, expr, s->v.Return.value);
}
else
@@ -4115,8 +4116,6 @@
case Yield_kind:
if (c->u->u_ste->ste_type != FunctionBlock)
return compiler_error(c, "'yield' outside function");
- if (c->u->u_scope_type == COMPILER_SCOPE_ASYNC_FUNCTION)
- return compiler_error(c, "'yield' inside async function");
if (e->v.Yield.value) {
VISIT(c, expr, e->v.Yield.value);
}
@@ -4992,8 +4991,12 @@
flags |= CO_NEWLOCALS | CO_OPTIMIZED;
if (ste->ste_nested)
flags |= CO_NESTED;
- if (ste->ste_generator)
+ if (ste->ste_generator && !ste->ste_coroutine)
flags |= CO_GENERATOR;
+ if (!ste->ste_generator && ste->ste_coroutine)
+ flags |= CO_COROUTINE;
+ if (ste->ste_generator && ste->ste_coroutine)
+ flags |= CO_ASYNC_GENERATOR;
if (ste->ste_varargs)
flags |= CO_VARARGS;
if (ste->ste_varkeywords)
diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c
index a2399ed..f93afd2 100644
--- a/Python/pylifecycle.c
+++ b/Python/pylifecycle.c
@@ -694,6 +694,7 @@
_PyGC_Fini();
_PyRandom_Fini();
_PyArg_Fini();
+ PyAsyncGen_Fini();
/* Cleanup Unicode implementation */
_PyUnicode_Fini();
diff --git a/Python/pystate.c b/Python/pystate.c
index 959354d..a0a8c97 100644
--- a/Python/pystate.c
+++ b/Python/pystate.c
@@ -229,6 +229,9 @@
tstate->in_coroutine_wrapper = 0;
tstate->co_extra_user_count = 0;
+ tstate->async_gen_firstiter = NULL;
+ tstate->async_gen_finalizer = NULL;
+
if (init)
_PyThreadState_Init(tstate);
@@ -408,6 +411,8 @@
Py_CLEAR(tstate->c_traceobj);
Py_CLEAR(tstate->coroutine_wrapper);
+ Py_CLEAR(tstate->async_gen_firstiter);
+ Py_CLEAR(tstate->async_gen_finalizer);
}
diff --git a/Python/symtable.c b/Python/symtable.c
index b8d9398..e55813f 100644
--- a/Python/symtable.c
+++ b/Python/symtable.c
@@ -63,6 +63,7 @@
ste->ste_nested = 1;
ste->ste_child_free = 0;
ste->ste_generator = 0;
+ ste->ste_coroutine = 0;
ste->ste_returns_value = 0;
ste->ste_needs_class_closure = 0;
@@ -378,7 +379,7 @@
PyLong_AsLong(PyTuple_GET_ITEM(data, 2)));
return 0;
- }
+ }
}
PyErr_SetString(PyExc_RuntimeError,
"BUG: internal directive bookkeeping broken");
@@ -1397,6 +1398,7 @@
FunctionBlock, (void *)s, s->lineno,
s->col_offset))
VISIT_QUIT(st, 0);
+ st->st_cur->ste_coroutine = 1;
VISIT(st, arguments, s->v.AsyncFunctionDef.args);
VISIT_SEQ(st, stmt, s->v.AsyncFunctionDef.body);
if (!symtable_exit_block(st, s))
@@ -1492,7 +1494,7 @@
break;
case Await_kind:
VISIT(st, expr, e->v.Await.value);
- st->st_cur->ste_generator = 1;
+ st->st_cur->ste_coroutine = 1;
break;
case Compare_kind:
VISIT(st, expr, e->v.Compare.left);
diff --git a/Python/sysmodule.c b/Python/sysmodule.c
index 0fe76b7..3a02ae9 100644
--- a/Python/sysmodule.c
+++ b/Python/sysmodule.c
@@ -717,6 +717,113 @@
);
+static PyTypeObject AsyncGenHooksType;
+
+PyDoc_STRVAR(asyncgen_hooks_doc,
+"asyncgen_hooks\n\
+\n\
+A struct sequence providing information about asynhronous\n\
+generators hooks. The attributes are read only.");
+
+static PyStructSequence_Field asyncgen_hooks_fields[] = {
+ {"firstiter", "Hook to intercept first iteration"},
+ {"finalizer", "Hook to intercept finalization"},
+ {0}
+};
+
+static PyStructSequence_Desc asyncgen_hooks_desc = {
+ "asyncgen_hooks", /* name */
+ asyncgen_hooks_doc, /* doc */
+ asyncgen_hooks_fields , /* fields */
+ 2
+};
+
+
+static PyObject *
+sys_set_asyncgen_hooks(PyObject *self, PyObject *args, PyObject *kw)
+{
+ static char *keywords[] = {"firstiter", "finalizer", NULL};
+ PyObject *firstiter = NULL;
+ PyObject *finalizer = NULL;
+
+ if (!PyArg_ParseTupleAndKeywords(
+ args, kw, "|OO", keywords,
+ &firstiter, &finalizer)) {
+ return NULL;
+ }
+
+ if (finalizer && finalizer != Py_None) {
+ if (!PyCallable_Check(finalizer)) {
+ PyErr_Format(PyExc_TypeError,
+ "callable finalizer expected, got %.50s",
+ Py_TYPE(finalizer)->tp_name);
+ return NULL;
+ }
+ _PyEval_SetAsyncGenFinalizer(finalizer);
+ }
+ else if (finalizer == Py_None) {
+ _PyEval_SetAsyncGenFinalizer(NULL);
+ }
+
+ if (firstiter && firstiter != Py_None) {
+ if (!PyCallable_Check(firstiter)) {
+ PyErr_Format(PyExc_TypeError,
+ "callable firstiter expected, got %.50s",
+ Py_TYPE(firstiter)->tp_name);
+ return NULL;
+ }
+ _PyEval_SetAsyncGenFirstiter(firstiter);
+ }
+ else if (firstiter == Py_None) {
+ _PyEval_SetAsyncGenFirstiter(NULL);
+ }
+
+ Py_RETURN_NONE;
+}
+
+PyDoc_STRVAR(set_asyncgen_hooks_doc,
+"set_asyncgen_hooks(*, firstiter=None, finalizer=None)\n\
+\n\
+Set a finalizer for async generators objects."
+);
+
+static PyObject *
+sys_get_asyncgen_hooks(PyObject *self, PyObject *args)
+{
+ PyObject *res;
+ PyObject *firstiter = _PyEval_GetAsyncGenFirstiter();
+ PyObject *finalizer = _PyEval_GetAsyncGenFinalizer();
+
+ res = PyStructSequence_New(&AsyncGenHooksType);
+ if (res == NULL) {
+ return NULL;
+ }
+
+ if (firstiter == NULL) {
+ firstiter = Py_None;
+ }
+
+ if (finalizer == NULL) {
+ finalizer = Py_None;
+ }
+
+ Py_INCREF(firstiter);
+ PyStructSequence_SET_ITEM(res, 0, firstiter);
+
+ Py_INCREF(finalizer);
+ PyStructSequence_SET_ITEM(res, 1, finalizer);
+
+ return res;
+}
+
+PyDoc_STRVAR(get_asyncgen_hooks_doc,
+"get_asyncgen_hooks()\n\
+\n\
+Return a namedtuple of installed asynchronous generators hooks \
+(firstiter, finalizer)."
+);
+
+
static PyTypeObject Hash_InfoType;
PyDoc_STRVAR(hash_info_doc,
@@ -1315,6 +1422,10 @@
set_coroutine_wrapper_doc},
{"get_coroutine_wrapper", sys_get_coroutine_wrapper, METH_NOARGS,
get_coroutine_wrapper_doc},
+ {"set_asyncgen_hooks", sys_set_asyncgen_hooks,
+ METH_VARARGS | METH_KEYWORDS, set_asyncgen_hooks_doc},
+ {"get_asyncgen_hooks", sys_get_asyncgen_hooks, METH_NOARGS,
+ get_asyncgen_hooks_doc},
{NULL, NULL} /* sentinel */
};
@@ -1950,6 +2061,14 @@
SET_SYS_FROM_STRING("thread_info", PyThread_GetInfo());
#endif
+ /* initialize asyncgen_hooks */
+ if (AsyncGenHooksType.tp_name == NULL) {
+ if (PyStructSequence_InitType2(
+ &AsyncGenHooksType, &asyncgen_hooks_desc) < 0) {
+ return NULL;
+ }
+ }
+
#undef SET_SYS_FROM_STRING
#undef SET_SYS_FROM_STRING_BORROW
if (PyErr_Occurred())