bpo-32311: Implement asyncio.create_task() shortcut (#4848)
* Implement functionality
* Add documentation
diff --git a/Lib/asyncio/base_futures.py b/Lib/asyncio/base_futures.py
index 2ee82c3..008812e 100644
--- a/Lib/asyncio/base_futures.py
+++ b/Lib/asyncio/base_futures.py
@@ -3,7 +3,7 @@
import concurrent.futures._base
import reprlib
-from . import events
+from . import format_helpers
Error = concurrent.futures._base.Error
CancelledError = concurrent.futures.CancelledError
@@ -38,7 +38,7 @@
cb = ''
def format_cb(callback):
- return events._format_callback_source(callback, ())
+ return format_helpers._format_callback_source(callback, ())
if size == 1:
cb = format_cb(cb[0])
diff --git a/Lib/asyncio/constants.py b/Lib/asyncio/constants.py
index dfe97f4..52169c3 100644
--- a/Lib/asyncio/constants.py
+++ b/Lib/asyncio/constants.py
@@ -6,5 +6,5 @@
# Number of stack entries to capture in debug mode.
# The larger the number, the slower the operation in debug mode
-# (see extract_stack() in events.py).
+# (see extract_stack() in format_helpers.py).
DEBUG_STACK_DEPTH = 10
diff --git a/Lib/asyncio/coroutines.py b/Lib/asyncio/coroutines.py
index bca7fe3..e3c0162 100644
--- a/Lib/asyncio/coroutines.py
+++ b/Lib/asyncio/coroutines.py
@@ -9,9 +9,9 @@
from collections.abc import Awaitable, Coroutine
-from . import constants
-from . import events
from . import base_futures
+from . import constants
+from . import format_helpers
from .log import logger
@@ -48,7 +48,7 @@
assert inspect.isgenerator(gen) or inspect.iscoroutine(gen), gen
self.gen = gen
self.func = func # Used to unwrap @coroutine decorator
- self._source_traceback = events.extract_stack(sys._getframe(1))
+ self._source_traceback = format_helpers.extract_stack(sys._getframe(1))
self.__name__ = getattr(gen, '__name__', None)
self.__qualname__ = getattr(gen, '__qualname__', None)
@@ -243,7 +243,7 @@
func = coro
if coro_name is None:
- coro_name = events._format_callback(func, (), {})
+ coro_name = format_helpers._format_callback(func, (), {})
try:
coro_code = coro.gi_code
@@ -260,7 +260,7 @@
if (isinstance(coro, CoroWrapper) and
not inspect.isgeneratorfunction(coro.func) and
coro.func is not None):
- source = events._get_function_source(coro.func)
+ source = format_helpers._get_function_source(coro.func)
if source is not None:
filename, lineno = source
if coro_frame is None:
diff --git a/Lib/asyncio/events.py b/Lib/asyncio/events.py
index a00f861..974a4a2 100644
--- a/Lib/asyncio/events.py
+++ b/Lib/asyncio/events.py
@@ -11,86 +11,14 @@
'_get_running_loop',
)
-import functools
-import inspect
import os
-import reprlib
import socket
import subprocess
import sys
import threading
-import traceback
from . import constants
-
-
-def _get_function_source(func):
- func = inspect.unwrap(func)
- if inspect.isfunction(func):
- code = func.__code__
- return (code.co_filename, code.co_firstlineno)
- if isinstance(func, functools.partial):
- return _get_function_source(func.func)
- if isinstance(func, functools.partialmethod):
- return _get_function_source(func.func)
- return None
-
-
-def _format_args_and_kwargs(args, kwargs):
- """Format function arguments and keyword arguments.
-
- Special case for a single parameter: ('hello',) is formatted as ('hello').
- """
- # use reprlib to limit the length of the output
- items = []
- if args:
- items.extend(reprlib.repr(arg) for arg in args)
- if kwargs:
- items.extend(f'{k}={reprlib.repr(v)}' for k, v in kwargs.items())
- return '({})'.format(', '.join(items))
-
-
-def _format_callback(func, args, kwargs, suffix=''):
- if isinstance(func, functools.partial):
- suffix = _format_args_and_kwargs(args, kwargs) + suffix
- return _format_callback(func.func, func.args, func.keywords, suffix)
-
- if hasattr(func, '__qualname__'):
- func_repr = getattr(func, '__qualname__')
- elif hasattr(func, '__name__'):
- func_repr = getattr(func, '__name__')
- else:
- func_repr = repr(func)
-
- func_repr += _format_args_and_kwargs(args, kwargs)
- if suffix:
- func_repr += suffix
- return func_repr
-
-
-def _format_callback_source(func, args):
- func_repr = _format_callback(func, args, None)
- source = _get_function_source(func)
- if source:
- func_repr += f' at {source[0]}:{source[1]}'
- return func_repr
-
-
-def extract_stack(f=None, limit=None):
- """Replacement for traceback.extract_stack() that only does the
- necessary work for asyncio debug mode.
- """
- if f is None:
- f = sys._getframe().f_back
- if limit is None:
- # Limit the amount of work to a reasonable amount, as extract_stack()
- # can be called for each coroutine and future in debug mode.
- limit = constants.DEBUG_STACK_DEPTH
- stack = traceback.StackSummary.extract(traceback.walk_stack(f),
- limit=limit,
- lookup_lines=False)
- stack.reverse()
- return stack
+from . import format_helpers
class Handle:
@@ -106,7 +34,8 @@
self._cancelled = False
self._repr = None
if self._loop.get_debug():
- self._source_traceback = extract_stack(sys._getframe(1))
+ self._source_traceback = format_helpers.extract_stack(
+ sys._getframe(1))
else:
self._source_traceback = None
@@ -115,7 +44,8 @@
if self._cancelled:
info.append('cancelled')
if self._callback is not None:
- info.append(_format_callback_source(self._callback, self._args))
+ info.append(format_helpers._format_callback_source(
+ self._callback, self._args))
if self._source_traceback:
frame = self._source_traceback[-1]
info.append(f'created at {frame[0]}:{frame[1]}')
@@ -145,7 +75,8 @@
try:
self._callback(*self._args)
except Exception as exc:
- cb = _format_callback_source(self._callback, self._args)
+ cb = format_helpers._format_callback_source(
+ self._callback, self._args)
msg = f'Exception in callback {cb}'
context = {
'message': msg,
diff --git a/Lib/asyncio/format_helpers.py b/Lib/asyncio/format_helpers.py
new file mode 100644
index 0000000..39cfcee
--- /dev/null
+++ b/Lib/asyncio/format_helpers.py
@@ -0,0 +1,75 @@
+import functools
+import inspect
+import reprlib
+import traceback
+
+from . import constants
+
+
+def _get_function_source(func):
+ func = inspect.unwrap(func)
+ if inspect.isfunction(func):
+ code = func.__code__
+ return (code.co_filename, code.co_firstlineno)
+ if isinstance(func, functools.partial):
+ return _get_function_source(func.func)
+ if isinstance(func, functools.partialmethod):
+ return _get_function_source(func.func)
+ return None
+
+
+def _format_callback_source(func, args):
+ func_repr = _format_callback(func, args, None)
+ source = _get_function_source(func)
+ if source:
+ func_repr += f' at {source[0]}:{source[1]}'
+ return func_repr
+
+
+def _format_args_and_kwargs(args, kwargs):
+ """Format function arguments and keyword arguments.
+
+ Special case for a single parameter: ('hello',) is formatted as ('hello').
+ """
+ # use reprlib to limit the length of the output
+ items = []
+ if args:
+ items.extend(reprlib.repr(arg) for arg in args)
+ if kwargs:
+ items.extend(f'{k}={reprlib.repr(v)}' for k, v in kwargs.items())
+ return '({})'.format(', '.join(items))
+
+
+def _format_callback(func, args, kwargs, suffix=''):
+ if isinstance(func, functools.partial):
+ suffix = _format_args_and_kwargs(args, kwargs) + suffix
+ return _format_callback(func.func, func.args, func.keywords, suffix)
+
+ if hasattr(func, '__qualname__'):
+ func_repr = getattr(func, '__qualname__')
+ elif hasattr(func, '__name__'):
+ func_repr = getattr(func, '__name__')
+ else:
+ func_repr = repr(func)
+
+ func_repr += _format_args_and_kwargs(args, kwargs)
+ if suffix:
+ func_repr += suffix
+ return func_repr
+
+
+def extract_stack(f=None, limit=None):
+ """Replacement for traceback.extract_stack() that only does the
+ necessary work for asyncio debug mode.
+ """
+ if f is None:
+ f = sys._getframe().f_back
+ if limit is None:
+ # Limit the amount of work to a reasonable amount, as extract_stack()
+ # can be called for each coroutine and future in debug mode.
+ limit = constants.DEBUG_STACK_DEPTH
+ stack = traceback.StackSummary.extract(traceback.walk_stack(f),
+ limit=limit,
+ lookup_lines=False)
+ stack.reverse()
+ return stack
diff --git a/Lib/asyncio/futures.py b/Lib/asyncio/futures.py
index d46a295..b310962 100644
--- a/Lib/asyncio/futures.py
+++ b/Lib/asyncio/futures.py
@@ -11,6 +11,7 @@
from . import base_futures
from . import events
+from . import format_helpers
CancelledError = base_futures.CancelledError
@@ -79,7 +80,8 @@
self._loop = loop
self._callbacks = []
if self._loop.get_debug():
- self._source_traceback = events.extract_stack(sys._getframe(1))
+ self._source_traceback = format_helpers.extract_stack(
+ sys._getframe(1))
_repr_info = base_futures._future_repr_info
diff --git a/Lib/asyncio/tasks.py b/Lib/asyncio/tasks.py
index c5122f7..172057e 100644
--- a/Lib/asyncio/tasks.py
+++ b/Lib/asyncio/tasks.py
@@ -1,7 +1,7 @@
"""Support for tasks, coroutines and the scheduler."""
__all__ = (
- 'Task',
+ 'Task', 'create_task',
'FIRST_COMPLETED', 'FIRST_EXCEPTION', 'ALL_COMPLETED',
'wait', 'wait_for', 'as_completed', 'sleep',
'gather', 'shield', 'ensure_future', 'run_coroutine_threadsafe',
@@ -67,13 +67,19 @@
return {t for t in cls._all_tasks if t._loop is loop}
def __init__(self, coro, *, loop=None):
- assert coroutines.iscoroutine(coro), repr(coro)
super().__init__(loop=loop)
if self._source_traceback:
del self._source_traceback[-1]
- self._coro = coro
- self._fut_waiter = None
+ if not coroutines.iscoroutine(coro):
+ # raise after Future.__init__(), attrs are required for __del__
+ # prevent logging for pending task in __del__
+ self._log_destroy_pending = False
+ raise TypeError(f"a coroutine was expected, got {coro!r}")
+
self._must_cancel = False
+ self._fut_waiter = None
+ self._coro = coro
+
self._loop.call_soon(self._step)
self.__class__._all_tasks.add(self)
@@ -263,6 +269,15 @@
Task = _CTask = _asyncio.Task
+def create_task(coro):
+ """Schedule the execution of a coroutine object in a spawn task.
+
+ Return a Task object.
+ """
+ loop = events.get_running_loop()
+ return loop.create_task(coro)
+
+
# wait() and as_completed() similar to those in PEP 3148.
FIRST_COMPLETED = concurrent.futures.FIRST_COMPLETED