bpo-32436: Implement PEP 567 (#5027)
diff --git a/Lib/asyncio/base_events.py b/Lib/asyncio/base_events.py
index ca9eee7..e722cf2 100644
--- a/Lib/asyncio/base_events.py
+++ b/Lib/asyncio/base_events.py
@@ -489,7 +489,7 @@
"""
return time.monotonic()
- def call_later(self, delay, callback, *args):
+ def call_later(self, delay, callback, *args, context=None):
"""Arrange for a callback to be called at a given time.
Return a Handle: an opaque object with a cancel() method that
@@ -505,12 +505,13 @@
Any positional arguments after the callback will be passed to
the callback when it is called.
"""
- timer = self.call_at(self.time() + delay, callback, *args)
+ timer = self.call_at(self.time() + delay, callback, *args,
+ context=context)
if timer._source_traceback:
del timer._source_traceback[-1]
return timer
- def call_at(self, when, callback, *args):
+ def call_at(self, when, callback, *args, context=None):
"""Like call_later(), but uses an absolute time.
Absolute time corresponds to the event loop's time() method.
@@ -519,14 +520,14 @@
if self._debug:
self._check_thread()
self._check_callback(callback, 'call_at')
- timer = events.TimerHandle(when, callback, args, self)
+ timer = events.TimerHandle(when, callback, args, self, context)
if timer._source_traceback:
del timer._source_traceback[-1]
heapq.heappush(self._scheduled, timer)
timer._scheduled = True
return timer
- def call_soon(self, callback, *args):
+ def call_soon(self, callback, *args, context=None):
"""Arrange for a callback to be called as soon as possible.
This operates as a FIFO queue: callbacks are called in the
@@ -540,7 +541,7 @@
if self._debug:
self._check_thread()
self._check_callback(callback, 'call_soon')
- handle = self._call_soon(callback, args)
+ handle = self._call_soon(callback, args, context)
if handle._source_traceback:
del handle._source_traceback[-1]
return handle
@@ -555,8 +556,8 @@
f'a callable object was expected by {method}(), '
f'got {callback!r}')
- def _call_soon(self, callback, args):
- handle = events.Handle(callback, args, self)
+ def _call_soon(self, callback, args, context):
+ handle = events.Handle(callback, args, self, context)
if handle._source_traceback:
del handle._source_traceback[-1]
self._ready.append(handle)
@@ -579,12 +580,12 @@
"Non-thread-safe operation invoked on an event loop other "
"than the current one")
- def call_soon_threadsafe(self, callback, *args):
+ def call_soon_threadsafe(self, callback, *args, context=None):
"""Like call_soon(), but thread-safe."""
self._check_closed()
if self._debug:
self._check_callback(callback, 'call_soon_threadsafe')
- handle = self._call_soon(callback, args)
+ handle = self._call_soon(callback, args, context)
if handle._source_traceback:
del handle._source_traceback[-1]
self._write_to_self()
diff --git a/Lib/asyncio/base_futures.py b/Lib/asyncio/base_futures.py
index 008812e..5182884 100644
--- a/Lib/asyncio/base_futures.py
+++ b/Lib/asyncio/base_futures.py
@@ -41,13 +41,13 @@
return format_helpers._format_callback_source(callback, ())
if size == 1:
- cb = format_cb(cb[0])
+ cb = format_cb(cb[0][0])
elif size == 2:
- cb = '{}, {}'.format(format_cb(cb[0]), format_cb(cb[1]))
+ cb = '{}, {}'.format(format_cb(cb[0][0]), format_cb(cb[1][0]))
elif size > 2:
- cb = '{}, <{} more>, {}'.format(format_cb(cb[0]),
+ cb = '{}, <{} more>, {}'.format(format_cb(cb[0][0]),
size - 2,
- format_cb(cb[-1]))
+ format_cb(cb[-1][0]))
return f'cb=[{cb}]'
diff --git a/Lib/asyncio/events.py b/Lib/asyncio/events.py
index d5365dc..5c68d4c 100644
--- a/Lib/asyncio/events.py
+++ b/Lib/asyncio/events.py
@@ -11,6 +11,7 @@
'_get_running_loop',
)
+import contextvars
import os
import socket
import subprocess
@@ -32,9 +33,13 @@
"""Object returned by callback registration methods."""
__slots__ = ('_callback', '_args', '_cancelled', '_loop',
- '_source_traceback', '_repr', '__weakref__')
+ '_source_traceback', '_repr', '__weakref__',
+ '_context')
- def __init__(self, callback, args, loop):
+ def __init__(self, callback, args, loop, context=None):
+ if context is None:
+ context = contextvars.copy_context()
+ self._context = context
self._loop = loop
self._callback = callback
self._args = args
@@ -80,7 +85,7 @@
def _run(self):
try:
- self._callback(*self._args)
+ self._context.run(self._callback, *self._args)
except Exception as exc:
cb = format_helpers._format_callback_source(
self._callback, self._args)
@@ -101,9 +106,9 @@
__slots__ = ['_scheduled', '_when']
- def __init__(self, when, callback, args, loop):
+ def __init__(self, when, callback, args, loop, context=None):
assert when is not None
- super().__init__(callback, args, loop)
+ super().__init__(callback, args, loop, context)
if self._source_traceback:
del self._source_traceback[-1]
self._when = when
diff --git a/Lib/asyncio/futures.py b/Lib/asyncio/futures.py
index 1c05b22..59621ff 100644
--- a/Lib/asyncio/futures.py
+++ b/Lib/asyncio/futures.py
@@ -6,6 +6,7 @@
)
import concurrent.futures
+import contextvars
import logging
import sys
@@ -144,8 +145,8 @@
return
self._callbacks[:] = []
- for callback in callbacks:
- self._loop.call_soon(callback, self)
+ for callback, ctx in callbacks:
+ self._loop.call_soon(callback, self, context=ctx)
def cancelled(self):
"""Return True if the future was cancelled."""
@@ -192,7 +193,7 @@
self.__log_traceback = False
return self._exception
- def add_done_callback(self, fn):
+ def add_done_callback(self, fn, *, context=None):
"""Add a callback to be run when the future becomes done.
The callback is called with a single argument - the future object. If
@@ -200,9 +201,11 @@
scheduled with call_soon.
"""
if self._state != _PENDING:
- self._loop.call_soon(fn, self)
+ self._loop.call_soon(fn, self, context=context)
else:
- self._callbacks.append(fn)
+ if context is None:
+ context = contextvars.copy_context()
+ self._callbacks.append((fn, context))
# New method not in PEP 3148.
@@ -211,7 +214,9 @@
Returns the number of callbacks removed.
"""
- filtered_callbacks = [f for f in self._callbacks if f != fn]
+ filtered_callbacks = [(f, ctx)
+ for (f, ctx) in self._callbacks
+ if f != fn]
removed_count = len(self._callbacks) - len(filtered_callbacks)
if removed_count:
self._callbacks[:] = filtered_callbacks
diff --git a/Lib/asyncio/selector_events.py b/Lib/asyncio/selector_events.py
index 5692e38..9446ae6 100644
--- a/Lib/asyncio/selector_events.py
+++ b/Lib/asyncio/selector_events.py
@@ -256,7 +256,7 @@
def _add_reader(self, fd, callback, *args):
self._check_closed()
- handle = events.Handle(callback, args, self)
+ handle = events.Handle(callback, args, self, None)
try:
key = self._selector.get_key(fd)
except KeyError:
@@ -292,7 +292,7 @@
def _add_writer(self, fd, callback, *args):
self._check_closed()
- handle = events.Handle(callback, args, self)
+ handle = events.Handle(callback, args, self, None)
try:
key = self._selector.get_key(fd)
except KeyError:
diff --git a/Lib/asyncio/tasks.py b/Lib/asyncio/tasks.py
index b118088..609b8e8 100644
--- a/Lib/asyncio/tasks.py
+++ b/Lib/asyncio/tasks.py
@@ -10,6 +10,7 @@
)
import concurrent.futures
+import contextvars
import functools
import inspect
import types
@@ -96,8 +97,9 @@
self._must_cancel = False
self._fut_waiter = None
self._coro = coro
+ self._context = contextvars.copy_context()
- self._loop.call_soon(self._step)
+ self._loop.call_soon(self._step, context=self._context)
_register_task(self)
def __del__(self):
@@ -229,15 +231,18 @@
new_exc = RuntimeError(
f'Task {self!r} got Future '
f'{result!r} attached to a different loop')
- self._loop.call_soon(self._step, new_exc)
+ self._loop.call_soon(
+ self._step, new_exc, context=self._context)
elif blocking:
if result is self:
new_exc = RuntimeError(
f'Task cannot await on itself: {self!r}')
- self._loop.call_soon(self._step, new_exc)
+ self._loop.call_soon(
+ self._step, new_exc, context=self._context)
else:
result._asyncio_future_blocking = False
- result.add_done_callback(self._wakeup)
+ result.add_done_callback(
+ self._wakeup, context=self._context)
self._fut_waiter = result
if self._must_cancel:
if self._fut_waiter.cancel():
@@ -246,21 +251,24 @@
new_exc = RuntimeError(
f'yield was used instead of yield from '
f'in task {self!r} with {result!r}')
- self._loop.call_soon(self._step, new_exc)
+ self._loop.call_soon(
+ self._step, new_exc, context=self._context)
elif result is None:
# Bare yield relinquishes control for one event loop iteration.
- self._loop.call_soon(self._step)
+ self._loop.call_soon(self._step, context=self._context)
elif inspect.isgenerator(result):
# Yielding a generator is just wrong.
new_exc = RuntimeError(
f'yield was used instead of yield from for '
f'generator in task {self!r} with {result}')
- self._loop.call_soon(self._step, new_exc)
+ self._loop.call_soon(
+ self._step, new_exc, context=self._context)
else:
# Yielding something else is an error.
new_exc = RuntimeError(f'Task got bad yield: {result!r}')
- self._loop.call_soon(self._step, new_exc)
+ self._loop.call_soon(
+ self._step, new_exc, context=self._context)
finally:
_leave_task(self._loop, self)
self = None # Needed to break cycles when an exception occurs.
diff --git a/Lib/asyncio/unix_events.py b/Lib/asyncio/unix_events.py
index 028a0ca..9b9d004 100644
--- a/Lib/asyncio/unix_events.py
+++ b/Lib/asyncio/unix_events.py
@@ -92,7 +92,7 @@
except (ValueError, OSError) as exc:
raise RuntimeError(str(exc))
- handle = events.Handle(callback, args, self)
+ handle = events.Handle(callback, args, self, None)
self._signal_handlers[sig] = handle
try: