Fixed current_effective_deadline()'s -inf disparity on asyncio (agron…

…holm#485)

docs/versionhistory.rst

@@ -38,6 +38,8 @@ This library adheres to `Semantic Versioning 2.0 <http:https://semver.org/>`_.
 - Fixed ``start_blocking_portal()`` raising an unwarranted
  ``RuntimeError: This portal is not running`` if a task raises an exception that causes
  the event loop to be closed
+- Fixed ``current_effective_deadline()`` not returning ``-inf`` on asyncio when the
+ currently active cancel scope has been cancelled (PR by Ganden Schaffner)
 
 **3.6.1**
 

src/anyio/_backends/_asyncio.py

@@ -1876,7 +1876,10 @@ def current_effective_deadline(cls) -> float:
  deadline = math.inf
  while cancel_scope:
  deadline = min(deadline, cancel_scope.deadline)
- if cancel_scope.shield:
+ if cancel_scope._cancel_called:
+ deadline = -math.inf
+ break
+ elif cancel_scope.shield:
  break
  else:
  cancel_scope = cancel_scope._parent_scope

src/anyio/_core/_tasks.py

@@ -139,8 +139,9 @@ def current_effective_deadline() -> float:
  Return the nearest deadline among all the cancel scopes effective for the current
  task.
 
- :return: a clock value from the event loop's internal clock (``float('inf')`` if
- there is no deadline in effect)
+ :return: a clock value from the event loop's internal clock (or ``float('inf')`` if
+ there is no deadline in effect, or ``float('-inf')`` if the current scope has
+ been cancelled)
  :rtype: float
 
  """

src/anyio/abc/_eventloop.py

@@ -146,7 +146,7 @@ def current_effective_deadline(cls) -> float:
 
  :return:
  - a clock value from the event loop's internal clock
- - ``'inf`` if there is no deadline in effect
+ - ``inf`` if there is no deadline in effect
  - ``-inf`` if the current scope has been cancelled
  :rtype: float
  """

tests/test_taskgroups.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import asyncio
+import math
 import sys
 import time
 from collections.abc import AsyncGenerator, Coroutine, Generator
@@ -527,6 +528,9 @@ async def test_cancel_from_shielded_scope() -> None:
  with CancelScope(shield=True) as inner_scope:
  assert inner_scope.shield
  tg.cancel_scope.cancel()
+ assert current_effective_deadline() == math.inf
+
+ assert current_effective_deadline() == -math.inf
 
  with pytest.raises(get_cancelled_exc_class()):
  await sleep(0.01)
@@ -535,6 +539,16 @@ async def test_cancel_from_shielded_scope() -> None:
  await sleep(0.01)
 
 
+async def test_cancel_shielded_scope() -> None:
+ with CancelScope(shield=True) as cancel_scope:
+ assert cancel_scope.shield
+ cancel_scope.cancel()
+ assert current_effective_deadline() == -math.inf
+
+ with pytest.raises(get_cancelled_exc_class()):
+ await sleep(0)
+
+
 @pytest.mark.parametrize("anyio_backend", ["asyncio"])
 async def test_cancel_host_asyncgen() -> None:
  done = False