106 lines
4.0 KiB
Diff
106 lines
4.0 KiB
Diff
From 42d873c63aa9d160c132be4a34599531574db12c Mon Sep 17 00:00:00 2001
|
|
From: Andrew Svetlov <andrew.svetlov@gmail.com>
|
|
Date: Tue, 10 Nov 2020 15:58:31 +0200
|
|
Subject: [PATCH] bpo-42183: Fix a stack overflow error for asyncio Task or
|
|
Future repr() (GH-23020)
|
|
|
|
The overflow occurs under some circumstances when a task or future
|
|
recursively returns itself.
|
|
|
|
Co-authored-by: Kyle Stanley <aeros167@gmail.com>
|
|
---
|
|
Lib/asyncio/base_futures.py | 25 +++++++++++++++++++---
|
|
Lib/test/test_asyncio/test_futures2.py | 18 ++++++++++++++++
|
|
.../2020-10-29-11-17-35.bpo-42183.50ZcIi.rst | 4 ++++
|
|
3 files changed, 44 insertions(+), 3 deletions(-)
|
|
create mode 100644 Lib/test/test_asyncio/test_futures2.py
|
|
create mode 100644 Misc/NEWS.d/next/Library/2020-10-29-11-17-35.bpo-42183.50ZcIi.rst
|
|
|
|
diff --git a/Lib/asyncio/base_futures.py b/Lib/asyncio/base_futures.py
|
|
index 5182884..2646fde 100644
|
|
--- a/Lib/asyncio/base_futures.py
|
|
+++ b/Lib/asyncio/base_futures.py
|
|
@@ -2,6 +2,7 @@ __all__ = ()
|
|
|
|
import concurrent.futures._base
|
|
import reprlib
|
|
+from _thread import get_ident
|
|
|
|
from . import format_helpers
|
|
|
|
@@ -51,6 +52,16 @@ def _format_callbacks(cb):
|
|
return f'cb=[{cb}]'
|
|
|
|
|
|
+# bpo-42183: _repr_running is needed for repr protection
|
|
+# when a Future or Task result contains itself directly or indirectly.
|
|
+# The logic is borrowed from @reprlib.recursive_repr decorator.
|
|
+# Unfortunately, the direct decorator usage is impossible because of
|
|
+# AttributeError: '_asyncio.Task' object has no attribute '__module__' error.
|
|
+#
|
|
+# After fixing this thing we can return to the decorator based approach.
|
|
+_repr_running = set()
|
|
+
|
|
+
|
|
def _future_repr_info(future):
|
|
# (Future) -> str
|
|
"""helper function for Future.__repr__"""
|
|
@@ -59,9 +70,17 @@ def _future_repr_info(future):
|
|
if future._exception is not None:
|
|
info.append(f'exception={future._exception!r}')
|
|
else:
|
|
- # use reprlib to limit the length of the output, especially
|
|
- # for very long strings
|
|
- result = reprlib.repr(future._result)
|
|
+ key = id(future), get_ident()
|
|
+ if key in _repr_running:
|
|
+ result = '...'
|
|
+ else:
|
|
+ _repr_running.add(key)
|
|
+ try:
|
|
+ # use reprlib to limit the length of the output, especially
|
|
+ # for very long strings
|
|
+ result = reprlib.repr(future._result)
|
|
+ finally:
|
|
+ _repr_running.discard(key)
|
|
info.append(f'result={result}')
|
|
if future._callbacks:
|
|
info.append(_format_callbacks(future._callbacks))
|
|
diff --git a/Lib/test/test_asyncio/test_futures2.py b/Lib/test/test_asyncio/test_futures2.py
|
|
new file mode 100644
|
|
index 0000000..c78b0cb
|
|
--- /dev/null
|
|
+++ b/Lib/test/test_asyncio/test_futures2.py
|
|
@@ -0,0 +1,18 @@
|
|
+# IsolatedAsyncioTestCase based tests
|
|
+import asyncio
|
|
+import unittest
|
|
+
|
|
+
|
|
+class FutureTests(unittest.TestCase):
|
|
+ async def test_recursive_repr_for_pending_tasks(self):
|
|
+ # The call crashes if the guard for recursive call
|
|
+ # in base_futures:_future_repr_info is absent
|
|
+ # See Also: https://bugs.python.org/issue42183
|
|
+
|
|
+ async def func():
|
|
+ return asyncio.all_tasks()
|
|
+
|
|
+ # The repr() call should not raise RecursiveError at first.
|
|
+ # The check for returned string is not very reliable but
|
|
+ # exact comparison for the whole string is even weaker.
|
|
+ self.assertIn('...', repr(await asyncio.wait_for(func(), timeout=10)))
|
|
diff --git a/Misc/NEWS.d/next/Library/2020-10-29-11-17-35.bpo-42183.50ZcIi.rst b/Misc/NEWS.d/next/Library/2020-10-29-11-17-35.bpo-42183.50ZcIi.rst
|
|
new file mode 100644
|
|
index 0000000..f6d7653
|
|
--- /dev/null
|
|
+++ b/Misc/NEWS.d/next/Library/2020-10-29-11-17-35.bpo-42183.50ZcIi.rst
|
|
@@ -0,0 +1,4 @@
|
|
+Fix a stack overflow error for asyncio Task or Future repr().
|
|
+
|
|
+The overflow occurs under some circumstances when a Task or Future
|
|
+recursively returns itself.
|
|
--
|
|
1.8.3.1
|
|
|