[Python-checkins] [3.11] bpo-45924: Fix asyncio incorrect traceback when future's exception is raised multiple times (GH-30274) (#94747)

Mon Jul 11 09:17:56 EDT 2022

https://github.com/python/cpython/commit/91176d38836cceb0d8e6d8cf5dfe7fe089b821ae
commit: 91176d38836cceb0d8e6d8cf5dfe7fe089b821ae
branch: 3.11
author: Miss Islington (bot) <31488909+miss-islington at users.noreply.github.com>
committer: pablogsal <Pablogsal at gmail.com>
date: 2022年07月11日T14:17:32+01:00
summary:
[3.11] bpo-45924: Fix asyncio incorrect traceback when future's exception is raised multiple times (GH-30274) (#94747)
Co-authored-by: Kumar Aditya <59607654+kumaraditya303 at users.noreply.github.com>
files:
A Misc/NEWS.d/next/Library/2021-12-27-15-32-15.bpo-45924.0ZpHX2.rst
M Lib/asyncio/futures.py
M Lib/test/test_asyncio/test_futures2.py
M Modules/_asynciomodule.c

diff --git a/Lib/asyncio/futures.py b/Lib/asyncio/futures.py
index 08c79e7b5109b..4bd9629e9eb62 100644
--- a/Lib/asyncio/futures.py
+++ b/Lib/asyncio/futures.py
@@ -206,7 +206,7 @@ def result(self):
 raise exceptions.InvalidStateError('Result is not ready.')
 self.__log_traceback = False
 if self._exception is not None:
- raise self._exception
+ raise self._exception.with_traceback(self._exception_tb)
 return self._result
 
 def exception(self):
@@ -282,6 +282,7 @@ def set_exception(self, exception):
 raise TypeError("StopIteration interacts badly with generators "
 "and cannot be raised into a Future")
 self._exception = exception
+ self._exception_tb = exception.__traceback__
 self._state = _FINISHED
 self.__schedule_callbacks()
 self.__log_traceback = True
diff --git a/Lib/test/test_asyncio/test_futures2.py b/Lib/test/test_asyncio/test_futures2.py
index 60b58850369f0..71279b69c7929 100644
--- a/Lib/test/test_asyncio/test_futures2.py
+++ b/Lib/test/test_asyncio/test_futures2.py
@@ -1,13 +1,42 @@
 # IsolatedAsyncioTestCase based tests
 import asyncio
+import traceback
 import unittest
+from asyncio import tasks
 
 
 def tearDownModule():
 asyncio.set_event_loop_policy(None)
 
 
-class FutureTests(unittest.IsolatedAsyncioTestCase):
+class FutureTests:
+
+ async def test_future_traceback(self):
+
+ async def raise_exc():
+ raise TypeError(42)
+
+ future = self.cls(raise_exc())
+
+ for _ in range(5):
+ try:
+ await future
+ except TypeError as e:
+ tb = ''.join(traceback.format_tb(e.__traceback__))
+ self.assertEqual(tb.count("await future"), 1)
+ else:
+ self.fail('TypeError was not raised')
+
+ at unittest.skipUnless(hasattr(tasks, '_CTask'),
+ 'requires the C _asyncio module')
+class CFutureTests(FutureTests, unittest.IsolatedAsyncioTestCase):
+ cls = tasks._CTask
+
+class PyFutureTests(FutureTests, unittest.IsolatedAsyncioTestCase):
+ cls = tasks._PyTask
+
+class FutureReprTests(unittest.IsolatedAsyncioTestCase):
+
 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
diff --git a/Misc/NEWS.d/next/Library/2021-12-27-15-32-15.bpo-45924.0ZpHX2.rst b/Misc/NEWS.d/next/Library/2021-12-27-15-32-15.bpo-45924.0ZpHX2.rst
new file mode 100644
index 0000000000000..5cda22737adb7
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2021-12-27-15-32-15.bpo-45924.0ZpHX2.rst
@@ -0,0 +1 @@
+Fix :mod:`asyncio` incorrect traceback when future's exception is raised multiple times. Patch by Kumar Aditya.
diff --git a/Modules/_asynciomodule.c b/Modules/_asynciomodule.c
index 5fa722305757d..eae468d8d96a5 100644
--- a/Modules/_asynciomodule.c
+++ b/Modules/_asynciomodule.c
@@ -70,6 +70,7 @@ typedef enum {
 PyObject *prefix##_context0; \
 PyObject *prefix##_callbacks; \
 PyObject *prefix##_exception; \
+ PyObject *prefix##_exception_tb; \
 PyObject *prefix##_result; \
 PyObject *prefix##_source_tb; \
 PyObject *prefix##_cancel_msg; \
@@ -495,6 +496,7 @@ future_init(FutureObj *fut, PyObject *loop)
 Py_CLEAR(fut->fut_callbacks);
 Py_CLEAR(fut->fut_result);
 Py_CLEAR(fut->fut_exception);
+ Py_CLEAR(fut->fut_exception_tb);
 Py_CLEAR(fut->fut_source_tb);
 Py_CLEAR(fut->fut_cancel_msg);
 Py_CLEAR(fut->fut_cancelled_exc);
@@ -601,7 +603,9 @@ future_set_exception(FutureObj *fut, PyObject *exc)
 }
 
 assert(!fut->fut_exception);
+ assert(!fut->fut_exception_tb);
 fut->fut_exception = exc_val;
+ fut->fut_exception_tb = PyException_GetTraceback(exc_val);
 fut->fut_state = STATE_FINISHED;
 
 if (future_schedule_callbacks(fut) == -1) {
@@ -656,8 +660,16 @@ future_get_result(FutureObj *fut, PyObject **result)
 
 fut->fut_log_tb = 0;
 if (fut->fut_exception != NULL) {
+ PyObject *tb = fut->fut_exception_tb;
+ if (tb == NULL) {
+ tb = Py_None;
+ }
+ if (PyException_SetTraceback(fut->fut_exception, tb) < 0) {
+ return -1;
+ }
 Py_INCREF(fut->fut_exception);
 *result = fut->fut_exception;
+ Py_CLEAR(fut->fut_exception_tb);
 return 1;
 }
 
@@ -799,6 +811,7 @@ FutureObj_clear(FutureObj *fut)
 Py_CLEAR(fut->fut_callbacks);
 Py_CLEAR(fut->fut_result);
 Py_CLEAR(fut->fut_exception);
+ Py_CLEAR(fut->fut_exception_tb);
 Py_CLEAR(fut->fut_source_tb);
 Py_CLEAR(fut->fut_cancel_msg);
 Py_CLEAR(fut->fut_cancelled_exc);
@@ -815,6 +828,7 @@ FutureObj_traverse(FutureObj *fut, visitproc visit, void *arg)
 Py_VISIT(fut->fut_callbacks);
 Py_VISIT(fut->fut_result);
 Py_VISIT(fut->fut_exception);
+ Py_VISIT(fut->fut_exception_tb);
 Py_VISIT(fut->fut_source_tb);
 Py_VISIT(fut->fut_cancel_msg);
 Py_VISIT(fut->fut_cancelled_exc);
