If we have a chain of generators/coroutines that are 'yield from'ing
each other, then resuming the stack works like:
- call send() on the outermost generator
- this enters _PyEval_EvalFrameDefault, which re-executes the
YIELD_FROM opcode
- which calls send() on the next generator
- which enters _PyEval_EvalFrameDefault, which re-executes the
YIELD_FROM opcode
- ...etc.
However, every time we enter _PyEval_EvalFrameDefault, the first thing
we do is to check for pending signals, and if there are any then we
run the signal handler. And if it raises an exception, then we
immediately propagate that exception *instead* of starting to execute
bytecode. This means that e.g. a SIGINT at the wrong moment can "break
the chain" – it can be raised in the middle of our yield from chain,
with the bottom part of the stack abandoned for the garbage collector.
The fix is pretty simple: there's already a special case in
_PyEval_EvalFrameEx where it skips running signal handlers if the next
opcode is SETUP_FINALLY. (I don't see how this accomplishes anything
useful, but that's another story.) If we extend this check to also
skip running signal handlers when the next opcode is YIELD_FROM, then
that closes the hole – now the exception can only be raised at the
innermost stack frame.
This shouldn't have any performance implications, because the opcode
check happens inside the "slow path" after we've already determined
that there's a pending signal or something similar for us to process;
the vast majority of the time this isn't true and the new check
doesn't run at all.
* Adds lib.pyproj file to solution so that VS with Python support can open all the files in the standard library.
* Remove unexpected solution configuration.
* Remove lib.pyproj from solution to avoid memory issues on VS 2015.
test_is_alive_after_fork() now joins directly the thread to avoid the
following warning added by bpo-30357:
Warning -- threading_cleanup() failed to cleanup 0 threads
after 2 sec (count: 0, dangling: 21)
Use also a different exit code to catch generic exit code 1.
Before, it was possible to get the following sequence of
events (especially on Windows, where the C-level signal handler for
SIGINT is run in a separate thread):
- SIGINT arrives
- trip_signal is called
- trip_signal writes to the wakeup fd
- the main thread wakes up from select()-or-equivalent
- the main thread checks for pending signals, but doesn't see any
- the main thread drains the wakeup fd
- the main thread goes back to sleep
- trip_signal sets is_tripped=1 and calls Py_AddPendingCall to notify
the main thread the it should run the Python-level signal handler
- the main thread doesn't notice because it's asleep
This has been causing repeated failures in the Trio test suite:
https://github.com/python-trio/trio/issues/119
* Use explicit numbering for footnotes referred by explicit number.
* Restore missed footnote reference in stdtypes.rst.
* Fix literal strings formatting in howto/urllib2.rst.
* Update susp-ignored.csv for zipapp.rst.
* Fix suspicious mark up in Misc/NEWS.
Warnings emitted when compile a regular expression now always point
to the line in the user code. Previously they could point into inners
of the re module if emitted from inside of groups or conditionals.
test_thread: setUp() now uses support.threading_setup() and
support.threading_cleanup() to wait until threads complete to avoid
random side effects on following tests.
Co-Authored-By: Grzegorz Grzywacz <grzegorz.grzywacz@nazwa.pl>
Catch the Windows socket WSAEINVAL error (code 10022) in imaplib and
poplib on shutdown(SHUT_RDWR): An invalid operation was attempted
This error occurs sometimes on SSL connections.
The data model section of the language reference was written well
before the zero-argument form of super() was added.
To avoid giving the impression that they're doing something
unusual, this updates the description of `__new__` and `__init__`
to use the zero-argument form.
Patch by Cheryl Sabella.
Using a response file will eliminate the headache associated with batch argument/quote processing.
For example I unsucessfully compiled python with visualcpptools when specifying VSInstallDir in the batch file (cannot find vcruntime.h)
```batch
build.bat -p x64 -e -M --no-tkinter "/p:VCInstallDir=%VCInstallDir%"
```
but it build successfully when specifying it in a response file
msbuild.rsp:
```
/p:VCInstallDir=%VCInstallDir%
```
* bpo-30308: Code coverage for argument in random.shuffle
* bpo-30308: Code coverage for argument in random.shuffle
* bpo-30308: Code coverage for argument in random.shuffle
when there are no more `await` or `yield (from)` before return in coroutine,
cancel was ignored.
example:
async def coro():
asyncio.Task.current_task().cancel()
return 42
...
res = await coro() # should raise CancelledError
Now allowed several subsequential inline modifiers at the start of the
pattern (e.g. '(?i)(?s)...'). In verbose mode whitespaces and comments
now are allowed before and between inline modifiers (e.g.
'(?x) (?i) (?s)...').
Rewrite sigwaitinfo() and sigtimedwait() unit tests for EINTR using
pthread_sigmask() to fix a race condition between the child and the
parent process.
Remove the pipe which was used as a weak workaround against the race
condition.
sigtimedwait() is now tested with a child process sending a signal
instead of testing the timeout feature which is more unstable
(especially regarding to clock resolution depending on the platform).
Victor Stinner
Jon Dufresne
Senthil Kumaran
terryjreedy
Louie Lu
Nathaniel J. Smith
Steve Dower
Dong-hee Na
Xiang Zhang
csabella
Mariatta
Serhiy Storchaka
Dominik Miedziński
Berker Peksag
Howie Benefiel
Zachary Ware
morrme
Jim Fasarakis-Hilliard
Charles
Steve (Gadget) Barnes
Vinay Sajip
Brett Cannon
INADA Naoki
Giampaolo Rodola
stratakis