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
(cherry picked from commit 4ae0149697)
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..
(cherry picked from commit ab4413a7e9)
* RFC 1750 has been been obsoleted by RFC 4086.
* RFC 3280 has been obsoleted by RFC 5280.
* RFC 4366 has been obsoleted by RFC 6066.
(cherry picked from commit 63c2c8ac17)
Fix a reference leak in _io._WindowsConsoleIO: PyUnicode_FSDecoder()
always initialize decodedname when it succeed and it doesn't clear
input decodedname object.
(cherry picked from commit 29adc13bd7)
If pass a server_hostname= that fails IDNA decoding to SSLContext.wrap_socket or SSLContext.wrap_bio, then the SSLContext object had a spurious Py_DECREF called on it, eventually leading to segfaults.
(cherry picked from commit 65ece7ca23)
* bpo-30557: faulthandler now correctly filters and displays exception codes on Windows (#1924)
* bpo-30557: faulthandler now correctly filters and displays exception codes on Windows
* Adds test for non-fatal exceptions.
* Adds bpo number to comment.
* bpo-30557: Fix test_faulthandler (#1969)
On Windows 8, 8.1 and 10 at least, the exit code is the exception
code (no bit is cleared).
* bpo-30544: _io._WindowsConsoleIO.write raises the wrong error when WriteConsoleW fails
* bpo-30544: _io._WindowsConsoleIO.write raises the wrong error when WriteConsoleW fails
timegm() return type is time_t, not int. Use time_t to prevent the
following compiler warning on Windows:
timemodule.c: warning C4244: '=': conversion from 'time_t' to 'int',
possible loss of data
(cherry picked from commit 0d659e5614)
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
(cherry picked from commit 991adca012)
It was possible to get a core dump by using uninitialized
_json objects. Now __new__ methods create initialized objects.
__init__ methods are removed..
(cherry picked from commit 76a3e51a40)
* Remove conditional on free of `dps`, since `dps` is now allocated for
all versions of OpenSSL
* Remove call to `x509_check_ca` since it was only used to cache
the `crldp` field of the certificate
CRL_DIST_POINTS_free is available in all supported versions of OpenSSL
(recent 0.9.8+) and LibreSSL.
(cherry picked from commit 2849cc34a8)
bpo-29939: Changed test code to suppress a compiler warning, while taking care to avoid the code being optimized out by the compiler.
(cherry picked from commit 164d30eb1e)
* bpo-29942: Fix the use of recursion in itertools.chain.from_iterable.
Fix the use of recursion in itertools.chain.from_iterable. Using recursion
is unnecessary, and can easily cause stack overflows, especially when
building in low optimization modes or with Py_DEBUG enabled.
(cherry picked from commit 5466d4af5f)
Directory and zipfile execution previously added
the parent directory of the directory or zipfile
as sys.path[0] and then subsequently overwrote
it with the directory or zipfile itself.
This caused problems in isolated mode, as it
overwrote the "stdlib as a zip archive" entry
in sys.path, as the parent directory was
never added.
The attempted fix to that issue in bpo-29319
created the opposite problem in *non*-isolated
mode, by potentially leaving the parent
directory on sys.path instead of overwriting it.
This change fixes the root cause of the problem
by removing the whole "add-and-overwrite" dance
for sys.path[0], and instead simply never adds
the parent directory to sys.path in the first
place.
(cherry picked from commit d2977a3ae2)
bpo-29619: os.stat() and os.DirEntry.inodeo() now convert inode
(st_ino) using unsigned integers.
(cherry picked from commit 0f6d73343d)
(Misc/NEWS conflict handled manually.)
* bpo-27593: Get SCM build info from git instead of hg. (#446)
sys.version and the platform module python_build(),
python_branch(), and python_revision() functions now use
git information rather than hg when building from a repo.
Based on original patches by Brett Cannon and Steve Dower.
(cherry picked from commit 5c4b0d063a)
* Indent versionchanged at method level, not class level
* Mark up ``--help`` to avoid generating an en dash
* Use forward slash in Unix command line with a dollar sign ($) prompt
Fix time_hash() function: replace DATE_xxx() macros with TIME_xxx() macros.
Before, the hash function used a wrong value for microseconds if fold is set
(equal to 1).
Issue #28920: Replace _PyObject_CallMethodId(obj, meth, "O", arg) with
_PyObject_CallMethodIdObjArgs(obj, meth, arg, NULL) to avoid
_PyObject_CallMethodId() special case when arg is a tuple.
If arg is a tuple, _PyObject_CallMethodId() unpacks the tuple: obj.meth(*arg).