Drop handshake_done and peer_cert members from PySSLSocket struct. The
peer certificate can be acquired from *SSL directly.
SSL_get_peer_certificate() does not trigger any network activity.
Instead of manually tracking the handshake state, simply use
SSL_is_init_finished().
In combination these changes fix auto-handshake for non-blocking
MemoryBIO connections.
Signed-off-by: Christian Heimes <christian@python.org>
PEP 432 specifies a number of large changes to interpreter startup code, including exposing a cleaner C-API. The major changes depend on a number of smaller changes. This patch includes all those smaller changes.
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.
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
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
Compiled regular expression objects with the re.LOCALE flag no longer
depend on the locale at compile time. Only the locale at matching
time affects the result of matching.
FileIO.seek() and FileIO.tell() method now set the internal seekable
attribute to avoid one syscall on open() (in buffered or text mode).
The seekable property is now also more reliable since its value is
set correctly on memory allocation failure.
bpo-28769 changed PyUnicode_AsUTF8() return type from const char* to
char* in Python 3.7, but tm_zone field type of the tm structure is
char* on FreeBSD.
Cast PyUnicode_AsUTF8() to char* in gettmarg() to fix the warning:
Modules/timemodule.c:443:20: warning: assigning to 'char *'
from 'const char *' discards qualifiers
