bpo-30039: Don't run signal handlers while resuming a yield from stack (#1081)
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.
bpo-30038: fix race condition in signal delivery + wakeup fd (#1082)
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
Serhiy Storchaka [Tue, 16 May 2017 20:18:09 +0000 (23:18 +0300)]
bpo-30380: Fix Sphinx 1.6.1 warnings. (#1613)
* 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.
Serhiy Storchaka [Tue, 16 May 2017 12:16:15 +0000 (15:16 +0300)]
bpo-30375: Correct the stacklevel of regex compiling warnings. (#1595)
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.
Victor Stinner [Mon, 15 May 2017 15:55:32 +0000 (17:55 +0200)]
bpo-30357: test_thread now uses threading_cleanup() (#1592)
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>
csabella [Mon, 15 May 2017 03:42:00 +0000 (20:42 -0700)]
bpo-30354: Update data model documentation for super() (GH-1561)
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.
Serhiy Storchaka [Wed, 10 May 2017 03:05:20 +0000 (06:05 +0300)]
bpo-30298: Weaken the condition of deprecation warnings for inline modifiers. (#1490)
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)...').
Victor Stinner [Wed, 10 May 2017 00:37:42 +0000 (02:37 +0200)]
bpo-30320: test_eintr now uses pthread_sigmask() (#1523)
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).
torsava [Fri, 5 May 2017 15:35:50 +0000 (17:35 +0200)]
bpo-29243: Fix Makefile with respect to --enable-optimizations (#1478)
* bpo-29243: Fix Makefile with respect to --enable-optimizations
When using the Profile Guided Optimization (./configure --enable-optimizations)
Python is built not only during `make` but rebuilt again during `make test`,
`make install` and others. This patch fixes the issue.
Note that this fix produces no change at all in the Makefile if configure is
run witout --enable-optimizations.
Python/thread_foobar.h is the template code that is threading adaptation
for new platforms, also hasn't been used on actual platforms.
Python/thread_*.h give concrete examples of adaptation instead of the
template code.
Victor Stinner [Fri, 5 May 2017 07:46:47 +0000 (09:46 +0200)]
bpo-30264: ExpatParser closes the source on error (#1451)
ExpatParser.parse() of xml.sax.xmlreader now always closes the
source: close the file object or the urllib object if source is a
string (not an open file-like object). The change fixes a
ResourceWarning on parsing error.
bpo-30215: Make re.compile() locale agnostic. (#1361)
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.
Brett Cannon [Thu, 4 May 2017 21:58:54 +0000 (14:58 -0700)]
Make code coverage less strict (GH-1438)
Set the target to be 90% since there is enough OS-specific code and things that require manual testing that we will never hit 100%. Also turn off the status checks since they are so inconsistent in terms of flagging a PR as passing/failing that they aren't useful and can actually block merging from a phone.
Victor Stinner [Wed, 3 May 2017 22:45:56 +0000 (00:45 +0200)]
bpo-30225: Fix is_valid_fd() on macOS Tiger (#1443)
is_valid_fd() now uses fstat() instead of dup() on macOS to return 0
on a pipe when the other side of the pipe is closed. fstat() fails
with EBADF in that case, whereas dup() succeed.
Victor Stinner [Wed, 3 May 2017 16:21:48 +0000 (18:21 +0200)]
bpo-23404: make touch becomes make regen-all (#1405)
Don't rebuild generated files based on file modification time
anymore, the action is now explicit. Replace "make touch"
with "make regen-all".
Changes:
* Remove "make touch", Tools/hg/hgtouch.py and .hgtouch
* Add a new "make regen-all" command to rebuild all generated files
* Add subcommands to only generate specific files:
- regen-ast: Include/Python-ast.h and Python/Python-ast.c
- regen-grammar: Include/graminit.h and Python/graminit.c
- regen-importlib: Python/importlib_external.h and Python/importlib.h
- regen-opcode: Include/opcode.h
- regen-opcode-targets: Python/opcode_targets.h
- regen-typeslots: Objects/typeslots.inc
* Rename PYTHON_FOR_GEN to PYTHON_FOR_REGEN
* pgen is now only built by by "make regen-grammar"
* Add $(srcdir)/ prefix to paths to source files to handle correctly
compilation outside the source directory
Note: $(PYTHON_FOR_REGEN) is no more used nor needed by "make"
default target building Python.
Victor Stinner [Tue, 2 May 2017 11:12:02 +0000 (13:12 +0200)]
bpo-30199: test_ssl closes all asyncore channels (#1381)
AsyncoreEchoServer of test_ssl now calls
asyncore.close_all(ignore_all=True) to ensure that
asyncore.socket_map is cleared once the test completes, even if
ConnectionHandler was not correctly unregistered.
Fix the following warning:
Warning -- asyncore.socket_map was modified by test_ssl
Before: {}
After: {6: <test.test_ssl.AsyncoreEchoServer.EchoServer.ConnectionHandler>}
Victor Stinner [Tue, 2 May 2017 11:11:50 +0000 (13:11 +0200)]
bpo-30132: distutils BuildExtTestCase use temp_cwd (#1380)
BuildExtTestCase of test_distutils now uses support.temp_cwd() in
setUp() to remove files created in the current working in all
BuildExtTestCase unit tests, not only test_build_ext().