Make `warnings.catch_warnings()` use a context variable for holding
the warning filtering state if the `sys.flags.context_aware_warnings`
flag is set to true. This makes using the context manager thread-safe in
multi-threaded programs.
Add the `sys.flags.thread_inherit_context` flag. If true, starting a new
thread with `threading.Thread` will use a copy of the context
from the caller of `Thread.start()`.
Both these flags are set to true by default for the free-threaded build
and false for the default build.
Move the Python implementation of warnings.py into _py_warnings.py.
Make _contextvars a builtin module.
Co-authored-by: Kumar Aditya <kumaraditya@python.org>
* Make musl test skips smarter (fixes Alpine errors)
A relatively small number of tests fail when the underlying c library is
provided by musl. This was originally reported in bpo-46390 by
Christian Heimes. Among other changes, these tests were marked for
skipping in gh-31947/ef1327e3 as part of bpo-40280 (emscripten support),
but the skips were conditioned on the *platform* being emscripten (or
wasi, skips for which ere added in 9b50585e02).
In gh-131071 Victor Stinner added a linked_to_musl function to enable
skipping a test in test_math that fails under musl, like it does on a
number of other platforms. This check can successfully detect that
python is running under musl on Alpine, which was the original problem
report in bpo-46390.
This PR replaces Victor's solution with an enhancement to
platform.libc_ver that does the check more cheaply, and also gets the
version number. The latter is important because the math test being
skipped is due to a bug in musl that has been fixed, but as of this
checkin date has not yet been released. When it is, the test skip can
be fixed to check for the minimum needed version.
The enhanced version of linked_to_musl is also used to do the skips of
the other tests that generically fail under musl, as opposed to
emscripten or wasi only failures. This will allow these tests to be
skipped automatically on Alpine.
This PR does *not* enhance libc_ver to support emscripten and wasi, as
I'm not familiar with those platforms; instead it returns a version
triple of (0, 0, 0) for those platforms. This means the musl tests will
be skipped regardless of musl version, so ideally someone will add
support to libc_ver for these platforms.
* Platform tests and bug fixes.
In adding tests for the new platform code I found a bug in the old code:
if a valid version is passed for version and it is greater than the
version found for an so *and* there is no glibc version, then the
version from the argument was returned. The code changes here fix
that.
* Add support docs, including for some preexisting is_xxx's.
* Add news item about libc_ver enhancement.
* Prettify platform re expression using re.VERBOSE.
* Implement C recursion protection with limit pointers for Linux, MacOS and Windows
* Remove calls to PyOS_CheckStack
* Add stack protection to parser
* Make tests more robust to low stacks
* Improve error messages for stack overflow
Revert "GH-91079: Implement C stack limits using addresses, not counters. (GH-130007)" for now
Unfortunatlely, the change broke some buildbots.
This reverts commit 2498c22fa0.
* Implement C recursion protection with limit pointers
* Remove calls to PyOS_CheckStack
* Add stack protection to parser
* Make tests more robust to low stacks
* Improve error messages for stack overflow
This adds a new command line argument, `--parallel-threads` to the
regression test runner to allow it to run individual tests in multiple
threads in parallel in order to find multithreading bugs.
Some tests pass when run with `--parallel-threads`, but there's still
more work before the entire suite passes.
Remove _PyInterpreterState_GetConfigCopy() and
_PyInterpreterState_SetConfig() private functions. PEP 741 "Python
Configuration C API" added a better public C API: PyConfig_Get() and
PyConfig_Set().
A part of `Lib/test/test_pdb.py` was previously unable to run on WASI/Emscripten
platforms because it lacked support for `asyncio`.
In fact, these tests could be rewritten without the `asyncio` framework because
`test_pdb` tests the behavior of coroutines, which are not part of `asyncio`.
Now reliance on the availability of `asyncio` has been removed and
part of `test_pdb` that deals with coroutines working on WASI/Emscripten platforms.
Each thread specializes a thread-local copy of the bytecode, created on the first RESUME, in free-threaded builds. All copies of the bytecode for a code object are stored in the co_tlbc array on the code object. Threads reserve a globally unique index identifying its copy of the bytecode in all co_tlbc arrays at thread creation and release the index at thread destruction. The first entry in every co_tlbc array always points to the "main" copy of the bytecode that is stored at the end of the code object. This ensures that no bytecode is copied for programs that do not use threads.
Thread-local bytecode can be disabled at runtime by providing either -X tlbc=0 or PYTHON_TLBC=0. Disabling thread-local bytecode also disables specialization.
Concurrent modifications to the bytecode made by the specializing interpreter and instrumentation use atomics, with specialization taking care not to overwrite an instruction that was instrumented concurrently.
* Remove `@suppress_immortalization` decorator
* Make suppression flag per-thread instead of per-interpreter
* Suppress immortalization in `eval()` to avoid refleaks in three tests
(test_datetime.test_roundtrip, test_logging.test_config8_ok, and
test_random.test_after_fork).
* frozenset() is constant, but not a singleton. When run multiple times,
the test could fail due to constant interning.
Run them with different locales and different date and time.
Add the @run_with_locales() decorator to run the test with multiple
locales.
Improve the run_with_locale() context manager/decorator -- it now
catches only expected exceptions and reports the test as skipped if no
appropriate locale is available.
Fix the incorrect use of `os.open()` result as a context manager,
while it is actually a numeric file descriptor.
I have missed the problem, because in the original version the
`os.open()` call would always fail, and I failed to test the final
version in all possible scenarios properly.
Change the default multiprocessing start method away from fork to forkserver or spawn on the remaining platforms where it was fork. See the issue for context. This makes the default far more thread safe (other than for people spawning threads at import time... - don't do that!).
Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>
Add a helper function that checks whether the test suite is running
inside a systemd-nspawn container, and skip the few tests failing
with `--suppress-sync=true` in that case. The tests are failing because
`--suppress-sync=true` stubs out `fsync()`, `fdatasync()` and `msync()`
calls, and therefore they always return success without checking for
invalid arguments.
Call `os.open(__file__, os.O_RDONLY | os.O_SYNC)` and check the errno to
detect whether `--suppress-sync=true` is actually used, and skip
the tests only in that scenario.
There were a still a number of gaps in the tests, including not looking
at all the builtin types and not checking wrappers in subinterpreters
that weren't in the main interpreter. This fixes all that.
I considered incorporating the names of the PyTypeObject fields
(a la gh-122866), but figured doing so doesn't add much value.
The tests were only checking cases where the slot wrapper was present in the initial case. They were missing when the slot wrapper was added in the additional initializations. This fixes that.
* Move get_signal_name() from test.libregrtest to test.support.
* Use get_signal_name() in support.script_helper.
* support.script_helper now decodes stdout and stderr from UTF-8,
instead of ASCII, if a command failed.
The tests were accidentally disabled by 2da0dc0, which didn't handle classes correctly.
I considered updating no_rerun() to support classes, but the way test_datetime.py works would have made things fairly messy. Plus, it looks like the refleaks we had encountered before have been resolved.
The free-threaded build currently immortalizes objects that use deferred
reference counting (see gh-117783). This typically happens once the
first non-main thread is created, but the behavior can be suppressed for
tests, in subinterpreters, or during a compile() call.
This fixes a race condition involving the tracking of whether the
behavior is suppressed.
We already intern and immortalize most string constants. In the
free-threaded build, other constants can be a source of reference count
contention because they are shared by all threads running the same code
objects.
sobolevn