In general, when `_PyThreadState_GET()` is non-NULL then the current
thread is "attached", but there is a small window during
`PyThreadState_DeleteCurrent()` where that's not true:
tstate_delete_common() is called when the thread is detached, but before
current_fast_clear().
Co-authored-by: Eric Snow <ericsnowcurrently@gmail.com>
* set default return value of functional types as _mock_return_value
* added test of wrapping child attributes
* added backward compatibility with explicit return
* added docs on the order of precedence
* added test to check default return_value
Modernize code to use the new API which avoids the usage of the stat
module just to read os.stat() members.
* Sort logging.handlers imports.
* Rework reopenIfNeeded() code to make it easier to follow.
* Replace "not self.stream" with "self.stream is None".
If a thread blocks while waiting on the `shared->mutex` lock, the array
of QSBR states may be reallocated. The `tstate->qsbr` values before the
lock is acquired may not be the same as the value after the lock is acquired.
Add a new C extension "_testlimitedcapi" which is only built with the
limited C API.
Move heaptype_relative.c and vectorcall_limited.c from
Modules/_testcapi/ to Modules/_testlimitedcapi/.
* configure: add _testlimitedcapi test extension.
* Update generate_stdlib_module_names.py.
* Update make check-c-globals.
Co-authored-by: Erlend E. Aasland <erlend.aasland@protonmail.com>
Co-authored-by: Erlend E. Aasland <erlend@python.org>
Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>
Co-authored-by: Victor Stinner <vstinner@python.org>
This follows in the footsteps of #21586
This speeds up import uuid by about 6ms on Linux.
Before:
```
λ hyperfine -w 4 "./python -c 'import uuid'"
Benchmark 1: ./python -c 'import uuid'
Time (mean ± σ): 20.4 ms ± 0.4 ms [User: 16.7 ms, System: 3.8 ms]
Range (min … max): 19.6 ms … 21.8 ms 136 runs
```
After:
```
λ hyperfine -w 4 "./python -c 'import uuid'"
Benchmark 1: ./python -c 'import uuid'
Time (mean ± σ): 14.5 ms ± 0.3 ms [User: 11.5 ms, System: 3.2 ms]
Range (min … max): 13.9 ms … 16.0 ms 175 runs
```
This adds `VERIFY_X509_STRICT` to make the default
SSL context perform stricter (per RFC 5280) validation, as well
as `VERIFY_X509_PARTIAL_CHAIN` to enforce more standards-compliant
path-building behavior.
As part of this changeset, I had to tweak `make_ssl_certs.py`
slightly to emit 5280-conforming CA certs. This changeset includes
the regenerated certificates after that change.
Signed-off-by: William Woodruff <william@yossarian.net>
Co-authored-by: Victor Stinner <vstinner@python.org>
Fix some test_multiprocessing flakiness.
Potentially introduced by https://github.com/python/cpython/pull/25845
not joining that thread likely leads to recently observed "environment
changed" logically passing but overall failing tests seen on some
buildbots similar to:
```
1 test altered the execution environment (env changed):
test.test_multiprocessing_fork.test_processes
2 re-run tests:
test.test_multiprocessing_fork.test_processes
test.test_multiprocessing_forkserver.test_processes
```
Previously, the `locked` field was set after releasing the lock. This reverses
the order so that the `locked` field is set while the lock is still held.
There is still one thread-safety issue where `locked` is checked prior to
releasing the lock, however, in practice that will only be an issue when
unlocking the lock is contended, which should be rare.
Revert "gh-115398: Increment PyExpat_CAPI_MAGIC for SetReparseDeferralEnabled addition (GH-116301)"
This reverts part of commit eda2963378. Why? this comment buried in an earlier code review explains:
I checked again how that value is used in practice, it's here:
0c80da4c14/Modules/_elementtree.c (L4363-L4372)
Based on that code my understanding is that loading bigger structs from the future is considered okay unless `PyExpat_CAPI_MAGIC` differs, which implies that (1) magic needs to stay the same to support loading the future from the past and (2) that `PyExpat_CAPI_MAGIC` should only ever change for changes that do not increase size (but keep it constant).
To summarize, that supports your argument.
I checked branches 3.8, 3.9, 3.10, 3.11, 3.12 now and they all have the same comparison code there so reverting that magic string bump will support seamless backporting.
This implements the delayed reuse of mimalloc pages that contain Python
objects in the free-threaded build.
Allocations of the same size class are grouped in data structures called
pages. These are different from operating system pages. For thread-safety, we
want to ensure that memory used to store PyObjects remains valid as long as
there may be concurrent lock-free readers; we want to delay using it for
other size classes, in other heaps, or returning it to the operating system.
When a mimalloc page becomes empty, instead of immediately freeing it, we tag
it with a QSBR goal and insert it into a per-thread state linked list of
pages to be freed. When mimalloc needs a fresh page, we process the queue and
free any still empty pages that are now deemed safe to be freed. Pages
waiting to be freed are still available for allocations of the same size
class and allocating from a page prevent it from being freed. There is
additional logic to handle abandoned pages when threads exit.
This sets `MI_DEBUG` to `2` in debug builds to enable `mi_assert_internal()`
calls. Expensive internal assertions are not enabled.
This also disables an assertion in free-threaded builds that would be
triggered by the free-threaded GC because we traverse heaps that are not
owned by the current thread.
