Sam Gross [Fri, 8 Mar 2024 20:26:36 +0000 (15:26 -0500)]
gh-108724: Fix _PySemaphore_Wait call during thread deletion (#116483)
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>
Sam Gross [Fri, 8 Mar 2024 17:39:53 +0000 (12:39 -0500)]
gh-115103: Fix unregistering of QSBR state (#116480)
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.
Skip Montanaro [Thu, 7 Mar 2024 17:21:28 +0000 (11:21 -0600)]
gh-106259: Add minimal help target to Makefile (#106260)
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 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>
gh-88118: Fix some test_multiprocessing flakiness. (#116434)
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
mpage [Wed, 6 Mar 2024 20:46:36 +0000 (12:46 -0800)]
gh-114271: Make `_thread.lock` thread-safe in free-threaded builds (#116433)
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.
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.
Sam Gross [Wed, 6 Mar 2024 14:42:11 +0000 (09:42 -0500)]
gh-115103: Delay reuse of mimalloc pages that store PyObjects (#115435)
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.
Sam Gross [Tue, 5 Mar 2024 18:54:20 +0000 (13:54 -0500)]
gh-115103: Enable internal mimalloc assertions in debug builds (#116343)
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.
Eric Snow [Mon, 4 Mar 2024 20:59:30 +0000 (13:59 -0700)]
gh-115490: Make the interpreter.channels and interpreter.queues Modules Handle Reloading Properly (gh-115493)
The problem manifested when the .py module got reloaded and the corresponding extension module didn't. The .py module registers types with the extension and the extension was not allowing that to happen more than once. The solution: let it happen more than once.
Brett Simmers [Mon, 4 Mar 2024 16:29:39 +0000 (08:29 -0800)]
gh-115832: Fix instrumentation version mismatch during interpreter shutdown (#115856)
A previous commit introduced a bug to `interpreter_clear()`: it set
`interp->ceval.instrumentation_version` to 0, without making the corresponding
change to `tstate->eval_breaker` (which holds a thread-local copy of the
version). After this happens, Python code can still run due to object finalizers
during a GC, and the version check in bytecodes.c will see a different result
than the one in instrumentation.c causing an infinite loop.
The fix itself is straightforward: clear `tstate->eval_breaker` when clearing
`interp->ceval.instrumentation_version`.
* Move param guard to param state machine
* Override return converter during parsing
* Don't use a custom type slot return converter; instead
special case type slot functions during generation.
Barney Gale [Mon, 4 Mar 2024 02:26:33 +0000 (02:26 +0000)]
pathlib ABCs: follow all symlinks in `PathBase.glob()` (#116293)
Switch the default value of *follow_symlinks* from `None` to `True` in
`pathlib._abc.PathBase.glob()` and `rglob()`. This speeds up recursive
globbing.
Improve algorithm for computing which rolled-over log files to delete
in logging.TimedRotatingFileHandler. It is now reliable for handlers
without namer and with arbitrary deterministic namer that leaves
the datetime part in the file name unmodified.
Marco Trevisan [Sat, 2 Mar 2024 12:48:24 +0000 (13:48 +0100)]
gh-85644: webbrowser: Use $XDG_CURRENT_DESKTOP to check desktop (GH-21731)
Usage of $GNOME_DESKTOP_SESSION_ID env variable is deprecated since
GNOME 3.30.0 [1], so should not be used, while the standard
XDG_CURRENT_DESKTOP should be instead preferred.
mpage [Fri, 1 Mar 2024 21:43:12 +0000 (13:43 -0800)]
gh-114271: Make `_thread.ThreadHandle` thread-safe in free-threaded builds (GH-115190)
Make `_thread.ThreadHandle` thread-safe in free-threaded builds
We protect the mutable state of `ThreadHandle` using a `_PyOnceFlag`.
Concurrent operations (i.e. `join` or `detach`) on `ThreadHandle` block
until it is their turn to execute or an earlier operation succeeds.
Once an operation has been applied successfully all future operations
complete immediately.
The `join()` method is now idempotent. It may be called multiple times
but the underlying OS thread will only be joined once. After `join()`
succeeds, any future calls to `join()` will succeed immediately.
The internal thread handle `detach()` method has been removed.