lseek() always returns 0 for character pseudo-devices like
`/dev/urandom` (for other non-regular files, e.g. `/dev/stdin`, it
always returns -1, to which CPython reacts by raising appropriate
exceptions). They are thus technically seekable despite not having seek
semantics.
When calling read() on e.g. an instance of `io.BufferedReader` that
wraps such a file, `BufferedReader` reads ahead, filling its buffer,
creating a discrepancy between the number of bytes read and the internal
`tell()` always returning 0, which previously resulted in e.g.
`BufferedReader.tell()` or `BufferedReader.seek()` being able to return
positions < 0 even though these are supposed to be always >= 0.
Invariably keep the return value non-negative by returning
max(former_return_value, 0) instead, and add some corresponding tests.
Update documentation for re library to explain that a backreference `\g<0>` is
expanded to the entire string when using Match.expand().
Note that numeric backreferences to group 0 (`\0`) are not supported.
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
This adds a safe memory reclamation scheme based on FreeBSD's "GUS" and
quiescent state based reclamation (QSBR). The API provides a mechanism
for callers to detect when it is safe to free memory that may be
concurrently accessed by readers.
This change essentially replaces usage of `%1` with `%~1`, which removes
quotes, if any. Without this change, the if statements fail due to
the quotes mangling the syntax.
Additionally, this change works around comma being treated as a parameter
delimiter in test.bat by escaping commas at time of parsing. Tested
combinations of rt and regrtest arguments, all seems to work as before
but now you can specify commas in arguments like "-uall,extralargefile".
The ID of the owning thread (`rlock_owner`) may be accessed by
multiple threads without holding the underlying lock; relaxed
atomics are used in place of the previous loads/stores.
The number of times that the lock has been acquired (`rlock_count`)
is only ever accessed by the thread that holds the lock; we do not
need to use atomics to access it.
The GC keeps track of the number of allocations (less deallocations)
since the last GC. This buffers the count in thread-local state and uses
atomic operations to modify the per-interpreter count. The thread-local
buffering avoids contention on shared state.
A consequence is that the GC scheduling is not as precise, so
"test_sneaky_frame_object" is skipped because it requires that the GC be
run exactly after allocating a frame object.
* gh-114572: Fix locking in cert_store_stats and get_ca_certs
cert_store_stats and get_ca_certs query the SSLContext's X509_STORE with
X509_STORE_get0_objects, but reading the result requires a lock. See
https://github.com/openssl/openssl/pull/23224 for details.
Instead, use X509_STORE_get1_objects, newly added in that PR.
X509_STORE_get1_objects does not exist in current OpenSSLs, but we can
polyfill it with X509_STORE_lock and X509_STORE_unlock.
* Work around const-correctness problem
* Add missing X509_STORE_get1_objects failure check
* Add blurb
Makes _PyType_Lookup thread safe, including:
Thread safety of the underlying cache.
Make mutation of mro and type members thread safe
Also _PyType_GetMRO and _PyType_GetBases are currently returning borrowed references which aren't safe.
This adds `Py_XBEGIN_CRITICAL_SECTION` and
`Py_XEND_CRITICAL_SECTION`, which accept a possibly NULL object as an
argument. If the argument is NULL, then nothing is locked or unlocked.
Otherwise, they behave like `Py_BEGIN/END_CRITICAL_SECTION`.
Work around test.support.interpreters.channels not handling unloading, which
regrtest does when running tests sequentially, by explicitly skipping the
unloading of test.support.interpreters and its submodules.
This can be rolled back once test.support.interpreters.channels supports
unloading, if we are keeping sequential runs in the same process around.
Kirill Podoprigora
wookie184
Matthew Hughes
6t8k
Furkan Onder
Rami
Thomas Weißschuh
Derek Higgins
Hugo van Kemenade
Peter Jiping Xie
Stevoisiak
Jamie Phan
Donghee Na
Brian Schubert
Ammar Askar
Sam Gross
Łukasz Langa
Irit Katriel
mpage
Peter Lazorchak
Michael Droettboom
Benjamin Peterson
Ken Jin
Victor Stinner
Nikita Sobolev
Erlend E. Aasland
Dino Viehland
David Benjamin
Thomas Wouters
monkeyman192