Fix data races in the method cache in free-threaded builds
These are technically data races, but I think they're benign (to
the extent that that is actually possible). We update cache entries
non-atomically but read them atomically from another thread, and there's
nothing that establishes a happens-before relationship between the
reads and writes that I can see.
Fix mimalloc allocator for huge memory allocation (around
8,589,934,592 GiB) on s390x.
Abort allocation early in mimalloc if the number of slices doesn't
fit into uint32_t, to prevent a integer overflow (cast 64-bit
size_t to uint32_t).
We want code objects to use deferred reference counting in the
free-threaded build. This requires them to be tracked by the GC, so we
set `Py_TPFLAGS_HAVE_GC` in the free-threaded build, but not the default
build.
Guido pointed out to me that some details about the per-interpreter state for the builtin types aren't especially clear. I'm addressing that by:
* adding a comment explaining that state
* adding some asserts to point out the relationship between each index and the interp/global runtime state
This change gives a significant speedup, as the METH_FASTCALL calling
convention is now used. The following bytes and bytearray methods are adapted:
- count()
- find()
- index()
- rfind()
- rindex()
Co-authored-by: Inada Naoki <songofacandy@gmail.com>
Fall back to tp_call() for cases when arguments are passed by name.
Co-authored-by: Donghee Na <donghee.na@python.org>
Co-authored-by: Victor Stinner <vstinner@python.org>
This keeps track of the per-thread total reference count operations in
PyThreadState in the free-threaded builds. The count is merged into the
interpreter's total when the thread exits.
Most mutable data is protected by a striped lock that is keyed on the
referenced object's address. The weakref's hash is protected using the
weakref's per-object lock.
Note that this only affects free-threaded builds. Apart from some minor
refactoring, the added code is all either gated by `ifdef`s or is a no-op
(e.g. `Py_BEGIN_CRITICAL_SECTION`).
I had meant to switch everything to InterpreterError when I added it a while back. At the time I missed a few key spots.
As part of this, I've added print-the-exception to _PyXI_InitTypes() and fixed an error case in `_PyStaticType_InitBuiltin().
This change gives a significant speedup, as the METH_FASTCALL calling
convention is now used. The following methods are adapted:
- str.count
- str.find
- str.index
- str.rfind
- str.rindex
Use the fully qualified type name in repr() of weakref.ref and
weakref.proxy types.
Fix a crash in proxy_repr() when the reference is dead.
Add also test_ref_repr() and test_proxy_repr().
Add a special case for `list.extend(dict)` and `list(dict)` so that those
patterns behave atomically with respect to modifications to the list or
dictionary.
This is required by multiprocessing, which assumes that
`list(_finalizer_registry)` is atomic.
Read the MRO in a thread-unsafe way in `PyType_IsSubtype` to avoid locking. Fixing this is tracked in #117306.
The motivation for this change is in support of making weakrefs thread-safe in free-threaded builds:
`WeakValueDictionary` uses a special dictionary function, `_PyDict_DelItemIf`
to remove dead weakrefs from the dictionary. `_PyDict_DelItemIf` removes a key
if a user supplied predicate evaluates to true for the value associated with
the key. Crucially for the `WeakValueDictionary` use case, the predicate
evaluation + deletion sequence is atomic, provided that the predicate doesn’t
suspend. The predicate used by `WeakValueDictionary` includes a subtype check,
which we must ensure doesn't suspend in free-threaded builds.
Donghee Na
neonene
Mark Shannon
Serhiy Storchaka
Thomas Grainger
Shantanu
Dino Viehland
Kirill Podoprigora
Noah Kim
Rostyslav Lobov
Jens Hedegaard Nielsen
Nikita Sobolev
Erlend E. Aasland
mpage
Irit Katriel
Victor Stinner
Sam Gross
Eric Snow
Brett Simmers
Steve Dower