Lower the C recursion limit for HPPA, PPC64 and SPARC, as they use
relatively large stack frames that cause e.g. `test_descr` to hit
a stack overflow. According to quick testing, it seems that values
around 8000 are max for HPPA and PPC64 (ELFv1 ABI) and 7000 for SPARC64.
To keep things safe, let's use 5000 for PPC64 and 4000 for SPARC.
Co-authored-by: Michał Górny <mgorny@gentoo.org>
Use a `_PyStackRef` and defer the reference to `f_executable` when
possible. This avoids some reference count contention in the common case
of executing the same code object from multiple threads concurrently in
the free-threaded build.
In gh-121602, I applied a fix to a builtin types initialization bug.
That fix made sense in the context of some broader future changes,
but introduced a little bit of extra complexity. That fix has turned
out to be incomplete for some of the builtin types we haven't
been testing. I found that out while improving the tests.
A while back, @markshannon suggested a simpler fix that doesn't
have that problem, which I've already applied to 3.12 and 3.13.
I'm switching to that here. Given the potential long-term
benefits of the more complex (but still incomplete) approach,
I'll circle back to it in the future, particularly after I've improved
the tests so no corner cases slip through the cracks.
(This is effectively a "forward-port" of 716c677 from 3.13.)
Add PyConfig_Get(), PyConfig_GetInt(), PyConfig_Set() and
PyConfig_Names() functions to get and set the current runtime Python
configuration.
Add visibility and "sys spec" to config and preconfig specifications.
_PyConfig_AsDict() now converts PyConfig.xoptions as a dictionary.
Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
Switch more _Py_IsImmortal(...) assertions to _Py_IsImmortalLoose(...)
The remaining calls to _Py_IsImmortal are in free-threaded-only code,
initialization of core objects, tests, and guards that fall back to
code that works with mortal objects.
The `zip_next` function uses a common optimization technique for methods
that generate tuples. The iterator maintains an internal reference to
the returned tuple. When the method is called again, it checks if the
internal tuple's reference count is 1. If so, the tuple can be reused.
However, this approach is not safe under the free-threading build:
after checking the reference count, another thread may perform the same
check and also reuse the tuple. This can result in a double decref on
the items of the replaced tuple and a double incref (memory leak) on
the items of the tuple being set.
This adds a function, `_PyObject_IsUniquelyReferenced` that
encapsulates the stricter logic necessary for the free-threaded build:
the internal tuple must be owned by the current thread, have a local
refcount of one, and a shared refcount of zero.
`Py_DECREF` and `PyStackRef_CLOSE` are now implemented as macros in the
free-threaded build in ceval.c. There are two motivations;
* MSVC has problems inlining functions in ceval.c in the PGO build.
* We will want to mark escaping calls in order to spill the stack
pointer in ceval.c and we will want to do this around `_Py_Dealloc`
(or `_Py_MergeZeroLocalRefcount` or `_Py_DecRefShared`), not around
the entire `Py_DECREF` or `PyStackRef_CLOSE` call.
The free-threaded GC now visits interpreter stacks to keep objects
that use deferred reference counting alive.
Interpreter frames are zero initialized in the free-threaded GC so
that the GC doesn't see garbage data. This is a temporary measure
until stack spilling around escaping calls is implemented.
Co-authored-by: Ken Jin <kenjin@python.org>
As of 529a160 (gh-118204), building with HAVE_DYNAMIC_LOADING stopped working. This is a minimal fix just to get builds working again. There are actually a number of long-standing deficiencies with HAVE_DYNAMIC_LOADING builds that need to be resolved separately.
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.
This replaces `_PyList_FromArraySteal` with `_PyList_FromStackRefSteal`.
It's functionally equivalent, but takes a `_PyStackRef` array instead of
an array of `PyObject` pointers.
Co-authored-by: Ken Jin <kenjin@python.org>
Return -1 and set an exception on error; return 0 if the iterator is
exhausted, and return 1 if the next item was fetched successfully.
Prefer this API to PyIter_Next(), which requires the caller to use
PyErr_Occurred() to differentiate between iterator exhaustion and errors.
Co-authered-by: Irit Katriel <iritkatriel@yahoo.com>
The free-threaded build partially stores heap type reference counts in
distributed manner in per-thread arrays. This avoids reference count
contention when creating or destroying instances.
Co-authored-by: Ken Jin <kenjin@python.org>
* gh-122188: Move magic number to its own file
* Add versionadded directive
* Do work in C
* Integrate launcher.c
* Make _pyc_magic_number private
* Remove metadata
* Move sys.implementation -> _imp
* Modernize comment
* Move _RAW_MAGIC_NUMBER to the C side as well
* _pyc_magic_number -> pyc_magic_number
* Remove unused import
* Update docs
* Apply suggestions from code review
Co-authored-by: Eric Snow <ericsnowcurrently@gmail.com>
* Fix typo in tests
---------
Co-authored-by: Eric Snow <ericsnowcurrently@gmail.com>
Change _PyLong_IsCompact() and _PyLong_CompactValue() parameter type
from 'PyObject*' to 'const PyObject*'. Avoid the Py_TYPE() macro
which does not support const parameter.
* gh-120974: Make _asyncio._leave_task atomic in the free-threaded build
Update `_PyDict_DelItemIf` to allow for an argument to be passed to the
predicate.
This refactors asyncio to use the common freelist helper functions and
macros. As a side effect, the freelist for _asyncio.Future is now
re-enabled in the free-threaded build.
This combines and updates our freelist handling to use a consistent
implementation. Objects in the freelist are linked together using the
first word of memory block.
If configured with freelists disabled, these operations are essentially
no-ops.
When builtin static types are initialized for a subinterpreter, various "tp" slots have already been inherited (for the main interpreter). This was interfering with the logic in add_operators() (in Objects/typeobject.c), causing a wrapper to get created when it shouldn't. This change fixes that by preserving the original data from the static type struct and checking that.
The `_PySeqLock_EndRead` function needs an acquire fence to ensure that
the load of the sequence happens after any loads within the read side
critical section. The missing fence can trigger bugs on macOS arm64.
Additionally, we need a release fence in `_PySeqLock_LockWrite` to
ensure that the sequence update is visible before any modifications to
the cache entry.
Add more offsets to _Py_DebugOffsets
We add a few more offsets that are required by some out-of-process
tools, such as [Austin](https://github.com/p403n1x87/austin).
Refactor the fast Unicode hash check into `_PyObject_HashFast` and use relaxed
atomic loads in the free-threaded build.
After this change, the TSAN doesn't report data races for this method.
1. Use pkg-config to check for ncursesw/panelw. If that fails, use
pkg-config to check for ncurses/panel.
2. Regardless of pkg-config output, search for curses/panel headers, so
we're sure we have all defines in pyconfig.h.
3. Regardless of pkg-config output, check if libncurses or libncursesw
contains the 'initscr' symbol; if it does _and_ pkg-config failed
earlier, add the resulting -llib linker option to CURSES_LIBS.
Ditto for 'update_panels' and PANEL_LIBS.
4. Wrap the rest of the checks with WITH_SAVE_ENV and make sure we're
using updated LIBS and CPPFLAGS for those.
Add the PY_CHECK_CURSES convenience macro.
On Windows, test_cext and test_cppext now pass /WX flag to the MSC
compiler to treat all compiler warnings as errors. In verbose mode,
these tests now log the compiler commands to help debugging.
Change Py_BUILD_ASSERT_EXPR implementation on Windows to avoid a
compiler warning about an unnamed structure.
Fix warnings when using -Wimplicit-fallthrough compiler flag.
Annotate explicitly "fall through" switch cases with a new
_Py_FALLTHROUGH macro which uses __attribute__((fallthrough)) if
available. Replace "fall through" comments with _Py_FALLTHROUGH.
Add _Py__has_attribute() macro. No longer define __has_attribute()
macro if it's not defined. Move also _Py__has_builtin() at the top
of pyport.h.
Co-Authored-By: Nikita Sobolev <mail@sobolevn.me>
This PR sets up tagged pointers for CPython.
The general idea is to create a separate struct _PyStackRef for everything on the evaluation stack to store the bits. This forces the C compiler to warn us if we try to cast things or pull things out of the struct directly.
Only for free threading: We tag the low bit if something is deferred - that means we skip incref and decref operations on it. This behavior may change in the future if Mark's plans to defer all objects in the interpreter loop pans out.
This implies a strict stack reference discipline is required. ALL incref and decref operations on stackrefs must use the stackref variants. It is unsafe to untag something then do normal incref/decref ops on it.
The new incref and decref variants are called dup and close. They mimic a "handle" API operating on these stackrefs.
Please read Include/internal/pycore_stackref.h for more information!
---------
Co-authored-by: Mark Shannon <9448417+markshannon@users.noreply.github.com>
Remove the const qualifier of the argument of functions:
* _PyLong_IsCompact()
* _PyLong_CompactValue()
Py_TYPE() argument is not const.
Fix the compiler warning:
Include/cpython/longintrepr.h: In function ‘_PyLong_CompactValue’:
Include/pyport.h:19:31: error: cast discards ‘const’ qualifier from
pointer target type [-Werror=cast-qual]
(...)
Include/cpython/longintrepr.h:133:30: note: in expansion of macro
‘Py_TYPE’
assert(PyType_HasFeature(Py_TYPE(op), Py_TPFLAGS_LONG_SUBCLASS));
* linked list
* add tail optmiization to linked list
* wip
* wip
* wip
* more fixes
* finally it works
* add tests
* remove weakreflist
* add some comments
* reduce code duplication in _asynciomodule.c
* address some review comments
* add invariants about the state of the linked list
* add better explanation
* clinic regen
* reorder branches for better branch prediction
* Update Modules/_asynciomodule.c
* Apply suggestions from code review
Co-authored-by: Itamar Oren <itamarost@gmail.com>
* fix capturing of eager tasks
* add comment to task finalization
* fix tests and couple c implmentation to c task
improved linked-list logic and more comments
* fix test
---------
Co-authored-by: Itamar Oren <itamarost@gmail.com>
This makes the following macros public as part of the non-limited C-API for
locking a single object or two objects at once.
* `Py_BEGIN_CRITICAL_SECTION(op)` / `Py_END_CRITICAL_SECTION()`
* `Py_BEGIN_CRITICAL_SECTION2(a, b)` / `Py_END_CRITICAL_SECTION2()`
The supporting functions and structs used by the macros are also exposed for
cases where C macros are not available.
* Add an InternalDocs file describing how interning should work and how to use it.
* Add internal functions to *explicitly* request what kind of interning is done:
- `_PyUnicode_InternMortal`
- `_PyUnicode_InternImmortal`
- `_PyUnicode_InternStatic`
* Switch uses of `PyUnicode_InternInPlace` to those.
* Disallow using `_Py_SetImmortal` on strings directly.
You should use `_PyUnicode_InternImmortal` instead:
- Strings should be interned before immortalization, otherwise you're possibly
interning a immortalizing copy.
- `_Py_SetImmortal` doesn't handle the `SSTATE_INTERNED_MORTAL` to
`SSTATE_INTERNED_IMMORTAL` update, and those flags can't be changed in
backports, as they are now part of public API and version-specific ABI.
* Add private `_only_immortal` argument for `sys.getunicodeinternedsize`, used in refleak test machinery.
* Make sure the statically allocated string singletons are unique. This means these sets are now disjoint:
- `_Py_ID`
- `_Py_STR` (including the empty string)
- one-character latin-1 singletons
Now, when you intern a singleton, that exact singleton will be interned.
* Add a `_Py_LATIN1_CHR` macro, use it instead of `_Py_ID`/`_Py_STR` for one-character latin-1 singletons everywhere (including Clinic).
* Intern `_Py_STR` singletons at startup.
* For free-threaded builds, intern `_Py_LATIN1_CHR` singletons at startup.
* Beef up the tests. Cover internal details (marked with `@cpython_only`).
* Add lots of assertions
Co-Authored-By: Eric Snow <ericsnowcurrently@gmail.com>
This exposes `PyUnstable_Object_ClearWeakRefsNoCallbacks` as an unstable
C-API function to provide a thread-safe mechanism for clearing weakrefs
without executing callbacks.
Some C-API extensions need to clear weakrefs without calling callbacks,
such as after running finalizers like we do in subtype_dealloc.
Previously they could use `_PyWeakref_ClearRef` on each weakref, but
that's not thread-safe in the free-threaded build.
Co-authored-by: Petr Viktorin <encukou@gmail.com>
In gh-120009 I used an atexit hook to finalize the _datetime module's static types at interpreter shutdown. However, atexit hooks are executed very early in finalization, which is a problem in the few cases where a subclass of one of those static types is still alive until the final GC collection. The static builtin types don't have this probably because they are finalized toward the end, after the final GC collection. To avoid the problem for _datetime, I have applied a similar approach here.
Also, credit goes to @mgorny and @neonene for the new tests.
FYI, I would have liked to take a slightly cleaner approach with managed static types, but wanted to get a smaller fix in first for the sake of backporting. I'll circle back to the cleaner approach with a future change on the main branch.
The _strptime module object was cached in a static local variable (in the datetime.strptime() implementation). That's a problem when it crosses isolation boundaries, such as reinitializing the runtme or between interpreters. This change fixes the problem by dropping the static variable, instead always relying on the normal sys.modules cache (via PyImport_Import()).
This adds a `_PyRecursiveMutex` type based on `PyMutex` and uses that
for the import lock. This fixes some data races in the free-threaded
build and generally simplifies the import lock code.
The `_PyThreadState_Bind()` function is called before the first
`PyEval_AcquireThread()` so it's not synchronized with the stop the
world GC. We had a race where `gc_visit_heaps()` might visit a thread's
heap while it's being initialized.
Use a simple atomic int to avoid visiting heaps for threads that are not
yet fully initialized (i.e., before `tstate_mimalloc_bind()` is called).
The race was reproducible by running:
`python Lib/test/test_importlib/partial/pool_in_threads.py`.
Mark Shannon
Sam James
neonene
Victor Stinner
Irit Katriel
Ken Jin
Wenzel Jakob
Sam Gross
Eric Snow
Petr Viktorin
Matt Wozniski
Serhiy Storchaka
Pieter Eendebak
Pablo Galindo Salgado
Michael Droettboom
Brandt Bucher
Erlend E. Aasland
Lysandros Nikolaou
Jelle Zijlstra
jianghuyiyuan
Marc Mueller
Jakub Kulík
mpage
Tian Gao
Hood Chatham
Gabriele N. Tornetta
AN Long
Yureka
Steve Dower
Kumar Aditya
Xie Yanbo
Bénédikt Tran
Kirill Podoprigora
Saul Shanabrook