"Stateless" code is a function or code object which does not rely on external state or internal state.
It may rely on arguments and builtins, but not globals or a closure. I've left a comment in
pycore_code.h that provides more detail.
We also add _PyFunction_VerifyStateless(). The new functions will be used in several later changes
that facilitate "sharing" functions and code objects between interpreters.
This reverts commit 811edcf (gh-133232), which itself reverted the original commit 811edcf (gh-133128).
We reverted the original change due to failing s390 builds (a big-endian architecture).
It ended up that I had not accommodated op caches.
For the free-threaded build, check the process resident set size (RSS)
increase before triggering a full automatic garbage collection. If the RSS
has not increased 10% since the last collection then it is deferred.
In certain cases it's possible for locals loaded by `LOAD_FAST` instructions
to be on the stack when the local is killed by `DEL_FAST`. These `LOAD_FAST`
instructions should not be optimized into `LOAD_FAST_BORROW` as the strong
reference in the frame is killed while there is still a reference on the stack.
The X/Open curses specification[0] and ncurses documentation[1]
both state that subwindows must be deleted before the main window.
Deleting the windows in the wrong order causes a double-free with
NetBSD's curses implementation.
To fix this, keep track of the original window object in the subwindow
object, and keep a reference to the original for the lifetime of
the subwindow.
[0] https://pubs.opengroup.org/onlinepubs/7908799/xcurses/delwin.html
[1] https://invisible-island.net/ncurses/man/curs_window.3x.html
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
* Track the current executor, not the previous one, on the thread-state.
* Batch executors for deallocation to avoid having to constantly incref executors; this is an ad-hoc form of deferred reference counting.
Add `_Py_ALIGN_AS` as per C API WG vote: https://github.com/capi-workgroup/decisions/issues/61
This patch only adds it to free-threaded builds; the `#ifdef Py_GIL_DISABLED`
can be removed in the future.
Use this to revert `PyASCIIObject` memory layout for non-free-threaded builds.
The long-term plan is to deprecate the entire struct; until that happens
it's better to keep it unchanged, as courtesy to people that rely on it despite
it not being stable ABI.
After gh-130704, the interpreter replaces some uses of `LOAD_FAST` with
`LOAD_FAST_BORROW` which avoid incref/decrefs by "borrowing" references
on the interpreter stack when the bytecode compiler can determine that
it's safe.
This change broke some checks in C API extensions that relied on
`Py_REFCNT()` of `1` to determine if it's safe to modify an object
in-place. Objects may have a reference count of one, but still be
referenced further up the interpreter stack due to borrowing of
references.
This provides a replacement function for those checks.
`PyUnstable_Object_IsUniqueReferencedTemporary` is more conservative:
it checks that the object has a reference count of one and that it exists as a
unique strong reference in the interpreter's stack of temporary
variables in the top most frame.
See also:
* https://github.com/numpy/numpy/issues/28681
Co-authored-by: Pieter Eendebak <pieter.eendebak@gmail.com>
Co-authored-by: T. Wouters <thomas@python.org>
Co-authored-by: mpage <mpage@cs.stanford.edu>
Co-authored-by: Mark Shannon <mark@hotpy.org>
Co-authored-by: Victor Stinner <vstinner@python.org>
There's some extra complexity due to making sure we we get things right when handling functions and classes defined in the __main__ module. This is also reflected in the tests, including the addition of extra functions in test.support.import_helper.
This helper is useful in a variety of ways, including in demonstrating how the different counts relate to one another.
It will be used in a later change to help identify if a function is "stateless", meaning it doesn't have any free vars or globals.
Note that a majority of this change is tests.
Both were added in 3.13, are undocumented, and don't make sense in 3.14 due to
changes in the stack overflow detection machinery (gh-112282).
PEP 387 exception for skipping a deprecation period: https://github.com/python/steering-council/issues/288
The function indicates whether or not the function has a return statement.
This is used by a later change related treating some functions like scripts.
In the free-threaded build, avoid data races caused by updating type slots
or type flags after the type was initially created. For those (typically
rare) cases, use the stop-the-world mechanism. Remove the use of atomics
when reading or writing type flags. The use of atomics is not sufficient to
avoid races (since flags are sometimes read without a lock and without
atomics) and are no longer required.
We replace it with _Py_GetMainModule(), and add _Py_CheckMainModule(), but both in the internal-only C-API. We also add _PyImport_GetModulesRef(), which is the equivalent of _PyImport_GetModules(), but which increfs before the lock is released.
This is used by a later change related to pickle and handling __main__.
The following are added to the internal C-API:
* _PyErr_FormatV()
* _PyErr_SetModuleNotFoundError()
* _PyXIData_GetNotShareableErrorType()
* _PyXIData_FormatNotShareableError()
We also drop _PyXIData_lookup_context_t and _PyXIData_GetLookupContext().
For the same reasons as running the GC, this will allow sections that
run in native code for long periods without executing bytecode to also
run the remote debugger protocol without having to wait until bytecode
is executed
Signed-off-by: Pablo Galindo <pablogsal@gmail.com>
