gh-113750: Fix object resurrection on free-threaded builds
This avoids the undesired re-initializing of fields like `ob_gc_bits`,
`ob_mutex`, and `ob_tid` when an object is resurrected due to its
finalizer being called.
This change has no effect on the default (with GIL) build.
* gh-112532: Tag mimalloc heaps and pages
Mimalloc pages are data structures that contain contiguous allocations
of the same block size. Note that they are distinct from operating
system pages. Mimalloc pages are contained in segments.
When a thread exits, it abandons any segments and contained pages that
have live allocations. These segments and pages may be later reclaimed
by another thread. To support GC and certain thread-safety guarantees in
free-threaded builds, we want pages to only be reclaimed by the
corresponding heap in the claimant thread. For example, we want pages
containing GC objects to only be claimed by GC heaps.
This allows heaps and pages to be tagged with an integer tag that is
used to ensure that abandoned pages are only claimed by heaps with the
same tag. Heaps can be initialized with a tag (0-15); any page allocated
by that heap copies the corresponding tag.
* Fix conversion warning
* gh-112532: Isolate abandoned segments by interpreter
Mimalloc segments are data structures that contain memory allocations along
with metadata. Each segment is "owned" by a thread. When a thread exits,
it abandons its segments to a global pool to be later reclaimed by other
threads. This changes the pool to be per-interpreter instead of process-wide.
This will be important for when we use mimalloc to find GC objects in the
`--disable-gil` builds. We want heaps to only store Python objects from a
single interpreter. Absent this change, the abandoning and reclaiming process
could break this isolation.
* Add missing '&_mi_abandoned_default' to 'tld_empty'
Fix undefined behavior warnings (UBSan -fsanitize=function), for example:
Python/generated_cases.c.h:3315:13: runtime error: call to function mappingproxy_dealloc through pointer to incorrect function type 'void (*)(struct _object *)'
descrobject.c:1160: note: mappingproxy_dealloc defined here
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior Python/generated_cases.c.h:3315:13 in
Fix undefined behavior warnings (UBSan -fsanitize=function), for example:
Objects/object.c:674:11: runtime error: call to function list_repr through pointer to incorrect function type 'struct _object *(*)(struct _object *)'
listobject.c:382: note: list_repr defined here
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior Objects/object.c:674:11 in
* gh-112532: Use separate mimalloc heaps for GC objects
In `--disable-gil` builds, we now use four separate heaps in
anticipation of using mimalloc to find GC objects when the GIL is
disabled. To support this, we also make a few changes to mimalloc:
* `mi_heap_t` and `mi_tld_t` initialization is split from allocation.
This allows us to have a `mi_tld_t` per-`PyThreadState`, which is
important to keep interpreter isolation, since the same OS thread may
run in multiple interpreters (using different PyThreadStates.)
* Heap abandoning (mi_heap_collect_ex) can now be called from a
different thread than the one that created the heap. This is necessary
because we may clear and delete the containing PyThreadStates from a
different thread during finalization and after fork().
* Use enum instead of defines and guard mimalloc includes.
* The enum typedef will be convenient for future PRs that use the type.
* Guarding the mimalloc includes allows us to unconditionally include
pycore_mimalloc.h from other header files that rely on things like
`struct _mimalloc_thread_state`.
* Only define _mimalloc_thread_state in Py_GIL_DISABLED builds
gh-112027: Don't print mimalloc warning after mmap
This changes the warning to a "verbose"-level message in prim.c. The
address passed to mmap is only a hint -- it's normal for mmap() to
sometimes not respect the hint and return a different address.
* Make memory_clear() compatible with inquiry
* Make memory_traverse() compatible with traverseproc
* Make memory_dealloc() compatible with destructor
* Make memory_repr() compatible with reprfunc
* Make memory_hash() compatible with hashfunc
* Make memoryiter_next() compatible with iternextfunc
* Make memoryiter_traverse() compatible with traverseproc
* Make memoryiter_dealloc() compatible with destructor
* Make several functions compatible with getter
* Make a few functions compatible with getter
* Make memory_item() compatible with ssizeargfunc
* Make memory_subscript() compatible with binaryfunc
* Make memory_length() compatible with lenfunc
* Make memory_ass_sub() compatible with objobjargproc
* Make memory_releasebuf() compatible with releasebufferproc
* Make memory_getbuf() compatible with getbufferproc
* Make mbuf_clear() compatible with inquiry
* Make mbuf_traverse() compatible with traverseproc
* Make mbuf_dealloc() compatible with destructor
This replaces some usages of PyThread_type_lock with PyMutex, which does not require memory allocation to initialize.
This simplifies some of the runtime initialization and is also one step towards avoiding changing the default raw memory allocator during initialize/finalization, which can be non-thread-safe in some circumstances.
Previously arbitrary errors could be cleared during formatting error
messages for ImportError or AttributeError for modules. Now all
unexpected errors are reported.
This avoids:
python3.13 Tools/unicode/makeunicodedata.py
python3.13: can't open file '.../build/debug/Tools/unicode/makeunicodedata.py': [Errno 2] No such file or directory
make: *** [Makefile:1498: regen-unicodedata] Error 2
Re-run `make regen-unicodedata` to update the script path in generated files.
_PyDict_Pop_KnownHash(): remove the default value and the return type
becomes an int.
Co-authored-by: Stefan Behnel <stefan_ml@behnel.de>
Co-authored-by: Antoine Pitrou <pitrou@free.fr>
* Split list_extend() into two sub-functions: list_extend_fast() and
list_extend_iter().
* list_inplace_concat() no longer has to call Py_DECREF() on the
list_extend() result, since list_extend() now returns an int.
Donghee Na
Nikita Sobolev
Sam Gross
Jakub Kulík
Alex Waygood
Christopher Chavez
Yan Yanchii
Raymond Hettinger
Shantanu
Erlend E. Aasland
Carey Metcalfe
andrewluotechnologies
Serhiy Storchaka
Sergey B Kirpichev
chilaxan
Irit Katriel
Kirill Podoprigora
Eric Snow
Hugo van Kemenade
Victor Stinner
Miro Hrončok
Furkan Onder
Pavel Ovchinnikov