mirrors/cpython
1
0
Fork 0
mirror of https://github.com/python/cpython.git synced 2025-10-17 12:18:23 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 9

GH-125174: Mark objects as statically allocated. (#127797)

Browse source 
* Set a bit in the unused part of the refcount on 64 bit machines and the free-threaded build.

* Use the top of the refcount range on 32 bit machines
This commit is contained in:
Mark Shannon 2024-12-11 17:37:38 +00:00 • committed by GitHub
parent dd9da738ad
commit bc262de06b
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
7 changed files with 99 additions and 13 deletions
Download patch file Download diff file Expand all files Collapse all files

20
Include/object.h
View file

@ -71,7 +71,7 @@ whose size is determined when the object is allocated.
#define PyObject_HEAD_INIT(type) \
{ \
0, \
0, \
_Py_STATICALLY_ALLOCATED_FLAG, \
{ 0 }, \
0, \
_Py_IMMORTAL_REFCNT_LOCAL, \
@ -81,7 +81,7 @@ whose size is determined when the object is allocated.
#else
#define PyObject_HEAD_INIT(type) \
{ \
{ _Py_IMMORTAL_INITIAL_REFCNT }, \
{ _Py_STATIC_IMMORTAL_INITIAL_REFCNT }, \
(type) \
},
#endif
@ -120,9 +120,19 @@ struct _object {
__pragma(warning(disable: 4201))
#endif
union {
Py_ssize_t ob_refcnt;
#if SIZEOF_VOID_P > 4
PY_UINT32_T ob_refcnt_split[2];
PY_INT64_T ob_refcnt_full; /* This field is needed for efficient initialization with Clang on ARM */
struct {
# if PY_BIG_ENDIAN
PY_UINT32_T ob_flags;
PY_UINT32_T ob_refcnt;
# else
PY_UINT32_T ob_refcnt;
PY_UINT32_T ob_flags;
# endif
};
#else
Py_ssize_t ob_refcnt;
#endif
};
#ifdef _MSC_VER
@ -142,7 +152,7 @@ struct _object {
// trashcan mechanism as a linked list pointer and by the GC to store the
// computed "gc_refs" refcount.
uintptr_t ob_tid;
uint16_t _padding;
uint16_t ob_flags;
PyMutex ob_mutex; // per-object lock
uint8_t ob_gc_bits; // gc-related state
uint32_t ob_ref_local; // local reference count