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| author | Peter Bierma <zintensitydev@gmail.com> | 2024-11-13 13:27:16 (GMT) |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2024-11-13 13:27:16 (GMT) |
| commit | d00878b06a05ea04790813dba70b09cc1d11bf45 (patch) | |
| tree | e7508c9d7769379ae50a0f6e7572a61bb6dc952f /Objects | |
| parent | 29b5323c4567dc7772e1d30a7ba1cbad52fe10a9 (diff) | |
| download | cpython-d00878b06a05ea04790813dba70b09cc1d11bf45.zip cpython-d00878b06a05ea04790813dba70b09cc1d11bf45.tar.gz cpython-d00878b06a05ea04790813dba70b09cc1d11bf45.tar.bz2 | |
gh-123619: Add an unstable C API function for enabling deferred reference counting (GH-123635)
Co-authored-by: Sam Gross <colesbury@gmail.com>
Diffstat (limited to 'Objects')
| -rw-r--r-- | Objects/object.c | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/Objects/object.c b/Objects/object.c index 7cc74a8..052dea9 100644 --- a/Objects/object.c +++ b/Objects/object.c @@ -2519,6 +2519,35 @@ _PyObject_SetDeferredRefcount(PyObject *op) #endif } +int +PyUnstable_Object_EnableDeferredRefcount(PyObject *op) +{ +#ifdef Py_GIL_DISABLED + if (!PyType_IS_GC(Py_TYPE(op))) { + // Deferred reference counting doesn't work + // on untracked types. + return 0; + } + + uint8_t bits = _Py_atomic_load_uint8(&op->ob_gc_bits); + if ((bits & _PyGC_BITS_DEFERRED) != 0) + { + // Nothing to do. + return 0; + } + + if (_Py_atomic_compare_exchange_uint8(&op->ob_gc_bits, &bits, bits | _PyGC_BITS_DEFERRED) == 0) + { + // Someone beat us to it! + return 0; + } + _Py_atomic_add_ssize(&op->ob_ref_shared, _Py_REF_SHARED(_Py_REF_DEFERRED, 0)); + return 1; +#else + return 0; +#endif +} + void _Py_ResurrectReference(PyObject *op) { |