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| author | Sam Gross <colesbury@gmail.com> | 2025-03-26 16:08:20 (GMT) |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2025-03-26 16:08:20 (GMT) |
| commit | 3d4ac1a2c2b610f35a9e164878d67185e4a3546f (patch) | |
| tree | 3f5c5a1347accef950ebfce5d7204864daaf0b41 /Python/bytecodes.c | |
| parent | 1b8bb1ed0c4243796af531a35de982bc4f028215 (diff) | |
| download | cpython-3d4ac1a2c2b610f35a9e164878d67185e4a3546f.zip cpython-3d4ac1a2c2b610f35a9e164878d67185e4a3546f.tar.gz cpython-3d4ac1a2c2b610f35a9e164878d67185e4a3546f.tar.bz2 | |
gh-123358: Use `_PyStackRef` in `LOAD_DEREF` (gh-130064)
Concurrent accesses from multiple threads to the same `cell` object did not
scale well in the free-threaded build. Use `_PyStackRef` and optimistically
avoid locking to improve scaling.
With the locks around cell reads gone, some of the free threading tests were
prone to starvation: the readers were able to run in a tight loop and the
writer threads weren't scheduled frequently enough to make timely progress.
Adjust the tests to avoid this.
Co-authored-by: Donghee Na <donghee.na@python.org>
Diffstat (limited to 'Python/bytecodes.c')
| -rw-r--r-- | Python/bytecodes.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/Python/bytecodes.c b/Python/bytecodes.c index 44e8ea2..b6a4821 100644 --- a/Python/bytecodes.c +++ b/Python/bytecodes.c @@ -1822,12 +1822,11 @@ dummy_func( inst(LOAD_DEREF, ( -- value)) { PyCellObject *cell = (PyCellObject *)PyStackRef_AsPyObjectBorrow(GETLOCAL(oparg)); - PyObject *value_o = PyCell_GetRef(cell); - if (value_o == NULL) { + value = _PyCell_GetStackRef(cell); + if (PyStackRef_IsNull(value)) { _PyEval_FormatExcUnbound(tstate, _PyFrame_GetCode(frame), oparg); ERROR_IF(true, error); } - value = PyStackRef_FromPyObjectSteal(value_o); } inst(STORE_DEREF, (v --)) { |