make lock with fine-grianed

python · colesbury · Nov 19, 2025 · Nov 15, 2025 · Nov 15, 2025 · Nov 15, 2025
commit fbda041c8f87152010d1f6aa364511c7f7d8b5bb
@@ -6546,6 +6546,18 @@ type_setattro(PyObject *self, PyObject *name, PyObject *value)
     assert(!_PyType_HasFeature(metatype, Py_TPFLAGS_INLINE_VALUES));
     assert(!_PyType_HasFeature(metatype, Py_TPFLAGS_MANAGED_DICT));
 
+#ifdef Py_GIL_DISABLED
+    if (value != NULL && PyFunction_Check(value)) {
+        if (!_PyObject_HasDeferredRefcount(value)) {
+            BEGIN_TYPE_LOCK();
 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)); 
 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)); 
+            if (!_PyObject_HasDeferredRefcount(value)) {
+                PyUnstable_Object_EnableDeferredRefcount(value);
+            }
+            END_TYPE_LOCK();
+        }
+    }
+#endif
+
     PyObject *old_value = NULL;
     PyObject *descr = _PyType_LookupRef(metatype, name);
     if (descr != NULL) {
@@ -6573,6 +6585,7 @@ type_setattro(PyObject *self, PyObject *name, PyObject *value)
         }
     }
 
+
     BEGIN_TYPE_DICT_LOCK(dict);
     res = type_update_dict(type, (PyDictObject *)dict, name, value, &old_value);
     assert(_PyType_CheckConsistency(type));

diff --git a/edward-test-bench.py b/edward-test-bench.py
@@ -0,0 +1,94 @@
+import _testcapi
+from threading import Thread
+from time import time
+
+def test_1():
+    class Foo:
+        def __init__(self, x):
+            self.x = x
+
+    niter = 5 * 1000 * 1000
+
+    def benchmark(n):
+        for i in range(n):
+            Foo(x=1)
+
+    for nth in (1, 4):
+        t0 = time()
+        threads = [Thread(target=benchmark, args=(niter,)) for _ in range(nth)]
+        for t in threads:
+            t.start()
+        for t in threads:
+            t.join()
+        print(f"{nth=} {(time() - t0) / nth}")
+
+def test_2():
+    class Foo2:
+        def __init__(self, x):
+                pass
+        pass
+
+    _Foo2_x = int
+
+    create_str = """def create_init(_Foo2_x,):
+        def __init__(self, x: _Foo2_x):
+            self.x = x
+        return (__init__,)
+    """
+    ns = {}
+    exec(create_str, globals(), ns)
+    fn = ns['create_init']({**locals()})
+    setattr(Foo2, '__init__', fn[0])
+    niter = 5 * 1000 * 1000
+    def benchmark(n):
+        for i in range(n):
+            Foo2(x=1)
+
+    for nth in (1, 4):
+        t0 = time()
+        threads = [Thread(target=benchmark, args=(niter,)) for _ in range(nth)]
+        for t in threads:
+            t.start()
+        for t in threads:
+            t.join()
+        print(f"{nth=} {(time() - t0) / nth}")
+
+def test_3():
+    class Foo3:
+        def __init__(self, x):
+                pass
+        pass
+
+    _Foo3_x = int
+
+    create_str = """def create_init(_Foo3_x,):
+        def __init__(self, x: _Foo3_x):
+            self.x = x
+        return (__init__,)
+    """
+    ns = {}
+    exec(create_str, globals(), ns)
+    fn = ns['create_init']({**locals()})
+    setattr(Foo3, '__init__', fn[0])
+    _testcapi.pyobject_enable_deferred_refcount(Foo3.__init__)
+    niter = 5 * 1000 * 1000
+    def benchmark(n):
+        for i in range(n):
+            Foo3(x=1)
+
+    for nth in (1, 4):
+        t0 = time()
+        threads = [Thread(target=benchmark, args=(niter,)) for _ in range(nth)]
+        for t in threads:
+            t.start()
+        for t in threads:
+            t.join()
+        print(f"{nth=} {(time() - t0) / nth}")
+
+if __name__ == "__main__":
+    print("------test_1-------")
+    test_1()
+    print("------test_2-------")
+    test_2()
+    print("------test_3-------")
+    test_3()