RustPython · youknowone · Jul 8, 2026 · Mar 9, 2026 · Mar 17, 2026 · Apr 13, 2026
diff --git a/.cspell.dict/rustpython.txt b/.cspell.dict/rustpython.txt
@@ -27,6 +27,7 @@ pystr
 pystruct
 pystructseq
 pytype
+qsbr
 rustix
 struc
 zelf
diff --git a/.cspell.json b/.cspell.json
@@ -79,8 +79,11 @@
     "mcache",
     "oparg",
     "opargs",
+    "pointee",
     "pyc",
     "reborrow",
+    "reborrows",
+    "reparenting",
     "reraises",
     "reraising",
     "significand",

diff --git a/.gitignore b/.gitignore
@@ -27,4 +27,5 @@ Lib/site-packages/*
 Lib/test/data/*
 !Lib/test/data/README
 cpython/
-.claude/scheduled_tasks.lock
+.claude/scheduled_tasks.lock
+docs/superpowers/
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/Cargo.toml b/Cargo.toml
@@ -229,6 +229,7 @@ hmac = "0.13"
 indexmap = { version = "2.14.0", features = ["std"] }
 insta = "1.47"
 itertools = { version = "0.15.0", default-features = false, features = ["use_alloc"] }
+itoa = "1"
 is-macro = "0.3.7"
 js-sys = "0.3"
 junction = "2.0.0"

diff --git a/Lib/test/test_asyncio/test_base_events.py b/Lib/test/test_asyncio/test_base_events.py
@@ -1019,7 +1019,6 @@ async def iter_one():
         asyncio.create_task(iter_one())
         return status
 
-    @unittest.expectedFailure  # TODO: RUSTPYTHON; - GC doesn't finalize async generators
     def test_asyncgen_finalization_by_gc(self):
         # Async generators should be finalized when garbage collected.
         self.loop._process_events = mock.Mock()
@@ -1035,7 +1034,6 @@ def test_asyncgen_finalization_by_gc(self):
             test_utils.run_briefly(self.loop)
             self.assertTrue(status['finalized'])
 
-    @unittest.expectedFailure  # TODO: RUSTPYTHON; - GC doesn't finalize async generators
     def test_asyncgen_finalization_by_gc_in_other_thread(self):
         # Python issue 34769: If garbage collector runs in another
         # thread, async generators will not finalize in debug

diff --git a/Lib/test/test_descr.py b/Lib/test/test_descr.py
@@ -4154,7 +4154,6 @@ class E(D):
         else:
             self.fail("shouldn't be able to create inheritance cycles")
 
-    @unittest.expectedFailure  # TODO: RUSTPYTHON
     def test_builtin_bases(self):
         # Make sure all the builtin types can have their base queried without
         # segfaulting. See issue #5787.
@@ -4199,7 +4198,6 @@ class D(C):
         else:
             self.fail("best_base calculation found wanting")
 
-    @unittest.expectedFailure  # TODO: RUSTPYTHON
     def test_unsubclassable_types(self):
         with self.assertRaises(TypeError):
             class X(type(None)):

diff --git a/Lib/test/test_frame.py b/Lib/test/test_frame.py
@@ -315,7 +315,6 @@ def inner():
                          % (file_repr, offset + 5))
 
 class TestFrameLocals(unittest.TestCase):
-    @unittest.expectedFailure  # TODO: RUSTPYTHON
     def test_scope(self):
         class A:
             x = 1
@@ -333,7 +332,6 @@ def f():
             self.assertEqual(locals()['y'], 2)
         f()
 
-    @unittest.expectedFailure  # TODO: RUSTPYTHON; AssertionError: 1 != 2
     def test_closure(self):
         x = 1
         y = 2
@@ -356,7 +354,6 @@ def test_closure_with_inline_comprehension(self):
         lst = [locals() for k in [0]]
         self.assertEqual(lst[0]['k'], 0)
 
-    @unittest.expectedFailure  # TODO: RUSTPYTHON; AssertionError: 3 != 4
     def test_as_dict(self):
         x = 1
         y = 2
@@ -414,7 +411,6 @@ def test_non_string_key(self):
         d[1] = 2
         self.assertEqual(d[1], 2)
 
-    @unittest.expectedFailure  # TODO: RUSTPYTHON; UnboundLocalError: local variable 'b' referenced before assignment
     def test_write_with_hidden(self):
         def f():
             f_locals = [sys._getframe().f_locals for b in [0]][0]
@@ -426,7 +422,6 @@ def f():
             c = 0
         f()
 
-    @unittest.expectedFailure  # TODO: RUSTPYTHON; AssertionError: <object object at 0xb4000072b6930480> != 'a.b.c'
     def test_local_objects(self):
         o = object()
         k = '.'.join(['a', 'b', 'c'])
@@ -457,7 +452,6 @@ def test_repr(self):
         frame = sys._getframe()
         self.assertEqual(repr(frame.f_locals), repr(dict(frame.f_locals)))
 
-    @unittest.expectedFailure  # TODO: RUSTPYTHON; AssertionError: ValueError not raised
     def test_delete(self):
         x = 1
         d = sys._getframe().f_locals
@@ -501,7 +495,6 @@ def test_sizeof(self):
         proxy = sys._getframe().f_locals
         support.check_sizeof(self, proxy, support.calcobjsize("P"))
 
-    @unittest.expectedFailure  # TODO: RUSTPYTHON; AssertionError: TypeError not raised
     def test_unsupport(self):
         x = 1
         d = sys._getframe().f_locals
@@ -536,7 +529,6 @@ def __eq__(self, other):
 
         return StringSubclass('x'), ImpostorX(), 'x'
 
-    @unittest.expectedFailure  # TODO: RUSTPYTHON; AssertionError: dict_keys(['obj', 'x']) != ['obj', 'x', 'proxy']
     def test_proxy_key_stringlikes_overwrite(self):
         def f(obj):
             x = 1
@@ -559,7 +551,6 @@ def f(obj):
                 self.assertEqual(keys_snapshot,  expected_keys)
                 self.assertEqual(proxy_snapshot, expected_dict)
 
-    @unittest.expectedFailure  # TODO: RUSTPYTHON; UnboundLocalError: local variable 'b' referenced before assignment
     def test_proxy_key_stringlikes_ftrst_write(self):
         def f(obj):
             proxy = sys._getframe().f_locals
@@ -587,7 +578,6 @@ class ObjectSubclass:
                 with self.assertRaises(TypeError):
                     proxy[obj] = 0
 
-    @unittest.expectedFailure  # TODO: RUSTPYTHON; AssertionError: 'dict' != 'FrameLocalsProxy'
     def test_constructor(self):
         FrameLocalsProxy = type([sys._getframe().f_locals
                                  for x in range(1)][0])

diff --git a/Lib/test/test_generators.py b/Lib/test/test_generators.py
@@ -762,7 +762,6 @@ def get_frame(index):
                 self.assertIn('a', frame_locals)
                 self.assertEqual(frame_locals['a'], 42)
 
-    @unittest.expectedFailure  # TODO: RUSTPYTHON; frame locals don't survive generator deallocation
     def test_frame_locals_outlive_generator(self):
         frame_locals1 = None
 

diff --git a/Lib/test/test_inspect/test_inspect.py b/Lib/test/test_inspect/test_inspect.py
@@ -588,7 +588,6 @@ def test_frame(self):
         self.assertEqual(inspect.formatargvalues(args, varargs, varkw, locals),
                          '(x=11, y=14)')
 
-    @unittest.expectedFailure  # TODO: RUSTPYTHON; AttributeError: 'NoneType' object has no attribute 'f_code'
     def test_previous_frame(self):
         args, varargs, varkw, locals = inspect.getargvalues(mod.fr.f_back)
         self.assertEqual(args, ['a', 'b', 'c', 'd', 'e', 'f'])

diff --git a/Lib/test/test_io.py b/Lib/test/test_io.py
@@ -4473,7 +4473,6 @@ def test_io_after_close(self):
             self.assertRaises(ValueError, f.writelines, [])
             self.assertRaises(ValueError, next, f)
 
-    @unittest.expectedFailure  # TODO: RUSTPYTHON; cyclic gc
     def test_blockingioerror(self):
         # Various BlockingIOError issues
         class C(str):

diff --git a/Lib/test/test_monitoring.py b/Lib/test/test_monitoring.py
@@ -1984,7 +1984,6 @@ def f():
         ]
         return d["f"], expected
 
-    @unittest.expectedFailure  # TODO: RUSTPYTHON; line number differences in multi-line super() calls
     def test_method_call_error(self):
         nonopt_func, nonopt_expected = self._super_method_call_error(optimized=False)
         opt_func, opt_expected = self._super_method_call_error(optimized=True)
@@ -2022,7 +2021,6 @@ def f():
         ]
         return d["f"], expected
 
-    @unittest.expectedFailure  # TODO: RUSTPYTHON; line number differences in multi-line super() calls
     def test_attr(self):
         nonopt_func, nonopt_expected = self._super_attr(optimized=False)
         opt_func, opt_expected = self._super_attr(optimized=True)

diff --git a/Lib/test/test_pdb.py b/Lib/test/test_pdb.py
@@ -3122,7 +3122,7 @@ def test_pdb_issue_gh_101673():
     ...    a = 1
     ...    import pdb; pdb.Pdb(nosigint=True, readrc=False).set_trace()
 
-    >>> with PdbTestInput([  # TODO: RUSTPYTHON # doctest: +NORMALIZE_WHITESPACE +EXPECTED_FAILURE
+    >>> with PdbTestInput([  # doctest: +NORMALIZE_WHITESPACE
     ...     '!a = 2',
     ...     'll',
     ...     'p a',

diff --git a/Lib/test/test_ssl.py b/Lib/test/test_ssl.py
@@ -1526,7 +1526,6 @@ def sni_callback(sock, servername, ctx): pass
         self.assertIn(libssl_error_reason, str(cm.exception))
         self.assertEqual(cm.exception.errno, ssl.SSL_ERROR_SSL)
 
-    @unittest.expectedFailure  # TODO: RUSTPYTHON; AssertionError: <SSLContext(protocol=17)> is not None
     def test_sni_callback_refcycle(self):
         # Reference cycles through the servername callback are detected
         # and cleared.

diff --git a/Lib/test/test_traceback.py b/Lib/test/test_traceback.py
@@ -3141,7 +3141,6 @@ def last_returns_frame4(self):
     def last_returns_frame5(self):
         return self.last_returns_frame4()
 
-    @unittest.expectedFailure  # TODO: RUSTPYTHON; AssertionError: 1 not greater than 5
     def test_extract_stack(self):
         frame = self.last_returns_frame5()
         def extract(**kwargs):

diff --git a/crates/capi/src/refcount.rs b/crates/capi/src/refcount.rs
@@ -26,14 +26,18 @@ pub unsafe extern "C" fn Py_REFCNT(op: *mut PyObject) -> isize {
 
 #[cfg(test)]
 mod tests {
+    use pyo3::ffi;
     use pyo3::prelude::*;
-    use pyo3::types::PyInt;
-    use pyo3::{PyTypeInfo, ffi};
+    use pyo3::types::PyList;
 
     #[test]
     fn refcount() {
         Python::attach(|py| unsafe {
-            let obj = PyInt::type_object(py);
+            // A freshly created, non-empty list is uniquely owned here: its
+            // reference count is private to this test (so parallel tests cannot
+            // perturb it) and it is mortal (not interned), so incref then decref
+            // must move the count by exactly one and back.
+            let obj = PyList::new(py, [1, 2, 3]).unwrap();
             let ref_count = ffi::Py_REFCNT(obj.as_ptr());
             let obj_clone = obj.clone();
             assert_eq!(ffi::Py_REFCNT(obj.as_ptr()), ref_count + 1);

diff --git a/crates/common/src/refcount.rs b/crates/common/src/refcount.rs
@@ -1,10 +1,14 @@
 use crate::atomic::{Ordering, PyAtomic, Radium};
 
 // State layout (usize):
-//   [1 bit: destructed] [1 bit: reserved] [1 bit: leaked] [N bits: weak_count] [M bits: strong_count]
+//   [1 bit: destructed] [1 bit: published] [1 bit: leaked] [N bits: weak_count] [M bits: strong_count]
 // 64-bit: N=30, M=31.  32-bit: N=14, M=15.
 const FLAG_BITS: u32 = 3;
 const DESTRUCTED: usize = 1 << (usize::BITS - 1);
+/// Object was published to a lock-free cache; memory reclamation is
+/// deferred through QSBR so concurrent try-incref readers never touch
+/// freed memory. Sticky once set.
+const PUBLISHED: usize = 1 << (usize::BITS - 2);
 const LEAKED: usize = 1 << (usize::BITS - 3);
 const TOTAL_COUNT_WIDTH: u32 = usize::BITS - FLAG_BITS;
 const WEAK_WIDTH: u32 = TOTAL_COUNT_WIDTH / 2;
@@ -72,8 +76,8 @@ impl State {
 /// Reference count using state layout with LEAKED support.
 ///
 /// State layout (usize):
-/// 64-bit: [1 bit: destructed] [1 bit: reserved] [1 bit: leaked] [30 bits: weak_count] [31 bits: strong_count]
-/// 32-bit: [1 bit: destructed] [1 bit: reserved] [1 bit: leaked] [14 bits: weak_count] [15 bits: strong_count]
+/// 64-bit: [1 bit: destructed] [1 bit: published] [1 bit: leaked] [30 bits: weak_count] [31 bits: strong_count]
+/// 32-bit: [1 bit: destructed] [1 bit: published] [1 bit: leaked] [14 bits: weak_count] [15 bits: strong_count]
 pub struct RefCount {
     state: PyAtomic<usize>,
 }
@@ -187,6 +191,17 @@ impl RefCount {
     pub fn is_leaked(&self) -> bool {
         State::from_raw(self.state.load(Ordering::Acquire)).leaked()
     }
+
+    /// Mark the object as published to a lock-free cache (sticky).
+    #[inline]
+    pub fn mark_published(&self) {
+        self.state.fetch_or(PUBLISHED, Ordering::Release);
+    }
+
+    #[inline]
+    pub fn is_published(&self) -> bool {
+        (self.state.load(Ordering::Acquire) & PUBLISHED) != 0
+    }
 }
 
 // Deferred Drop Infrastructure
@@ -279,3 +294,24 @@ pub fn flush_deferred_drops() {
         }
     });
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn published_bit_survives_refcount_traffic() {
+        let rc = RefCount::new(); // strong = 1
+        assert!(!rc.is_published());
+        rc.mark_published();
+        assert!(rc.is_published());
+        rc.inc(); // strong = 2
+        assert!(rc.is_published());
+        assert!(!rc.dec()); // strong = 1
+        assert!(rc.is_published());
+        assert!(rc.safe_inc()); // strong = 2
+        assert!(!rc.dec()); // strong = 1
+        assert!(rc.dec()); // strong = 0 -> true
+        assert!(rc.is_published());
+    }
+}
-Original file line number
+Diff line change
@@ Expand Up / @@ -27,6 +27,7 @@ pystr @@
     pystruct
     pystructseq
     pytype
+    qsbr
     rustix
     struc
     zelf