Move exact type check from freelist_push to call-site in default_dealloc

Remove typ parameter from freelist_push trait signature. The exact type check is now done once at the call-site alongside the heaptype check, simplifying all freelist_push implementations.
youknowone · Mar 9, 2026 · Mar 5, 2026 · Mar 6, 2026 · Mar 8, 2026 · Mar 8, 2026
commit aad6d6d34f78e0895a7e7acd340146e5f32f54b8
diff --git a/crates/vm/src/builtins/complex.rs b/crates/vm/src/builtins/complex.rs
@@ -41,7 +41,7 @@ impl PyPayload for PyComplex {
     }
 
     #[inline]
-    unsafe fn freelist_push(obj: *mut PyObject, _hint: usize, _typ: &Py<PyType>) -> bool {
+    unsafe fn freelist_push(obj: *mut PyObject, _hint: usize) -> bool {
         COMPLEX_FREELIST
             .try_with(|fl| {
                 let mut list = fl.take();

diff --git a/crates/vm/src/builtins/dict.rs b/crates/vm/src/builtins/dict.rs
@@ -76,7 +76,7 @@ impl PyPayload for PyDict {
     }
 
     #[inline]
-    unsafe fn freelist_push(obj: *mut PyObject, _hint: usize, _typ: &Py<PyType>) -> bool {
+    unsafe fn freelist_push(obj: *mut PyObject, _hint: usize) -> bool {
         DICT_FREELIST
             .try_with(|fl| {
                 let mut list = fl.take();

diff --git a/crates/vm/src/builtins/float.rs b/crates/vm/src/builtins/float.rs
@@ -48,7 +48,7 @@ impl PyPayload for PyFloat {
     }
 
     #[inline]
-    unsafe fn freelist_push(obj: *mut PyObject, _hint: usize, _typ: &Py<PyType>) -> bool {
+    unsafe fn freelist_push(obj: *mut PyObject, _hint: usize) -> bool {
         FLOAT_FREELIST
             .try_with(|fl| {
                 let mut list = fl.take();

diff --git a/crates/vm/src/builtins/int.rs b/crates/vm/src/builtins/int.rs
@@ -69,7 +69,7 @@ impl PyPayload for PyInt {
     }
 
     #[inline]
-    unsafe fn freelist_push(obj: *mut PyObject, _hint: usize, _typ: &Py<PyType>) -> bool {
+    unsafe fn freelist_push(obj: *mut PyObject, _hint: usize) -> bool {
         INT_FREELIST
             .try_with(|fl| {
                 let mut list = fl.take();

diff --git a/crates/vm/src/builtins/list.rs b/crates/vm/src/builtins/list.rs
@@ -88,7 +88,7 @@ impl PyPayload for PyList {
     }
 
     #[inline]
-    unsafe fn freelist_push(obj: *mut PyObject, _hint: usize, _typ: &Py<PyType>) -> bool {
+    unsafe fn freelist_push(obj: *mut PyObject, _hint: usize) -> bool {
         LIST_FREELIST
             .try_with(|fl| {
                 let mut list = fl.take();

diff --git a/crates/vm/src/builtins/range.rs b/crates/vm/src/builtins/range.rs
@@ -84,7 +84,7 @@ impl PyPayload for PyRange {
     }
 
     #[inline]
-    unsafe fn freelist_push(obj: *mut PyObject, _hint: usize, _typ: &Py<PyType>) -> bool {
+    unsafe fn freelist_push(obj: *mut PyObject, _hint: usize) -> bool {
         RANGE_FREELIST
             .try_with(|fl| {
                 let mut list = fl.take();

diff --git a/crates/vm/src/builtins/slice.rs b/crates/vm/src/builtins/slice.rs
@@ -59,7 +59,7 @@ impl PyPayload for PySlice {
     }
 
     #[inline]
-    unsafe fn freelist_push(obj: *mut PyObject, _hint: usize, _typ: &Py<PyType>) -> bool {
+    unsafe fn freelist_push(obj: *mut PyObject, _hint: usize) -> bool {
         SLICE_FREELIST
             .try_with(|fl| {
                 let mut list = fl.take();

diff --git a/crates/vm/src/builtins/tuple.rs b/crates/vm/src/builtins/tuple.rs
@@ -113,11 +113,7 @@ impl PyPayload for PyTuple {
     }
 
     #[inline]
-    unsafe fn freelist_push(obj: *mut PyObject, hint: usize, typ: &Py<PyType>) -> bool {
-        // Py_IS_TYPE(op, &PyTuple_Type): reject structseq and other subtypes
-        if !core::ptr::eq(typ, Self::class(crate::vm::Context::genesis())) {
-            return false;
-        }
+    unsafe fn freelist_push(obj: *mut PyObject, hint: usize) -> bool {
         let len = hint;
         if len == 0 || len > TupleFreeList::MAX_SAVE_SIZE {
             return false;

diff --git a/crates/vm/src/object/core.rs b/crates/vm/src/object/core.rs
@@ -204,12 +204,13 @@ pub(super) unsafe fn default_dealloc<T: PyPayload>(obj: *mut PyObject) {
     }
 
     // Try to store in freelist for reuse; otherwise deallocate.
-    // Only exact types (not heaptype subclasses) go into the freelist.
-    // The runtime type is passed to freelist_push for Py_IS_TYPE-style
-    // exact type checking (e.g. reject structseq subtypes of PyTuple).
+    // Only exact base types (not heaptype or structseq subtypes) go into the freelist.
     let typ = obj_ref.class();
-    let pushed = if T::HAS_FREELIST && typ.heaptype_ext.is_none() {
-        unsafe { T::freelist_push(obj, freelist_hint, typ) }
+    let pushed = if T::HAS_FREELIST
+        && typ.heaptype_ext.is_none()
+        && core::ptr::eq(typ, T::class(crate::vm::Context::genesis()))
+    {
+        unsafe { T::freelist_push(obj, freelist_hint) }
     } else {
         false
     };

diff --git a/crates/vm/src/object/payload.rs b/crates/vm/src/object/payload.rs
@@ -69,13 +69,12 @@ pub trait PyPayload: MaybeTraverse + PyThreadingConstraint + Sized + 'static {
     /// Try to push a dead object onto this type's freelist for reuse.
     /// Returns true if the object was stored (caller must NOT free the memory).
     /// `hint` is the value returned by `freelist_hint` before tp_clear.
-    /// `typ` is the runtime type of the object, for exact-type filtering.
     ///
     /// # Safety
     /// `obj` must be a valid pointer to a `PyInner<Self>` with refcount 0,
     /// after `drop_slow_inner` and `tp_clear` have already run.
     #[inline]
-    unsafe fn freelist_push(_obj: *mut PyObject, _hint: usize, _typ: &Py<PyType>) -> bool {
+    unsafe fn freelist_push(_obj: *mut PyObject, _hint: usize) -> bool {
         false
     }