fix(gc): root the raw handle reads over the raw_handle_debt ceiling

changelog.d/11911-raw-handle-debt-roots.md

@@ -0,0 +1,7 @@
+Rooted the raw-pointer reads that pushed `raw_handle_debt` over its ceiling.
+JSON.stringify of a proxy with a function replacer now hands the replacer to
+its consumer through the root (`with_const_ptr`) instead of binding a raw
+closure pointer, and keeps the replacer result rooted across the key write.
+Two test-only reads (private storage cache, eden entry residency) moved into
+scoped-pointer closures. The baseline falls from 871 to 869 and
+`reflect_support.rs` drops its stale ceiling from 3 to 2.

crates/perry-runtime/src/gc/tests/eden_entry_residency.rs

@@ -79,12 +79,14 @@ fn real_full_collection_gives_eden_a_reuse_interval_then_discards_idle_pages() {
             );
         }
         for root in [live, extra_root] {
-            let string = root.get_raw_const_ptr::<crate::string::StringHeader>();
-            assert_eq!((*string).byte_len, bytes.len() as u32);
-            assert_eq!(
-                std::slice::from_raw_parts(crate::string::string_data(string), bytes.len()),
-                bytes
-            );
+            // The closure only reads the string; nothing here allocates.
+            root.with_const_ptr(|string: *const crate::string::StringHeader| {
+                assert_eq!((*string).byte_len, bytes.len() as u32);
+                assert_eq!(
+                    std::slice::from_raw_parts(crate::string::string_data(string), bytes.len()),
+                    bytes
+                );
+            });
         }
     })
     .join()

crates/perry-runtime/src/json/stringify_proxy.rs

@@ -112,21 +112,22 @@ pub(super) unsafe fn try_stringify(
         let member = crate::proxy::js_proxy_get(receiver.get_nanbox_f64(), key.get_nanbox_f64());
         let member = super::replacer::apply_to_json_keyed(member, key.get_nanbox_f64());
         let member = member_scope.root_nanbox_f64(member);
-        let replacer = match replacer_root.as_ref() {
-            Some(root) => Replacer::Function(root.get_raw_const_ptr()),
-            None => replacer,
-        };
-        let member = if let Replacer::Function(f) = replacer {
-            super::replacer::call_replacer(
-                f,
-                key.get_nanbox_f64(),
-                member.get_nanbox_f64(),
-                receiver.get_nanbox_f64(),
-            )
-        } else {
-            member.get_nanbox_f64()
+        let member = match replacer_root.as_ref() {
+            Some(root) => root.with_const_ptr(|f: *const crate::ClosureHeader| {
+                super::replacer::call_replacer(
+                    f,
+                    key.get_nanbox_f64(),
+                    member.get_nanbox_f64(),
+                    receiver.get_nanbox_f64(),
+                )
+            }),
+            None => member.get_nanbox_f64(),
         };
-        if !is_array && omitted(member) {
+        // The replacer result is the value emitted below; keep it rooted across
+        // the key write and any allocation in the emit.
+        let member = member_scope.root_nanbox_f64(member);
+        let member_bits = member.get_nanbox_f64();
+        if !is_array && omitted(member_bits) {
             continue;
         }
         if !first {
@@ -141,11 +142,13 @@ pub(super) unsafe fn try_stringify(
                 buf.push(' ');
             }
         }
-        let replacer = match replacer_root.as_ref() {
-            Some(root) => Replacer::Function(root.get_raw_const_ptr()),
-            None => replacer,
-        };
-        emit_prepared(member, buf, indent, depth + 1, replacer);
+        let member = member.get_nanbox_f64();
+        match replacer_root.as_ref() {
+            Some(root) => root.with_const_ptr(|f: *const crate::ClosureHeader| {
+                emit_prepared(member, buf, indent, depth + 1, Replacer::Function(f))
+            }),
+            None => emit_prepared(member, buf, indent, depth + 1, replacer),
+        }
     }
     if !first {
         newline(buf, indent, depth);

crates/perry-runtime/src/object/field_get_set/ic_miss/private_storage_cache.rs

@@ -290,13 +290,13 @@ mod private_storage_cache_tests {
         });
         let held = scope.root_raw_mut_ptr(crate::object::js_object_alloc(62_641, 0));
         let _ = held;
-        unsafe {
-            let holder = other.get_raw_mut_ptr::<ObjectHeader>();
+        // `apply_edits` suppresses moving collection for its whole body.
+        other.with_mut_ptr(|holder: *mut ObjectHeader| unsafe {
             crate::object::key_attrs::apply_edits(
                 holder,
                 &[crate::object::key_attrs::AttrsEdit::Private(key.as_bytes())],
             );
-        }
+        });
         assert!(key.set_cached(other_receiver(), 11.0));
         assert_eq!(key.get_cached(other_receiver()), Some(11.0));
         let first_shape = key.slot.get().unwrap().0;

scripts/raw_handle_debt_baseline.txt

@@ -1 +1 @@
-871
+869

scripts/raw_handle_debt_files.txt

@@ -131,7 +131,7 @@
 4 crates/perry-runtime/src/object/object_ops/from_entries.rs
 5 crates/perry-runtime/src/object/object_ops/keys_array.rs
 6 crates/perry-runtime/src/object/polymorphic_index.rs
-3 crates/perry-runtime/src/object/reflect_support.rs
+2 crates/perry-runtime/src/object/reflect_support.rs
 2 crates/perry-runtime/src/object/spill.rs
 2 crates/perry-runtime/src/object/typed_array_define.rs
 3 crates/perry-runtime/src/os.rs