From 3aad31bbde20243e69b69cca4ecd1a177df027eb Mon Sep 17 00:00:00 2001
From: Matt Yan <syan4@ualberta.ca>
Date: Sun, 29 Mar 2026 23:36:43 +0900
Subject: [PATCH] perf: cache empty VList Rc in VNode::default to avoid
 repeated heap allocation

VNode::default() is called on every mem::take() during reconciliation.
Previously each call heap-allocated a new Rc<VList>. Use a thread_local
to cache a single Rc<VList> and reuse it via Rc::clone (refcount bump only).
---
 packages/yew/src/virtual_dom/vnode.rs | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/packages/yew/src/virtual_dom/vnode.rs b/packages/yew/src/virtual_dom/vnode.rs
index baf12f857a3..e544c821976 100644
--- a/packages/yew/src/virtual_dom/vnode.rs
+++ b/packages/yew/src/virtual_dom/vnode.rs
@@ -106,7 +106,10 @@ impl VNode {
 
 impl Default for VNode {
     fn default() -> Self {
-        VNode::VList(Rc::new(VList::default()))
+        thread_local! {
+            static EMPTY_VLIST: Rc<VList> = Rc::new(VList::default());
+        }
+        VNode::VList(EMPTY_VLIST.with(Rc::clone))
     }
 }