From 3949d920e86d52f4d6cd614380ccc6b862dfe004 Mon Sep 17 00:00:00 2001
From: fzyzcjy <5236035+fzyzcjy@users.noreply.github.com>
Date: Wed, 6 Dec 2023 14:02:15 +0800
Subject: [PATCH] Update lib.rs

---
 src/lib.rs | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/src/lib.rs b/src/lib.rs
index f38d6a3e2c4..021d8ee930a 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -481,6 +481,16 @@ impl JsValue {
     }
 }
 
+/// The JsValue type wraps a slab/heap of js objects which is managed by
+/// the wasm-bindgen shim, and everything here is not actually able to cross
+/// any thread boundaries. When wasm actually has threads, for example, each
+/// thread will have to have its own slab of objects generated by
+/// wasm-bindgen, and indices in one slab aren't valid in any other slabs.
+impl !Send for JsValue {}
+
+/// Please refer to `!Send` for documentation.
+impl !Sync for JsValue {}
+
 impl PartialEq for JsValue {
     /// Compares two `JsValue`s for equality, using the `===` operator in JS.
     ///