From f88c2139bc25efe94b6040271d134fa5ea7c4b4c Mon Sep 17 00:00:00 2001
From: Jorrit Rouwe <jrouwe@gmail.com>
Date: Tue, 22 Oct 2024 01:30:23 +0200
Subject: [PATCH] Make WebIDL binder temp locals threadsafe (#22772)

---
 tools/webidl_binder.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/webidl_binder.py b/tools/webidl_binder.py
index 9cdb6a83f57d..d7ce3acfc8c3 100644
--- a/tools/webidl_binder.py
+++ b/tools/webidl_binder.py
@@ -629,7 +629,8 @@ def make_call_args(i):
     if non_pointer:
       return_prefix += '&'
     if copy:
-      pre += '  static %s temp;\n' % type_to_c(return_type, non_pointing=True)
+      # Avoid sharing this static temp var between threads, which could race.
+      pre += '  static thread_local %s temp;\n' % type_to_c(return_type, non_pointing=True)
       return_prefix += '(temp = '
       return_postfix += ', &temp)'