From 8aa938aa89dc300edc8f1f0b4b61d8d34e75ed22 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Guilherme=20Ara=C3=BAjo?= <arauujogui@gmail.com>
Date: Mon, 9 Nov 2026 14:50:42 -0300
Subject: [PATCH] src: stop shrinking async resource stack on pop
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

pop_async_context() called shrink_to_fit() on every pop. The stack is
usually empty once a callback returns, so libc++ and MSVC free the
deque's storage and the next push allocates it again, several times
per HTTP request.

Assisted-by: Claude Code
Signed-off-by: Guilherme Araújo <arauujogui@gmail.com>
---
 src/env.cc | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/env.cc b/src/env.cc
index c30b6e2f5049..50737c3dead3 100644
--- a/src/env.cc
+++ b/src/env.cc
@@ -205,7 +205,6 @@ bool AsyncHooks::pop_async_context(double async_id) {
     } else {
       native_execution_async_resources_.resize(offset);
     }
-    native_execution_async_resources_.shrink_to_fit();
   }
 
   if (js_execution_async_resources()->Length() > offset) [[unlikely]] {