From e068da4f6b9ca08909f089ce94b1f0e9f55d393b Mon Sep 17 00:00:00 2001
From: yhirose <yuji.hirose.bug@gmail.com>
Date: Sun, 22 Feb 2026 08:46:30 -0500
Subject: [PATCH] Fix race condittion with logging

---
 httplib.h | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/httplib.h b/httplib.h
index a2f8fa51..16da7b2d 100644
--- a/httplib.h
+++ b/httplib.h
@@ -10726,6 +10726,10 @@ inline bool Server::write_response_core(Stream &strm, bool close_connection,
     bstrm.write(res.body.data(), res.body.size());
   }
 
+  // Log before writing to avoid race condition with client-side code that
+  // accesses logger-captured data immediately after receiving the response.
+  output_log(req, res);
+
   // Flush buffer
   auto &data = bstrm.get_buffer();
   if (!detail::write_data(strm, data.data(), data.size())) { return false; }
@@ -10740,9 +10744,6 @@ inline bool Server::write_response_core(Stream &strm, bool close_connection,
     }
   }
 
-  // Log
-  output_log(req, res);
-
   return ret;
 }