From d9ddb73a74f78fddaedc14a77b99078e2378966d Mon Sep 17 00:00:00 2001
From: moe <moe@moe.moe>
Date: Sat, 25 Dec 2021 22:48:03 +0100
Subject: [PATCH] prevents data race in server.stop() - see bug #1661

---
 src/asio_server.cc | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/asio_server.cc b/src/asio_server.cc
index 74c92276..dbb72462 100644
--- a/src/asio_server.cc
+++ b/src/asio_server.cc
@@ -188,7 +188,13 @@ void server::start_accept(tcp::acceptor &acceptor, serve_mux &mux) {
 
 void server::stop() {
   for (auto &acceptor : acceptors_) {
-    acceptor.close();
+    std::promise<void> promise;
+    GET_IO_SERVICE ( acceptor ).dispatch ( [&acceptor, &promise]() {
+      boost::system::error_code ignored_ec;
+      acceptor.close ( ignored_ec );
+      promise.set_value();
+    } );
+    promise.get_future().get();
   }
   io_service_pool_.stop();
 }