From 19e607e486c24eb317633b794df72249e91c0c6e Mon Sep 17 00:00:00 2001
From: Dennis Klein <d.klein@gsi.de>
Date: Wed, 10 Jun 2026 16:12:35 +0200
Subject: [PATCH] test: fix racy loop-variable capture in
 SubscriptionThreadSafety

- the subscriber threads captured the loop counter by reference while
  the spawning loop kept incrementing it: a genuine data race
- depending on timing, threads could also end up with duplicate
  subscriber names; capture the counter by value instead
---
 test/plugin_services/_control.cxx | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/plugin_services/_control.cxx b/test/plugin_services/_control.cxx
index 498c44a8..ebe8e9ee 100644
--- a/test/plugin_services/_control.cxx
+++ b/test/plugin_services/_control.cxx
@@ -156,7 +156,7 @@ TEST_F(PluginServices, SubscriptionThreadSafety)
     std::array<std::unique_ptr<std::thread>, subscribers> threads;
     auto id = 0;
     for (auto& thread : threads) {
-        thread = std::make_unique<std::thread>([&](){
+        thread = std::make_unique<std::thread>([&, id](){
             auto const subscriber = fair::mq::tools::ToString("subscriber_", id);
             for (auto i = 0; i < attempts; ++i) {
                 mServices.SubscribeToDeviceStateChange(subscriber, [](DeviceState){});