From 3919d1c5dd3ef7ed82ba99520462096c5defe7cc Mon Sep 17 00:00:00 2001
From: Remi Gacogne <remi.gacogne@powerdns.com>
Date: Mon, 29 Sep 2025 14:39:14 +0200
Subject: [PATCH] dnsdist: Make the health-check latency atomic

Otherwise TSAN rightfully complain that it is written from one thread
and read from several others.

Signed-off-by: Remi Gacogne <remi.gacogne@powerdns.com>
---
 pdns/dnsdistdist/dnsdist-healthchecks.cc | 2 +-
 pdns/dnsdistdist/dnsdist.hh              | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/pdns/dnsdistdist/dnsdist-healthchecks.cc b/pdns/dnsdistdist/dnsdist-healthchecks.cc
index e0d82f8bf6..3081efdcb1 100644
--- a/pdns/dnsdistdist/dnsdist-healthchecks.cc
+++ b/pdns/dnsdistdist/dnsdist-healthchecks.cc
@@ -134,7 +134,7 @@ static bool handleResponse(std::shared_ptr<HealthCheckData>& data)
     return false;
   }
 
-  data->d_ds->d_healthCheckLatency = data->d_elapsed.udiff();
+  data->d_ds->d_healthCheckLatency.store(data->d_elapsed.udiff());
   return true;
 }
 
diff --git a/pdns/dnsdistdist/dnsdist.hh b/pdns/dnsdistdist/dnsdist.hh
index ecc1caca66..eff68ab13b 100644
--- a/pdns/dnsdistdist/dnsdist.hh
+++ b/pdns/dnsdistdist/dnsdist.hh
@@ -719,10 +719,10 @@ public:
   std::vector<std::shared_ptr<XskSocket>> d_xskSockets;
 #endif
   std::atomic<uint64_t> idOffset{0};
+  std::atomic<double> d_healthCheckLatency{0.0};
   size_t socketsOffset{0};
   double latencyUsec{0.0};
   double latencyUsecTCP{0.0};
-  double d_healthCheckLatency{0.0};
   unsigned int d_nextCheck{0};
   uint16_t currentCheckFailures{0};
   std::atomic<bool> hashesComputed{false};
-- 
2.47.3