From: Remi Gacogne <remi.gacogne@powerdns.com>
Date: Wed, 12 Jan 2022 15:39:30 +0000 (+0100)
Subject: dnsdist: Avoid a race if one is careless enough to call Rings::init() from two thread... 
X-Git-Tag: auth-4.7.0-alpha1~65^2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=refs%2Fpull%2F11171%2Fhead;p=thirdparty%2Fpdns.git

dnsdist: Avoid a race if one is careless enough to call Rings::init() from two threads at once
---

diff --git a/pdns/dnsdist-rings.cc b/pdns/dnsdist-rings.cc
index fe35307922..6b044273a4 100644
--- a/pdns/dnsdist-rings.cc
+++ b/pdns/dnsdist-rings.cc
@@ -35,10 +35,9 @@ void Rings::setCapacity(size_t newCapacity, size_t numberOfShards)
 
 void Rings::init()
 {
-  if (d_initialized) {
+  if (d_initialized.exchange(true)) {
     throw std::runtime_error("Rings::init() should only be called once");
   }
-  d_initialized = true;
 
   if (d_numberOfShards <= 1) {
     d_nbLockTries = 0;