From: Remi Gacogne <remi.gacogne@powerdns.com>
Date: Thu, 20 May 2021 07:12:25 +0000 (+0200)
Subject: rec: Store the carbon configuration in a StateHolder
X-Git-Tag: dnsdist-1.7.0-alpha1~62^2~5
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=58d7ad6bfb0d46b7617ca984b90feacae35752c8;p=thirdparty%2Fpdns.git

rec: Store the carbon configuration in a StateHolder
---

diff --git a/pdns/pdns_recursor.cc b/pdns/pdns_recursor.cc
index 28470b55e2..f29d5a8285 100644
--- a/pdns/pdns_recursor.cc
+++ b/pdns/pdns_recursor.cc
@@ -5119,6 +5119,15 @@ static int serviceMain(int argc, char*argv[])
     g_DoTToAuthNames.setState(std::move(dotauthNames));
   }
 
+  {
+    CarbonConfig config;
+    stringtok(config.servers, arg()["carbon-server"], ", ");
+    config.hostname = arg()["carbon-server"];
+    config.instance_name = arg()["carbon-instance"];
+    config.namespace_name = arg()["carbon-namespace"];
+    g_carbonConfig.setState(std::move(config));
+  }
+
   s_balancingFactor = ::arg().asDouble("distribution-load-factor");
   if (s_balancingFactor != 0.0 && s_balancingFactor < 1.0) {
     s_balancingFactor = 0.0;
diff --git a/pdns/rec-carbon.cc b/pdns/rec-carbon.cc
index 479d12ace9..55604fdbed 100644
--- a/pdns/rec-carbon.cc
+++ b/pdns/rec-carbon.cc
@@ -9,44 +9,38 @@
 #include "arguments.hh"
 #include "lock.hh"
 
+GlobalStateHolder<CarbonConfig> g_carbonConfig;
 
 void doCarbonDump(void*)
+{
 try
 {
-  string hostname;
-  string instance_name;
-  string namespace_name;
-  vector<string> carbonServers;
-
-  {
-    std::lock_guard<std::mutex> l(g_carbon_config_lock);
-    stringtok(carbonServers, arg()["carbon-server"], ", ");
-    namespace_name=arg()["carbon-namespace"];
-    hostname=arg()["carbon-ourname"];
-    instance_name=arg()["carbon-instance"];
-  }
+  static thread_local auto configHolder = g_carbonConfig.getLocal();
 
-  if(carbonServers.empty())
+  auto config = *configHolder;
+  if (config.servers.empty()) {
     return;
+  }
 
-  if(namespace_name.empty()) {
-    namespace_name="pdns";
+  if (config.namespace_name.empty()) {
+    config.namespace_name = "pdns";
   }
-  if (hostname.empty()) {
+
+  if (config.hostname.empty()) {
     try {
-      hostname = getCarbonHostName();
+      config.hostname = getCarbonHostName();
     }
     catch(const std::exception& e) {
       throw std::runtime_error(std::string("The 'carbon-ourname' setting has not been set and we are unable to determine the system's hostname: ") + e.what());
     }
   }
-  if(instance_name.empty()) {
-    instance_name="recursor";
+  if (config.instance_name.empty()) {
+    config.instance_name = "recursor";
   }
 
   registerAllStats();
   PacketBuffer msg;
-  for(const auto& carbonServer: carbonServers) {
+  for (const auto& carbonServer: config.servers) {
     ComboAddress remote(carbonServer, 2003);
     Socket s(remote.sin4.sin_family, SOCK_STREAM);
     s.setNonBlocking();
@@ -62,7 +56,7 @@ try
       time_t now=time(0);
 
       for(const auto& val : all) {
-        str<<namespace_name<<'.'<<hostname<<'.'<<instance_name<<'.'<<val.first<<' '<<val.second.d_value<<' '<<now<<"\r\n";
+        str<<config.namespace_name<<'.'<<config.hostname<<'.'<<config.instance_name<<'.'<<val.first<<' '<<val.second.d_value<<' '<<now<<"\r\n";
       }
       const string& x = str.str();
       msg.insert(msg.end(), x.cbegin(), x.cend());
@@ -78,11 +72,11 @@ try
     handler->close();
   }
  }
-catch(PDNSException& e)
+catch (const PDNSException& e)
 {
   g_log<<Logger::Error<<"Error in carbon thread: "<<e.reason<<endl;
 }
-catch(std::exception& e)
+catch(const std::exception& e)
 {
   g_log<<Logger::Error<<"Error in carbon thread: "<<e.what()<<endl;
 }
@@ -90,3 +84,4 @@ catch(...)
 {
   g_log<<Logger::Error<<"Unknown error in carbon thread"<<endl;
 }
+}
diff --git a/pdns/rec_channel.hh b/pdns/rec_channel.hh
index 737df84381..b89267aaaa 100644
--- a/pdns/rec_channel.hh
+++ b/pdns/rec_channel.hh
@@ -107,7 +107,16 @@ typedef std::map<std::string, StatsMapEntry, PrefixDashNumberCompare> StatsMap;
 
 StatsMap getAllStatsMap(StatComponent component);
 
-extern std::mutex g_carbon_config_lock;
+struct CarbonConfig
+{
+  std::string hostname;
+  std::string instance_name;
+  std::string namespace_name;
+  std::vector<std::string> servers;
+};
+
+extern GlobalStateHolder<CarbonConfig> g_carbonConfig;
+
 std::vector<std::pair<DNSName, uint16_t> >* pleaseGetQueryRing();
 std::vector<std::pair<DNSName, uint16_t> >* pleaseGetServfailQueryRing();
 std::vector<std::pair<DNSName, uint16_t> >* pleaseGetBogusQueryRing();
diff --git a/pdns/rec_channel_rec.cc b/pdns/rec_channel_rec.cc
index b8231e4ab5..5ad9c634b3 100644
--- a/pdns/rec_channel_rec.cc
+++ b/pdns/rec_channel_rec.cc
@@ -72,8 +72,6 @@ bool PrefixDashNumberCompare::operator()(const std::string& a, const std::string
   return aa < bb;
 }
 
-std::mutex g_carbon_config_lock;
-
 static map<string, const uint32_t*> d_get32bitpointers;
 static map<string, const std::atomic<uint64_t>*> d_getatomics;
 static map<string, std::function<uint64_t()>>  d_get64bitmembers;
@@ -533,33 +531,42 @@ static string doWipeCache(T begin, T end, uint16_t qtype)
 template<typename T>
 static string doSetCarbonServer(T begin, T end)
 {
-  std::lock_guard<std::mutex> l(g_carbon_config_lock);
-  if(begin==end) {
-    ::arg().set("carbon-server").clear();
+  auto config = g_carbonConfig.getCopy();
+  if (begin == end) {
+    config.servers.clear();
+    g_carbonConfig.setState(std::move(config));
     return "cleared carbon-server setting\n";
   }
+
   string ret;
-  ::arg().set("carbon-server")=*begin;
-  ret="set carbon-server to '"+::arg()["carbon-server"]+"'\n";
+  stringtok(config.servers, *begin, ", ");
+  ret = "set carbon-server to '" + *begin + "'\n";
+
   ++begin;
-  if(begin != end) {
-    ::arg().set("carbon-ourname")=*begin;
-    ret+="set carbon-ourname to '"+*begin+"'\n";
+  if (begin != end) {
+    config.hostname = *begin;
+    ret += "set carbon-ourname to '" + *begin + "'\n";
   } else {
+    g_carbonConfig.setState(std::move(config));
     return ret;
   }
+
   ++begin;
-  if(begin != end) {
-    ::arg().set("carbon-namespace")=*begin;
-    ret+="set carbon-namespace to '"+*begin+"'\n";
+  if (begin != end) {
+    config.namespace_name = *begin;
+    ret += "set carbon-namespace to '" + *begin + "'\n";
   } else {
+    g_carbonConfig.setState(std::move(config));
     return ret;
   }
+
   ++begin;
-  if(begin != end) {
-    ::arg().set("carbon-instance")=*begin;
-    ret+="set carbon-instance to '"+*begin+"'\n";
+  if (begin != end) {
+    config.instance_name = *begin;
+    ret += "set carbon-instance to '" + *begin + "'\n";
   }
+
+  g_carbonConfig.setState(std::move(config));
   return ret;
 }