From: Otto Moerbeek <otto.moerbeek@open-xchange.com>
Date: Mon, 28 Mar 2022 11:53:14 +0000 (+0200)
Subject: In the handler, call sd_notify just befere entering the main loop in RecursorThread
X-Git-Tag: rec-4.7.0-beta1~27^2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=b441c2fd41feb48a1c27b7faf89babc4ab11977c;p=thirdparty%2Fpdns.git

In the handler, call sd_notify just befere entering the main loop in RecursorThread

There still is a race, but this is better than calling sd_notify before the handler is created.
---

diff --git a/pdns/recursordist/rec-main.cc b/pdns/recursordist/rec-main.cc
index dc9b1f3e85..7f80028a1f 100644
--- a/pdns/recursordist/rec-main.cc
+++ b/pdns/recursordist/rec-main.cc
@@ -200,10 +200,6 @@ int RecThreadInfo::runThreads()
   if (RecThreadInfo::numDistributors() + RecThreadInfo::numWorkers() == 1) {
     g_log << Logger::Warning << "Operating with single distributor/worker thread" << endl;
 
-#ifdef HAVE_SYSTEMD
-    sd_notify(0, "READY=1");
-#endif
-
     /* This thread handles the web server, carbon, statistics and the control channel */
     auto& handlerInfo = RecThreadInfo::info(0);
     handlerInfo.setHandler();
@@ -266,10 +262,6 @@ int RecThreadInfo::runThreads()
       info.start(currentThreadId++, "taskThread", cpusMap);
     }
 
-#ifdef HAVE_SYSTEMD
-    sd_notify(0, "READY=1");
-#endif
-
     /* This thread handles the web server, carbon, statistics and the control channel */
     auto& info = RecThreadInfo::info(0);
     info.setHandler();
@@ -2178,6 +2170,15 @@ static void recursorThread()
     time_t luaMaintenanceInterval = ::arg().asNum("lua-maintenance-interval");
     s_counter.store(0); // used to periodically execute certain tasks
 
+#ifdef HAVE_SYSTEMD
+    if (threadInfo.isHandler()) {
+      // There is a race, as some threads might not be ready yet to do work.
+      // To solve that, threads should notify RecThreadInfo they are done initializing.
+      // But we lack a mechanism for that at this point in time.
+      sd_notify(0, "READY=1");
+    }
+#endif
+
     while (!RecursorControlChannel::stop) {
       while (MT->schedule(&g_now))
         ; // MTasker letting the mthreads do their thing