bug 1470215 let Telemetry::DNS_NATIVE_QUEUING measure queue times r=mcmanus

MozReview-Commit-ID: 77FE4SJOXMG

--HG--
extra : rebase_source : 545961452d5d32b2ce65376e8ed680d6413eaa30

netwerk/dns/nsHostResolver.cpp

@@ -1818,6 +1818,9 @@ nsHostResolver::ThreadFunc()
 
         TimeStamp startTime = TimeStamp::Now();
         bool getTtl = rec->mGetTtl;
+        TimeDuration inQueue = startTime - rec->mNativeStart;
+        uint32_t ms = static_cast<uint32_t>(inQueue.ToMilliseconds());
+        Telemetry::Accumulate(Telemetry::DNS_NATIVE_QUEUING, ms);
         nsresult status = GetAddrInfo(rec->host, rec->af,
                                       rec->flags, &ai,
                                       getTtl);

toolkit/components/telemetry/Histograms.json

@@ -3247,6 +3247,17 @@
     "n_buckets": 50,
     "description": "Time for a completed native name resolution (msec)"
   },
+  "DNS_NATIVE_QUEUING": {
+    "record_in_processes": ["main"],
+    "expires_in_version": "never",
+    "kind": "exponential",
+    "high": 60000,
+    "releaseChannelCollection": "opt-out",
+    "alert_emails": ["necko@mozilla.com", "dstenberg@mozilla.com"],
+    "bug_numbers": [1470215],
+    "n_buckets": 50,
+    "description": "Time in resolve queue waiting to getaddrinfo (msec)"
+  },
   "DNS_TRR_RACE": {
     "record_in_processes": ["main"],
     "alert_emails": ["necko@mozilla.com", "dstenberg@mozilla.com"],