Bug 1135076 - Missing histograms in childPayloads. r=vladan

--HG--
extra : rebase_source : 997a36b9375d054406b51fae768bc01a2d75fe46

toolkit/components/telemetry/Histograms.json

@@ -4338,6 +4338,12 @@
     "extended_statistics_ok": true,
     "description": "Number of histograms with total count low errors"
   },
+  "TELEMETRY_DISCARDED_CONTENT_PINGS_COUNT": {
+    "alert_emails": ["perf-telemetry-alerts@mozilla.com"],
+    "expires_in_version": "never",
+    "kind": "count",
+    "description": "Count of discarded content payloads."
+  },
   "TELEMETRY_FILES_EVICTED": {
     "alert_emails": ["rvitillo@mozilla.com"],
     "expires_in_version": "36",

toolkit/components/telemetry/Telemetry.cpp

@@ -1805,7 +1805,8 @@ TelemetryImpl::AsyncFetchTelemetryData(nsIFetchTelemetryDataCallback *aCallback)
 
 TelemetryImpl::TelemetryImpl():
 mHistogramMap(Telemetry::HistogramCount),
-mCanRecord(XRE_GetProcessType() == GeckoProcessType_Default),
+mCanRecord(XRE_GetProcessType() == GeckoProcessType_Default ||
+           XRE_GetProcessType() == GeckoProcessType_Content),
 mHashMutex("Telemetry::mHashMutex"),
 mHangReportsMutex("Telemetry::mHangReportsMutex"),
 mThreadHangStatsMutex("Telemetry::mThreadHangStatsMutex"),

toolkit/components/telemetry/TelemetrySession.jsm

@@ -64,9 +64,13 @@ const PREF_FHR_UPLOAD_ENABLED = "datareporting.healthreport.uploadEnabled";
 const PREF_ASYNC_PLUGIN_INIT = "dom.ipc.plugins.asyncInit";
 
 const MESSAGE_TELEMETRY_PAYLOAD = "Telemetry:Payload";
+const MESSAGE_TELEMETRY_GET_CHILD_PAYLOAD = "Telemetry:GetChildPayload";
 
 const SESSION_STATE_FILE_NAME = "session-state.json";
 
+// Maximum number of content payloads that we are willing to store.
+const MAX_NUM_CONTENT_PAYLOADS = 10;
+
 // Do not gather data more than once a minute
 const TELEMETRY_INTERVAL = 60000;
 // Delay before intializing telemetry (ms)
@@ -98,7 +102,13 @@ XPCOMUtils.defineLazyServiceGetter(this, "idleService",
 XPCOMUtils.defineLazyServiceGetter(this, "cpmm",
                                    "@mozilla.org/childprocessmessagemanager;1",
                                    "nsIMessageSender");
+XPCOMUtils.defineLazyServiceGetter(this, "cpml",
+                                   "@mozilla.org/childprocessmessagemanager;1",
+                                   "nsIMessageListenerManager");
 XPCOMUtils.defineLazyServiceGetter(this, "ppmm",
+                                   "@mozilla.org/parentprocessmessagemanager;1",
+                                   "nsIMessageBroadcaster");
+XPCOMUtils.defineLazyServiceGetter(this, "ppml",
                                    "@mozilla.org/parentprocessmessagemanager;1",
                                    "nsIMessageListenerManager");
 
@@ -352,6 +362,13 @@ this.TelemetrySession = Object.freeze({
   getPayload: function(reason, clearSubsession = false) {
     return Impl.getPayload(reason, clearSubsession);
   },
+  /**
+   * Asks the content processes to send their payloads.
+   * @returns Object
+   */
+  requestChildPayloads: function() {
+    return Impl.requestChildPayloads();
+  },
   /**
    * Save histograms to a file.
    * Used only for testing purposes.
@@ -1127,7 +1144,7 @@ let Impl = {
     this._hasWindowRestoredObserver = true;
     this._hasXulWindowVisibleObserver = true;
 
-    ppmm.addMessageListener(MESSAGE_TELEMETRY_PAYLOAD, this);
+    ppml.addMessageListener(MESSAGE_TELEMETRY_PAYLOAD, this);
 
     // Delay full telemetry initialization to give the browser time to
     // run various late initializers. Otherwise our gathered memory
@@ -1178,6 +1195,7 @@ let Impl = {
     }
 
     Services.obs.addObserver(this, "content-child-shutdown", false);
+    cpml.addMessageListener(MESSAGE_TELEMETRY_GET_CHILD_PAYLOAD, this);
 
     this.gatherStartupHistograms();
 
@@ -1209,9 +1227,11 @@ let Impl = {
     switch (message.name) {
     case MESSAGE_TELEMETRY_PAYLOAD:
     {
-      let target = message.target;
+      let source = message.data.childUUID;
+      delete message.data.childUUID;
+
       for (let child of this._childTelemetry) {
-        if (child.source.get() === target) {
+        if (child.source === source) {
           // Update existing telemetry data.
           child.payload = message.data;
           return;
@@ -1219,9 +1239,20 @@ let Impl = {
       }
       // Did not find existing child in this._childTelemetry.
       this._childTelemetry.push({
-        source: Cu.getWeakReference(target),
+        source: source,
         payload: message.data,
       });
+
+      if (this._childTelemetry.length == MAX_NUM_CONTENT_PAYLOADS + 1) {
+        this._childTelemetry.shift();
+        Telemetry.getHistogramById("TELEMETRY_DISCARDED_CONTENT_PINGS_COUNT").add();
+      }
+
+      break;
+    }
+    case MESSAGE_TELEMETRY_GET_CHILD_PAYLOAD:
+    {
+      this.sendContentProcessPing("saved-session");
       break;
     }
     default:
@@ -1229,10 +1260,13 @@ let Impl = {
     }
   },
 
+  _processUUID: generateUUID(),
+
   sendContentProcessPing: function sendContentProcessPing(reason) {
     this._log.trace("sendContentProcessPing - Reason " + reason);
     const isSubsession = !this._isClassicReason(reason);
     let payload = this.getSessionPayload(reason, isSubsession);
+    payload.childUUID = this._processUUID;
     cpmm.sendAsyncMessage(MESSAGE_TELEMETRY_PAYLOAD, payload);
   },
 
@@ -1291,6 +1325,11 @@ let Impl = {
     return this.getSessionPayload(reason, clearSubsession);
   },
 
+  requestChildPayloads: function() {
+    this._log.trace("requestChildPayloads");
+    ppmm.broadcastAsyncMessage(MESSAGE_TELEMETRY_GET_CHILD_PAYLOAD, {});
+  },
+
   gatherStartup: function gatherStartup() {
     this._log.trace("gatherStartup");
     let counters = processInfo.getCounters();