Bug 708962 - Start Telemetry service at application start to avoid deadlock from GetService spinning event loop. r=benjamin

toolkit/components/telemetry/Telemetry.cpp

@@ -581,14 +581,7 @@ TelemetryImpl::RecordSlowStatement(const nsACString &statement,
                                    const nsACString &dbName,
                                    PRUint32 delay)
 {
-  if (!sTelemetry) {
-    // Make the service manager hold a long-lived reference to the service
-    nsCOMPtr<nsITelemetry> telemetryService =
-      do_GetService("@mozilla.org/base/telemetry;1");
-    if (!telemetryService || !sTelemetry)
-      return;
-  }
-
+  MOZ_ASSERT(sTelemetry);
   if (!sTelemetry->mCanRecord || !sTelemetry->mTrackedDBs.GetEntry(dbName))
     return;
 
@@ -678,6 +671,14 @@ RecordSlowSQLStatement(const nsACString &statement,
   TelemetryImpl::RecordSlowStatement(statement, dbName, delay);
 }
 
+void Init()
+{
+  // Make the service manager hold a long-lived reference to the service
+  nsCOMPtr<nsITelemetry> telemetryService =
+    do_GetService("@mozilla.org/base/telemetry;1");
+  MOZ_ASSERT(telemetryService);
+}
+
 } // namespace Telemetry
 } // namespace mozilla
 

toolkit/components/telemetry/Telemetry.h

@@ -59,6 +59,11 @@ enum ID {
 HistogramCount
 };
 
+/**
+ * Initialize the Telemetry service on the main thread at startup.
+ */
+void Init();
+
 /**
  * Adds sample to a histogram defined in TelemetryHistograms.h
  *

xpcom/build/nsXPComInit.cpp

@@ -140,6 +140,7 @@ extern nsresult nsStringInputStreamConstructor(nsISupports *, REFNSIID, void **)
 #include "mozilla/FunctionTimer.h"
 #include "mozilla/Omnijar.h"
 #include "mozilla/HangMonitor.h"
+#include "mozilla/Telemetry.h"
 
 #include "nsChromeRegistry.h"
 #include "nsChromeProtocolHandler.h"
@@ -536,6 +537,8 @@ NS_InitXPCOM2(nsIServiceManager* *result,
 
     mozilla::HangMonitor::Startup();
 
+    mozilla::Telemetry::Init();
+
     return NS_OK;
 }