Skip initialisation if not running in own thread

Summary:
One design goal of sonar is to never cause the host app to crash or hang.
For this reason, we do all heavy work in a background thread.
If we detect that it's not running in it's own thread, just return so we don't hold up the caller.

Reviewed By: danielbuechele

Differential Revision: D8767288

fbshipit-source-id: e146cc2cfe5c3e62d12f527ff79f24c74873d4ff

xplat/Sonar/SonarWebSocketImpl.h

@@ -62,6 +62,7 @@ class SonarWebSocketImpl : public SonarWebSocket {
   bool isCertificateExchangeNeeded();
   void requestSignedCertFromSonar();
   bool ensureSonarDirExists();
+  bool isRunningInOwnThread();
 };
 
 } // namespace sonar