Lazily initialize GeckoWebExecutor

app/src/common/shared/org/mozilla/vrbrowser/VRBrowserApplication.java

@@ -8,6 +8,7 @@
 import android.app.Application;
 import android.content.Context;
 import android.content.res.Configuration;
+import android.os.Looper;
 
 import androidx.annotation.NonNull;
 
@@ -52,11 +53,18 @@ public void onCreate() {
             return;
         }
 
+        // Fix potential Gecko static initialization order.
+        // GeckoResult.ALLOW and GeckoResult.DENY static initializer might get a null mDispatcher
+        // depending on how JVM classloader does the initialization job.
+        // See https://github.com/MozillaReality/FirefoxReality/issues/3651
+        Looper.getMainLooper().getThread();
+
         TelemetryWrapper.init(this, EngineProvider.INSTANCE.getDefaultClient(this));
         GleanMetricsService.init(this, EngineProvider.INSTANCE.getDefaultClient(this));
     }
 
     protected void onActivityCreate(@NonNull Context activityContext) {
+        EngineProvider.INSTANCE.getDefaultGeckoWebExecutor(activityContext);
         mPlaces = new Places(this);
         mServices = new Services(this, mPlaces);
         mAccounts = new Accounts(this);

app/src/common/shared/org/mozilla/vrbrowser/browser/engine/EngineProvider.kt

@@ -58,20 +58,24 @@ object EngineProvider {
         return runtime!!
     }
 
-    fun createGeckoWebExecutor(context: Context): GeckoWebExecutor {
+    private fun createGeckoWebExecutor(context: Context): GeckoWebExecutor {
         return GeckoWebExecutor(getOrCreateRuntime(context))
     }
 
     fun getDefaultGeckoWebExecutor(context: Context): GeckoWebExecutor {
         if (executor == null) {
             executor = createGeckoWebExecutor(context)
+            client?.let { it.executor = executor }
+
         }
 
         return executor!!
     }
 
     fun createClient(context: Context): GeckoViewFetchClient {
-        return GeckoViewFetchClient(context)
+        val client = GeckoViewFetchClient(context)
+        client.executor = executor
+        return client
     }
 
     fun getDefaultClient(context: Context): GeckoViewFetchClient {

app/src/common/shared/org/mozilla/vrbrowser/browser/engine/GeckoViewFetchClient.kt

@@ -28,10 +28,13 @@ class GeckoViewFetchClient(
 ) : Client() {
 
     @VisibleForTesting(otherwise = VisibleForTesting.PRIVATE)
-    internal var executor: GeckoWebExecutor = EngineProvider.createGeckoWebExecutor(context)
+    internal var executor: GeckoWebExecutor? = null
 
     @Throws(IOException::class)
     override fun fetch(request: Request): Response {
+        if (executor == null) {
+            throw IOException("GeckoWebExecutor not initialized")
+        }
         val webRequest = request.toWebRequest(defaultHeaders)
 
         val readTimeOut = request.readTimeout ?: maxReadTimeOut
@@ -47,7 +50,7 @@ class GeckoViewFetchClient(
             if (request.redirect == Request.Redirect.MANUAL) {
                 fetchFlags += GeckoWebExecutor.FETCH_FLAGS_NO_REDIRECTS
             }
-            val webResponse = executor.fetch(webRequest, fetchFlags).poll(readTimeOutMillis)
+            val webResponse = executor!!.fetch(webRequest, fetchFlags).poll(readTimeOutMillis)
             webResponse?.toResponse() ?: throw IOException("Fetch failed with null response")
         } catch (e: TimeoutException) {
             throw SocketTimeoutException()