Fix for ForegroundServiceDidNotStartInTimeException for FcmFetchForegroundService.

app/src/main/java/org/thoughtcrime/securesms/gcm/FcmFetchManager.kt

@@ -72,6 +72,13 @@ object FcmFetchManager {
     return true
   }
 
+  @JvmStatic
+  fun isForegroundStarted(): Boolean {
+    synchronized(this) {
+      return startedForeground
+    }
+  }
+
   private fun fetch(context: Context) {
     retrieveMessages(context)
 
@@ -95,6 +102,25 @@ object FcmFetchManager {
     }
   }
 
+  @JvmStatic
+  fun tryLegacyFallback(context: Context) {
+    synchronized(this) {
+      if (startedForeground) {
+        val performedReplace = EXECUTOR.enqueue { fetch(context) }
+
+        if (performedReplace) {
+          Log.i(TAG, "Legacy fallback: already have one running and one enqueued. Ignoring.")
+        } else {
+          activeCount++
+          Log.i(TAG, "Legacy fallback: Incrementing active count to $activeCount")
+        }
+        return
+      }
+    }
+    Log.i(TAG, "No foreground running, performing legacy fallback")
+    retrieveMessages(context)
+  }
+
   @JvmStatic
   fun retrieveMessages(context: Context) {
     val success = ApplicationDependencies.getBackgroundMessageRetriever().retrieveMessages(context, WebSocketStrategy())

app/src/main/java/org/thoughtcrime/securesms/gcm/FcmReceiveService.java

@@ -102,7 +102,7 @@ public class FcmReceiveService extends FirebaseMessagingService {
 
     if (!enqueueSuccessful) {
       Log.w(TAG, "Unable to start service. Falling back to legacy approach.");
-      FcmFetchManager.retrieveMessages(context);
+      FcmFetchManager.tryLegacyFallback(context);
     }
   }