bug fix. I disimproved (learned that word today :) ) the asap service message handler some versions ago. Anyway fixed and dealt with a race condition.

Author: thsc42

app/build.gradle

@@ -3,14 +3,14 @@ https://developer.android.com/studio/projects/android-library
  */
 
 // choose one line either for an app or a lib
-apply plugin: 'com.android.application'
-//apply plugin: 'com.android.library'
+//apply plugin: 'com.android.application'
+apply plugin: 'com.android.library'
 
 android {
     compileSdkVersion 28
     defaultConfig {
         // we produce a library by commenting out that line:
-        applicationId "net.sharksystem.asap.example"
+        //applicationId "net.sharksystem.asap.example"
         minSdkVersion 23
         targetSdkVersion 28
         versionCode 1

app/src/main/java/net/sharksystem/asap/android/apps/ASAPActivity.java

@@ -219,14 +219,28 @@ public void startBluetoothDiscovery() {
         this.sendMessage2Service(ASAPServiceMethods.START_BLUETOOTH_DISCOVERY);
     }
 
+    /*
+    There is a race condition:
+    ASAPActivity a can launch ASAPActivity b. It happens (quite often actually) that a.onStop()
+    is processed after b.onStart() or b.onResume(). In that case, startASAPBroadcast are called
+    twice in the row (a.onStart() sometimes earlier, than b.onStart()) followed by
+    stopASAPBroadcast issued by a.onStop(). b would not receive any broadcast - ASAP service
+    was told to stop to send broadcasts.
+
+    Solution: We only stop broadcasting if there if the last activity signs off.
+     */
     public void startASAPEngineBroadcasts() {
         Log.d(this.getLogStart(), "send message to service: start ASAP Engine Broadcasts");
         this.sendMessage2Service(ASAPServiceMethods.START_BROADCASTS);
     }
 
     public void stopASAPEngineBroadcasts() {
-        Log.d(this.getLogStart(), "send message to service: stop ASAP Engine Broadcasts");
-        this.sendMessage2Service(ASAPServiceMethods.STOP_BROADCASTS);
+        if(this.getASAPApplication().getNumberASAPActivities() == 1) {
+            Log.d(this.getLogStart(), "send message to service: stop ASAP Engine Broadcasts");
+            this.sendMessage2Service(ASAPServiceMethods.STOP_BROADCASTS);
+        } else {
+            Log.d(this.getLogStart(), "don't stop broadcasts there are still listeners");
+        }
     }
 
     public void refreshProtocolStatus() {

app/src/main/java/net/sharksystem/asap/android/apps/ASAPApplication.java

@@ -52,7 +52,7 @@ public class ASAPApplication extends BroadcastReceiver {
     private List<String> requiredPermissions;
     private List<String> grantedPermissions = new ArrayList<>();
     private List<String> deniedPermissions = new ArrayList<>();
-    private int activityCount = 0;
+    private int activityASAPActivities = 0;
     private List<CharSequence> onlinePeerList = new ArrayList<>();
 
     /**
@@ -65,6 +65,10 @@ protected ASAPApplication(Collection<CharSequence> supportedFormats) {
                 ASAPAndroid.ONLINE_EXCHANGE_DEFAULT);
     }
 
+    int getNumberASAPActivities() {
+        return this.activityASAPActivities;
+    }
+
     /**
      * setup application without parameter. Use default for owner, root folder for asap storage
      * and online exchange behaviour. Don't setup any asap engine - take engines which are
@@ -206,15 +210,15 @@ public void activityCreated(ASAPActivity asapActivity, boolean initASAPApplicati
         this.setActivity(asapActivity);
         if(initASAPApplication) this.initialize();
 
-        this.activityCount++;
+        this.activityASAPActivities++;
         Log.d(this.getLogStart(), "activity created. New activity count == "
-                + this.activityCount);
+                + this.activityASAPActivities);
     }
 
     public void activityDestroyed(ASAPActivity asapActivity) {
-        this.activityCount--;
+        this.activityASAPActivities--;
         Log.d(this.getLogStart(), "activity destroyed. New activity count == "
-                + this.activityCount);
+                + this.activityASAPActivities);
     }
 
     public ASAPActivity getActivity() {

app/src/main/java/net/sharksystem/asap/android/service/ASAPMessageHandler.java

@@ -38,6 +38,14 @@ public void handleMessage(Message msg) {
                     this.handleCreateClosedChannel(msg);
                     break;
 
+                case ASAPServiceMethods.START_BROADCASTS:
+                    this.asapService.resumeBroadcasts();
+                    break;
+
+                case ASAPServiceMethods.STOP_BROADCASTS:
+                    this.asapService.pauseBroadcasts();
+                    break;
+
                 case ASAPServiceMethods.START_WIFI_DIRECT:
                     this.asapService.startWifiDirect();
                     break;
@@ -74,10 +82,6 @@ public void handleMessage(Message msg) {
                     this.asapService.startReconnectPairedDevices();
                     break;
 
-                case ASAPServiceMethods.STOP_BROADCASTS:
-                    this.asapService.pauseBroadcasts();
-                    break;
-
                 default:
                     super.handleMessage(msg);
             }