ConcurrentModificationException iterating Backstack

[toddhodes]

Hi! I'm seeing the following. The flow is from a conductor activity, to a dialog, the calling out to the SMS app, and then when the user hits the back button from the native SMS app, we get the following:

java.util.ConcurrentModificationException                                                            
   at java.util.ArrayDeque$DeqIterator.next(ArrayDeque.java:608)                                     
   at com.bluelinelabs.conductor.Router.onActivityStarted(Router.java:532)                           
   at com.bluelinelabs.conductor.internal.LifecycleHandler.onActivityStarted(LifecycleHandler.java:334)
   at android.app.Application.dispatchActivityStarted(Application.java:205)                          
   at android.app.Activity.onStart(Activity.java:1150)                                               
   at android.support.v4.app.FragmentActivity.onStart(FragmentActivity.java:564)                     
   at android.support.v7.app.AppCompatActivity.onStart(AppCompatActivity.java:177)                   
   at com.locationlabs.cni.mvp.BaseControlsActivity.onStart(BaseControlsActivity.java:51)            
   at com.locationlabs.cni.contentfiltering.AppControlsActivity.onStart(AppControlsActivity.java:117)
   at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1237)                     
   at android.app.Activity.performStart(Activity.java:6268)                                          
   at android.app.Activity.performRestart(Activity.java:6314)                                        
   at android.app.Activity.performResume(Activity.java:6319)                                         
   at android.app.ActivityThread.performResumeActivity(ActivityThread.java:3092)                     
   at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:3134)                      
   at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1388)                           
   at android.os.Handler.dispatchMessage(Handler.java:102)                                           
   at android.os.Looper.loop(Looper.java:148)                                                        
   at android.app.ActivityThread.main(ActivityThread.java:5417)                                      
   at java.lang.reflect.Method.invoke(Native Method)                                                 
   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)                
   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)

can you make the Router's Backstack iterator thread-safe, or, provide any other advice? as a workaround, I'm simply catching it and moving on...

   @Override
   protected void onStart() {
      try {
         super.onStart();
         getPresenter().onViewStarted();
      } catch (RuntimeException e) {
         Log.dw("we still need a proper fix for <our-issue-#>");
      }
   }

tried conductor_version=2.1.4 and conductor_version=2.1.5-SNAPSHOT

[SamYStudiO]

+1 got it as well

[dimsuz]

This seems like a duplicate of #396 which has a PR submitted (#406). I'd suggest to close this issue in favor of #396 as it contains more info and comments.

[SamYStudiO]

Hum mine is different

java.util.ConcurrentModificationException
at java.util.ArrayDeque$DescendingIterator.next(ArrayDeque.java:681)
at com.bluelinelabs.conductor.Router.rebindIfNeeded(Router.java:498)
at com.bluelinelabs.conductor.Conductor.attachRouter(Conductor.java:39)

Can be reproduce from this git https://github.com/SamYStudiO/beaver, launch app click invalidate button , then click sign button (2 dialogs controller should be opened over a thirdcontroller) then rotate screen > crash

[SamYStudiO]

Ok I figure out what happend, in fact this is similar to #396, crash happens when you push a new controller while Router.rebindIfNeeded loop is executed, in my case the push is an error on my side, i'm not sure if it has to be fixed or not.

[FunnyDevs]

any news???

[dimsuz]

@SamYStudiO can you check if this is still reproducable for you on recent snapshot? #396 got fixed, chances are your case will be fixed too.

[mateherber]

Same happens for us on 3.0.0-rc2. Any update or possible workaround? It happens while handling push notifications but really hard to repro.

[eaglecs]

Same issue. Please fix it.

[daewin]

Hi @EricKuck, is this issue resolved by https://github.com/bluelinelabs/Conductor/commit/bd584727be913e520baae21cc8013cb5e5d60f11?