java - How to update something in main class in thread -

hi trying make multiplayer game find opponent in thread, not sure why code running in thread not update model in main class...

here code in main class. call loadtask starts thread

// start model, passing number of words, user name, , selected animal         model = new multiplayermodel(num_words, username, anmid);         model.addobserver(this);          new loadtask().execute();          setcontentview(r.layout.activity_multi_player);         initialdisplay(animal, background, oppanimal); 

here code thread class

    private class loadtask extends asynctask<void, integer, void> {          // called before running code in separate thread         private boolean quitflag;         @override         protected void onpreexecute() {             progressdialog = progressdialog.show(multiplayer.this,"finding game...",                       "searching opponent, please wait...", false, false);         }          @override         protected void doinbackground(void... params) {             synchronized (this) {                 try {                     model.beginmatchmaking();                     model.setwordslist();                     // opponent's animal model                     oppanimal = reversedrawable(model.getopponentanimal());                     // display multiplayer screen                  } catch (internetconnectionexception e) {                     e.fillinstacktrace();                     quitflag = true;                     error(states.error.connection);                     return null;                 } catch (emptyqueueexception e) {                     e.fillinstacktrace();                     quitflag = true;                     error(states.error.noopponent);                     return null;                 } catch (internalerrorexception e) {                     e.fillinstacktrace();                     quitflag = true;                     error(states.error.internal);                     return null;                 }             }             return null;         }          @override         protected void onpostexecute(void result) {             if (!quitflag) {               progressdialog.dismiss();               gametimer = new gametimer(start_time, interval);               gametimer.start();             }         }     } 

and segfaults on initialdisplay after thread called because fields in model class not updated @ all. acts though created , nothing done it

i'm not sure asynctask class if it's configurated thread , next line

new loadtask().execute(); 

will start thread properly, in case thread execute inparallel usualy after lines:

setcontentview(r.layout.activity_multi_player); initialdisplay(animal, background, oppanimal); 

to prove may print messages main methods. solve may add next line after starting thread:

new loadtask().execute(); thread.sleep(100)