how to update the php class array values while using pthreads

class Field extends Thread{
        public $dataFields;

        public function addValue($table,$key,$data){
          print_r($this->dataFields[$table]);
          echo "\ndata: ".$data."\n";
          if(isset($this->dataFields[$table][$key])){
              $this->dataFields[$table][$key]= $data;
              echo "yes\n";
            }
          else echo "no\n";
          print_r($this->dataFields[$table]);

         }

         public function setVariables($con){
            $result = mysqli_query($con,"select * from property,city limit 1");
            $row=mysqli_fetch_fields($result);
            foreach ($row as $key => $value) {
                $propData[$value->table][$value->name]="";
            }
            $propData["property"]["portalId"]=2;
            $propData["property"]["area"]="delhi";
            $this->dataFields=$propData;
            $this->addValue("property","id","1");
            //print_r($this->dataFields);
            $this->dataFields["property"]["id"]=1;
            var_dump($propData);
            var_dump($this->dataFields);
        }
    }

as you can see the code I am updating the value of array through function addValue, if the key is set in the dataFields array then it will get updated but in this its not happening when I try to call the function:

addValue("property","id","1"); through function setVariables() (see the output below)

it prints the value of $data it prints "yes". The class variable dataFields is not getting updated.

[Edit] When I am using Threads extended class it don't get updated but when I don't use Thread extended class then it get updated.

    Array                                 
    (                                             
        [id] =>                                   
        [portalId] => 2                          
        [area] => delhi                           
    )                                             

    data: 1                                 
    yes                                           
    Array                                         
    (                                             
        [id] =>                                   
        [portalId] => 2                          
        [area] => delhi
    ) 
    array(2) {                        
         ["city"]=>                              
         array(3) {                              
           ["id"]=>                              
           string(0) ""                          
           ["name"]=>                            
           string(0) ""                          
           ["otherNames"]=>                      
           string(0) ""                          
         }                                                                
         ["property"]=>                          
         array(3) {                             
           ["id"]=>                              
           string(0) ""                          
           ["portalId"]=>                        
           int(2)                                
           ["area"]=>                            
           string(5) "delhi"                     
         }
        }
    array(2) {
          ["city"]=>
          array(3) {
            ["id"]=>
            string(0) ""
            ["name"]=>
            string(0) ""
            ["otherNames"]=>
            string(0) ""
          }
          ["property"]=>
          array(3) {
            ["id"]=>
            string(0) ""
            ["portalId"]=>
            int(2)
            ["area"]=>
            string(5) "delhi"
           }
        }