Thread problem,about Abort()

Can anybody help me? The deadline of my project is approaching, but this problem stuck me. my ultimate task is to use the serialport in c#.Now I'm trying to create a thread that continuously read the serial port. Actually I'm now just at the beginning, trying to test if a loop in a thread can work. Here's my problem:If I do not explicitly Abort() the thread before I click the arrow to end the program, the thread may seem unable to be closed. The fact is, I could not run the program again unless I restart Unity3d.` the test code is here: using UnityEngine; using System.Collections; using System; using System.IO; using System.IO.Ports; using System.Threading;

 public class TestThread2 : MonoBehaviour {
     //variables
     public int str;
     public int str2;
     Boolean Run=true;
     Thread t;
     float ThreadCount;
 
     // Use this for initialization
     void Start () {
             t = new Thread(new ThreadStart(ThreadProc));
         t.Start();
         str=0;
         ThreadCount=10;
 
     }
     
     // Update is called once per frame
     void Update () {
         
         ThreadCount -= Time.deltaTime;
         if(ThreadCount<=0){
             t.Abort();
             Run=false;
         }
         
     
     
     }
 
 //线程函数
     public void ThreadProc() {
         str=0;
         Run=true;
         while(Run){
             
     
         }
         
 
     }
 }

I used a ThreadCount so the thread will Abort after a certain time. But if i exit the program before that span of time, the problem will appear.