The problem about multi-thread in java application

Question

i have problem with the multi-thread in java application, i don't know how to stop and restart a thread safely, because the function thread.stop(),thread.suspend() are both deprecated.
now what i can only do is making the thread check a flag(true or false) to determine whether to start or to stop, but i think this thread will always be in the memory and maybe it will lower the performance of the system, as the program i am developping is working under realtime enviorement.
please help me about it. thanks !

Answer 1

hi,
you can stop a thread by exiting it's run()-method which in terms can be done by checking the interrupted-flag:
public void run(){
while(interrupted()){ //if the thread consists of a loop
or
public void run(){
if(interrupted())return;
if(interrupted())return;
or by the use of the return-statement anywhere withing the run-method. Afterwards, that is when the thread is no longer needed, you clear all the references to the specific thread object by setting them to null:
Thread t;
... //working
t.interrupt(); //interrupting
while(t.isAlive()){
Thread.yield(); //wait till thread t has stopped
t=null;
best regards, Michael