Wait for only some threads to complete after fork join_none in SystemVerilog

In SystemVerilog I need to wait for some threads that have been executed inside a fork join_none structure to finish. But there is another process inside another fork join_none structure that will never end.

My code looks like this:

  fork
     process_that_will_never_end();
  join_none

  fork
     for(int i = 0; i < 40; i++) begin
        fork
           process_that_must_end(i);
        join_none
     end
  join

The fork join containing the for loop has no effect (which is what I expected). I thought about using a "wait fork" at the end but this will also wait for process_that_will_never_end(), so it won't work.

Is there any way to wait only for all the process_that_must_end() threads to finish?

You almost had it. You just need to move the scope of the begin/end to outside the for loop. Then the wait fork only applies to the children of the second fork.

fork : first_fork
     process_that_will_never_end();
join_none

fork begin : second_fork
  for(int i = 0; i < 40; i++) 
     fork : third_forks
       automatic int k = i;
       process_that_must_end(k);
     join_none
   wait fork;
end join