multi-thread review

--Corporate multi-task OS: DOS, Linux
The OS must get the approval of the Thread before it want change the state of the Thread.
Especially, the Linux Kerl is non-preemptive system, it 'implement' thread via interpreting and implement LWP machinism and take 'thread' as the special process which share the same context.

--Racing multi-task OS: Windows NT and inheritance OS
The OS will make the decision to change the specific Thread according to the racing condition of the Threads. So the execution of the Threads is not in the control of the programmer.

So make the Threads works as you expect, the elaborate plan must be made before the Treads are created.