Managing thread scheduling

The initial thread of a newly executing program (a process returning from exec(S)) is always a multiplexed thread running under the SCHED_TS policy. The scheduling characteristics of new threads are generally derived from the creator thread. (There are some interesting variations when a bound thread creates a multiplexed thread and vice versa. See the thr_create(S) manual page for details.)

To create a thread with different scheduling characteristics the programmer can:

1. Create a new thread with thr_create(S) using the THR_SUSPENDED flag. This will create a new thread but not allow it to execute.

2. Use the returned thread ID to change the characteristics of the new thread with the thr_setprio(S) or thr_setscheduler(S) functions.

3. Use the thr_continue(S) function to make the new thread runnable.

Alternatively, a thread can use thr_setscheduler(S) or thr_setprio(S) to modify its own scheduling class or priority.