Xinu7/man/man2/chprio.doc

CHPRIO(2)           Xinu Programmer's Manual            CHPRIO(2)



NAME
     chprio - change the priority of a process

SYNOPSIS
     int chprio(pid,newprio)
     int pid;
     int newprio;

DESCRIPTION
     _C_h_p_r_i_o changes the scheduling priority of process _p_i_d to
     _n_e_w_p_r_i_o. Priorities are positive integers.  At any instant,
     the highest priority process  that is ready will be running.
     A set of processes with equal priority is scheduled round-
     robin.

     If the new priority is invalid, or the process id is invalid
     _c_h_p_r_i_o returns SYSERR.  Otherwise, it returns the old pro-
     cess priority.  It is forbidden to change the priority of
     the null process, which always remains zero.

SEE ALSO
     create(2), getprio(2), resume(2)

BUGS
     Because _c_h_p_r_i_o changes priorities without rearranging
     processes on the ready list, it should only be used on wait-
     ing, sleeping, suspended, or current processes.




























Version 6b               Printed 1/12/87                        1