Manual Pages for UNIX Operating System command usage for man sched_setscheduler

Standard C Library Functions               sched_setscheduler(3C)



NAME
     sched_setscheduler - set scheduling  policy  and  scheduling
     parameters

SYNOPSIS
     #include 

     int sched_setscheduler(pid_t pid, int policy,
          const struct sched_param *param);


DESCRIPTION
     The sched_setscheduler() function sets the scheduling policy
     and scheduling parameters of the process specified by pid to
     policy and  the  parameters  specified  in  the  sched_param
     structure  pointed  to  by param, respectively. The value of
     the sched_priority member in the  sched_param  structure  is
     any  integer  within  the  inclusive  priority range for the
     scheduling    policy    specified     by     policy.     The
     sched_setscheduler()  function  ignores the other members of
     the sched_param structure. If the value of pid is  negative,
     the   behavior   of  the  sched_setscheduler()  function  is
     unspecified.


     The possible values for the policy parameter are defined  in
     the header  (see sched.h(3HEAD)):


     If a process specified by pid exists and if the calling pro-
     cess  has  permission,  the scheduling policy and scheduling
     parameters are set for the  process  whose  process   ID  is
     equal  to pid. The real or effective user  ID of the calling
     process must match the real or saved (from exec(2)) user  ID
     of  the  target process unless the effective user  ID of the
     calling process is 0. See Intro(2).


     If pid is 0, the scheduling policy and scheduling parameters
     are set for the calling process.


     To change the policy of any process to either  of  the  real
     time  policies   SCHED_FIFO or SCHED_RR, the calling process
     must either have the SCHED_FIFO or SCHED_RR policy  or  have
     an effective user ID of 0.


     The sched_setscheduler() function is  considered  successful
     if it succeeds in setting the scheduling policy and schedul-
     ing parameters of the process specified by pid to the values
     specified  by  policy and the structure pointed to by param,



SunOS 5.11           Last change: 1 Apr 2008                    1






Standard C Library Functions               sched_setscheduler(3C)



     respectively.

RETURN VALUES
     Upon successful completion, the function returns the  former
     scheduling   policy   of   the  specified  process.  If  the
     sched_setscheduler() function  fails  to  complete  success-
     fully,   the   policy   and  scheduling  paramenters  remain
     unchanged, and the function returns -1  and  sets  errno  to
     indicate the error.

ERRORS
     The sched_setscheduler() function will fail if:

     EINVAL    The value of policy is invalid, or one or more  of
               the  parameters  contained in param is outside the
               valid range for the specified scheduling policy.


     EPERM     The requesting process does not have permission to
               set either or both of the scheduling parameters or
               the scheduling policy of the specified process.


     ESRCH     No process can  be  found  corresponding  to  that
               specified by pid.


ATTRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:



     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Interface Stability         | Committed                   |
    |_____________________________|_____________________________|
    | MT-Level                    | MT-Safe                     |
    |_____________________________|_____________________________|
    | Standard                    | See standards(5).           |
    |_____________________________|_____________________________|


SEE ALSO
     priocntl(1), Intro(2),  exec(2),  priocntl(2),  librt(3LIB),
     sched.h(3HEAD),                  sched_get_priority_max(3C),
     sched_getparam(3C),                  sched_getscheduler(3C),
     sched_setparam(3C), attributes(5), standards(5)






SunOS 5.11           Last change: 1 Apr 2008                    2