_lwp_setscheduler(2) System Calls Manual _lwp_setscheduler(2)
NAME
_lwp_setscheduler() - set LWP(Lightweight Process) scheduling policy and parameters
SYNOPSIS
DESCRIPTION
The function allows the scheduling policy and parameters of an individual LWP in any process to be set. For and the only required member
of the sched_param structure is the priority sched_priority.
The cmd argument determines the action to be performed by the system call and supports one of the following values. Other values of cmd
are reserved for use by HP and may change without notice. The behavior of _lwp_setscheduler is undefined if any other value is passed to
the cmd argument and it may change without notice.
This request sets the scheduling policy and associated scheduling parameters
for the LWP whose LWP ID is specified by target_lwp to the policy and associated parameters provided in policy and param
respectively. The LWPID specified by target_lwp can be in any process. If the value of target_lwp is zero(0), the target
LWP will be the calling LWP.
This request sets the scheduling policy and associated scheduling parameters
for all LWPs in the target process specified by target_lwp to the policy and associated parameters provided in policy and
param, respectively. For this request, the PID value should be passed in the target_lwp parameter. The policy and param
arguments are stored in the process so they may be assigned to the child process during a fork operation.
If the function fails, no scheduling parameters or policies shall be changed for the specified LWP(s).
Appropriate privileges are required to change the scheduling parameters of another LWP. The calling LWP must have appropriate privileges
or be a member of a group having access to successfully call
Refer to the rtsched(2) manpage for a complete description of scheduling policies and priorities available. is similar to the function
except that it operates on lightweight processes instead of processes.
RETURN VALUE
Upon successful completion, returns with a value of 0; otherwise, it returns an error number to indicate the error. The variable is NOT
set if an error occurs.
ERRORS
For each of the following conditions, if the condition is detected, the function fails and returns the corresponding error number:
The target process could not be accessed due to compartmental restrictions.
The param parameter points to an illegal address.
The cmd parameter is invalid.
The value of the
policy parameter is invalid, or the param parameter is NULL, or one or more parameters contained in param is outside
the valid range for the specified scheduling policy.
The requesting LWP does not have permission to set the scheduling policy
and parameter for the specified LWP(s).
No LWP can be found corresponding to that specified by
target_lwp.
No process can be found corresponding to that specified by
target_lwp for the request.
WARNINGS
In general, the POSIX pthread interfaces should be used by multi-threaded applications. This system call may be used directly only when
the application has a need to operate on LWPs in another process. This system call may result in undefined behavior if the usage is mixed
with POSIX pthread APIs.
SEE ALSO
_lwp_getscheduler(2), sched_setscheduler(2), pthread_setschedparam(3t).
_lwp_setscheduler(2)
