getquantum(2)

NAME

getquantum, setquantum − get/set process time quantum

SYNOPSIS

#include <sys/resource.h>
#include <sys/time.h>

prio = getquantum (who)
int who;

int setquantum (which, who, quantum)
int which, who, quantum;

DESCRIPTION

The time quantum of the process as indicated by who is obtained with the getquantum call and set with the setquantum call. Which is one of

PRIO_PROCESSprocess id
PRIO_PGRPprocess group id
PRIO_USERuser id

and who is interpreted relative to which (a process identifier for PRIO_PROCESS, process group identifier for PRIO_PGRP, and a user ID for PRIO_USER). Quantum is a positive value indicating a time quantum, in clock ticks.

The getquantum call returns the time quantum, in clock ticks, of the specified process. The setquantum call sets the time quantum of all of the specified processes to the specified value. Only the super-user or a user with the ACC_SETPRI privilege can increase a time quantum.

RETURN VALUE

Upon successful completion, getquantum returns the time quantum, in clock ticks, of the specified process; setquantum returns 0. If not successful, −1 is returned and errno is set to indicate the error.

ERRORS

getquantum and setquantum may return one of the following errors:

[ESRCH] No process(es) were located using the which and who values specified.

[EINVAL] Which was not one of PRIO_PROCESS, PRIO_PGRP, or PRIO_USER.

In addition to the errors indicated above, setquantum may fail with one of the following errors returned:

[EACCES] The time quantum specified was not positive.

[EACCES] A process was located, but neither its effective nor real user ID matched the effective user ID of the caller.

[EACCES] The caller attempted to increase a time quantum and the caller does not have an effective user ID equal to the super-user and the caller does not have the ACC_SETPRI privilege (if access vectors are configured).

Museum