pthread_get_nice_np(3T)pthread_get_nice_np(3T)NAMEpthread_get_nice_np(), pthread_set_nice_np() - get or set the nice
value of a thread
SYNOPSISPARAMETERS
thread The thread whose nice value is to be set/retrieved.
nice_val Value of nice to be applied to the target thread is
returned (get function) or it specifies the new value
of nice for thread (set function).
DESCRIPTION
These functions are used to set and retrieve the nice value of an indi‐
vidual thread.
returns the current nice value setting of the target thread and stores
it in nice_val. adds the value of nice_val to the current nice value
of the target thread.
A thread's nice value is a non-negative number. The system imposes a
minimum nice value of 0 and a maximum of 39 with lower nice values pro‐
viding more favorable scheduling. If calling results in a nice value
outside the range of 0 to 39, the value will be set to the nearest
limit. A process must have appropriate privileges to lower a thread's
nice value. The function allows individual threads in the process to
have different nice values.
returns the current nice value less 20 and will be in the range -20 to
+19.
The nice value of only system scope threads can be changed. An attempt
to change the nice value of a process-scope thread will result in a
return value of Calling on a thread that has a scheduling policy other
than will have an effect only when the thread's scheduling policy
changes to If a thread calls the system call to create a new process,
the new process inherits the process-level nice value. Calling to cre‐
ate a new thread will result in the new thread inheriting the creating
thread's nice value.
Note
If the nice value of the entire process is changed through or all the
threads in the process will have their nice values reset to the new
process-level nice value. The new process's nice value setting over‐
writes the old thread's setting. Thus its possible that a thread whose
nice value had been set higher than the process-level nice value have
its nice value lowered as a result of the process-level re-nicing.
RETURN VALUE
Upon successful completion, and return zero.
Otherwise, an error number is returned to indicate the error (the vari‐
able is not set).
ERRORS
If any of the following occur, the and functions return the correspond‐
ing error:
A process-scope thread was specified.
The caller does not have permission to lower the nice
value specified in nice_val.
No thread could be found corresponding to
thread.
AUTHOR
and were developed by HP.
SEE ALSOfork(2), nice(2), setpriority(2), pthread_attr_getschedpolicy(3T),
pthread_setschedparam(3T).
Pthread Library pthread_get_nice_np(3T)
