.\" $NetBSD: sysmon_taskq.9,v 1.8 2014/03/18 18:20:40 riastradh Exp $
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.\" by Jukka Ruohonen.
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.Dd January 24, 2010
.Dt SYSMON_TASKQ 9
.Os
.Sh NAME
.Nm sysmon_taskq
.Nd general purpose system monitoring task queue
.Sh SYNOPSIS
.In dev/sysmon/sysmon_taskq.h
.Ft void
.Fn sysmon_task_queue_preinit "void"
.Ft void
.Fn sysmon_task_queue_init "void"
.Ft void
.Fn sysmon_task_queue_fini "void"
.Ft int
.Fn sysmon_task_queue_sched "u_int pri" "void (*func)(void *)" "void *arg"
.Sh DESCRIPTION
The machine-independent
.Nm
provides a simple general purpose task queue.
It can be used to run callbacks that require thread context,
but do not warrant the use of a more fine-grained solution.
.Pp
Although the intended usage is related to the context of system monitoring
and power management, also other comparable functions are suitable for
.Nm .
.Sh FUNCTIONS
The necessary internal data structures
are initialized during system startup by
.Fn sysmon_task_queue_preinit .
Before actual usage, a machine-dependent
procedure should finish the initialization
by calling
.Fn sysmon_task_queue_init .
This will create a kernel thread that can be later halted by
.Fn sysmon_task_queue_fini .
All scheduled tasks are executed before the queue is halted.
.Pp
The
.Fn sysmon_task_queue_sched
enqueues
.Fa func
to be executed at the priority
.Fa pri .
If
.Fa pri
is 0, the scheduled function will be placed as the last element in the queue.
The single argument passed to
.Fa func
is specified by
.Fa arg .
.Sh RETURN VALUES
Upon successful completion,
.Fn sysmon_task_queue_sched
returns 0.
Otherwise, the following error values are returned:
.Bl -tag -width [EINVAL]
.It Bq Er EINVAL
An invalid parameter was specified.
.It Bq Er ENOMEM
There was not enough memory.
.El
.Sh SEE ALSO
.Xr queue 3 ,
.Xr kthread 9 ,
.Xr workqueue 9
.Sh AUTHORS
.An Jason R. Thorpe Aq Mt thorpej@NetBSD.org