1.\" $NetBSD: sysmon_taskq.9,v 1.9 2021/12/31 14:22:10 riastradh Exp $ 2.\" 3.\" Copyright (c) 2010 The NetBSD Foundation, Inc. 4.\" All rights reserved. 5.\" 6.\" This code is derived from software contributed to The NetBSD Foundation 7.\" by Jukka Ruohonen. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 19.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 20.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 21.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 22.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 23.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 24.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 25.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 26.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 27.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 28.\" POSSIBILITY OF SUCH DAMAGE. 29.\" 30.Dd January 24, 2010 31.Dt SYSMON_TASKQ 9 32.Os 33.Sh NAME 34.Nm sysmon_taskq 35.Nd general purpose system monitoring task queue 36.Sh SYNOPSIS 37.In dev/sysmon/sysmon_taskq.h 38.Ft void 39.Fn sysmon_task_queue_preinit "void" 40.Ft void 41.Fn sysmon_task_queue_init "void" 42.Ft void 43.Fn sysmon_task_queue_fini "void" 44.Ft int 45.Fn sysmon_task_queue_sched "u_int pri" "void (*func)(void *)" "void *arg" 46.Ft void 47.Fn sysmon_task_queue_barrier "u_int pri" 48.Sh DESCRIPTION 49The machine-independent 50.Nm 51provides a simple general purpose task queue. 52It can be used to run callbacks that require thread context, 53but do not warrant the use of a more fine-grained solution. 54.Pp 55Although the intended usage is related to the context of system monitoring 56and power management, also other comparable functions are suitable for 57.Nm . 58.Sh FUNCTIONS 59The necessary internal data structures 60are initialized during system startup by 61.Fn sysmon_task_queue_preinit . 62Before actual usage, a machine-dependent 63procedure should finish the initialization 64by calling 65.Fn sysmon_task_queue_init . 66This will create a kernel thread that can be later halted by 67.Fn sysmon_task_queue_fini . 68All scheduled tasks are executed before the queue is halted. 69.Pp 70The 71.Fn sysmon_task_queue_sched 72function enqueues 73.Fa func 74to be executed at the priority 75.Fa pri . 76If 77.Fa pri 78is 0, the scheduled function will be placed as the last element in the queue. 79The single argument passed to 80.Fa func 81is specified by 82.Fa arg . 83.Pp 84The 85.Fn sysmon_task_queue_barrier 86function waits for the completion of all tasks at 87.Fa pri 88or lower currently queued at the time of the call. 89.Sh RETURN VALUES 90Upon successful completion, 91.Fn sysmon_task_queue_sched 92returns 0. 93Otherwise, the following error values are returned: 94.Bl -tag -width [EINVAL] 95.It Bq Er EINVAL 96An invalid parameter was specified. 97.It Bq Er ENOMEM 98There was not enough memory. 99.El 100.Sh SEE ALSO 101.Xr queue 3 , 102.Xr kthread 9 , 103.Xr workqueue 9 104.Sh AUTHORS 105.An Jason R. Thorpe Aq Mt thorpej@NetBSD.org 106