+++ /dev/null
-.\" $OpenBSD: workq_add_task.9,v 1.17 2014/01/21 03:15:46 schwarze Exp $
-.\"
-.\" Copyright (c) 2007 David Gwynne <dlg@openbsd.org>
-.\"
-.\" Permission to use, copy, modify, and distribute this software for any
-.\" purpose with or without fee is hereby granted, provided that the above
-.\" copyright notice and this permission notice appear in all copies.
-.\"
-.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
-.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
-.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
-.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
-.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
-.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
-.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
-.\"
-.Dd $Mdocdate: January 21 2014 $
-.Dt WORKQ_ADD_TASK 9
-.Os
-.Sh NAME
-.Nm workq_add_task ,
-.Nm workq_queue_task ,
-.Nm workq_create ,
-.Nm workq_destroy
-.Nd work queues
-.Sh SYNOPSIS
-.In sys/workq.h
-.Ft int
-.Fn "workq_add_task" "struct workq *wq" "int flags" "void (*func)(void *, void *)" "void *arg1" "void *arg2"
-.Ft void
-.Fn "workq_queue_task" "struct workq *wq" "struct workq_task *wqt" "int flags" "void (*func)(void *, void *)" "void *arg1" "void *arg2"
-.Ft struct workq *
-.Fn "workq_create" "const char *name" "int maxthreads" "int ipl"
-.Ft void
-.Fn "workq_destroy" "struct workq *wq"
-.Sh DESCRIPTION
-The
-workq
-framework API provides a mechanism to defer tasks to a process context when
-it is impossible to run such a task in the current context.
-.Pp
-.Fn workq_add_task
-adds a task to the workq specified by the
-.Fa wq
-argument.
-If
-.Fa wq
-is
-.Dv NULL
-the task will be run by the kernel's generic work queue.
-Tasks in the kernel's generic work queue should not run for long periods of
-time, they should use their own workq for task processing.
-A task is specified by the
-.Fa func
-argument, and will be called with
-.Fa arg1
-and
-.Fa arg2 .
-Two arguments are allowed to provide additional flexibility to the called
-function.
-In many cases, one may wish to perform an action on a target.
-Two arguments allow both target and action to be passed without
-the need for a wrapper struct to contain them in a single argument.
-The
-.Fa flags
-argument specifies creation and runtime characteristics of the task.
-The possible flags are:
-.Pp
-.Bl -tag -offset indent -width WQ_WAITOKXXX -compact
-.It Dv WQ_WAITOK
-Wait for resources to become available.
-If resources are not available and this flag is not set then
-.Fn workq_add_task
-will return
-.Dv ENOMEM .
-.El
-.Pp
-.Fn workq_queue_task
-adds a task to the workq specified by the
-.Fa wq
-argument, using the memory provided by the
-.Fa wqt
-argument to store that task's entry on the workq.
-The
-.Fa flags ,
-.Fa func ,
-.Fa arg1 ,
-and
-.Fa arg2
-arguments are the same as those in the
-.Fn workq_add_task
-function.
-However, because the caller is responsible for providing the memory
-needed to store the task on the workq,
-.Fn workq_queue_task
-is guaranteed to succeed.
-.Pp
-.Fn workq_create
-creates a workq to be used when tasks would unnecessarily block the kernel
-workq.
-The
-.Fa name
-argument specifies the name of the kernel threads that run the tasks.
-.Fa maxthreads
-specifies the maximum number of worker threads that will service the work
-queue.
-.Fa ipl
-specifies the interrupt protection level at which the workq can be safely used.
-See
-.Xr spl 9
-for a list of the IPLs.
-.Pp
-.Fn workq_destroy
-causes the resources associated with a previously created workq to be freed.
-It will wait till all the tasks in the work queue are completed before
-returning.
-.Pp
-.Fn workq_add_task ,
-.Fn workq_create ,
-and
-.Fn workq_destroy
-can be called during
-.Xr autoconf 9
-or from process context.
-.Fn workq_add_task
-can additionally be called from interrupt context if
-.Dv WQ_WAITOK
-is not specified.
-.Sh SEE ALSO
-.Xr autoconf 9 ,
-.Xr spl 9
-.Sh HISTORY
-The workq framework was originally written by
-.An Ted Unangst Aq Mt tedu@openbsd.org ,
-and heavily influenced by arguments with
-.An David Gwynne Aq Mt dlg@openbsd.org .
-The workq framework first appeared in
-.Ox 4.2 .
+++ /dev/null
-/* $OpenBSD: kern_workq.c,v 1.17 2014/11/01 23:58:28 tedu Exp $ */
-
-/*
- * Copyright (c) 2007 David Gwynne <dlg@openbsd.org>
- * Copyright (c) 2007 Ted Unangst <tedu@openbsd.org>
- *
- * Permission to use, copy, modify, and distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
- * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
- * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
- * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
- * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
- */
-
-#include <sys/param.h>
-#include <sys/systm.h>
-#include <sys/malloc.h>
-#include <sys/pool.h>
-#include <sys/queue.h>
-#include <sys/mutex.h>
-#include <sys/kthread.h>
-#include <sys/workq.h>
-
-struct workq {
- enum {
- WQ_S_CREATED,
- WQ_S_RUNNING,
- WQ_S_DESTROYED
- } wq_state;
- int wq_running;
- int wq_max;
- const char *wq_name;
-
- struct mutex wq_mtx;
- SIMPLEQ_HEAD(, workq_task) wq_tasklist;
-};
-
-struct pool workq_task_pool;
-struct workq workq_syswq = {
- WQ_S_CREATED,
- 0,
- 1,
- "syswq"
-};
-
-/* if we allocate the wqt, we need to know we free it too */
-#define WQT_F_POOL (1U << 31)
-
-void workq_init(void); /* called in init_main.c */
-void workq_create_thread(void *);
-struct workq_task * workq_next_task(struct workq *);
-void workq_thread(void *);
-
-void
-workq_init(void)
-{
- pool_init(&workq_task_pool, sizeof(struct workq_task), 0, 0,
- 0, "wqtasks", NULL);
- pool_setipl(&workq_task_pool, IPL_HIGH);
-
- mtx_init(&workq_syswq.wq_mtx, IPL_HIGH);
- SIMPLEQ_INIT(&workq_syswq.wq_tasklist);
- kthread_create_deferred(workq_create_thread, &workq_syswq);
-}
-
-struct workq *
-workq_create(const char *name, int maxqs, int ipl)
-{
- struct workq *wq;
-
- wq = malloc(sizeof(*wq), M_DEVBUF, M_NOWAIT);
- if (wq == NULL)
- return (NULL);
-
- wq->wq_state = WQ_S_CREATED;
- wq->wq_running = 0;
- wq->wq_max = maxqs;
- wq->wq_name = name;
-
- mtx_init(&wq->wq_mtx, ipl);
- SIMPLEQ_INIT(&wq->wq_tasklist);
-
- /* try to create a thread to guarantee that tasks will be serviced */
- kthread_create_deferred(workq_create_thread, wq);
-
- return (wq);
-}
-
-void
-workq_destroy(struct workq *wq)
-{
- mtx_enter(&wq->wq_mtx);
- switch (wq->wq_state) {
- case WQ_S_CREATED:
- /* wq is still referenced by workq_create_thread */
- wq->wq_state = WQ_S_DESTROYED;
- mtx_leave(&wq->wq_mtx);
- return;
-
- case WQ_S_RUNNING:
- wq->wq_state = WQ_S_DESTROYED;
- break;
-
- default:
- panic("unexpected %s wq state %d", wq->wq_name, wq->wq_state);
- }
-
- while (wq->wq_running != 0) {
- wakeup(wq);
- msleep(&wq->wq_running, &wq->wq_mtx, PWAIT, "wqdestroy", 0);
- }
- mtx_leave(&wq->wq_mtx);
-
- free(wq, M_DEVBUF, sizeof(*wq));
-}
-
-int
-workq_add_task(struct workq *wq, int flags, workq_fn func, void *a1, void *a2)
-{
- struct workq_task *wqt;
-
- wqt = pool_get(&workq_task_pool, (flags & WQ_WAITOK) ?
- PR_WAITOK : PR_NOWAIT);
- if (!wqt)
- return (ENOMEM);
-
- workq_queue_task(wq, wqt, WQT_F_POOL | flags, func, a1, a2);
-
- return (0);
-}
-
-void
-workq_queue_task(struct workq *wq, struct workq_task *wqt, int flags,
- workq_fn func, void *a1, void *a2)
-{
- wqt->wqt_flags = flags;
- wqt->wqt_func = func;
- wqt->wqt_arg1 = a1;
- wqt->wqt_arg2 = a2;
-
- if (wq == NULL)
- wq = &workq_syswq;
-
- mtx_enter(&wq->wq_mtx);
- SIMPLEQ_INSERT_TAIL(&wq->wq_tasklist, wqt, wqt_entry);
- mtx_leave(&wq->wq_mtx);
-
- wakeup_one(wq);
-}
-
-void
-workq_create_thread(void *arg)
-{
- struct workq *wq = arg;
- int rv;
-
- mtx_enter(&wq->wq_mtx);
-
- switch (wq->wq_state) {
- case WQ_S_DESTROYED:
- mtx_leave(&wq->wq_mtx);
- free(wq, M_DEVBUF, sizeof(*wq));
- return;
-
- case WQ_S_CREATED:
- wq->wq_state = WQ_S_RUNNING;
- break;
-
- default:
- panic("unexpected %s wq state %d", wq->wq_name, wq->wq_state);
- }
-
- do {
- wq->wq_running++;
- mtx_leave(&wq->wq_mtx);
-
- rv = kthread_create(workq_thread, wq, NULL, wq->wq_name);
-
- mtx_enter(&wq->wq_mtx);
- if (rv != 0) {
- printf("unable to create workq thread for \"%s\"\n",
- wq->wq_name);
-
- wq->wq_running--;
- /* could have been destroyed during kthread_create */
- if (wq->wq_state == WQ_S_DESTROYED &&
- wq->wq_running == 0)
- wakeup_one(&wq->wq_running);
- break;
- }
- } while (wq->wq_running < wq->wq_max);
- mtx_leave(&wq->wq_mtx);
-}
-
-
-struct workq_task *
-workq_next_task(struct workq *wq)
-{
- struct workq_task *wqt;
-
- mtx_enter(&wq->wq_mtx);
-
- for (;;) {
- wqt = SIMPLEQ_FIRST(&wq->wq_tasklist);
- if (wqt != NULL) {
- SIMPLEQ_REMOVE_HEAD(&wq->wq_tasklist, wqt_entry);
- break;
- } else if (wq->wq_state == WQ_S_RUNNING)
- msleep(wq, &wq->wq_mtx, PWAIT, "bored", 0);
- else {
- if (--wq->wq_running == 0)
- wakeup_one(&wq->wq_running);
- break;
- }
- }
-
- mtx_leave(&wq->wq_mtx);
-
- return (wqt);
-}
-
-void
-workq_thread(void *arg)
-{
- struct workq *wq = arg;
- struct workq_task *wqt;
- int mypool;
-
- while ((wqt = workq_next_task(wq)) != NULL) {
- mypool = (wqt->wqt_flags & WQT_F_POOL);
- wqt->wqt_func(wqt->wqt_arg1, wqt->wqt_arg2);
- if (mypool)
- pool_put(&workq_task_pool, wqt);
- sched_pause();
- }
-
- kthread_exit(0);
-}
+++ /dev/null
-/* $OpenBSD: workq.h,v 1.7 2013/10/31 04:33:32 deraadt Exp $ */
-
-/*
- * Copyright (c) 2007 David Gwynne <dlg@openbsd.org>
- * Copyright (c) 2007 Ted Unangst <tedu@openbsd.org>
- *
- * Permission to use, copy, modify, and distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
- * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
- * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
- * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
- * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
- */
-
-#ifndef _SYS_WORKQ_H_
-#define _SYS_WORKQ_H_
-
-#include <sys/queue.h>
-
-typedef void (*workq_fn)(void *, void *);
-
-struct workq_task {
- int wqt_flags;
- workq_fn wqt_func;
- void *wqt_arg1;
- void *wqt_arg2;
-
- SIMPLEQ_ENTRY(workq_task) wqt_entry;
-};
-
-#define WQ_WAITOK (1<<0)
-#define WQ_MPSAFE (1<<1)
-
-#ifdef _KERNEL
-struct workq;
-
-struct workq *workq_create(const char *, int, int);
-int workq_add_task(struct workq *, int /* flags */, workq_fn,
- void *, void *);
-void workq_queue_task(struct workq *, struct workq_task *,
- int /* flags */, workq_fn, void *, void *);
-void workq_destroy(struct workq *);
-#endif /* _KERNEL */
-
-#endif /* _SYS_WORKQ_H_ */
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