1 /* $NetBSD: sysmon_taskq.c,v 1.13 2008/04/06 09:42:04 xtraeme Exp $ */
4 * Copyright (c) 2001, 2003 Wasabi Systems, Inc.
7 * Written by Jason R. Thorpe for Wasabi Systems, Inc.
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
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 * 3. All advertising materials mentioning features or use of this software
18 * must display the following acknowledgement:
19 * This product includes software developed for the NetBSD Project by
20 * Wasabi Systems, Inc.
21 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
22 * or promote products derived from this software without specific prior
25 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC
29 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35 * POSSIBILITY OF SUCH DAMAGE.
39 * General purpose task queue for sysmon back-ends. This can be
40 * used to run callbacks that require thread context.
43 #include <sys/cdefs.h>
44 __KERNEL_RCSID(0, "$NetBSD: sysmon_taskq.c,v 1.13 2008/04/06 09:42:04 xtraeme Exp $");
46 #include <sys/param.h>
47 #include <sys/malloc.h>
48 #include <sys/queue.h>
50 #include <sys/kthread.h>
51 #include <sys/systm.h>
53 #include <dev/sysmon/sysmon_taskq.h>
56 TAILQ_ENTRY(sysmon_task
) st_list
;
57 void (*st_func
)(void *);
62 static TAILQ_HEAD(, sysmon_task
) sysmon_task_queue
=
63 TAILQ_HEAD_INITIALIZER(sysmon_task_queue
);
65 static kmutex_t sysmon_task_queue_mtx
;
66 static kmutex_t sysmon_task_queue_init_mtx
;
67 static kcondvar_t sysmon_task_queue_cv
;
69 static int sysmon_task_queue_initialized
;
70 static int sysmon_task_queue_cleanup_sem
;
71 static struct lwp
*sysmon_task_queue_lwp
;
72 static void sysmon_task_queue_thread(void *);
75 sysmon_task_queue_preinit(void)
77 mutex_init(&sysmon_task_queue_mtx
, MUTEX_DEFAULT
, IPL_VM
);
78 mutex_init(&sysmon_task_queue_init_mtx
, MUTEX_DEFAULT
, IPL_NONE
);
79 cv_init(&sysmon_task_queue_cv
, "smtaskq");
84 * sysmon_task_queue_init:
86 * Initialize the sysmon task queue.
89 sysmon_task_queue_init(void)
93 mutex_enter(&sysmon_task_queue_init_mtx
);
94 if (sysmon_task_queue_initialized
) {
95 mutex_exit(&sysmon_task_queue_init_mtx
);
99 sysmon_task_queue_initialized
= 1;
100 mutex_exit(&sysmon_task_queue_init_mtx
);
102 error
= kthread_create(PRI_NONE
, KTHREAD_MPSAFE
, NULL
,
103 sysmon_task_queue_thread
, NULL
, &sysmon_task_queue_lwp
, "sysmon");
105 printf("Unable to create sysmon task queue thread, "
106 "error = %d\n", error
);
107 panic("sysmon_task_queue_init");
112 * sysmon_task_queue_fini:
114 * Tear town the sysmon task queue.
117 sysmon_task_queue_fini(void)
120 mutex_enter(&sysmon_task_queue_mtx
);
122 sysmon_task_queue_cleanup_sem
= 1;
123 cv_signal(&sysmon_task_queue_cv
);
125 while (sysmon_task_queue_cleanup_sem
!= 0)
126 cv_wait(&sysmon_task_queue_cv
,
127 &sysmon_task_queue_mtx
);
129 mutex_exit(&sysmon_task_queue_mtx
);
133 * sysmon_task_queue_thread:
135 * The sysmon task queue execution thread. We execute callbacks that
136 * have been queued for us.
139 sysmon_task_queue_thread(void *arg
)
141 struct sysmon_task
*st
;
144 * Run through all the tasks before we check for the exit
145 * condition; it's probably more important to actually run
146 * all the tasks before we exit.
148 mutex_enter(&sysmon_task_queue_mtx
);
150 st
= TAILQ_FIRST(&sysmon_task_queue
);
152 TAILQ_REMOVE(&sysmon_task_queue
, st
, st_list
);
153 mutex_exit(&sysmon_task_queue_mtx
);
154 (*st
->st_func
)(st
->st_arg
);
156 mutex_enter(&sysmon_task_queue_mtx
);
158 /* Check for the exit condition. */
159 if (sysmon_task_queue_cleanup_sem
!= 0)
161 cv_wait(&sysmon_task_queue_cv
, &sysmon_task_queue_mtx
);
165 sysmon_task_queue_cleanup_sem
= 0;
166 cv_broadcast(&sysmon_task_queue_cv
);
167 mutex_exit(&sysmon_task_queue_mtx
);
172 * sysmon_task_queue_sched:
174 * Schedule a task for deferred execution.
177 sysmon_task_queue_sched(u_int pri
, void (*func
)(void *), void *arg
)
179 struct sysmon_task
*st
, *lst
;
181 if (sysmon_task_queue_lwp
== NULL
)
182 aprint_debug("WARNING: Callback scheduled before sysmon "
183 "task queue thread present\n");
188 st
= malloc(sizeof(*st
), M_TEMP
, M_NOWAIT
);
196 mutex_enter(&sysmon_task_queue_mtx
);
197 TAILQ_FOREACH(lst
, &sysmon_task_queue
, st_list
) {
198 if (st
->st_pri
> lst
->st_pri
) {
199 TAILQ_INSERT_BEFORE(lst
, st
, st_list
);
205 TAILQ_INSERT_TAIL(&sysmon_task_queue
, st
, st_list
);
207 cv_broadcast(&sysmon_task_queue_cv
);
208 mutex_exit(&sysmon_task_queue_mtx
);