NetBSD/sys/net/npf/npf_worker.c

162 lines
4.1 KiB
C

/* $NetBSD: npf_worker.c,v 1.1 2013/06/02 02:20:04 rmind Exp $ */
/*-
* Copyright (c) 2010-2013 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This material is based upon work partially supported by The
* NetBSD Foundation under a contract with Mindaugas Rasiukevicius.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: npf_worker.c,v 1.1 2013/06/02 02:20:04 rmind Exp $");
#include <sys/param.h>
#include <sys/types.h>
#include <sys/mutex.h>
#include <sys/kernel.h>
#include <sys/kthread.h>
#include "npf_impl.h"
#define NPF_MAX_WORKS 4
#define WORKER_INTERVAL mstohz(5 * 1000)
static kmutex_t worker_lock;
static kcondvar_t worker_cv;
static kcondvar_t worker_event_cv;
static lwp_t * worker_lwp;
static uint64_t worker_loop;
static npf_workfunc_t work_funcs[NPF_MAX_WORKS];
static void npf_worker(void *) __dead;
int
npf_worker_sysinit(void)
{
mutex_init(&worker_lock, MUTEX_DEFAULT, IPL_SOFTNET);
cv_init(&worker_cv, "npfgccv");
cv_init(&worker_event_cv, "npfevcv");
worker_lwp = (lwp_t *)0xdeadbabe;
worker_loop = 1;
if (kthread_create(PRI_NONE, KTHREAD_MPSAFE | KTHREAD_MUSTJOIN, NULL,
npf_worker, NULL, &worker_lwp, "npfgc")) {
return ENOMEM;
}
return 0;
}
void
npf_worker_sysfini(void)
{
lwp_t *l = worker_lwp;
/* Notify the worker and wait for the exit. */
mutex_enter(&worker_lock);
worker_lwp = NULL;
cv_broadcast(&worker_cv);
mutex_exit(&worker_lock);
kthread_join(l);
/* LWP has exited, destroy the structures. */
cv_destroy(&worker_cv);
cv_destroy(&worker_event_cv);
mutex_destroy(&worker_lock);
}
void
npf_worker_signal(void)
{
mutex_enter(&worker_lock);
cv_signal(&worker_cv);
mutex_exit(&worker_lock);
}
static bool
npf_worker_testset(npf_workfunc_t find, npf_workfunc_t set)
{
for (u_int i = 0; i < NPF_MAX_WORKS; i++) {
if (work_funcs[i] == find) {
work_funcs[i] = set;
return true;
}
}
return false;
}
void
npf_worker_register(npf_workfunc_t func)
{
mutex_enter(&worker_lock);
npf_worker_testset(NULL, func);
mutex_exit(&worker_lock);
}
void
npf_worker_unregister(npf_workfunc_t func)
{
uint64_t l = worker_loop;
mutex_enter(&worker_lock);
npf_worker_testset(func, NULL);
while (worker_loop == l) {
cv_signal(&worker_cv);
cv_wait(&worker_event_cv, &worker_lock);
}
mutex_exit(&worker_lock);
}
static void
npf_worker(void *arg)
{
for (;;) {
const bool finish = (worker_lwp == NULL);
u_int i = NPF_MAX_WORKS;
npf_workfunc_t work;
/* Run the jobs. */
while (i--) {
if ((work = work_funcs[i]) != NULL) {
work();
}
}
/* Exit if requested and all jobs are done. */
if (finish) {
break;
}
/* Sleep and periodically wake up, unless we get notified. */
mutex_enter(&worker_lock);
worker_loop++;
cv_broadcast(&worker_event_cv);
cv_timedwait(&worker_cv, &worker_lock, WORKER_INTERVAL);
mutex_exit(&worker_lock);
}
kthread_exit(0);
}