/*-
* Copyright (c) 2002 Poul-Henning Kamp
* Copyright (c) 2002 Networks Associates Technology, Inc.
* All rights reserved.
*
* This software was developed for the FreeBSD Project by Poul-Henning Kamp
* and NAI Labs, the Security Research Division of Network Associates, Inc.
* under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
* DARPA CHATS research program.
*
* 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.
* 3. The names of the authors may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*
* $FreeBSD$
*/
/*
* XXX: How do we in general know that objects referenced in events
* have not been destroyed before we get around to handle the event ?
*/
#include <sys/param.h>
#include <sys/malloc.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/eventhandler.h>
#include <machine/stdarg.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <geom/geom.h>
#include <geom/geom_int.h>
static struct event_tailq_head g_events = TAILQ_HEAD_INITIALIZER(g_events);
static u_int g_pending_events;
static void g_do_event(struct g_event *ep);
static TAILQ_HEAD(,g_provider) g_doorstep = TAILQ_HEAD_INITIALIZER(g_doorstep);
static struct mtx g_eventlock;
static struct sx g_eventstall;
static int g_shutdown;
void
g_waitidle(void)
{
while (g_pending_events)
tsleep(&g_pending_events, PPAUSE, "g_waitidle", hz/5);
}
void
g_stall_events(void)
{
sx_xlock(&g_eventstall);
}
void
g_release_events(void)
{
sx_xunlock(&g_eventstall);
}
void
g_orphan_provider(struct g_provider *pp, int error)
{
g_trace(G_T_TOPOLOGY, "g_orphan_provider(%p(%s), %d)",
pp, pp->name, error);
KASSERT(error != 0,
("g_orphan_provider(%p(%s), 0) error must be non-zero\n",
pp, pp->name));
pp->error = error;
mtx_lock(&g_eventlock);
TAILQ_INSERT_TAIL(&g_doorstep, pp, orphan);
mtx_unlock(&g_eventlock);
wakeup(&g_wait_event);
}
/*
* This function is called once on each provider which the event handler
* finds on its g_doorstep.
*/
static void
g_orphan_register(struct g_provider *pp)
{
struct g_consumer *cp, *cp2;
g_trace(G_T_TOPOLOGY, "g_orphan_register(%s)", pp->name);
g_topology_assert();
/*
* Tell all consumers the bad news.
* Don't be surprised if they self-destruct.
*/
cp = LIST_FIRST(&pp->consumers);
while (cp != NULL) {
cp2 = LIST_NEXT(cp, consumers);
KASSERT(cp->geom->orphan != NULL,
("geom %s has no orphan, class %s",
cp->geom->name, cp->geom->class->name));
cp->geom->orphan(cp);
cp = cp2;
}
#ifdef notyet
cp = LIST_FIRST(&pp->consumers);
if (cp != NULL)
return;
if (pp->geom->flags & G_GEOM_WITHER)
g_destroy_provider(pp);
#endif
}
static void
g_destroy_event(struct g_event *ep)
{
g_free(ep);
}
static void
g_do_event(struct g_event *ep)
{
struct g_class *mp, *mp2;
struct g_geom *gp;
struct g_consumer *cp, *cp2;
struct g_provider *pp;
int i;
g_trace(G_T_TOPOLOGY, "g_do_event(%p) %d - ", ep, ep->event);
g_topology_assert();
switch (ep->event) {
case EV_CALL_ME:
ep->func(ep->arg, 0);
g_topology_assert();
break;
case EV_NEW_CLASS:
if (g_shutdown)
break;
mp2 = ep->ref[0];
if (mp2->taste == NULL)
break;
LIST_FOREACH(mp, &g_classes, class) {
if (mp2 == mp)
continue;
LIST_FOREACH(gp, &mp->geom, geom) {
LIST_FOREACH(pp, &gp->provider, provider) {
mp2->taste(mp2, pp, 0);
g_topology_assert();
}
}
}
break;
case EV_NEW_PROVIDER:
if (g_shutdown)
break;
pp = ep->ref[0];
g_trace(G_T_TOPOLOGY, "EV_NEW_PROVIDER(%s)", pp->name);
LIST_FOREACH(mp, &g_classes, class) {
if (mp->taste == NULL)
continue;
i = 1;
LIST_FOREACH(cp, &pp->consumers, consumers)
if(cp->geom->class == mp)
i = 0;
if (i) {
mp->taste(mp, pp, 0);
g_topology_assert();
}
}
break;
case EV_SPOILED:
pp = ep->ref[0];
g_trace(G_T_TOPOLOGY, "EV_SPOILED(%p(%s),%p)",
pp, pp->name, ep->ref[1]);
cp = LIST_FIRST(&pp->consumers);
while (cp != NULL) {
cp2 = LIST_NEXT(cp, consumers);
if (cp->spoiled) {
g_trace(G_T_TOPOLOGY, "spoiling %p (%s) (%p)",
cp, cp->geom->name, cp->geom->spoiled);
if (cp->geom->spoiled != NULL)
cp->geom->spoiled(cp);
else
cp->spoiled = 0;
}
cp = cp2;
}
break;
case EV_LAST:
default:
KASSERT(1 == 0, ("Unknown event %d", ep->event));
}
}
static int
one_event(void)
{
struct g_event *ep;
struct g_provider *pp;
sx_xlock(&g_eventstall);
g_topology_lock();
for (;;) {
mtx_lock(&g_eventlock);
pp = TAILQ_FIRST(&g_doorstep);
if (pp != NULL)
TAILQ_REMOVE(&g_doorstep, pp, orphan);
mtx_unlock(&g_eventlock);
if (pp == NULL)
break;
g_orphan_register(pp);
}
mtx_lock(&g_eventlock);
ep = TAILQ_FIRST(&g_events);
if (ep == NULL) {
mtx_unlock(&g_eventlock);
g_topology_unlock();
sx_xunlock(&g_eventstall);
return (0);
}
TAILQ_REMOVE(&g_events, ep, events);
mtx_unlock(&g_eventlock);
g_do_event(ep);
g_destroy_event(ep);
g_pending_events--;
if (g_pending_events == 0)
wakeup(&g_pending_events);
g_topology_unlock();
sx_xunlock(&g_eventstall);
return (1);
}
void
g_run_events()
{
while (one_event())
;
}
void
g_post_event(enum g_events ev, ...)
{
struct g_event *ep;
va_list ap;
void *p;
int n;
g_trace(G_T_TOPOLOGY, "g_post_event(%d)", ev);
g_topology_assert();
ep = g_malloc(sizeof *ep, M_WAITOK | M_ZERO);
ep->event = ev;
va_start(ap, ev);
for (n = 0; n < G_N_EVENTREFS; n++) {
p = va_arg(ap, void *);
if (p == NULL)
break;
g_trace(G_T_TOPOLOGY, " ref %p", p);
ep->ref[n] = p;
}
va_end(ap);
KASSERT(p == NULL, ("Too many references to event"));
mtx_lock(&g_eventlock);
g_pending_events++;
TAILQ_INSERT_TAIL(&g_events, ep, events);
mtx_unlock(&g_eventlock);
wakeup(&g_wait_event);
}
void
g_cancel_event(void *ref)
{
struct g_event *ep, *epn;
u_int n;
mtx_lock(&g_eventlock);
for (ep = TAILQ_FIRST(&g_events); ep != NULL; ep = epn) {
epn = TAILQ_NEXT(ep, events);
for (n = 0; n < G_N_EVENTREFS; n++) {
if (ep->ref[n] == NULL)
break;
if (ep->ref[n] == ref) {
TAILQ_REMOVE(&g_events, ep, events);
if (ep->event == EV_CALL_ME)
ep->func(ep->arg, EV_CANCEL);
g_free(ep);
break;
}
}
}
mtx_unlock(&g_eventlock);
}
int
g_call_me(g_call_me_t *func, void *arg, ...)
{
struct g_event *ep;
va_list ap;
void *p;
u_int n;
g_trace(G_T_TOPOLOGY, "g_call_me(%p, %p", func, arg);
ep = g_malloc(sizeof *ep, M_NOWAIT | M_ZERO);
if (ep == NULL)
return (ENOMEM);
va_start(ap, arg);
for (n = 0; n < G_N_EVENTREFS; n++) {
p = va_arg(ap, void *);
if (p == NULL)
break;
g_trace(G_T_TOPOLOGY, " ref %p", p);
ep->ref[n++] = p;
}
va_end(ap);
KASSERT(p == NULL, ("Too many references to event"));
ep->event = EV_CALL_ME;
ep->func = func;
ep->arg = arg;
mtx_lock(&g_eventlock);
g_pending_events++;
TAILQ_INSERT_TAIL(&g_events, ep, events);
mtx_unlock(&g_eventlock);
wakeup(&g_wait_event);
return (0);
}
static void
geom_shutdown(void *foo __unused)
{
g_shutdown = 1;
}
void
g_event_init()
{
EVENTHANDLER_REGISTER(shutdown_pre_sync, geom_shutdown, NULL,
SHUTDOWN_PRI_FIRST);
mtx_init(&g_eventlock, "GEOM orphanage", NULL, MTX_DEF);
sx_init(&g_eventstall, "GEOM event stalling");
}
