freebsd-skq/sys/kern/subr_eventhandler.c
cem 3038f1af7b Include ktr.h in more compilation units
Similar to r348026, exhaustive search for uses of CTRn() and cross reference
ktr.h includes.  Where it was obvious that an OS compat header of some kind
included ktr.h indirectly, .c files were left alone.  Some of these files
clearly got ktr.h via header pollution in some scenarios, or tinderbox would
not be passing prior to this revision, but go ahead and explicitly include it
in files using it anyway.

Like r348026, these CUs did not show up in tinderbox as missing the include.

Reported by:	peterj (arm64/mp_machdep.c)
X-MFC-With:	r347984
Sponsored by:	Dell EMC Isilon
2019-05-21 20:38:48 +00:00

320 lines
9.2 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 1999 Michael Smith <msmith@freebsd.org>
* All rights reserved.
*
* 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 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/ktr.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/systm.h>
#include <sys/eventhandler.h>
static MALLOC_DEFINE(M_EVENTHANDLER, "eventhandler", "Event handler records");
/* List of all eventhandler lists */
static TAILQ_HEAD(, eventhandler_list) eventhandler_lists;
static int eventhandler_lists_initted = 0;
static struct mtx eventhandler_mutex;
struct eventhandler_entry_generic
{
struct eventhandler_entry ee;
void (* func)(void);
};
static struct eventhandler_list *_eventhandler_find_list(const char *name);
/*
* Initialize the eventhandler mutex and list.
*/
static void
eventhandler_init(void *dummy __unused)
{
TAILQ_INIT(&eventhandler_lists);
mtx_init(&eventhandler_mutex, "eventhandler", NULL, MTX_DEF);
atomic_store_rel_int(&eventhandler_lists_initted, 1);
}
SYSINIT(eventhandlers, SI_SUB_EVENTHANDLER, SI_ORDER_FIRST, eventhandler_init,
NULL);
static struct eventhandler_list *
eventhandler_find_or_create_list(const char *name)
{
struct eventhandler_list *list, *new_list;
/* look for a matching, existing list */
list = _eventhandler_find_list(name);
/* Do we need to create the list? */
if (list == NULL) {
mtx_unlock(&eventhandler_mutex);
new_list = malloc(sizeof(*new_list) + strlen(name) + 1,
M_EVENTHANDLER, M_WAITOK | M_ZERO);
/* If someone else created it already, then use that one. */
mtx_lock(&eventhandler_mutex);
list = _eventhandler_find_list(name);
if (list != NULL) {
free(new_list, M_EVENTHANDLER);
} else {
CTR2(KTR_EVH, "%s: creating list \"%s\"", __func__, name);
list = new_list;
TAILQ_INIT(&list->el_entries);
list->el_name = (char *)(list + 1);
strcpy(list->el_name, name);
mtx_init(&list->el_lock, list->el_name, "eventhandler list",
MTX_DEF);
TAILQ_INSERT_HEAD(&eventhandler_lists, list, el_link);
}
}
return (list);
}
/*
* Insertion is O(n) due to the priority scan, but optimises to O(1)
* if all priorities are identical.
*/
static eventhandler_tag
eventhandler_register_internal(struct eventhandler_list *list,
const char *name, eventhandler_tag epn)
{
struct eventhandler_entry *ep;
KASSERT(eventhandler_lists_initted, ("eventhandler registered too early"));
KASSERT(epn != NULL, ("%s: cannot register NULL event", __func__));
/* Do we need to find/create the list? */
if (list == NULL) {
mtx_lock(&eventhandler_mutex);
list = eventhandler_find_or_create_list(name);
mtx_unlock(&eventhandler_mutex);
}
KASSERT(epn->ee_priority != EHE_DEAD_PRIORITY,
("%s: handler for %s registered with dead priority", __func__, name));
/* sort it into the list */
CTR4(KTR_EVH, "%s: adding item %p (function %p) to \"%s\"", __func__, epn,
((struct eventhandler_entry_generic *)epn)->func, name);
EHL_LOCK(list);
TAILQ_FOREACH(ep, &list->el_entries, ee_link) {
if (ep->ee_priority != EHE_DEAD_PRIORITY &&
epn->ee_priority < ep->ee_priority) {
TAILQ_INSERT_BEFORE(ep, epn, ee_link);
break;
}
}
if (ep == NULL)
TAILQ_INSERT_TAIL(&list->el_entries, epn, ee_link);
EHL_UNLOCK(list);
return(epn);
}
eventhandler_tag
eventhandler_register(struct eventhandler_list *list, const char *name,
void *func, void *arg, int priority)
{
struct eventhandler_entry_generic *eg;
/* allocate an entry for this handler, populate it */
eg = malloc(sizeof(struct eventhandler_entry_generic), M_EVENTHANDLER,
M_WAITOK | M_ZERO);
eg->func = func;
eg->ee.ee_arg = arg;
eg->ee.ee_priority = priority;
return (eventhandler_register_internal(list, name, &eg->ee));
}
#ifdef VIMAGE
struct eventhandler_entry_generic_vimage
{
struct eventhandler_entry ee;
vimage_iterator_func_t func; /* Vimage iterator function. */
struct eventhandler_entry_vimage v_ee; /* Original func, arg. */
};
eventhandler_tag
vimage_eventhandler_register(struct eventhandler_list *list, const char *name,
void *func, void *arg, int priority, vimage_iterator_func_t iterfunc)
{
struct eventhandler_entry_generic_vimage *eg;
/* allocate an entry for this handler, populate it */
eg = malloc(sizeof(struct eventhandler_entry_generic_vimage),
M_EVENTHANDLER, M_WAITOK | M_ZERO);
eg->func = iterfunc;
eg->v_ee.func = func;
eg->v_ee.ee_arg = arg;
eg->ee.ee_arg = &eg->v_ee;
eg->ee.ee_priority = priority;
return (eventhandler_register_internal(list, name, &eg->ee));
}
#endif
static void
_eventhandler_deregister(struct eventhandler_list *list, eventhandler_tag tag,
bool wait)
{
struct eventhandler_entry *ep = tag;
EHL_LOCK_ASSERT(list, MA_OWNED);
if (ep != NULL) {
/* remove just this entry */
if (list->el_runcount == 0) {
CTR3(KTR_EVH, "%s: removing item %p from \"%s\"", __func__, ep,
list->el_name);
TAILQ_REMOVE(&list->el_entries, ep, ee_link);
free(ep, M_EVENTHANDLER);
} else {
CTR3(KTR_EVH, "%s: marking item %p from \"%s\" as dead", __func__,
ep, list->el_name);
ep->ee_priority = EHE_DEAD_PRIORITY;
}
} else {
/* remove entire list */
if (list->el_runcount == 0) {
CTR2(KTR_EVH, "%s: removing all items from \"%s\"", __func__,
list->el_name);
while (!TAILQ_EMPTY(&list->el_entries)) {
ep = TAILQ_FIRST(&list->el_entries);
TAILQ_REMOVE(&list->el_entries, ep, ee_link);
free(ep, M_EVENTHANDLER);
}
} else {
CTR2(KTR_EVH, "%s: marking all items from \"%s\" as dead",
__func__, list->el_name);
TAILQ_FOREACH(ep, &list->el_entries, ee_link)
ep->ee_priority = EHE_DEAD_PRIORITY;
}
}
while (wait && list->el_runcount > 0)
mtx_sleep(list, &list->el_lock, 0, "evhrm", 0);
EHL_UNLOCK(list);
}
void
eventhandler_deregister(struct eventhandler_list *list, eventhandler_tag tag)
{
_eventhandler_deregister(list, tag, true);
}
void
eventhandler_deregister_nowait(struct eventhandler_list *list,
eventhandler_tag tag)
{
_eventhandler_deregister(list, tag, false);
}
/*
* Internal version for use when eventhandler list is already locked.
*/
static struct eventhandler_list *
_eventhandler_find_list(const char *name)
{
struct eventhandler_list *list;
mtx_assert(&eventhandler_mutex, MA_OWNED);
TAILQ_FOREACH(list, &eventhandler_lists, el_link) {
if (!strcmp(name, list->el_name))
break;
}
return (list);
}
/*
* Lookup a "slow" list by name. Returns with the list locked.
*/
struct eventhandler_list *
eventhandler_find_list(const char *name)
{
struct eventhandler_list *list;
if (!eventhandler_lists_initted)
return(NULL);
/* scan looking for the requested list */
mtx_lock(&eventhandler_mutex);
list = _eventhandler_find_list(name);
if (list != NULL)
EHL_LOCK(list);
mtx_unlock(&eventhandler_mutex);
return(list);
}
/*
* Prune "dead" entries from an eventhandler list.
*/
void
eventhandler_prune_list(struct eventhandler_list *list)
{
struct eventhandler_entry *ep, *en;
int pruned = 0;
CTR2(KTR_EVH, "%s: pruning list \"%s\"", __func__, list->el_name);
EHL_LOCK_ASSERT(list, MA_OWNED);
TAILQ_FOREACH_SAFE(ep, &list->el_entries, ee_link, en) {
if (ep->ee_priority == EHE_DEAD_PRIORITY) {
TAILQ_REMOVE(&list->el_entries, ep, ee_link);
free(ep, M_EVENTHANDLER);
pruned++;
}
}
if (pruned > 0)
wakeup(list);
}
/*
* Create (or get the existing) list so the pointer can be stored by
* EVENTHANDLER_LIST_DEFINE.
*/
struct eventhandler_list *
eventhandler_create_list(const char *name)
{
struct eventhandler_list *list;
KASSERT(eventhandler_lists_initted,
("eventhandler list created too early"));
mtx_lock(&eventhandler_mutex);
list = eventhandler_find_or_create_list(name);
mtx_unlock(&eventhandler_mutex);
return (list);
}