Differential D36143 Diff 109199 sys/kern/subr_eventhandler.c

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sys/kern/subr_eventhandler.c

Show First 20 Lines • Show All 62 Lines • ▼ Show 20 Lines	eventhandler_init(void *dummy __unused)
TAILQ_INIT(&eventhandler_lists);		TAILQ_INIT(&eventhandler_lists);
mtx_init(&eventhandler_mutex, "eventhandler", NULL, MTX_DEF);		mtx_init(&eventhandler_mutex, "eventhandler", NULL, MTX_DEF);
atomic_store_rel_int(&eventhandler_lists_initted, 1);		atomic_store_rel_int(&eventhandler_lists_initted, 1);
}		}
SYSINIT(eventhandlers, SI_SUB_EVENTHANDLER, SI_ORDER_FIRST, eventhandler_init,		SYSINIT(eventhandlers, SI_SUB_EVENTHANDLER, SI_ORDER_FIRST, eventhandler_init,
NULL);		NULL);

static struct eventhandler_list *		static struct eventhandler_list *
eventhandler_find_or_create_list(const char *name)		eventhandler_find_or_create_list(const char name, epoch_t pepoch)
{		{
struct eventhandler_list list, new_list;		struct eventhandler_list list, new_list;

/* look for a matching, existing list */		/* look for a matching, existing list */
list = _eventhandler_find_list(name);		list = _eventhandler_find_list(name);

/* Do we need to create the list? */		/* Do we need to create the list? */
if (list == NULL) {		if (list == NULL) {
mtx_unlock(&eventhandler_mutex);		mtx_unlock(&eventhandler_mutex);

new_list = malloc(sizeof(*new_list) + strlen(name) + 1,		new_list = malloc(sizeof(*new_list) + strlen(name) + 1,
M_EVENTHANDLER, M_WAITOK \| M_ZERO);		M_EVENTHANDLER, M_WAITOK \| M_ZERO);

/* If someone else created it already, then use that one. */		/* If someone else created it already, then use that one. */
mtx_lock(&eventhandler_mutex);		mtx_lock(&eventhandler_mutex);
list = _eventhandler_find_list(name);		list = _eventhandler_find_list(name);
if (list != NULL) {		if (list != NULL) {
		/* Verify that both list definitions are the same */
		MPASS(list->el_pepoch == pepoch);
free(new_list, M_EVENTHANDLER);		free(new_list, M_EVENTHANDLER);
} else {		} else {
CTR2(KTR_EVH, "%s: creating list \"%s\"", __func__, name);		CTR2(KTR_EVH, "%s: creating list \"%s\"", __func__, name);
list = new_list;		list = new_list;
TAILQ_INIT(&list->el_entries);		CK_LIST_INIT(&list->el_entries);
list->el_name = (char *)(list + 1);		list->el_name = (char *)(list + 1);
		list->el_pepoch = pepoch;
strcpy(list->el_name, name);		strcpy(list->el_name, name);
mtx_init(&list->el_lock, list->el_name, "eventhandler list",		mtx_init(&list->el_lock, list->el_name, "eventhandler list",
MTX_DEF);		MTX_DEF);
TAILQ_INSERT_HEAD(&eventhandler_lists, list, el_link);		TAILQ_INSERT_HEAD(&eventhandler_lists, list, el_link);
}		}
}		}
return (list);		return (list);
}		}

/*		/*
* Insertion is O(n) due to the priority scan, but optimises to O(1)		* Insertion is O(n) due to the priority scan, but optimises to O(1)
* if all priorities are identical.		* if all priorities are identical.
*/		*/
static eventhandler_tag		static eventhandler_tag
eventhandler_register_internal(struct eventhandler_list *list,		eventhandler_register_internal(struct eventhandler_list *list,
const char *name, eventhandler_tag epn)		const char name, epoch_t pepoch, eventhandler_tag epn)
{		{
struct eventhandler_entry *ep;		struct eventhandler_entry ep, ep_last;

KASSERT(eventhandler_lists_initted, ("eventhandler registered too early"));		KASSERT(eventhandler_lists_initted, ("eventhandler registered too early"));
KASSERT(epn != NULL, ("%s: cannot register NULL event", __func__));		KASSERT(epn != NULL, ("%s: cannot register NULL event", __func__));

/* Do we need to find/create the list? */		/* Do we need to find/create the list? */
if (list == NULL) {		if (list == NULL) {
mtx_lock(&eventhandler_mutex);		mtx_lock(&eventhandler_mutex);
list = eventhandler_find_or_create_list(name);		list = eventhandler_find_or_create_list(name, pepoch);
mtx_unlock(&eventhandler_mutex);		mtx_unlock(&eventhandler_mutex);
}		}

KASSERT(epn->ee_priority != EHE_DEAD_PRIORITY,		KASSERT(epn->ee_priority != EHE_DEAD_PRIORITY,
("%s: handler for %s registered with dead priority", __func__, name));		("%s: handler for %s registered with dead priority", __func__, name));

/* sort it into the list */		/* sort it into the list */
CTR4(KTR_EVH, "%s: adding item %p (function %p) to \"%s\"", __func__, epn,		CTR4(KTR_EVH, "%s: adding item %p (function %p) to \"%s\"", __func__, epn,
((struct eventhandler_entry_generic *)epn)->func, name);		((struct eventhandler_entry_generic *)epn)->func, name);
EHL_LOCK(list);		EHL_LOCK(list);
TAILQ_FOREACH(ep, &list->el_entries, ee_link) {		ep_last = NULL;
		CK_LIST_FOREACH(ep, &list->el_entries, ee_link) {
if (ep->ee_priority != EHE_DEAD_PRIORITY &&		if (ep->ee_priority != EHE_DEAD_PRIORITY &&
epn->ee_priority < ep->ee_priority) {		epn->ee_priority < ep->ee_priority) {
TAILQ_INSERT_BEFORE(ep, epn, ee_link);		CK_LIST_INSERT_BEFORE(ep, epn, ee_link);
break;		break;
}		}
		ep_last = ep;
}		}
if (ep == NULL)		if (ep == NULL) {
TAILQ_INSERT_TAIL(&list->el_entries, epn, ee_link);		if (ep_last != NULL)
		CK_LIST_INSERT_AFTER(ep_last, epn, ee_link);
		else
		CK_LIST_INSERT_HEAD(&list->el_entries, epn, ee_link);
		}
EHL_UNLOCK(list);		EHL_UNLOCK(list);
return(epn);		return(epn);
}		}

eventhandler_tag		eventhandler_tag
eventhandler_register(struct eventhandler_list list, const char name,		eventhandler_register(struct eventhandler_list list, const char name,
void func, void arg, int priority)		void func, void arg, int priority)
{		{
		return (eventhandler_register_epoch(list, name, NULL, func, arg, priority));
		}

		eventhandler_tag
		eventhandler_register_epoch(struct eventhandler_list list, const char name,
		epoch_t pepoch, void func, void *arg, int priority)
		{
struct eventhandler_entry_generic *eg;		struct eventhandler_entry_generic *eg;

/* allocate an entry for this handler, populate it */		/* allocate an entry for this handler, populate it */
eg = malloc(sizeof(struct eventhandler_entry_generic), M_EVENTHANDLER,		eg = malloc(sizeof(struct eventhandler_entry_generic), M_EVENTHANDLER,
M_WAITOK \| M_ZERO);		M_WAITOK \| M_ZERO);
eg->func = func;		eg->func = func;
eg->ee.ee_arg = arg;		eg->ee.ee_arg = arg;
eg->ee.ee_priority = priority;		eg->ee.ee_priority = priority;

return (eventhandler_register_internal(list, name, &eg->ee));		return (eventhandler_register_internal(list, name, pepoch, &eg->ee));
}		}

#ifdef VIMAGE		#ifdef VIMAGE
struct eventhandler_entry_generic_vimage		struct eventhandler_entry_generic_vimage
{		{
struct eventhandler_entry ee;		struct eventhandler_entry ee;
vimage_iterator_func_t func; /* Vimage iterator function. */		vimage_iterator_func_t func; /* Vimage iterator function. */
struct eventhandler_entry_vimage v_ee; /* Original func, arg. */		struct eventhandler_entry_vimage v_ee; /* Original func, arg. */
Show All 9 Lines	vimage_eventhandler_register(struct eventhandler_list list, const char name,
eg = malloc(sizeof(struct eventhandler_entry_generic_vimage),		eg = malloc(sizeof(struct eventhandler_entry_generic_vimage),
M_EVENTHANDLER, M_WAITOK \| M_ZERO);		M_EVENTHANDLER, M_WAITOK \| M_ZERO);
eg->func = iterfunc;		eg->func = iterfunc;
eg->v_ee.func = func;		eg->v_ee.func = func;
eg->v_ee.ee_arg = arg;		eg->v_ee.ee_arg = arg;
eg->ee.ee_arg = &eg->v_ee;		eg->ee.ee_arg = &eg->v_ee;
eg->ee.ee_priority = priority;		eg->ee.ee_priority = priority;

return (eventhandler_register_internal(list, name, &eg->ee));		return (eventhandler_register_internal(list, name, NULL, &eg->ee));
}		}
#endif		#endif

static void		static void
		destroy_ep_epoch(epoch_context_t ctx)
		{
		struct eventhandler_entry *ep;

		ep = __containerof(ctx, struct eventhandler_entry, ee_epoch_ctx);

		free(ep, M_EVENTHANDLER);
		}

		static void
		free_list_item(struct eventhandler_list list, struct eventhandler_entry ep)
		{
		if (EHL_TYPE_EPOCH(list))
		epoch_call(*(list->el_pepoch), destroy_ep_epoch, &ep->ee_epoch_ctx);
		else
		free(ep, M_EVENTHANDLER);
		}

		static void
_eventhandler_deregister(struct eventhandler_list *list, eventhandler_tag tag,		_eventhandler_deregister(struct eventhandler_list *list, eventhandler_tag tag,
bool wait)		bool wait)
{		{
struct eventhandler_entry *ep = tag;		struct eventhandler_entry *ep = tag;

EHL_LOCK_ASSERT(list, MA_OWNED);		EHL_LOCK_ASSERT(list, MA_OWNED);
if (ep != NULL) {		if (ep != NULL) {
/* remove just this entry */		/* remove just this entry */
if (list->el_runcount == 0) {		if ((list->el_runcount == 0) \|\| EHL_TYPE_EPOCH(list)) {
CTR3(KTR_EVH, "%s: removing item %p from \"%s\"", __func__, ep,		CTR3(KTR_EVH, "%s: removing item %p from \"%s\"", __func__, ep,
list->el_name);		list->el_name);
TAILQ_REMOVE(&list->el_entries, ep, ee_link);		CK_LIST_REMOVE(ep, ee_link);
free(ep, M_EVENTHANDLER);		free_list_item(list, ep);
} else {		} else {
CTR3(KTR_EVH, "%s: marking item %p from \"%s\" as dead", __func__,		CTR3(KTR_EVH, "%s: marking item %p from \"%s\" as dead", __func__,
ep, list->el_name);		ep, list->el_name);
ep->ee_priority = EHE_DEAD_PRIORITY;		ep->ee_priority = EHE_DEAD_PRIORITY;
}		}
} else {		} else {
/* remove entire list */		/* remove entire list */
if (list->el_runcount == 0) {		if ((list->el_runcount == 0) \|\| EHL_TYPE_EPOCH(list)) {
CTR2(KTR_EVH, "%s: removing all items from \"%s\"", __func__,		CTR2(KTR_EVH, "%s: removing all items from \"%s\"", __func__,
list->el_name);		list->el_name);
while (!TAILQ_EMPTY(&list->el_entries)) {		while (!CK_LIST_EMPTY(&list->el_entries)) {
ep = TAILQ_FIRST(&list->el_entries);		ep = CK_LIST_FIRST(&list->el_entries);
TAILQ_REMOVE(&list->el_entries, ep, ee_link);		CK_LIST_REMOVE(ep, ee_link);
free(ep, M_EVENTHANDLER);		free_list_item(list, ep);
}		}
} else {		} else {
CTR2(KTR_EVH, "%s: marking all items from \"%s\" as dead",		CTR2(KTR_EVH, "%s: marking all items from \"%s\" as dead",
__func__, list->el_name);		__func__, list->el_name);
TAILQ_FOREACH(ep, &list->el_entries, ee_link)		CK_LIST_FOREACH(ep, &list->el_entries, ee_link)
ep->ee_priority = EHE_DEAD_PRIORITY;		ep->ee_priority = EHE_DEAD_PRIORITY;
}		}
}		}
while (wait && list->el_runcount > 0)		while (wait && list->el_runcount > 0)
mtx_sleep(list, &list->el_lock, 0, "evhrm", 0);		mtx_sleep(list, &list->el_lock, 0, "evhrm", 0);
EHL_UNLOCK(list);		EHL_UNLOCK(list);
}		}

▲ Show 20 Lines • Show All 53 Lines • ▼ Show 20 Lines
* Prune "dead" entries from an eventhandler list.		* Prune "dead" entries from an eventhandler list.
*/		*/
void		void
eventhandler_prune_list(struct eventhandler_list *list)		eventhandler_prune_list(struct eventhandler_list *list)
{		{
struct eventhandler_entry ep, en;		struct eventhandler_entry ep, en;
int pruned = 0;		int pruned = 0;

		if (EHL_TYPE_EPOCH(list))
		return;

CTR2(KTR_EVH, "%s: pruning list \"%s\"", __func__, list->el_name);		CTR2(KTR_EVH, "%s: pruning list \"%s\"", __func__, list->el_name);
EHL_LOCK_ASSERT(list, MA_OWNED);		EHL_LOCK_ASSERT(list, MA_OWNED);
TAILQ_FOREACH_SAFE(ep, &list->el_entries, ee_link, en) {		CK_LIST_FOREACH_SAFE(ep, &list->el_entries, ee_link, en) {
if (ep->ee_priority == EHE_DEAD_PRIORITY) {		if (ep->ee_priority == EHE_DEAD_PRIORITY) {
TAILQ_REMOVE(&list->el_entries, ep, ee_link);		CK_LIST_REMOVE(ep, ee_link);
free(ep, M_EVENTHANDLER);		free(ep, M_EVENTHANDLER);
pruned++;		pruned++;
}		}
}		}
if (pruned > 0)		if (pruned > 0)
wakeup(list);		wakeup(list);
}		}

/*		/*
* Create (or get the existing) list so the pointer can be stored by		* Create (or get the existing) list so the pointer can be stored by
* EVENTHANDLER_LIST_DEFINE.		* EVENTHANDLER_LIST_DEFINE.
*/		*/
struct eventhandler_list *		struct eventhandler_list *
eventhandler_create_list(const char *name)		eventhandler_create_list(const char *name)
{		{
		return (eventhandler_create_list_epoch(name, NULL));
		}

		struct eventhandler_list *
		eventhandler_create_list_epoch(const char name, epoch_t pepoch)
		{
struct eventhandler_list *list;		struct eventhandler_list *list;

KASSERT(eventhandler_lists_initted,		KASSERT(eventhandler_lists_initted,
("eventhandler list created too early"));		("eventhandler list created too early"));

mtx_lock(&eventhandler_mutex);		mtx_lock(&eventhandler_mutex);
list = eventhandler_find_or_create_list(name);		list = eventhandler_find_or_create_list(name, pepoch);
mtx_unlock(&eventhandler_mutex);		mtx_unlock(&eventhandler_mutex);

return (list);		return (list);
}		}