Add kern/subr_eventhandler.c to resolve more symbols

1 files changed, 282 insertions, 0 deletions

diff --git a/freebsd/kern/subr_eventhandler.c b/freebsd/kern/subr_eventhandler.c
new file mode 100644
index 00000000..af6c6295
--- /dev/null
+++ b/freebsd/kern/subr_eventhandler.c
@@ -0,0 +1,282 @@
+#include <freebsd/machine/rtems-bsd-config.h>
+
+/*-
+ * 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 <freebsd/sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <freebsd/sys/param.h>
+#include <freebsd/sys/kernel.h>
+#include <freebsd/sys/lock.h>
+#include <freebsd/sys/malloc.h>
+#include <freebsd/sys/mutex.h>
+#include <freebsd/sys/proc.h>
+#include <freebsd/sys/systm.h>
+#include <freebsd/sys/eventhandler.h>
+
+static MALLOC_DEFINE(M_EVENTHANDLER, "eventhandler", "Event handler records");
+
+/* List of 'slow' 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);
+
+/* 
+ * 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_list		*new_list;
+    struct eventhandler_entry		*ep;
+    
+    KASSERT(eventhandler_lists_initted, ("eventhandler registered too early"));
+    KASSERT(epn != NULL, ("%s: cannot register NULL event", __func__));
+
+    /* lock the eventhandler lists */
+    mtx_lock(&eventhandler_mutex);
+
+    /* Do we need to find/create the (slow) list? */
+    if (list == NULL) {
+	/* 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(struct eventhandler_list) +
+		strlen(name) + 1, M_EVENTHANDLER, M_WAITOK);
+
+	    /* 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;
+		list->el_flags = 0;
+		list->el_runcount = 0;
+		bzero(&list->el_lock, sizeof(list->el_lock));
+		list->el_name = (char *)list + sizeof(struct eventhandler_list);
+		strcpy(list->el_name, name);
+		TAILQ_INSERT_HEAD(&eventhandler_lists, list, el_link);
+	    }
+	}
+    }
+    if (!(list->el_flags & EHL_INITTED)) {
+	TAILQ_INIT(&list->el_entries);
+	mtx_init(&list->el_lock, name, "eventhandler list", MTX_DEF);
+	atomic_store_rel_int(&list->el_flags, EHL_INITTED);
+    }
+    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
+
+void
+eventhandler_deregister(struct eventhandler_list *list, eventhandler_tag tag)
+{
+    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 (list->el_runcount > 0)
+	    mtx_sleep(list, &list->el_lock, 0, "evhrm", 0);
+    EHL_UNLOCK(list);
+}
+
+/*
+ * 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);
+}