lib/nwamd/events.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
 */

#include <atomic.h>
#include <errno.h>
#include <execinfo.h>
#include <libuutil.h>
#include <pthread.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <syslog.h>
#include <sys/time.h>
#include <unistd.h>

#include "conditions.h"
#include "events.h"
#include "objects.h"
#include "util.h"

/*
 * events.c - contains routines which create/destroy event sources,
 * handle the event queue and process events from that queue.
 */

/* Add new event sources here. */
struct nwamd_event_source {
    char *name;
    void (*events_init)(void);
    void (*events_fini)(void);
} event_sources[] = {
    { "routing_events",
    nwamd_routing_events_init, nwamd_routing_events_fini },
    { "sysevent_events",
    nwamd_sysevent_events_init, nwamd_sysevent_events_fini },
};

/* Counter for event ids */
static uint64_t event_id_counter = 0;

static uu_list_pool_t *event_pool = NULL;
static uu_list_t *event_queue = NULL;
static pthread_mutex_t event_queue_mutex = PTHREAD_MUTEX_INITIALIZER;
static pthread_cond_t event_queue_cond = PTHREAD_COND_INITIALIZER;

static int nwamd_event_compare(const void *, const void *, void *);

static const char *
nwamd_event_name(int event_type)
{
    if (event_type <= NWAM_EVENT_MAX)
        return (nwam_event_type_to_string(event_type));

    switch (event_type) {
    case NWAM_EVENT_TYPE_OBJECT_INIT:
        return ("OBJECT_INIT");
    case NWAM_EVENT_TYPE_OBJECT_FINI:
        return ("OBJECT_FINI");
    case NWAM_EVENT_TYPE_TIMED_CHECK_CONDITIONS:
        return ("TIMED_CHECK_CONDITIONS");
    case NWAM_EVENT_TYPE_TRIGGERED_CHECK_CONDITIONS:
        return ("TRIGGERED_CHECK_CONDITIONS");
    case NWAM_EVENT_TYPE_NCU_CHECK:
        return ("NCU_CHECK");
    case NWAM_EVENT_TYPE_TIMER:
        return ("TIMER");
    case NWAM_EVENT_TYPE_UPGRADE:
        return ("UPGRADE");
    case NWAM_EVENT_TYPE_PERIODIC_SCAN:
        return ("PERIODIC_SCAN");
    case NWAM_EVENT_TYPE_QUEUE_QUIET:
        return ("QUEUE_QUIET");
    default:
        return ("N/A");
    }
}

void
nwamd_event_sources_init(void)
{
    int i;

    /*
     * Now we can safely initialize event sources.
     */
    for (i = 0;
        i < sizeof (event_sources) / sizeof (struct nwamd_event_source);
        i++) {
        if (event_sources[i].events_init != NULL)
            event_sources[i].events_init();
    }
}

void
nwamd_event_sources_fini(void)
{
    int i;

    for (i = 0;
        i < sizeof (event_sources) / sizeof (struct nwamd_event_source);
        i++) {
        if (event_sources[i].events_init != NULL)
            event_sources[i].events_fini();
    }
}

/*
 * Comparison function for events, passed in as callback to
 * uu_list_pool_create(). Compare by time, so that timer
 * event queue can be sorted by nearest time to present.
 */
/* ARGSUSED */
static int
nwamd_event_compare(const void *l_arg, const void *r_arg, void *private)
{
    nwamd_event_t l = (nwamd_event_t)l_arg;
    nwamd_event_t r = (nwamd_event_t)r_arg;
    int rv;

    rv = l->event_time.tv_sec - r->event_time.tv_sec;
    if (rv == 0)
        rv = l->event_time.tv_nsec - r->event_time.tv_nsec;

    return (rv);
}

void
nwamd_event_queue_init(void)
{
    event_pool = uu_list_pool_create("event_queue_pool",
        sizeof (struct nwamd_event),
        offsetof(struct nwamd_event, event_node),
        nwamd_event_compare, UU_LIST_POOL_DEBUG);
    if (event_pool == NULL)
        pfail("uu_list_pool_create failed with error %d", uu_error());
    event_queue = uu_list_create(event_pool, NULL, UU_LIST_SORTED);
    if (event_queue == NULL)
        pfail("uu_list_create failed with error %d", uu_error());
}

void
nwamd_event_queue_fini(void)
{
    void *cookie = NULL;
    nwamd_event_t event;

    while ((event = uu_list_teardown(event_queue, &cookie)) != NULL)
        nwamd_event_fini(event);
    uu_list_destroy(event_queue);
    if (event_pool != NULL)
        uu_list_pool_destroy(event_pool);
}

nwamd_event_t
nwamd_event_init(int32_t type, nwam_object_type_t object_type,
    size_t size, const char *object_name)
{
    nwamd_event_t event;

    event = calloc(1, sizeof (struct nwamd_event));
    if (event == NULL) {
        nlog(LOG_ERR, "nwamd_event_init: could not create %s event for "
            "object %s", nwamd_event_name(type),
            object_name != NULL ? object_name : "<no object>");
        return (NULL);
    }

    /* Is this an externally-visible event? */
    if (type <= NWAM_EVENT_MAX) {
        event->event_send = B_TRUE;
        event->event_msg = calloc(1, sizeof (struct nwam_event) + size);
        if (event->event_msg == NULL) {
            nlog(LOG_ERR,
                "nwamd_event_init: could not create %s event",
                nwamd_event_name(type));
            free(event);
            return (NULL);
        }
        event->event_msg->nwe_type = type;
        event->event_msg->nwe_size = sizeof (struct nwam_event) + size;
    } else {
        event->event_send = B_FALSE;
        event->event_msg = NULL;
    }

    event->event_type = type;

    if (object_name != NULL) {
        (void) strlcpy(event->event_object, object_name,
            NWAM_MAX_NAME_LEN);
        event->event_object_type = object_type;
    } else {
        event->event_object[0] = '\0';
    }

    /* Set event id */
    event->event_id = atomic_add_64_nv(&event_id_counter, 1);
    (void) clock_gettime(CLOCK_REALTIME, &event->event_time);

    return (event);
}

void
nwamd_event_do_not_send(nwamd_event_t event)
{
    nlog(LOG_DEBUG, "nwamd_event_do_not_send: cancelling delivery of "
        "event %s for object %s", nwamd_event_name(event->event_type),
        event->event_object[0] != '\0' ?
        event->event_object : "<no object>");
    event->event_send = B_FALSE;
}

void
nwamd_event_fini(nwamd_event_t event)
{
    if (event != NULL) {
        free(event->event_msg);
        free(event);
    }
}

nwamd_event_t
nwamd_event_init_object_action(nwam_object_type_t object_type,
    const char *object_name, const char *parent_name,
    nwam_action_t object_action)
{
    nwamd_event_t event;

    event = nwamd_event_init(NWAM_EVENT_TYPE_OBJECT_ACTION,
        object_type, 0, object_name);
    if (event == NULL)
        return (NULL);

    event->event_msg->nwe_data.nwe_object_action.nwe_action = object_action;
    event->event_msg->nwe_data.nwe_object_action.nwe_object_type =
        object_type;
    (void) strlcpy(event->event_msg->nwe_data.nwe_object_action.nwe_name,
        object_name,
        sizeof (event->event_msg->nwe_data.nwe_object_action.nwe_name));
    if (parent_name == NULL) {
        event->event_msg->nwe_data.nwe_object_action.nwe_parent[0] =
            '\0';
        return (event);
    }
    (void) strlcpy
        (event->event_msg->nwe_data.nwe_object_action.nwe_parent,
        parent_name,
        sizeof (event->event_msg->nwe_data.nwe_object_action.nwe_parent));
    return (event);
}

nwamd_event_t
nwamd_event_init_object_state(nwam_object_type_t object_type,
    const char *object_name, nwam_state_t state, nwam_aux_state_t aux_state)
{
    nwamd_event_t event;

    event = nwamd_event_init(NWAM_EVENT_TYPE_OBJECT_STATE,
        object_type, 0, object_name);
    if (event == NULL)
        return (NULL);

    event->event_msg->nwe_data.nwe_object_state.nwe_state = state;
    event->event_msg->nwe_data.nwe_object_state.nwe_aux_state = aux_state;
    event->event_msg->nwe_data.nwe_object_state.nwe_object_type =
        object_type;
    (void) strlcpy(event->event_msg->nwe_data.nwe_object_state.nwe_name,
        object_name,
        sizeof (event->event_msg->nwe_data.nwe_object_state.nwe_name));

    return (event);
}

nwamd_event_t
nwamd_event_init_priority_group_change(int64_t priority)
{
    nwamd_event_t event;

    event = nwamd_event_init(NWAM_EVENT_TYPE_PRIORITY_GROUP,
        NWAM_OBJECT_TYPE_UNKNOWN, 0, NULL);
    if (event == NULL)
        return (NULL);

    event->event_msg->nwe_data.nwe_priority_group_info.nwe_priority =
        priority;

    return (event);
}

nwamd_event_t
nwamd_event_init_link_action(const char *name, nwam_action_t link_action)
{
    nwamd_event_t event;
    nwam_error_t err;
    char *object_name;

    if ((err = nwam_ncu_name_to_typed_name(name, NWAM_NCU_TYPE_LINK,
        &object_name)) != NWAM_SUCCESS) {
        nlog(LOG_ERR, "nwamd_event_init_link_action: "
            "nwam_ncu_name_to_typed_name: %s",
            nwam_strerror(err));
        return (NULL);
    }
    event = nwamd_event_init(NWAM_EVENT_TYPE_LINK_ACTION,
        NWAM_OBJECT_TYPE_NCU, 0, object_name);
    free(object_name);
    if (event == NULL)
        return (NULL);

    (void) strlcpy(event->event_msg->nwe_data.nwe_link_action.nwe_name,
        name,
        sizeof (event->event_msg->nwe_data.nwe_link_action.nwe_name));
    event->event_msg->nwe_data.nwe_link_action.nwe_action = link_action;

    return (event);
}

nwamd_event_t
nwamd_event_init_link_state(const char *name, boolean_t up)
{
    nwamd_event_t event;
    nwam_error_t err;
    char *object_name;

    if ((err = nwam_ncu_name_to_typed_name(name, NWAM_NCU_TYPE_LINK,
        &object_name)) != NWAM_SUCCESS) {
        nlog(LOG_ERR, "nwamd_event_init_link_state: "
            "nwam_ncu_name_to_typed_name: %s",
            nwam_strerror(err));
        return (NULL);
    }

    event = nwamd_event_init(NWAM_EVENT_TYPE_LINK_STATE,
        NWAM_OBJECT_TYPE_NCU, 0, object_name);
    free(object_name);
    if (event == NULL)
        return (NULL);

    (void) strlcpy(event->event_msg->nwe_data.nwe_link_state.nwe_name, name,
        sizeof (event->event_msg->nwe_data.nwe_link_state.nwe_name));
    event->event_msg->nwe_data.nwe_link_state.nwe_link_up = up;

    return (event);
}

nwamd_event_t
nwamd_event_init_if_state(const char *linkname, uint32_t flags,
    uint32_t addr_added, struct sockaddr *addr, struct sockaddr *netmask)
{
    nwamd_event_t event;
    nwam_error_t err;
    char *object_name;

    /* linkname does not contain the lifnum */
    if ((err = nwam_ncu_name_to_typed_name(linkname,
        NWAM_NCU_TYPE_INTERFACE, &object_name)) != NWAM_SUCCESS) {
        nlog(LOG_ERR, "nwamd_event_init_if_state: "
            "nwam_ncu_name_to_typed_name: %s",
            nwam_strerror(err));
        return (NULL);
    }

    event = nwamd_event_init(NWAM_EVENT_TYPE_IF_STATE,
        NWAM_OBJECT_TYPE_NCU, 0, object_name);
    free(object_name);
    if (event == NULL)
        return (NULL);

    (void) strlcpy(event->event_msg->nwe_data.nwe_if_state.nwe_name,
        linkname,
        sizeof (event->event_msg->nwe_data.nwe_if_state.nwe_name));
    event->event_msg->nwe_data.nwe_if_state.nwe_flags = flags;
    event->event_msg->nwe_data.nwe_if_state.nwe_addr_added = addr_added;
    event->event_msg->nwe_data.nwe_if_state.nwe_addr_valid = (addr != NULL);

    if (addr != NULL) {
        bcopy(addr, &(event->event_msg->nwe_data.nwe_if_state.nwe_addr),
            addr->sa_family == AF_INET ? sizeof (struct sockaddr_in) :
            sizeof (struct sockaddr_in6));
    }
    if (netmask != NULL) {
        bcopy(netmask,
            &(event->event_msg->nwe_data.nwe_if_state.nwe_netmask),
            netmask->sa_family == AF_INET ?
            sizeof (struct sockaddr_in) : sizeof (struct sockaddr_in6));
    }

    return (event);
}

nwamd_event_t
nwamd_event_init_wlan(const char *name, int32_t type, boolean_t connected,
    nwam_wlan_t *wlans, uint_t num_wlans)
{
    size_t size = 0;
    char *object_name;
    nwamd_event_t event;
    nwam_error_t err;

    switch (type) {
    case NWAM_EVENT_TYPE_WLAN_SCAN_REPORT:
    case NWAM_EVENT_TYPE_WLAN_NEED_CHOICE:
        size = sizeof (nwam_wlan_t) * (num_wlans - 1);
        break;
    case NWAM_EVENT_TYPE_WLAN_NEED_KEY:
    case NWAM_EVENT_TYPE_WLAN_CONNECTION_REPORT:
        break;
    default:
        nlog(LOG_ERR, "nwamd_event_init_wlan: unexpected "
            "event type %s (%d)", nwamd_event_name(type), type);
        return (NULL);
    }
    if ((err = nwam_ncu_name_to_typed_name(name, NWAM_NCU_TYPE_LINK,
        &object_name)) != NWAM_SUCCESS) {
        nlog(LOG_ERR, "nwamd_event_init_wlan: "
            "nwam_ncu_name_to_typed_name: %s",
            nwam_strerror(err));
        return (NULL);
    }

    event = nwamd_event_init(type, NWAM_OBJECT_TYPE_NCU, size, object_name);
    free(object_name);
    if (event == NULL)
        return (NULL);

    (void) strlcpy(event->event_msg->nwe_data.nwe_wlan_info.nwe_name, name,
        sizeof (event->event_msg->nwe_data.nwe_wlan_info.nwe_name));
    event->event_msg->nwe_data.nwe_wlan_info.nwe_connected = connected;
    event->event_msg->nwe_data.nwe_wlan_info.nwe_num_wlans = num_wlans;

    /* copy the wlans */
    (void) memcpy(event->event_msg->nwe_data.nwe_wlan_info.nwe_wlans, wlans,
        num_wlans * sizeof (nwam_wlan_t));

    return (event);
}

nwamd_event_t
nwamd_event_init_ncu_check(void)
{
    return (nwamd_event_init(NWAM_EVENT_TYPE_NCU_CHECK,
        NWAM_OBJECT_TYPE_NCP, 0, NULL));
}

nwamd_event_t
nwamd_event_init_init(void)
{
    return (nwamd_event_init(NWAM_EVENT_TYPE_INIT,
        NWAM_OBJECT_TYPE_UNKNOWN, 0, NULL));
}

nwamd_event_t
nwamd_event_init_shutdown(void)
{
    return (nwamd_event_init(NWAM_EVENT_TYPE_SHUTDOWN,
        NWAM_OBJECT_TYPE_UNKNOWN, 0, NULL));
}

/*
 * Add event to the event list.
 */
void
nwamd_event_enqueue(nwamd_event_t event)
{
    nwamd_event_enqueue_timed(event, 0);
}

/*
 * Schedule an event to be added to the event list for future processing.
 * The event will be scheduled in delta_seconds seconds mod schedule delay and
 * time resolution.
 */
void
nwamd_event_enqueue_timed(nwamd_event_t event, int delta_seconds)
{
    uu_list_index_t idx;

    nlog(LOG_DEBUG, "enqueueing event %lld %d (%s) for object %s in %ds",
        event->event_id, event->event_type,
        nwamd_event_name(event->event_type),
        event->event_object[0] != 0 ?  event->event_object : "none",
        delta_seconds);

    (void) clock_gettime(CLOCK_REALTIME, &event->event_time);
    event->event_time.tv_sec += delta_seconds;

    uu_list_node_init(event, &event->event_node, event_pool);

    (void) pthread_mutex_lock(&event_queue_mutex);

    /*
     * Find appropriate location to insert the event based on time.
     */
    (void) uu_list_find(event_queue, event, NULL, &idx);
    (void) uu_list_insert(event_queue, event, idx);

    (void) pthread_cond_signal(&event_queue_cond);
    (void) pthread_mutex_unlock(&event_queue_mutex);
}

/*
 * Is the specified event enqueued on the event (or pending event queue)
 * for execution in when seconds? An object may be specified also.
 */
boolean_t
nwamd_event_enqueued(int32_t event_type, nwam_object_type_t object_type,
    const char *object)
{
    nwamd_event_t event;

    (void) pthread_mutex_lock(&event_queue_mutex);
    for (event = uu_list_first(event_queue);
        event != NULL;
        event = uu_list_next(event_queue, event)) {
        if (event->event_type != event_type)
            continue;
        if (object_type != NWAM_OBJECT_TYPE_UNKNOWN &&
            event->event_object_type != object_type)
            continue;
        if (object != NULL && strcmp(object, event->event_object) != 0)
            continue;
        (void) pthread_mutex_unlock(&event_queue_mutex);
        return (B_TRUE);
    }
    (void) pthread_mutex_unlock(&event_queue_mutex);

    return (B_FALSE);
}

/*
 * Is the time in the past.
 */
static boolean_t
in_past(struct timespec t)
{
    struct timespec now;

    (void) clock_gettime(CLOCK_REALTIME, &now);
    if (t.tv_sec < now.tv_sec)
        return (B_TRUE);
    if (t.tv_sec > now.tv_sec)
        return (B_FALSE);
    if (t.tv_nsec < now.tv_nsec)
        return (B_TRUE);
    return (B_FALSE);
}

/*
 * Remove event at head of event list for processing.  This takes a number of
 * nanoseconds to wait.  If the number is 0 then it blocks.  If there is
 * nothing on the queue then it returns an event which says that the queue
 * is quiet.
 */
static nwamd_event_t
nwamd_event_dequeue(long nsec)
{
    nwamd_event_t event;

    (void) pthread_mutex_lock(&event_queue_mutex);
    event = uu_list_first(event_queue);
    if (event == NULL && nsec == 0) {
        do {
            (void) pthread_cond_wait(&event_queue_cond,
                &event_queue_mutex);
        } while ((event = uu_list_first(event_queue)) == NULL);
    } else {
        struct timespec waitcap;

        if (nsec != 0) {
            (void) clock_gettime(CLOCK_REALTIME, &waitcap);
            waitcap.tv_nsec += nsec;
            waitcap.tv_sec += NSEC_TO_SEC(waitcap.tv_nsec);
            waitcap.tv_nsec = NSEC_TO_FRACNSEC(waitcap.tv_nsec);
        }

        /*
         * Keep going as long as the first event hasn't matured and
         * we havn't passed our maximum wait time.
         */
        while ((event == NULL || !in_past(event->event_time)) &&
            (nsec == 0 || !in_past(waitcap)))  {
            struct timespec eventwait;

            /*
             * Three cases:
             *  no maximum waittime - just use the event
             *  both an event and cap - take the least one
             *  just a maximum waittime - use it
             */
            if (nsec == 0) {
                eventwait = event->event_time;
            } else if (event != NULL) {
                uint64_t diff;
                diff = SEC_TO_NSEC(event->event_time.tv_sec -
                    waitcap.tv_sec) +
                    event->event_time.tv_nsec - waitcap.tv_nsec;

                if (diff > 0)
                    eventwait = waitcap;
                else
                    eventwait = event->event_time;
            } else {
                /*
                 * Note that if the event is NULL then nsec is
                 * nonzero and waitcap is valid.
                 */
                eventwait = waitcap;
            }

            (void) pthread_cond_timedwait(&event_queue_cond,
                &event_queue_mutex, &eventwait);
            event = uu_list_first(event_queue);
        }
    }

    /*
     * At this point we've met the guard contition of the while loop.
     * The event at the top of the queue might be mature in which case
     * we use it.  Otherwise we hit our cap and we need to enqueue a
     * quiesced queue event.
     */
    if (event != NULL && in_past(event->event_time)) {
        uu_list_remove(event_queue, event);
        uu_list_node_fini(event, &event->event_node, event_pool);
    } else {
        event = nwamd_event_init(NWAM_EVENT_TYPE_QUEUE_QUIET,
            NWAM_OBJECT_TYPE_UNKNOWN, 0, NULL);
    }

    if (event != NULL)
        nlog(LOG_DEBUG,
            "dequeueing event %lld of type %d (%s) for object %s",
            event->event_id, event->event_type,
            nwamd_event_name(event->event_type),
            event->event_object[0] != 0 ?  event->event_object :
            "none");

    (void) pthread_mutex_unlock(&event_queue_mutex);

    return (event);
}

void
nwamd_event_send(nwam_event_t event_msg)
{
    nwam_error_t err;

    if (shutting_down && event_msg->nwe_type != NWAM_EVENT_TYPE_SHUTDOWN) {
        nlog(LOG_DEBUG, "nwamd_event_send: tossing event as nwamd "
            "is shutting down");
        return;
    }

    err = nwam_event_send(event_msg);

    if (err != NWAM_SUCCESS) {
        nlog(LOG_ERR, "nwamd_event_send: nwam_event_send: %s",
            nwam_strerror(err));
    }
}

/*
 * Run state machine for object. Method is run if
 * - event method is non-null
 * - event method is valid for current object state (determined by
 * ORing the current state against the set of valid states for the method).
 *
 * If these criteria are met, the method is run.
 */
static void
nwamd_event_run_method(nwamd_event_t event)
{
    nwamd_event_method_t *event_methods;
    int i;

    event_methods = nwamd_object_event_methods(event->event_object_type);

    /* If we're shutting down, only fini events are accepted for objects */
    if (shutting_down && event->event_type != NWAM_EVENT_TYPE_OBJECT_FINI) {
        nlog(LOG_DEBUG, "nwamd_event_run_method: tossing non-fini "
            "event %s for object %s",
            nwamd_event_name(event->event_type), event->event_object);
        return;
    }

    for (i = 0;
        event_methods[i].event_type != NWAM_EVENT_TYPE_NOOP;
        i++) {
        if (event_methods[i].event_type ==
            event->event_type &&
            event_methods[i].event_method != NULL) {
            nlog(LOG_DEBUG,
                "(%p) %s: running method for event %s",
                (void *)event, event->event_object,
                nwamd_event_name(event->event_type));
            /* run method */
            event_methods[i].event_method(event);
            return;
        }
    }
    nlog(LOG_DEBUG, "(%p) %s: no matching method for event %d (%s)",
        (void *)event, event->event_object, event->event_type,
        nwamd_event_name(event->event_type));
}

/*
 * Called when we are checking to see what should be activated.  First activate
 * all of the manual NCUs.  Then see if we can find a valid priority group.
 * If we can, activate it.  Otherwise try all the priority groups starting
 * with the lowest one that makes sense.
 */
static void
nwamd_activate_ncus(void) {
    int64_t prio = INVALID_PRIORITY_GROUP;
    boolean_t selected;

    nwamd_ncp_activate_manual_ncus();
    selected = nwamd_ncp_check_priority_group(&prio);
    if (selected) {
        /*
         * Activate chosen priority group and stop anything going on in
         * lesser priority groups.
         */
        nwamd_ncp_activate_priority_group(prio);
        nwamd_ncp_deactivate_priority_group_all(prio + 1);
    } else {
        /*
         * Nothing unique could be started so try them all.  Once one
         * of them gets into a reasonable state then we will prune
         * everything below it (see first part of this conditional).
         */
        int64_t oldprio = INVALID_PRIORITY_GROUP;
        while (nwamd_ncp_find_next_priority_group(++oldprio, &prio)) {
            nwamd_ncp_activate_priority_group(prio);
            oldprio = prio;
        }
    }
}

/*
 * Event handler thread
 *
 * The complexity in this code comes about from wanting to delay the decision
 * making process until after bursts of events.  Keep roughly polling (waiting
 * for .1s) until we see the queue quiet event and then block.
 */
void
nwamd_event_handler(void)
{
    boolean_t got_shutdown_event = B_FALSE;
    boolean_t check_conditions = B_FALSE;
    boolean_t ncu_check = B_FALSE;
    int queue_quiet_time = 0;
    nwamd_event_t event;

    /*
     * Dequeue events and process them.  In most cases, events have
     * an assocated object type, and we use this to retrieve
     * the function that will process the event.
     */
    while (!got_shutdown_event) {
        event = nwamd_event_dequeue(queue_quiet_time);
        /* keep pulling events as long as they are close together */
        queue_quiet_time = SEC_TO_NSEC(1)/10;

        /*
         * This is an event with no associated object.
         */
        if (event->event_object[0] == '\0') {
            switch (event->event_type) {
            case NWAM_EVENT_TYPE_NOOP:
            case NWAM_EVENT_TYPE_INIT:
                /*
                 * The only action for an INIT event
                 * is to relay it to event listeners,
                 * which is done below.
                 */
                break;
            case NWAM_EVENT_TYPE_PRIORITY_GROUP:
                (void) pthread_mutex_lock(&active_ncp_mutex);
                current_ncu_priority_group =
                    event->event_msg->nwe_data.
                    nwe_priority_group_info.nwe_priority;
                (void) pthread_mutex_unlock(&active_ncp_mutex);
                break;
            case NWAM_EVENT_TYPE_TIMED_CHECK_CONDITIONS:
                if (!shutting_down) {
                    nwamd_set_timed_check_all_conditions();
                    check_conditions = B_TRUE;
                }
                break;
            case NWAM_EVENT_TYPE_TRIGGERED_CHECK_CONDITIONS:
                if (!shutting_down)
                    check_conditions = B_TRUE;
                break;
            case NWAM_EVENT_TYPE_NCU_CHECK:
                if (!shutting_down)
                    ncu_check = B_TRUE;
                break;
            case NWAM_EVENT_TYPE_UPGRADE:
                if (!shutting_down) {
                    /*
                     * Upgrade events have no associated
                     * object.
                     */
                    nwamd_event_run_method(event);
                }
                break;
            case NWAM_EVENT_TYPE_SHUTDOWN:
                got_shutdown_event = B_TRUE;
                break;

            /*
             * We want to delay processing of condition and ncu
             * checking until after short bursts of events.  So we
             * keep track of times we've scheduled checking and
             * wait for the queue to quiesce.
             */
            case NWAM_EVENT_TYPE_QUEUE_QUIET:
                queue_quiet_time = 0; /* now we can block */
                if (!shutting_down && check_conditions) {
                    nwamd_check_all_conditions();
                    check_conditions = B_FALSE;
                }

                if (!shutting_down && ncu_check) {
                    nwamd_activate_ncus();
                    ncu_check = B_FALSE;
                }
                break;

            default:
                nlog(LOG_ERR,
                    "event %d (%s)had no object associated "
                    "with it", event->event_type,
                    nwamd_event_name(event->event_type));
                break;
            }
        } else {
            /*
             * Event has an associated object - run event method
             * for that object type (if any).
             */
            nwamd_event_run_method(event);
        }
        /*
         * Send associated message to listeners if event type is
         * externally visible.
         */
        if (event->event_send)
            nwamd_event_send(event->event_msg);

        nwamd_event_fini(event);
    }
    /* If we get here, we got a shutdown event. */
    nwamd_event_queue_fini();
    nwamd_object_lists_fini();
}