Fixed issue with cmake version generation

[libevent.git] / event.c

/*
 * Copyright (c) 2000-2007 Niels Provos <provos@citi.umich.edu>
 * Copyright (c) 2007-2012 Niels Provos and Nick Mathewson
 *
 * 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 name of the author 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 ``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 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 "event2/event-config.h"
#include "evconfig-private.h"

#ifdef _WIN32
#include <winsock2.h>
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#undef WIN32_LEAN_AND_MEAN
#endif
#include <sys/types.h>
#if !defined(_WIN32) && defined(EVENT__HAVE_SYS_TIME_H)
#include <sys/time.h>
#endif
#include <sys/queue.h>
#ifdef EVENT__HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#ifdef EVENT__HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <ctype.h>
#include <errno.h>
#include <signal.h>
#include <string.h>
#include <time.h>
#include <limits.h>

#include "event2/event.h"
#include "event2/event_struct.h"
#include "event2/event_compat.h"
#include "event-internal.h"
#include "defer-internal.h"
#include "evthread-internal.h"
#include "event2/thread.h"
#include "event2/util.h"
#include "log-internal.h"
#include "evmap-internal.h"
#include "iocp-internal.h"
#include "changelist-internal.h"
#define HT_NO_CACHE_HASH_VALUES
#include "ht-internal.h"
#include "util-internal.h"


#ifdef EVENT__HAVE_WORKING_KQUEUE
#include "kqueue-internal.h"
#endif

#ifdef EVENT__HAVE_EVENT_PORTS
extern const struct eventop evportops;
#endif
#ifdef EVENT__HAVE_SELECT
extern const struct eventop selectops;
#endif
#ifdef EVENT__HAVE_POLL
extern const struct eventop pollops;
#endif
#ifdef EVENT__HAVE_EPOLL
extern const struct eventop epollops;
#endif
#ifdef EVENT__HAVE_WORKING_KQUEUE
extern const struct eventop kqops;
#endif
#ifdef EVENT__HAVE_DEVPOLL
extern const struct eventop devpollops;
#endif
#ifdef _WIN32
extern const struct eventop win32ops;
#endif

/* Array of backends in order of preference. */
static const struct eventop *eventops[] = {
#ifdef EVENT__HAVE_EVENT_PORTS
        &evportops,
#endif
#ifdef EVENT__HAVE_WORKING_KQUEUE
        &kqops,
#endif
#ifdef EVENT__HAVE_EPOLL
        &epollops,
#endif
#ifdef EVENT__HAVE_DEVPOLL
        &devpollops,
#endif
#ifdef EVENT__HAVE_POLL
        &pollops,
#endif
#ifdef EVENT__HAVE_SELECT
        &selectops,
#endif
#ifdef _WIN32
        &win32ops,
#endif
        NULL
};

/* Global state; deprecated */
struct event_base *event_global_current_base_ = NULL;
#define current_base event_global_current_base_

/* Global state */

static void *event_self_cbarg_ptr_ = NULL;

/* Prototypes */
static void     event_queue_insert_active(struct event_base *, struct event_callback *);
static void     event_queue_insert_active_later(struct event_base *, struct event_callback *);
static void     event_queue_insert_timeout(struct event_base *, struct event *);
static void     event_queue_insert_inserted(struct event_base *, struct event *);
static void     event_queue_remove_active(struct event_base *, struct event_callback *);
static void     event_queue_remove_active_later(struct event_base *, struct event_callback *);
static void     event_queue_remove_timeout(struct event_base *, struct event *);
static void     event_queue_remove_inserted(struct event_base *, struct event *);
static void event_queue_make_later_events_active(struct event_base *base);

static int evthread_make_base_notifiable_nolock_(struct event_base *base);
static int event_del_(struct event *ev, int blocking);

#ifdef USE_REINSERT_TIMEOUT
/* This code seems buggy; only turn it on if we find out what the trouble is. */
static void     event_queue_reinsert_timeout(struct event_base *,struct event *, int was_common, int is_common, int old_timeout_idx);
#endif

static int      event_haveevents(struct event_base *);

static int      event_process_active(struct event_base *);

static int      timeout_next(struct event_base *, struct timeval **);
static void     timeout_process(struct event_base *);

static inline void      event_signal_closure(struct event_base *, struct event *ev);
static inline void      event_persist_closure(struct event_base *, struct event *ev);

static int      evthread_notify_base(struct event_base *base);

static void insert_common_timeout_inorder(struct common_timeout_list *ctl,
    struct event *ev);

#ifndef EVENT__DISABLE_DEBUG_MODE
/* These functions implement a hashtable of which 'struct event *' structures
 * have been setup or added.  We don't want to trust the content of the struct
 * event itself, since we're trying to work through cases where an event gets
 * clobbered or freed.  Instead, we keep a hashtable indexed by the pointer.
 */

struct event_debug_entry {
        HT_ENTRY(event_debug_entry) node;
        const struct event *ptr;
        unsigned added : 1;
};

static inline unsigned
hash_debug_entry(const struct event_debug_entry *e)
{
        /* We need to do this silliness to convince compilers that we
         * honestly mean to cast e->ptr to an integer, and discard any
         * part of it that doesn't fit in an unsigned.
         */
        unsigned u = (unsigned) ((ev_uintptr_t) e->ptr);
        /* Our hashtable implementation is pretty sensitive to low bits,
         * and every struct event is over 64 bytes in size, so we can
         * just say >>6. */
        return (u >> 6);
}

static inline int
eq_debug_entry(const struct event_debug_entry *a,
    const struct event_debug_entry *b)
{
        return a->ptr == b->ptr;
}

int event_debug_mode_on_ = 0;


#if !defined(EVENT__DISABLE_THREAD_SUPPORT) && !defined(EVENT__DISABLE_DEBUG_MODE)
/**
 * @brief debug mode variable which is set for any function/structure that needs
 *        to be shared across threads (if thread support is enabled).
 *
 *        When and if evthreads are initialized, this variable will be evaluated,
 *        and if set to something other than zero, this means the evthread setup 
 *        functions were called out of order.
 *
 *        See: "Locks and threading" in the documentation.
 */
int event_debug_created_threadable_ctx_ = 0;
#endif

/* Set if it's too late to enable event_debug_mode. */
static int event_debug_mode_too_late = 0;
#ifndef EVENT__DISABLE_THREAD_SUPPORT
static void *event_debug_map_lock_ = NULL;
#endif
static HT_HEAD(event_debug_map, event_debug_entry) global_debug_map =
        HT_INITIALIZER();

HT_PROTOTYPE(event_debug_map, event_debug_entry, node, hash_debug_entry,
    eq_debug_entry)
HT_GENERATE(event_debug_map, event_debug_entry, node, hash_debug_entry,
    eq_debug_entry, 0.5, mm_malloc, mm_realloc, mm_free)

/* Macro: record that ev is now setup (that is, ready for an add) */
#define event_debug_note_setup_(ev) do {                                \
        if (event_debug_mode_on_) {                                     \
                struct event_debug_entry *dent,find;                    \
                find.ptr = (ev);                                        \
                EVLOCK_LOCK(event_debug_map_lock_, 0);                  \
                dent = HT_FIND(event_debug_map, &global_debug_map, &find); \
                if (dent) {                                             \
                        dent->added = 0;                                \
                } else {                                                \
                        dent = mm_malloc(sizeof(*dent));                \
                        if (!dent)                                      \
                                event_err(1,                            \
                                    "Out of memory in debugging code"); \
                        dent->ptr = (ev);                               \
                        dent->added = 0;                                \
                        HT_INSERT(event_debug_map, &global_debug_map, dent); \
                }                                                       \
                EVLOCK_UNLOCK(event_debug_map_lock_, 0);                \
        }                                                               \
        event_debug_mode_too_late = 1;                                  \
        } while (0)
/* Macro: record that ev is no longer setup */
#define event_debug_note_teardown_(ev) do {                             \
        if (event_debug_mode_on_) {                                     \
                struct event_debug_entry *dent,find;                    \
                find.ptr = (ev);                                        \
                EVLOCK_LOCK(event_debug_map_lock_, 0);                  \
                dent = HT_REMOVE(event_debug_map, &global_debug_map, &find); \
                if (dent)                                               \
                        mm_free(dent);                                  \
                EVLOCK_UNLOCK(event_debug_map_lock_, 0);                \
        }                                                               \
        event_debug_mode_too_late = 1;                                  \
        } while (0)
/* Macro: record that ev is now added */
#define event_debug_note_add_(ev)       do {                            \
        if (event_debug_mode_on_) {                                     \
                struct event_debug_entry *dent,find;                    \
                find.ptr = (ev);                                        \
                EVLOCK_LOCK(event_debug_map_lock_, 0);                  \
                dent = HT_FIND(event_debug_map, &global_debug_map, &find); \
                if (dent) {                                             \
                        dent->added = 1;                                \
                } else {                                                \
                        event_errx(EVENT_ERR_ABORT_,                    \
                            "%s: noting an add on a non-setup event %p" \
                            " (events: 0x%x, fd: "EV_SOCK_FMT           \
                            ", flags: 0x%x)",                           \
                            __func__, (ev), (ev)->ev_events,            \
                            EV_SOCK_ARG((ev)->ev_fd), (ev)->ev_flags);  \
                }                                                       \
                EVLOCK_UNLOCK(event_debug_map_lock_, 0);                \
        }                                                               \
        event_debug_mode_too_late = 1;                                  \
        } while (0)
/* Macro: record that ev is no longer added */
#define event_debug_note_del_(ev) do {                                  \
        if (event_debug_mode_on_) {                                     \
                struct event_debug_entry *dent,find;                    \
                find.ptr = (ev);                                        \
                EVLOCK_LOCK(event_debug_map_lock_, 0);                  \
                dent = HT_FIND(event_debug_map, &global_debug_map, &find); \
                if (dent) {                                             \
                        dent->added = 0;                                \
                } else {                                                \
                        event_errx(EVENT_ERR_ABORT_,                    \
                            "%s: noting a del on a non-setup event %p"  \
                            " (events: 0x%x, fd: "EV_SOCK_FMT           \
                            ", flags: 0x%x)",                           \
                            __func__, (ev), (ev)->ev_events,            \
                            EV_SOCK_ARG((ev)->ev_fd), (ev)->ev_flags);  \
                }                                                       \
                EVLOCK_UNLOCK(event_debug_map_lock_, 0);                \
        }                                                               \
        event_debug_mode_too_late = 1;                                  \
        } while (0)
/* Macro: assert that ev is setup (i.e., okay to add or inspect) */
#define event_debug_assert_is_setup_(ev) do {                           \
        if (event_debug_mode_on_) {                                     \
                struct event_debug_entry *dent,find;                    \
                find.ptr = (ev);                                        \
                EVLOCK_LOCK(event_debug_map_lock_, 0);                  \
                dent = HT_FIND(event_debug_map, &global_debug_map, &find); \
                if (!dent) {                                            \
                        event_errx(EVENT_ERR_ABORT_,                    \
                            "%s called on a non-initialized event %p"   \
                            " (events: 0x%x, fd: "EV_SOCK_FMT\
                            ", flags: 0x%x)",                           \
                            __func__, (ev), (ev)->ev_events,            \
                            EV_SOCK_ARG((ev)->ev_fd), (ev)->ev_flags);  \
                }                                                       \
                EVLOCK_UNLOCK(event_debug_map_lock_, 0);                \
        }                                                               \
        } while (0)
/* Macro: assert that ev is not added (i.e., okay to tear down or set
 * up again) */
#define event_debug_assert_not_added_(ev) do {                          \
        if (event_debug_mode_on_) {                                     \
                struct event_debug_entry *dent,find;                    \
                find.ptr = (ev);                                        \
                EVLOCK_LOCK(event_debug_map_lock_, 0);                  \
                dent = HT_FIND(event_debug_map, &global_debug_map, &find); \
                if (dent && dent->added) {                              \
                        event_errx(EVENT_ERR_ABORT_,                    \
                            "%s called on an already added event %p"    \
                            " (events: 0x%x, fd: "EV_SOCK_FMT", "       \
                            "flags: 0x%x)",                             \
                            __func__, (ev), (ev)->ev_events,            \
                            EV_SOCK_ARG((ev)->ev_fd), (ev)->ev_flags);  \
                }                                                       \
                EVLOCK_UNLOCK(event_debug_map_lock_, 0);                \
        }                                                               \
        } while (0)
#else
#define event_debug_note_setup_(ev) \
        ((void)0)
#define event_debug_note_teardown_(ev) \
        ((void)0)
#define event_debug_note_add_(ev) \
        ((void)0)
#define event_debug_note_del_(ev) \
        ((void)0)
#define event_debug_assert_is_setup_(ev) \
        ((void)0)
#define event_debug_assert_not_added_(ev) \
        ((void)0)
#endif

#define EVENT_BASE_ASSERT_LOCKED(base)          \
        EVLOCK_ASSERT_LOCKED((base)->th_base_lock)

/* How often (in seconds) do we check for changes in wall clock time relative
 * to monotonic time?  Set this to -1 for 'never.' */
#define CLOCK_SYNC_INTERVAL 5

/** Set 'tp' to the current time according to 'base'.  We must hold the lock
 * on 'base'.  If there is a cached time, return it.  Otherwise, use
 * clock_gettime or gettimeofday as appropriate to find out the right time.
 * Return 0 on success, -1 on failure.
 */
static int
gettime(struct event_base *base, struct timeval *tp)
{
        EVENT_BASE_ASSERT_LOCKED(base);

        if (base->tv_cache.tv_sec) {
                *tp = base->tv_cache;
                return (0);
        }

        if (evutil_gettime_monotonic_(&base->monotonic_timer, tp) == -1) {
                return -1;
        }

        if (base->last_updated_clock_diff + CLOCK_SYNC_INTERVAL
            < tp->tv_sec) {
                struct timeval tv;
                evutil_gettimeofday(&tv,NULL);
                evutil_timersub(&tv, tp, &base->tv_clock_diff);
                base->last_updated_clock_diff = tp->tv_sec;
        }

        return 0;
}

int
event_base_gettimeofday_cached(struct event_base *base, struct timeval *tv)
{
        int r;
        if (!base) {
                base = current_base;
                if (!current_base)
                        return evutil_gettimeofday(tv, NULL);
        }

        EVBASE_ACQUIRE_LOCK(base, th_base_lock);
        if (base->tv_cache.tv_sec == 0) {
                r = evutil_gettimeofday(tv, NULL);
        } else {
                evutil_timeradd(&base->tv_cache, &base->tv_clock_diff, tv);
                r = 0;
        }
        EVBASE_RELEASE_LOCK(base, th_base_lock);
        return r;
}

/** Make 'base' have no current cached time. */
static inline void
clear_time_cache(struct event_base *base)
{
        base->tv_cache.tv_sec = 0;
}

/** Replace the cached time in 'base' with the current time. */
static inline void
update_time_cache(struct event_base *base)
{
        base->tv_cache.tv_sec = 0;
        if (!(base->flags & EVENT_BASE_FLAG_NO_CACHE_TIME))
            gettime(base, &base->tv_cache);
}

int
event_base_update_cache_time(struct event_base *base)
{

        if (!base) {
                base = current_base;
                if (!current_base)
                        return -1;
        }

        EVBASE_ACQUIRE_LOCK(base, th_base_lock);
        if (base->running_loop)
                update_time_cache(base);
        EVBASE_RELEASE_LOCK(base, th_base_lock);
        return 0;
}

static inline struct event *
event_callback_to_event(struct event_callback *evcb)
{
        EVUTIL_ASSERT((evcb->evcb_flags & EVLIST_INIT));
        return EVUTIL_UPCAST(evcb, struct event, ev_evcallback);
}

static inline struct event_callback *
event_to_event_callback(struct event *ev)
{
        return &ev->ev_evcallback;
}

struct event_base *
event_init(void)
{
        struct event_base *base = event_base_new_with_config(NULL);

        if (base == NULL) {
                event_errx(1, "%s: Unable to construct event_base", __func__);
                return NULL;
        }

        current_base = base;

        return (base);
}

struct event_base *
event_base_new(void)
{
        struct event_base *base = NULL;
        struct event_config *cfg = event_config_new();
        if (cfg) {
                base = event_base_new_with_config(cfg);
                event_config_free(cfg);
        }
        return base;
}

/** Return true iff 'method' is the name of a method that 'cfg' tells us to
 * avoid. */
static int
event_config_is_avoided_method(const struct event_config *cfg,
    const char *method)
{
        struct event_config_entry *entry;

        TAILQ_FOREACH(entry, &cfg->entries, next) {
                if (entry->avoid_method != NULL &&
                    strcmp(entry->avoid_method, method) == 0)
                        return (1);
        }

        return (0);
}

/** Return true iff 'method' is disabled according to the environment. */
static int
event_is_method_disabled(const char *name)
{
        char environment[64];
        int i;

        evutil_snprintf(environment, sizeof(environment), "EVENT_NO%s", name);
        for (i = 8; environment[i] != '\0'; ++i)
                environment[i] = EVUTIL_TOUPPER_(environment[i]);
        /* Note that evutil_getenv_() ignores the environment entirely if
         * we're setuid */
        return (evutil_getenv_(environment) != NULL);
}

int
event_base_get_features(const struct event_base *base)
{
        return base->evsel->features;
}

void
event_enable_debug_mode(void)
{
#ifndef EVENT__DISABLE_DEBUG_MODE
        if (event_debug_mode_on_)
                event_errx(1, "%s was called twice!", __func__);
        if (event_debug_mode_too_late)
                event_errx(1, "%s must be called *before* creating any events "
                    "or event_bases",__func__);

        event_debug_mode_on_ = 1;

        HT_INIT(event_debug_map, &global_debug_map);
#endif
}

void
event_disable_debug_mode(void)
{
#ifndef EVENT__DISABLE_DEBUG_MODE
        struct event_debug_entry **ent, *victim;

        EVLOCK_LOCK(event_debug_map_lock_, 0);
        for (ent = HT_START(event_debug_map, &global_debug_map); ent; ) {
                victim = *ent;
                ent = HT_NEXT_RMV(event_debug_map, &global_debug_map, ent);
                mm_free(victim);
        }
        HT_CLEAR(event_debug_map, &global_debug_map);
        EVLOCK_UNLOCK(event_debug_map_lock_ , 0);

        event_debug_mode_on_  = 0;
#endif
}

struct event_base *
event_base_new_with_config(const struct event_config *cfg)
{
        int i;
        struct event_base *base;
        int should_check_environment;

#ifndef EVENT__DISABLE_DEBUG_MODE
        event_debug_mode_too_late = 1;
#endif

        if ((base = mm_calloc(1, sizeof(struct event_base))) == NULL) {
                event_warn("%s: calloc", __func__);
                return NULL;
        }

        if (cfg)
                base->flags = cfg->flags;

        should_check_environment =
            !(cfg && (cfg->flags & EVENT_BASE_FLAG_IGNORE_ENV));

        {
                struct timeval tmp;
                int precise_time =
                    cfg && (cfg->flags & EVENT_BASE_FLAG_PRECISE_TIMER);
                int flags;
                if (should_check_environment && !precise_time) {
                        precise_time = evutil_getenv_("EVENT_PRECISE_TIMER") != NULL;
                        base->flags |= EVENT_BASE_FLAG_PRECISE_TIMER;
                }
                flags = precise_time ? EV_MONOT_PRECISE : 0;
                evutil_configure_monotonic_time_(&base->monotonic_timer, flags);

                gettime(base, &tmp);
        }

        min_heap_ctor_(&base->timeheap);

        base->sig.ev_signal_pair[0] = -1;
        base->sig.ev_signal_pair[1] = -1;
        base->th_notify_fd[0] = -1;
        base->th_notify_fd[1] = -1;

        TAILQ_INIT(&base->active_later_queue);

        evmap_io_initmap_(&base->io);
        evmap_signal_initmap_(&base->sigmap);
        event_changelist_init_(&base->changelist);

        base->evbase = NULL;

        if (cfg) {
                memcpy(&base->max_dispatch_time,
                    &cfg->max_dispatch_interval, sizeof(struct timeval));
                base->limit_callbacks_after_prio =
                    cfg->limit_callbacks_after_prio;
        } else {
                base->max_dispatch_time.tv_sec = -1;
                base->limit_callbacks_after_prio = 1;
        }
        if (cfg && cfg->max_dispatch_callbacks >= 0) {
                base->max_dispatch_callbacks = cfg->max_dispatch_callbacks;
        } else {
                base->max_dispatch_callbacks = INT_MAX;
        }
        if (base->max_dispatch_callbacks == INT_MAX &&
            base->max_dispatch_time.tv_sec == -1)
                base->limit_callbacks_after_prio = INT_MAX;

        for (i = 0; eventops[i] && !base->evbase; i++) {
                if (cfg != NULL) {
                        /* determine if this backend should be avoided */
                        if (event_config_is_avoided_method(cfg,
                                eventops[i]->name))
                                continue;
                        if ((eventops[i]->features & cfg->require_features)
                            != cfg->require_features)
                                continue;
                }

                /* also obey the environment variables */
                if (should_check_environment &&
                    event_is_method_disabled(eventops[i]->name))
                        continue;

                base->evsel = eventops[i];

                base->evbase = base->evsel->init(base);
        }

        if (base->evbase == NULL) {
                event_warnx("%s: no event mechanism available",
                    __func__);
                base->evsel = NULL;
                event_base_free(base);
                return NULL;
        }

        if (evutil_getenv_("EVENT_SHOW_METHOD"))
                event_msgx("libevent using: %s", base->evsel->name);

        /* allocate a single active event queue */
        if (event_base_priority_init(base, 1) < 0) {
                event_base_free(base);
                return NULL;
        }

        /* prepare for threading */

#if !defined(EVENT__DISABLE_THREAD_SUPPORT) && !defined(EVENT__DISABLE_DEBUG_MODE)
        event_debug_created_threadable_ctx_ = 1;
#endif

#ifndef EVENT__DISABLE_THREAD_SUPPORT
        if (EVTHREAD_LOCKING_ENABLED() &&
            (!cfg || !(cfg->flags & EVENT_BASE_FLAG_NOLOCK))) {
                int r;
                EVTHREAD_ALLOC_LOCK(base->th_base_lock, 0);
                EVTHREAD_ALLOC_COND(base->current_event_cond);
                r = evthread_make_base_notifiable(base);
                if (r<0) {
                        event_warnx("%s: Unable to make base notifiable.", __func__);
                        event_base_free(base);
                        return NULL;
                }
        }
#endif

#ifdef _WIN32
        if (cfg && (cfg->flags & EVENT_BASE_FLAG_STARTUP_IOCP))
                event_base_start_iocp_(base, cfg->n_cpus_hint);
#endif

        return (base);
}

int
event_base_start_iocp_(struct event_base *base, int n_cpus)
{
#ifdef _WIN32
        if (base->iocp)
                return 0;
        base->iocp = event_iocp_port_launch_(n_cpus);
        if (!base->iocp) {
                event_warnx("%s: Couldn't launch IOCP", __func__);
                return -1;
        }
        return 0;
#else
        return -1;
#endif
}

void
event_base_stop_iocp_(struct event_base *base)
{
#ifdef _WIN32
        int rv;

        if (!base->iocp)
                return;
        rv = event_iocp_shutdown_(base->iocp, -1);
        EVUTIL_ASSERT(rv >= 0);
        base->iocp = NULL;
#endif
}

static int
event_base_cancel_single_callback_(struct event_base *base,
    struct event_callback *evcb,
    int run_finalizers)
{
        int result = 0;

        if (evcb->evcb_flags & EVLIST_INIT) {
                struct event *ev = event_callback_to_event(evcb);
                if (!(ev->ev_flags & EVLIST_INTERNAL)) {
                        event_del_(ev, EVENT_DEL_EVEN_IF_FINALIZING);
                        result = 1;
                }
        } else {
                EVBASE_ACQUIRE_LOCK(base, th_base_lock);
                event_callback_cancel_nolock_(base, evcb, 1);
                EVBASE_RELEASE_LOCK(base, th_base_lock);
                result = 1;
        }

        if (run_finalizers && (evcb->evcb_flags & EVLIST_FINALIZING)) {
                switch (evcb->evcb_closure) {
                case EV_CLOSURE_EVENT_FINALIZE:
                case EV_CLOSURE_EVENT_FINALIZE_FREE: {
                        struct event *ev = event_callback_to_event(evcb);
                        ev->ev_evcallback.evcb_cb_union.evcb_evfinalize(ev, ev->ev_arg);
                        if (evcb->evcb_closure == EV_CLOSURE_EVENT_FINALIZE_FREE)
                                mm_free(ev);
                        break;
                }
                case EV_CLOSURE_CB_FINALIZE:
                        evcb->evcb_cb_union.evcb_cbfinalize(evcb, evcb->evcb_arg);
                        break;
                default:
                        break;
                }
        }
        return result;
}

static int event_base_free_queues_(struct event_base *base, int run_finalizers)
{
        int deleted = 0, i;

        for (i = 0; i < base->nactivequeues; ++i) {
                struct event_callback *evcb, *next;
                for (evcb = TAILQ_FIRST(&base->activequeues[i]); evcb; ) {
                        next = TAILQ_NEXT(evcb, evcb_active_next);
                        deleted += event_base_cancel_single_callback_(base, evcb, run_finalizers);
                        evcb = next;
                }
        }

        {
                struct event_callback *evcb;
                while ((evcb = TAILQ_FIRST(&base->active_later_queue))) {
                        deleted += event_base_cancel_single_callback_(base, evcb, run_finalizers);
                }
        }

        return deleted;
}

static void
event_base_free_(struct event_base *base, int run_finalizers)
{
        int i, n_deleted=0;
        struct event *ev;
        /* XXXX grab the lock? If there is contention when one thread frees
         * the base, then the contending thread will be very sad soon. */

        /* event_base_free(NULL) is how to free the current_base if we
         * made it with event_init and forgot to hold a reference to it. */
        if (base == NULL && current_base)
                base = current_base;
        /* Don't actually free NULL. */
        if (base == NULL) {
                event_warnx("%s: no base to free", __func__);
                return;
        }
        /* XXX(niels) - check for internal events first */

#ifdef _WIN32
        event_base_stop_iocp_(base);
#endif

        /* threading fds if we have them */
        if (base->th_notify_fd[0] != -1) {
                event_del(&base->th_notify);
                EVUTIL_CLOSESOCKET(base->th_notify_fd[0]);
                if (base->th_notify_fd[1] != -1)
                        EVUTIL_CLOSESOCKET(base->th_notify_fd[1]);
                base->th_notify_fd[0] = -1;
                base->th_notify_fd[1] = -1;
                event_debug_unassign(&base->th_notify);
        }

        /* Delete all non-internal events. */
        evmap_delete_all_(base);

        while ((ev = min_heap_top_(&base->timeheap)) != NULL) {
                event_del(ev);
                ++n_deleted;
        }
        for (i = 0; i < base->n_common_timeouts; ++i) {
                struct common_timeout_list *ctl =
                    base->common_timeout_queues[i];
                event_del(&ctl->timeout_event); /* Internal; doesn't count */
                event_debug_unassign(&ctl->timeout_event);
                for (ev = TAILQ_FIRST(&ctl->events); ev; ) {
                        struct event *next = TAILQ_NEXT(ev,
                            ev_timeout_pos.ev_next_with_common_timeout);
                        if (!(ev->ev_flags & EVLIST_INTERNAL)) {
                                event_del(ev);
                                ++n_deleted;
                        }
                        ev = next;
                }
                mm_free(ctl);
        }
        if (base->common_timeout_queues)
                mm_free(base->common_timeout_queues);

        for (;;) {
                /* For finalizers we can register yet another finalizer out from
                 * finalizer, and iff finalizer will be in active_later_queue we can
                 * add finalizer to activequeues, and we will have events in
                 * activequeues after this function returns, which is not what we want
                 * (we even have an assertion for this).
                 *
                 * A simple case is bufferevent with underlying (i.e. filters).
                 */
                int i = event_base_free_queues_(base, run_finalizers);
                if (!i) {
                        break;
                }
                n_deleted += i;
        }

        if (n_deleted)
                event_debug(("%s: %d events were still set in base",
                        __func__, n_deleted));

        while (LIST_FIRST(&base->once_events)) {
                struct event_once *eonce = LIST_FIRST(&base->once_events);
                LIST_REMOVE(eonce, next_once);
                mm_free(eonce);
        }

        if (base->evsel != NULL && base->evsel->dealloc != NULL)
                base->evsel->dealloc(base);

        for (i = 0; i < base->nactivequeues; ++i)
                EVUTIL_ASSERT(TAILQ_EMPTY(&base->activequeues[i]));

        EVUTIL_ASSERT(min_heap_empty_(&base->timeheap));
        min_heap_dtor_(&base->timeheap);

        mm_free(base->activequeues);

        evmap_io_clear_(&base->io);
        evmap_signal_clear_(&base->sigmap);
        event_changelist_freemem_(&base->changelist);

        EVTHREAD_FREE_LOCK(base->th_base_lock, 0);
        EVTHREAD_FREE_COND(base->current_event_cond);

        /* If we're freeing current_base, there won't be a current_base. */
        if (base == current_base)
                current_base = NULL;
        mm_free(base);
}

void
event_base_free_nofinalize(struct event_base *base)
{
        event_base_free_(base, 0);
}

void
event_base_free(struct event_base *base)
{
        event_base_free_(base, 1);
}

/* Fake eventop; used to disable the backend temporarily inside event_reinit
 * so that we can call event_del() on an event without telling the backend.
 */
static int
nil_backend_del(struct event_base *b, evutil_socket_t fd, short old,
    short events, void *fdinfo)
{
        return 0;
}
const struct eventop nil_eventop = {
        "nil",
        NULL, /* init: unused. */
        NULL, /* add: unused. */
        nil_backend_del, /* del: used, so needs to be killed. */
        NULL, /* dispatch: unused. */
        NULL, /* dealloc: unused. */
        0, 0, 0
};

/* reinitialize the event base after a fork */
int
event_reinit(struct event_base *base)
{
        const struct eventop *evsel;
        int res = 0;
        int was_notifiable = 0;
        int had_signal_added = 0;

        EVBASE_ACQUIRE_LOCK(base, th_base_lock);

        evsel = base->evsel;

        /* check if this event mechanism requires reinit on the backend */
        if (evsel->need_reinit) {
                /* We're going to call event_del() on our notify events (the
                 * ones that tell about signals and wakeup events).  But we
                 * don't actually want to tell the backend to change its
                 * state, since it might still share some resource (a kqueue,
                 * an epoll fd) with the parent process, and we don't want to
                 * delete the fds from _that_ backend, we temporarily stub out
                 * the evsel with a replacement.
                 */
                base->evsel = &nil_eventop;
        }

        /* We need to re-create a new signal-notification fd and a new
         * thread-notification fd.  Otherwise, we'll still share those with
         * the parent process, which would make any notification sent to them
         * get received by one or both of the event loops, more or less at
         * random.
         */
        if (base->sig.ev_signal_added) {
                event_del_nolock_(&base->sig.ev_signal, EVENT_DEL_AUTOBLOCK);
                event_debug_unassign(&base->sig.ev_signal);
                memset(&base->sig.ev_signal, 0, sizeof(base->sig.ev_signal));
                if (base->sig.ev_signal_pair[0] != -1)
                        EVUTIL_CLOSESOCKET(base->sig.ev_signal_pair[0]);
                if (base->sig.ev_signal_pair[1] != -1)
                        EVUTIL_CLOSESOCKET(base->sig.ev_signal_pair[1]);
                had_signal_added = 1;
                base->sig.ev_signal_added = 0;
        }
        if (base->th_notify_fn != NULL) {
                was_notifiable = 1;
                base->th_notify_fn = NULL;
        }
        if (base->th_notify_fd[0] != -1) {
                event_del_nolock_(&base->th_notify, EVENT_DEL_AUTOBLOCK);
                EVUTIL_CLOSESOCKET(base->th_notify_fd[0]);
                if (base->th_notify_fd[1] != -1)
                        EVUTIL_CLOSESOCKET(base->th_notify_fd[1]);
                base->th_notify_fd[0] = -1;
                base->th_notify_fd[1] = -1;
                event_debug_unassign(&base->th_notify);
        }

        /* Replace the original evsel. */
        base->evsel = evsel;

        if (evsel->need_reinit) {
                /* Reconstruct the backend through brute-force, so that we do
                 * not share any structures with the parent process. For some
                 * backends, this is necessary: epoll and kqueue, for
                 * instance, have events associated with a kernel
                 * structure. If didn't reinitialize, we'd share that
                 * structure with the parent process, and any changes made by
                 * the parent would affect our backend's behavior (and vice
                 * versa).
                 */
                if (base->evsel->dealloc != NULL)
                        base->evsel->dealloc(base);
                base->evbase = evsel->init(base);
                if (base->evbase == NULL) {
                        event_errx(1,
                           "%s: could not reinitialize event mechanism",
                           __func__);
                        res = -1;
                        goto done;
                }

                /* Empty out the changelist (if any): we are starting from a
                 * blank slate. */
                event_changelist_freemem_(&base->changelist);

                /* Tell the event maps to re-inform the backend about all
                 * pending events. This will make the signal notification
                 * event get re-created if necessary. */
                if (evmap_reinit_(base) < 0)
                        res = -1;
        } else {
                if (had_signal_added)
                        res = evsig_init_(base);
        }

        /* If we were notifiable before, and nothing just exploded, become
         * notifiable again. */
        if (was_notifiable && res == 0)
                res = evthread_make_base_notifiable_nolock_(base);

done:
        EVBASE_RELEASE_LOCK(base, th_base_lock);
        return (res);
}

/* Get the monotonic time for this event_base' timer */
int
event_gettime_monotonic(struct event_base *base, struct timeval *tv)
{
  int rv = -1;

  if (base && tv) {
    EVBASE_ACQUIRE_LOCK(base, th_base_lock);
    rv = evutil_gettime_monotonic_(&(base->monotonic_timer), tv);
    EVBASE_RELEASE_LOCK(base, th_base_lock);
  }

  return rv;
}

const char **
event_get_supported_methods(void)
{
        static const char **methods = NULL;
        const struct eventop **method;
        const char **tmp;
        int i = 0, k;

        /* count all methods */
        for (method = &eventops[0]; *method != NULL; ++method) {
                ++i;
        }

        /* allocate one more than we need for the NULL pointer */
        tmp = mm_calloc((i + 1), sizeof(char *));
        if (tmp == NULL)
                return (NULL);

        /* populate the array with the supported methods */
        for (k = 0, i = 0; eventops[k] != NULL; ++k) {
                tmp[i++] = eventops[k]->name;
        }
        tmp[i] = NULL;

        if (methods != NULL)
                mm_free((char**)methods);

        methods = tmp;

        return (methods);
}

struct event_config *
event_config_new(void)
{
        struct event_config *cfg = mm_calloc(1, sizeof(*cfg));

        if (cfg == NULL)
                return (NULL);

        TAILQ_INIT(&cfg->entries);
        cfg->max_dispatch_interval.tv_sec = -1;
        cfg->max_dispatch_callbacks = INT_MAX;
        cfg->limit_callbacks_after_prio = 1;

        return (cfg);
}

static void
event_config_entry_free(struct event_config_entry *entry)
{
        if (entry->avoid_method != NULL)
                mm_free((char *)entry->avoid_method);
        mm_free(entry);
}

void
event_config_free(struct event_config *cfg)
{
        struct event_config_entry *entry;

        while ((entry = TAILQ_FIRST(&cfg->entries)) != NULL) {
                TAILQ_REMOVE(&cfg->entries, entry, next);
                event_config_entry_free(entry);
        }
        mm_free(cfg);
}

int
event_config_set_flag(struct event_config *cfg, int flag)
{
        if (!cfg)
                return -1;
        cfg->flags |= flag;
        return 0;
}

int
event_config_avoid_method(struct event_config *cfg, const char *method)
{
        struct event_config_entry *entry = mm_malloc(sizeof(*entry));
        if (entry == NULL)
                return (-1);

        if ((entry->avoid_method = mm_strdup(method)) == NULL) {
                mm_free(entry);
                return (-1);
        }

        TAILQ_INSERT_TAIL(&cfg->entries, entry, next);

        return (0);
}

int
event_config_require_features(struct event_config *cfg,
    int features)
{
        if (!cfg)
                return (-1);
        cfg->require_features = features;
        return (0);
}

int
event_config_set_num_cpus_hint(struct event_config *cfg, int cpus)
{
        if (!cfg)
                return (-1);
        cfg->n_cpus_hint = cpus;
        return (0);
}

int
event_config_set_max_dispatch_interval(struct event_config *cfg,
    const struct timeval *max_interval, int max_callbacks, int min_priority)
{
        if (max_interval)
                memcpy(&cfg->max_dispatch_interval, max_interval,
                    sizeof(struct timeval));
        else
                cfg->max_dispatch_interval.tv_sec = -1;
        cfg->max_dispatch_callbacks =
            max_callbacks >= 0 ? max_callbacks : INT_MAX;
        if (min_priority < 0)
                min_priority = 0;
        cfg->limit_callbacks_after_prio = min_priority;
        return (0);
}

int
event_priority_init(int npriorities)
{
        return event_base_priority_init(current_base, npriorities);
}

int
event_base_priority_init(struct event_base *base, int npriorities)
{
        int i, r;
        r = -1;

        EVBASE_ACQUIRE_LOCK(base, th_base_lock);

        if (N_ACTIVE_CALLBACKS(base) || npriorities < 1
            || npriorities >= EVENT_MAX_PRIORITIES)
                goto err;

        if (npriorities == base->nactivequeues)
                goto ok;

        if (base->nactivequeues) {
                mm_free(base->activequeues);
                base->nactivequeues = 0;
        }

        /* Allocate our priority queues */
        base->activequeues = (struct evcallback_list *)
          mm_calloc(npriorities, sizeof(struct evcallback_list));
        if (base->activequeues == NULL) {
                event_warn("%s: calloc", __func__);
                goto err;
        }
        base->nactivequeues = npriorities;

        for (i = 0; i < base->nactivequeues; ++i) {
                TAILQ_INIT(&base->activequeues[i]);
        }

ok:
        r = 0;
err:
        EVBASE_RELEASE_LOCK(base, th_base_lock);
        return (r);
}

int
event_base_get_npriorities(struct event_base *base)
{

        int n;
        if (base == NULL)
                base = current_base;

        EVBASE_ACQUIRE_LOCK(base, th_base_lock);
        n = base->nactivequeues;
        EVBASE_RELEASE_LOCK(base, th_base_lock);
        return (n);
}

int
event_base_get_num_events(struct event_base *base, unsigned int type)
{
        int r = 0;

        EVBASE_ACQUIRE_LOCK(base, th_base_lock);

        if (type & EVENT_BASE_COUNT_ACTIVE)
                r += base->event_count_active;

        if (type & EVENT_BASE_COUNT_VIRTUAL)
                r += base->virtual_event_count;

        if (type & EVENT_BASE_COUNT_ADDED)
                r += base->event_count;

        EVBASE_RELEASE_LOCK(base, th_base_lock);

        return r;
}

int
event_base_get_max_events(struct event_base *base, unsigned int type, int clear)
{
        int r = 0;

        EVBASE_ACQUIRE_LOCK(base, th_base_lock);

        if (type & EVENT_BASE_COUNT_ACTIVE) {
                r += base->event_count_active_max;
                if (clear)
                        base->event_count_active_max = 0;
        }

        if (type & EVENT_BASE_COUNT_VIRTUAL) {
                r += base->virtual_event_count_max;
                if (clear)
                        base->virtual_event_count_max = 0;
        }

        if (type & EVENT_BASE_COUNT_ADDED) {
                r += base->event_count_max;
                if (clear)
                        base->event_count_max = 0;
        }

        EVBASE_RELEASE_LOCK(base, th_base_lock);

        return r;
}

/* Returns true iff we're currently watching any events. */
static int
event_haveevents(struct event_base *base)
{
        /* Caller must hold th_base_lock */
        return (base->virtual_event_count > 0 || base->event_count > 0);
}

/* "closure" function called when processing active signal events */
static inline void
event_signal_closure(struct event_base *base, struct event *ev)
{
        short ncalls;
        int should_break;

        /* Allows deletes to work */
        ncalls = ev->ev_ncalls;
        if (ncalls != 0)
                ev->ev_pncalls = &ncalls;
        EVBASE_RELEASE_LOCK(base, th_base_lock);
        while (ncalls) {
                ncalls--;
                ev->ev_ncalls = ncalls;
                if (ncalls == 0)
                        ev->ev_pncalls = NULL;
                (*ev->ev_callback)(ev->ev_fd, ev->ev_res, ev->ev_arg);

                EVBASE_ACQUIRE_LOCK(base, th_base_lock);
                should_break = base->event_break;
                EVBASE_RELEASE_LOCK(base, th_base_lock);

                if (should_break) {
                        if (ncalls != 0)
                                ev->ev_pncalls = NULL;
                        return;
                }
        }
}

/* Common timeouts are special timeouts that are handled as queues rather than
 * in the minheap.  This is more efficient than the minheap if we happen to
 * know that we're going to get several thousands of timeout events all with
 * the same timeout value.
 *
 * Since all our timeout handling code assumes timevals can be copied,
 * assigned, etc, we can't use "magic pointer" to encode these common
 * timeouts.  Searching through a list to see if every timeout is common could
 * also get inefficient.  Instead, we take advantage of the fact that tv_usec
 * is 32 bits long, but only uses 20 of those bits (since it can never be over
 * 999999.)  We use the top bits to encode 4 bites of magic number, and 8 bits
 * of index into the event_base's aray of common timeouts.
 */

#define MICROSECONDS_MASK       COMMON_TIMEOUT_MICROSECONDS_MASK
#define COMMON_TIMEOUT_IDX_MASK 0x0ff00000
#define COMMON_TIMEOUT_IDX_SHIFT 20
#define COMMON_TIMEOUT_MASK     0xf0000000
#define COMMON_TIMEOUT_MAGIC    0x50000000

#define COMMON_TIMEOUT_IDX(tv) \
        (((tv)->tv_usec & COMMON_TIMEOUT_IDX_MASK)>>COMMON_TIMEOUT_IDX_SHIFT)

/** Return true iff if 'tv' is a common timeout in 'base' */
static inline int
is_common_timeout(const struct timeval *tv,
    const struct event_base *base)
{
        int idx;
        if ((tv->tv_usec & COMMON_TIMEOUT_MASK) != COMMON_TIMEOUT_MAGIC)
                return 0;
        idx = COMMON_TIMEOUT_IDX(tv);
        return idx < base->n_common_timeouts;
}

/* True iff tv1 and tv2 have the same common-timeout index, or if neither
 * one is a common timeout. */
static inline int
is_same_common_timeout(const struct timeval *tv1, const struct timeval *tv2)
{
        return (tv1->tv_usec & ~MICROSECONDS_MASK) ==
            (tv2->tv_usec & ~MICROSECONDS_MASK);
}

/** Requires that 'tv' is a common timeout.  Return the corresponding
 * common_timeout_list. */
static inline struct common_timeout_list *
get_common_timeout_list(struct event_base *base, const struct timeval *tv)
{
        return base->common_timeout_queues[COMMON_TIMEOUT_IDX(tv)];
}

#if 0
static inline int
common_timeout_ok(const struct timeval *tv,
    struct event_base *base)
{
        const struct timeval *expect =
            &get_common_timeout_list(base, tv)->duration;
        return tv->tv_sec == expect->tv_sec &&
            tv->tv_usec == expect->tv_usec;
}
#endif

/* Add the timeout for the first event in given common timeout list to the
 * event_base's minheap. */
static void
common_timeout_schedule(struct common_timeout_list *ctl,
    const struct timeval *now, struct event *head)
{
        struct timeval timeout = head->ev_timeout;
        timeout.tv_usec &= MICROSECONDS_MASK;
        event_add_nolock_(&ctl->timeout_event, &timeout, 1);
}

/* Callback: invoked when the timeout for a common timeout queue triggers.
 * This means that (at least) the first event in that queue should be run,
 * and the timeout should be rescheduled if there are more events. */
static void
common_timeout_callback(evutil_socket_t fd, short what, void *arg)
{
        struct timeval now;
        struct common_timeout_list *ctl = arg;
        struct event_base *base = ctl->base;
        struct event *ev = NULL;
        EVBASE_ACQUIRE_LOCK(base, th_base_lock);
        gettime(base, &now);
        while (1) {
                ev = TAILQ_FIRST(&ctl->events);
                if (!ev || ev->ev_timeout.tv_sec > now.tv_sec ||
                    (ev->ev_timeout.tv_sec == now.tv_sec &&
                        (ev->ev_timeout.tv_usec&MICROSECONDS_MASK) > now.tv_usec))
                        break;
                event_del_nolock_(ev, EVENT_DEL_NOBLOCK);
                event_active_nolock_(ev, EV_TIMEOUT, 1);
        }
        if (ev)
                common_timeout_schedule(ctl, &now, ev);
        EVBASE_RELEASE_LOCK(base, th_base_lock);
}

#define MAX_COMMON_TIMEOUTS 256

const struct timeval *
event_base_init_common_timeout(struct event_base *base,
    const struct timeval *duration)
{
        int i;
        struct timeval tv;
        const struct timeval *result=NULL;
        struct common_timeout_list *new_ctl;

        EVBASE_ACQUIRE_LOCK(base, th_base_lock);
        if (duration->tv_usec > 1000000) {
                memcpy(&tv, duration, sizeof(struct timeval));
                if (is_common_timeout(duration, base))
                        tv.tv_usec &= MICROSECONDS_MASK;
                tv.tv_sec += tv.tv_usec / 1000000;
                tv.tv_usec %= 1000000;
                duration = &tv;
        }
        for (i = 0; i < base->n_common_timeouts; ++i) {
                const struct common_timeout_list *ctl =
                    base->common_timeout_queues[i];
                if (duration->tv_sec == ctl->duration.tv_sec &&
                    duration->tv_usec ==
                    (ctl->duration.tv_usec & MICROSECONDS_MASK)) {
                        EVUTIL_ASSERT(is_common_timeout(&ctl->duration, base));
                        result = &ctl->duration;
                        goto done;
                }
        }
        if (base->n_common_timeouts == MAX_COMMON_TIMEOUTS) {
                event_warnx("%s: Too many common timeouts already in use; "
                    "we only support %d per event_base", __func__,
                    MAX_COMMON_TIMEOUTS);
                goto done;
        }
        if (base->n_common_timeouts_allocated == base->n_common_timeouts) {
                int n = base->n_common_timeouts < 16 ? 16 :
                    base->n_common_timeouts*2;
                struct common_timeout_list **newqueues =
                    mm_realloc(base->common_timeout_queues,
                        n*sizeof(struct common_timeout_queue *));
                if (!newqueues) {
                        event_warn("%s: realloc",__func__);
                        goto done;
                }
                base->n_common_timeouts_allocated = n;
                base->common_timeout_queues = newqueues;
        }
        new_ctl = mm_calloc(1, sizeof(struct common_timeout_list));
        if (!new_ctl) {
                event_warn("%s: calloc",__func__);
                goto done;
        }
        TAILQ_INIT(&new_ctl->events);
        new_ctl->duration.tv_sec = duration->tv_sec;
        new_ctl->duration.tv_usec =
            duration->tv_usec | COMMON_TIMEOUT_MAGIC |
            (base->n_common_timeouts << COMMON_TIMEOUT_IDX_SHIFT);
        evtimer_assign(&new_ctl->timeout_event, base,
            common_timeout_callback, new_ctl);
        new_ctl->timeout_event.ev_flags |= EVLIST_INTERNAL;
        event_priority_set(&new_ctl->timeout_event, 0);
        new_ctl->base = base;
        base->common_timeout_queues[base->n_common_timeouts++] = new_ctl;
        result = &new_ctl->duration;

done:
        if (result)
                EVUTIL_ASSERT(is_common_timeout(result, base));

        EVBASE_RELEASE_LOCK(base, th_base_lock);
        return result;
}

/* Closure function invoked when we're activating a persistent event. */
static inline void
event_persist_closure(struct event_base *base, struct event *ev)
{
        void (*evcb_callback)(evutil_socket_t, short, void *);

        // Other fields of *ev that must be stored before executing
        evutil_socket_t evcb_fd;
        short evcb_res;
        void *evcb_arg;

        /* reschedule the persistent event if we have a timeout. */
        if (ev->ev_io_timeout.tv_sec || ev->ev_io_timeout.tv_usec) {
                /* If there was a timeout, we want it to run at an interval of
                 * ev_io_timeout after the last time it was _scheduled_ for,
                 * not ev_io_timeout after _now_.  If it fired for another
                 * reason, though, the timeout ought to start ticking _now_. */
                struct timeval run_at, relative_to, delay, now;
                ev_uint32_t usec_mask = 0;
                EVUTIL_ASSERT(is_same_common_timeout(&ev->ev_timeout,
                        &ev->ev_io_timeout));
                gettime(base, &now);
                if (is_common_timeout(&ev->ev_timeout, base)) {
                        delay = ev->ev_io_timeout;
                        usec_mask = delay.tv_usec & ~MICROSECONDS_MASK;
                        delay.tv_usec &= MICROSECONDS_MASK;
                        if (ev->ev_res & EV_TIMEOUT) {
                                relative_to = ev->ev_timeout;
                                relative_to.tv_usec &= MICROSECONDS_MASK;
                        } else {
                                relative_to = now;
                        }
                } else {
                        delay = ev->ev_io_timeout;
                        if (ev->ev_res & EV_TIMEOUT) {
                                relative_to = ev->ev_timeout;
                        } else {
                                relative_to = now;
                        }
                }
                evutil_timeradd(&relative_to, &delay, &run_at);
                if (evutil_timercmp(&run_at, &now, <)) {
                        /* Looks like we missed at least one invocation due to
                         * a clock jump, not running the event loop for a
                         * while, really slow callbacks, or
                         * something. Reschedule relative to now.
                         */
                        evutil_timeradd(&now, &delay, &run_at);
                }
                run_at.tv_usec |= usec_mask;
                event_add_nolock_(ev, &run_at, 1);
        }

        // Save our callback before we release the lock
        evcb_callback = ev->ev_callback;
        evcb_fd = ev->ev_fd;
        evcb_res = ev->ev_res;
        evcb_arg = ev->ev_arg;

        // Release the lock
        EVBASE_RELEASE_LOCK(base, th_base_lock);

        // Execute the callback
        (evcb_callback)(evcb_fd, evcb_res, evcb_arg);
}

/*
  Helper for event_process_active to process all the events in a single queue,
  releasing the lock as we go.  This function requires that the lock be held
  when it's invoked.  Returns -1 if we get a signal or an event_break that
  means we should stop processing any active events now.  Otherwise returns
  the number of non-internal event_callbacks that we processed.
*/
static int
event_process_active_single_queue(struct event_base *base,
    struct evcallback_list *activeq,
    int max_to_process, const struct timeval *endtime)
{
        struct event_callback *evcb;
        int count = 0;

        EVUTIL_ASSERT(activeq != NULL);

        for (evcb = TAILQ_FIRST(activeq); evcb; evcb = TAILQ_FIRST(activeq)) {
                struct event *ev=NULL;
                if (evcb->evcb_flags & EVLIST_INIT) {
                        ev = event_callback_to_event(evcb);

                        if (ev->ev_events & EV_PERSIST || ev->ev_flags & EVLIST_FINALIZING)
                                event_queue_remove_active(base, evcb);
                        else
                                event_del_nolock_(ev, EVENT_DEL_NOBLOCK);
                        event_debug((
                            "event_process_active: event: %p, %s%s%scall %p",
                            ev,
                            ev->ev_res & EV_READ ? "EV_READ " : " ",
                            ev->ev_res & EV_WRITE ? "EV_WRITE " : " ",
                            ev->ev_res & EV_CLOSED ? "EV_CLOSED " : " ",
                            ev->ev_callback));
                } else {
                        event_queue_remove_active(base, evcb);
                        event_debug(("event_process_active: event_callback %p, "
                                "closure %d, call %p",
                                evcb, evcb->evcb_closure, evcb->evcb_cb_union.evcb_callback));
                }

                if (!(evcb->evcb_flags & EVLIST_INTERNAL))
                        ++count;


                base->current_event = evcb;
#ifndef EVENT__DISABLE_THREAD_SUPPORT
                base->current_event_waiters = 0;
#endif

                switch (evcb->evcb_closure) {
                case EV_CLOSURE_EVENT_SIGNAL:
                        EVUTIL_ASSERT(ev != NULL);
                        event_signal_closure(base, ev);
                        break;
                case EV_CLOSURE_EVENT_PERSIST:
                        EVUTIL_ASSERT(ev != NULL);
                        event_persist_closure(base, ev);
                        break;
                case EV_CLOSURE_EVENT: {
                        void (*evcb_callback)(evutil_socket_t, short, void *);
                        EVUTIL_ASSERT(ev != NULL);
                        evcb_callback = *ev->ev_callback;
                        EVBASE_RELEASE_LOCK(base, th_base_lock);
                        evcb_callback(ev->ev_fd, ev->ev_res, ev->ev_arg);
                }
                break;
                case EV_CLOSURE_CB_SELF: {
                        void (*evcb_selfcb)(struct event_callback *, void *) = evcb->evcb_cb_union.evcb_selfcb;
                        EVBASE_RELEASE_LOCK(base, th_base_lock);
                        evcb_selfcb(evcb, evcb->evcb_arg);
                }
                break;
                case EV_CLOSURE_EVENT_FINALIZE:
                case EV_CLOSURE_EVENT_FINALIZE_FREE: {
                        void (*evcb_evfinalize)(struct event *, void *);
                        int evcb_closure = evcb->evcb_closure;
                        EVUTIL_ASSERT(ev != NULL);
                        base->current_event = NULL;
                        evcb_evfinalize = ev->ev_evcallback.evcb_cb_union.evcb_evfinalize;
                        EVUTIL_ASSERT((evcb->evcb_flags & EVLIST_FINALIZING));
                        EVBASE_RELEASE_LOCK(base, th_base_lock);
                        evcb_evfinalize(ev, ev->ev_arg);
                        event_debug_note_teardown_(ev);
                        if (evcb_closure == EV_CLOSURE_EVENT_FINALIZE_FREE)
                                mm_free(ev);
                }
                break;
                case EV_CLOSURE_CB_FINALIZE: {
                        void (*evcb_cbfinalize)(struct event_callback *, void *) = evcb->evcb_cb_union.evcb_cbfinalize;
                        base->current_event = NULL;
                        EVUTIL_ASSERT((evcb->evcb_flags & EVLIST_FINALIZING));
                        EVBASE_RELEASE_LOCK(base, th_base_lock);
                        evcb_cbfinalize(evcb, evcb->evcb_arg);
                }
                break;
                default:
                        EVUTIL_ASSERT(0);
                }

                EVBASE_ACQUIRE_LOCK(base, th_base_lock);
                base->current_event = NULL;
#ifndef EVENT__DISABLE_THREAD_SUPPORT
                if (base->current_event_waiters) {
                        base->current_event_waiters = 0;
                        EVTHREAD_COND_BROADCAST(base->current_event_cond);
                }
#endif

                if (base->event_break)
                        return -1;
                if (count >= max_to_process)
                        return count;
                if (count && endtime) {
                        struct timeval now;
                        update_time_cache(base);
                        gettime(base, &now);
                        if (evutil_timercmp(&now, endtime, >=))
                                return count;
                }
                if (base->event_continue)
                        break;
        }
        return count;
}

/*
 * Active events are stored in priority queues.  Lower priorities are always
 * process before higher priorities.  Low priority events can starve high
 * priority ones.
 */

static int
event_process_active(struct event_base *base)
{
        /* Caller must hold th_base_lock */
        struct evcallback_list *activeq = NULL;
        int i, c = 0;
        const struct timeval *endtime;
        struct timeval tv;
        const int maxcb = base->max_dispatch_callbacks;
        const int limit_after_prio = base->limit_callbacks_after_prio;
        if (base->max_dispatch_time.tv_sec >= 0) {
                update_time_cache(base);
                gettime(base, &tv);
                evutil_timeradd(&base->max_dispatch_time, &tv, &tv);
                endtime = &tv;
        } else {
                endtime = NULL;
        }

        for (i = 0; i < base->nactivequeues; ++i) {
                if (TAILQ_FIRST(&base->activequeues[i]) != NULL) {
                        base->event_running_priority = i;
                        activeq = &base->activequeues[i];
                        if (i < limit_after_prio)
                                c = event_process_active_single_queue(base, activeq,
                                    INT_MAX, NULL);
                        else
                                c = event_process_active_single_queue(base, activeq,
                                    maxcb, endtime);
                        if (c < 0) {
                                goto done;
                        } else if (c > 0)
                                break; /* Processed a real event; do not
                                        * consider lower-priority events */
                        /* If we get here, all of the events we processed
                         * were internal.  Continue. */
                }
        }

done:
        base->event_running_priority = -1;

        return c;
}

/*
 * Wait continuously for events.  We exit only if no events are left.
 */

int
event_dispatch(void)
{
        return (event_loop(0));
}

int
event_base_dispatch(struct event_base *event_base)
{
        return (event_base_loop(event_base, 0));
}

const char *
event_base_get_method(const struct event_base *base)
{
        EVUTIL_ASSERT(base);
        return (base->evsel->name);
}

/** Callback: used to implement event_base_loopexit by telling the event_base
 * that it's time to exit its loop. */
static void
event_loopexit_cb(evutil_socket_t fd, short what, void *arg)
{
        struct event_base *base = arg;
        base->event_gotterm = 1;
}

int
event_loopexit(const struct timeval *tv)
{
        return (event_once(-1, EV_TIMEOUT, event_loopexit_cb,
                    current_base, tv));
}

int
event_base_loopexit(struct event_base *event_base, const struct timeval *tv)
{
        return (event_base_once(event_base, -1, EV_TIMEOUT, event_loopexit_cb,
                    event_base, tv));
}

int
event_loopbreak(void)
{
        return (event_base_loopbreak(current_base));
}

int
event_base_loopbreak(struct event_base *event_base)
{
        int r = 0;
        if (event_base == NULL)
                return (-1);

        EVBASE_ACQUIRE_LOCK(event_base, th_base_lock);
        event_base->event_break = 1;

        if (EVBASE_NEED_NOTIFY(event_base)) {
                r = evthread_notify_base(event_base);
        } else {
                r = (0);
        }
        EVBASE_RELEASE_LOCK(event_base, th_base_lock);
        return r;
}

int
event_base_loopcontinue(struct event_base *event_base)
{
        int r = 0;
        if (event_base == NULL)
                return (-1);

        EVBASE_ACQUIRE_LOCK(event_base, th_base_lock);
        event_base->event_continue = 1;

        if (EVBASE_NEED_NOTIFY(event_base)) {
                r = evthread_notify_base(event_base);
        } else {
                r = (0);
        }
        EVBASE_RELEASE_LOCK(event_base, th_base_lock);
        return r;
}

int
event_base_got_break(struct event_base *event_base)
{
        int res;
        EVBASE_ACQUIRE_LOCK(event_base, th_base_lock);
        res = event_base->event_break;
        EVBASE_RELEASE_LOCK(event_base, th_base_lock);
        return res;
}

int
event_base_got_exit(struct event_base *event_base)
{
        int res;
        EVBASE_ACQUIRE_LOCK(event_base, th_base_lock);
        res = event_base->event_gotterm;
        EVBASE_RELEASE_LOCK(event_base, th_base_lock);
        return res;
}

/* not thread safe */

int
event_loop(int flags)
{
        return event_base_loop(current_base, flags);
}

int
event_base_loop(struct event_base *base, int flags)
{
        const struct eventop *evsel = base->evsel;
        struct timeval tv;
        struct timeval *tv_p;
        int res, done, retval = 0;

        /* Grab the lock.  We will release it inside evsel.dispatch, and again
         * as we invoke user callbacks. */
        EVBASE_ACQUIRE_LOCK(base, th_base_lock);

        if (base->running_loop) {
                event_warnx("%s: reentrant invocation.  Only one event_base_loop"
                    " can run on each event_base at once.", __func__);
                EVBASE_RELEASE_LOCK(base, th_base_lock);
                return -1;
        }

        base->running_loop = 1;

        clear_time_cache(base);

        if (base->sig.ev_signal_added && base->sig.ev_n_signals_added)
                evsig_set_base_(base);

        done = 0;

#ifndef EVENT__DISABLE_THREAD_SUPPORT
        base->th_owner_id = EVTHREAD_GET_ID();
#endif

        base->event_gotterm = base->event_break = 0;

        while (!done) {
                base->event_continue = 0;
                base->n_deferreds_queued = 0;

                /* Terminate the loop if we have been asked to */
                if (base->event_gotterm) {
                        break;
                }

                if (base->event_break) {
                        break;
                }

                tv_p = &tv;
                if (!N_ACTIVE_CALLBACKS(base) && !(flags & EVLOOP_NONBLOCK)) {
                        timeout_next(base, &tv_p);
                } else {
                        /*
                         * if we have active events, we just poll new events
                         * without waiting.
                         */
                        evutil_timerclear(&tv);
                }

                /* If we have no events, we just exit */
                if (0==(flags&EVLOOP_NO_EXIT_ON_EMPTY) &&
                    !event_haveevents(base) && !N_ACTIVE_CALLBACKS(base)) {
                        event_debug(("%s: no events registered.", __func__));
                        retval = 1;
                        goto done;
                }

                event_queue_make_later_events_active(base);

                clear_time_cache(base);

                res = evsel->dispatch(base, tv_p);

                if (res == -1) {
                        event_debug(("%s: dispatch returned unsuccessfully.",
                                __func__));
                        retval = -1;
                        goto done;
                }

                update_time_cache(base);

                timeout_process(base);

                if (N_ACTIVE_CALLBACKS(base)) {
                        int n = event_process_active(base);
                        if ((flags & EVLOOP_ONCE)
                            && N_ACTIVE_CALLBACKS(base) == 0
                            && n != 0)
                                done = 1;
                } else if (flags & EVLOOP_NONBLOCK)
                        done = 1;
        }
        event_debug(("%s: asked to terminate loop.", __func__));

done:
        clear_time_cache(base);
        base->running_loop = 0;

        EVBASE_RELEASE_LOCK(base, th_base_lock);

        return (retval);
}

/* One-time callback to implement event_base_once: invokes the user callback,
 * then deletes the allocated storage */
static void
event_once_cb(evutil_socket_t fd, short events, void *arg)
{
        struct event_once *eonce = arg;

        (*eonce->cb)(fd, events, eonce->arg);
        EVBASE_ACQUIRE_LOCK(eonce->ev.ev_base, th_base_lock);
        LIST_REMOVE(eonce, next_once);
        EVBASE_RELEASE_LOCK(eonce->ev.ev_base, th_base_lock);
        event_debug_unassign(&eonce->ev);
        mm_free(eonce);
}

/* not threadsafe, event scheduled once. */
int
event_once(evutil_socket_t fd, short events,
    void (*callback)(evutil_socket_t, short, void *),
    void *arg, const struct timeval *tv)
{
        return event_base_once(current_base, fd, events, callback, arg, tv);
}

/* Schedules an event once */
int
event_base_once(struct event_base *base, evutil_socket_t fd, short events,
    void (*callback)(evutil_socket_t, short, void *),
    void *arg, const struct timeval *tv)
{
        struct event_once *eonce;
        int res = 0;
        int activate = 0;

        /* We cannot support signals that just fire once, or persistent
         * events. */
        if (events & (EV_SIGNAL|EV_PERSIST))
                return (-1);

        if ((eonce = mm_calloc(1, sizeof(struct event_once))) == NULL)
                return (-1);

        eonce->cb = callback;
        eonce->arg = arg;

        if ((events & (EV_TIMEOUT|EV_SIGNAL|EV_READ|EV_WRITE|EV_CLOSED)) == EV_TIMEOUT) {
                evtimer_assign(&eonce->ev, base, event_once_cb, eonce);

                if (tv == NULL || ! evutil_timerisset(tv)) {
                        /* If the event is going to become active immediately,
                         * don't put it on the timeout queue.  This is one
                         * idiom for scheduling a callback, so let's make
                         * it fast (and order-preserving). */
                        activate = 1;
                }
        } else if (events & (EV_READ|EV_WRITE|EV_CLOSED)) {
                events &= EV_READ|EV_WRITE|EV_CLOSED;

                event_assign(&eonce->ev, base, fd, events, event_once_cb, eonce);
        } else {
                /* Bad event combination */
                mm_free(eonce);
                return (-1);
        }

        if (res == 0) {
                EVBASE_ACQUIRE_LOCK(base, th_base_lock);
                if (activate)
                        event_active_nolock_(&eonce->ev, EV_TIMEOUT, 1);
                else
                        res = event_add_nolock_(&eonce->ev, tv, 0);

                if (res != 0) {
                        mm_free(eonce);
                        return (res);
                } else {
                        LIST_INSERT_HEAD(&base->once_events, eonce, next_once);
                }
                EVBASE_RELEASE_LOCK(base, th_base_lock);
        }

        return (0);
}

int
event_assign(struct event *ev, struct event_base *base, evutil_socket_t fd, short events, void (*callback)(evutil_socket_t, short, void *), void *arg)
{
        if (!base)
                base = current_base;
        if (arg == &event_self_cbarg_ptr_)
                arg = ev;

        event_debug_assert_not_added_(ev);

        ev->ev_base = base;

        ev->ev_callback = callback;
        ev->ev_arg = arg;
        ev->ev_fd = fd;
        ev->ev_events = events;
        ev->ev_res = 0;
        ev->ev_flags = EVLIST_INIT;
        ev->ev_ncalls = 0;
        ev->ev_pncalls = NULL;

        if (events & EV_SIGNAL) {
                if ((events & (EV_READ|EV_WRITE|EV_CLOSED)) != 0) {
                        event_warnx("%s: EV_SIGNAL is not compatible with "
                            "EV_READ, EV_WRITE or EV_CLOSED", __func__);
                        return -1;
                }
                ev->ev_closure = EV_CLOSURE_EVENT_SIGNAL;
        } else {
                if (events & EV_PERSIST) {
                        evutil_timerclear(&ev->ev_io_timeout);
                        ev->ev_closure = EV_CLOSURE_EVENT_PERSIST;
                } else {
                        ev->ev_closure = EV_CLOSURE_EVENT;
                }
        }

        min_heap_elem_init_(ev);

        if (base != NULL) {
                /* by default, we put new events into the middle priority */
                ev->ev_pri = base->nactivequeues / 2;
        }

        event_debug_note_setup_(ev);

        return 0;
}

int
event_base_set(struct event_base *base, struct event *ev)
{
        /* Only innocent events may be assigned to a different base */
        if (ev->ev_flags != EVLIST_INIT)
                return (-1);

        event_debug_assert_is_setup_(ev);

        ev->ev_base = base;
        ev->ev_pri = base->nactivequeues/2;

        return (0);
}

void
event_set(struct event *ev, evutil_socket_t fd, short events,
          void (*callback)(evutil_socket_t, short, void *), void *arg)
{
        int r;
        r = event_assign(ev, current_base, fd, events, callback, arg);
        EVUTIL_ASSERT(r == 0);
}

void *
event_self_cbarg(void)
{
        return &event_self_cbarg_ptr_;
}

struct event *
event_base_get_running_event(struct event_base *base)
{
        struct event *ev = NULL;
        EVBASE_ACQUIRE_LOCK(base, th_base_lock);
        if (EVBASE_IN_THREAD(base)) {
                struct event_callback *evcb = base->current_event;
                if (evcb->evcb_flags & EVLIST_INIT)
                        ev = event_callback_to_event(evcb);
        }
        EVBASE_RELEASE_LOCK(base, th_base_lock);
        return ev;
}

struct event *
event_new(struct event_base *base, evutil_socket_t fd, short events, void (*cb)(evutil_socket_t, short, void *), void *arg)
{
        struct event *ev;
        ev = mm_malloc(sizeof(struct event));
        if (ev == NULL)
                return (NULL);
        if (event_assign(ev, base, fd, events, cb, arg) < 0) {
                mm_free(ev);
                return (NULL);
        }

        return (ev);
}

void
event_free(struct event *ev)
{
        /* This is disabled, so that events which have been finalized be a
         * valid target for event_free(). That's */
        // event_debug_assert_is_setup_(ev);

        /* make sure that this event won't be coming back to haunt us. */
        event_del(ev);
        event_debug_note_teardown_(ev);
        mm_free(ev);

}

void
event_debug_unassign(struct event *ev)
{
        event_debug_assert_not_added_(ev);
        event_debug_note_teardown_(ev);

        ev->ev_flags &= ~EVLIST_INIT;
}

#define EVENT_FINALIZE_FREE_ 0x10000
static int
event_finalize_nolock_(struct event_base *base, unsigned flags, struct event *ev, event_finalize_callback_fn cb)
{
        ev_uint8_t closure = (flags & EVENT_FINALIZE_FREE_) ?
            EV_CLOSURE_EVENT_FINALIZE_FREE : EV_CLOSURE_EVENT_FINALIZE;

        event_del_nolock_(ev, EVENT_DEL_NOBLOCK);
        ev->ev_closure = closure;
        ev->ev_evcallback.evcb_cb_union.evcb_evfinalize = cb;
        event_active_nolock_(ev, EV_FINALIZE, 1);
        ev->ev_flags |= EVLIST_FINALIZING;
        return 0;
}

static int
event_finalize_impl_(unsigned flags, struct event *ev, event_finalize_callback_fn cb)
{
        int r;
        struct event_base *base = ev->ev_base;
        if (EVUTIL_FAILURE_CHECK(!base)) {
                event_warnx("%s: event has no event_base set.", __func__);
                return -1;
        }

        EVBASE_ACQUIRE_LOCK(base, th_base_lock);
        r = event_finalize_nolock_(base, flags, ev, cb);
        EVBASE_RELEASE_LOCK(base, th_base_lock);
        return r;
}

int
event_finalize(unsigned flags, struct event *ev, event_finalize_callback_fn cb)
{
        return event_finalize_impl_(flags, ev, cb);
}

int
event_free_finalize(unsigned flags, struct event *ev, event_finalize_callback_fn cb)
{
        return event_finalize_impl_(flags|EVENT_FINALIZE_FREE_, ev, cb);
}

void
event_callback_finalize_nolock_(struct event_base *base, unsigned flags, struct event_callback *evcb, void (*cb)(struct event_callback *, void *))
{
        struct event *ev = NULL;
        if (evcb->evcb_flags & EVLIST_INIT) {
                ev = event_callback_to_event(evcb);
                event_del_nolock_(ev, EVENT_DEL_NOBLOCK);
        } else {
                event_callback_cancel_nolock_(base, evcb, 0); /*XXX can this fail?*/
        }

        evcb->evcb_closure = EV_CLOSURE_CB_FINALIZE;
        evcb->evcb_cb_union.evcb_cbfinalize = cb;
        event_callback_activate_nolock_(base, evcb); /* XXX can this really fail?*/
        evcb->evcb_flags |= EVLIST_FINALIZING;
}

void
event_callback_finalize_(struct event_base *base, unsigned flags, struct event_callback *evcb, void (*cb)(struct event_callback *, void *))
{
        EVBASE_ACQUIRE_LOCK(base, th_base_lock);
        event_callback_finalize_nolock_(base, flags, evcb, cb);
        EVBASE_RELEASE_LOCK(base, th_base_lock);
}

/** Internal: Finalize all of the n_cbs callbacks in evcbs.  The provided
 * callback will be invoked on *one of them*, after they have *all* been
 * finalized. */
int
event_callback_finalize_many_(struct event_base *base, int n_cbs, struct event_callback **evcbs, void (*cb)(struct event_callback *, void *))
{
        int n_pending = 0, i;

        if (base == NULL)
                base = current_base;

        EVBASE_ACQUIRE_LOCK(base, th_base_lock);

        event_debug(("%s: %d events finalizing", __func__, n_cbs));

        /* At most one can be currently executing; the rest we just
         * cancel... But we always make sure that the finalize callback
         * runs. */
        for (i = 0; i < n_cbs; ++i) {
                struct event_callback *evcb = evcbs[i];
                if (evcb == base->current_event) {
                        event_callback_finalize_nolock_(base, 0, evcb, cb);
                        ++n_pending;
                } else {
                        event_callback_cancel_nolock_(base, evcb, 0);
                }
        }

        if (n_pending == 0) {
                /* Just do the first one. */
                event_callback_finalize_nolock_(base, 0, evcbs[0], cb);
        }

        EVBASE_RELEASE_LOCK(base, th_base_lock);
        return 0;
}

/*
 * Set's the priority of an event - if an event is already scheduled
 * changing the priority is going to fail.
 */

int
event_priority_set(struct event *ev, int pri)
{
        event_debug_assert_is_setup_(ev);

        if (ev->ev_flags & EVLIST_ACTIVE)
                return (-1);
        if (pri < 0 || pri >= ev->ev_base->nactivequeues)
                return (-1);

        ev->ev_pri = pri;

        return (0);
}

/*
 * Checks if a specific event is pending or scheduled.
 */

int
event_pending(const struct event *ev, short event, struct timeval *tv)
{
        int flags = 0;

        if (EVUTIL_FAILURE_CHECK(ev->ev_base == NULL)) {
                event_warnx("%s: event has no event_base set.", __func__);
                return 0;
        }

        EVBASE_ACQUIRE_LOCK(ev->ev_base, th_base_lock);
        event_debug_assert_is_setup_(ev);

        if (ev->ev_flags & EVLIST_INSERTED)
                flags |= (ev->ev_events & (EV_READ|EV_WRITE|EV_CLOSED|EV_SIGNAL));
        if (ev->ev_flags & (EVLIST_ACTIVE|EVLIST_ACTIVE_LATER))
                flags |= ev->ev_res;
        if (ev->ev_flags & EVLIST_TIMEOUT)
                flags |= EV_TIMEOUT;

        event &= (EV_TIMEOUT|EV_READ|EV_WRITE|EV_CLOSED|EV_SIGNAL);

        /* See if there is a timeout that we should report */
        if (tv != NULL && (flags & event & EV_TIMEOUT)) {
                struct timeval tmp = ev->ev_timeout;
                tmp.tv_usec &= MICROSECONDS_MASK;
                /* correctly remamp to real time */
                evutil_timeradd(&ev->ev_base->tv_clock_diff, &tmp, tv);
        }

        EVBASE_RELEASE_LOCK(ev->ev_base, th_base_lock);

        return (flags & event);
}

int
event_initialized(const struct event *ev)
{
        if (!(ev->ev_flags & EVLIST_INIT))
                return 0;

        return 1;
}

void
event_get_assignment(const struct event *event, struct event_base **base_out, evutil_socket_t *fd_out, short *events_out, event_callback_fn *callback_out, void **arg_out)
{
        event_debug_assert_is_setup_(event);

        if (base_out)
                *base_out = event->ev_base;
        if (fd_out)
                *fd_out = event->ev_fd;
        if (events_out)
                *events_out = event->ev_events;
        if (callback_out)
                *callback_out = event->ev_callback;
        if (arg_out)
                *arg_out = event->ev_arg;
}

size_t
event_get_struct_event_size(void)
{
        return sizeof(struct event);
}

evutil_socket_t
event_get_fd(const struct event *ev)
{
        event_debug_assert_is_setup_(ev);
        return ev->ev_fd;
}

struct event_base *
event_get_base(const struct event *ev)
{
        event_debug_assert_is_setup_(ev);
        return ev->ev_base;
}

short
event_get_events(const struct event *ev)
{
        event_debug_assert_is_setup_(ev);
        return ev->ev_events;
}

event_callback_fn
event_get_callback(const struct event *ev)
{
        event_debug_assert_is_setup_(ev);
        return ev->ev_callback;
}

void *
event_get_callback_arg(const struct event *ev)
{
        event_debug_assert_is_setup_(ev);
        return ev->ev_arg;
}

int
event_get_priority(const struct event *ev)
{
        event_debug_assert_is_setup_(ev);
        return ev->ev_pri;
}

int
event_add(struct event *ev, const struct timeval *tv)
{
        int res;

        if (EVUTIL_FAILURE_CHECK(!ev->ev_base)) {
                event_warnx("%s: event has no event_base set.", __func__);
                return -1;
        }

        EVBASE_ACQUIRE_LOCK(ev->ev_base, th_base_lock);

        res = event_add_nolock_(ev, tv, 0);

        EVBASE_RELEASE_LOCK(ev->ev_base, th_base_lock);

        return (res);
}

/* Helper callback: wake an event_base from another thread.  This version
 * works by writing a byte to one end of a socketpair, so that the event_base
 * listening on the other end will wake up as the corresponding event
 * triggers */
static int
evthread_notify_base_default(struct event_base *base)
{
        char buf[1];
        int r;
        buf[0] = (char) 0;
#ifdef _WIN32
        r = send(base->th_notify_fd[1], buf, 1, 0);
#else
        r = write(base->th_notify_fd[1], buf, 1);
#endif
        return (r < 0 && ! EVUTIL_ERR_IS_EAGAIN(errno)) ? -1 : 0;
}

#ifdef EVENT__HAVE_EVENTFD
/* Helper callback: wake an event_base from another thread.  This version
 * assumes that you have a working eventfd() implementation. */
static int
evthread_notify_base_eventfd(struct event_base *base)
{
        ev_uint64_t msg = 1;
        int r;
        do {
                r = write(base->th_notify_fd[0], (void*) &msg, sizeof(msg));
        } while (r < 0 && errno == EAGAIN);

        return (r < 0) ? -1 : 0;
}
#endif


/** Tell the thread currently running the event_loop for base (if any) that it
 * needs to stop waiting in its dispatch function (if it is) and process all
 * active callbacks. */
static int
evthread_notify_base(struct event_base *base)
{
        EVENT_BASE_ASSERT_LOCKED(base);
        if (!base->th_notify_fn)
                return -1;
        if (base->is_notify_pending)
                return 0;
        base->is_notify_pending = 1;
        return base->th_notify_fn(base);
}

/* Implementation function to remove a timeout on a currently pending event.
 */
int
event_remove_timer_nolock_(struct event *ev)
{
        struct event_base *base = ev->ev_base;

        EVENT_BASE_ASSERT_LOCKED(base);
        event_debug_assert_is_setup_(ev);

        event_debug(("event_remove_timer_nolock: event: %p", ev));

        /* If it's not pending on a timeout, we don't need to do anything. */
        if (ev->ev_flags & EVLIST_TIMEOUT) {
                event_queue_remove_timeout(base, ev);
                evutil_timerclear(&ev->ev_.ev_io.ev_timeout);
        }

        return (0);
}

int
event_remove_timer(struct event *ev)
{
        int res;

        if (EVUTIL_FAILURE_CHECK(!ev->ev_base)) {
                event_warnx("%s: event has no event_base set.", __func__);
                return -1;
        }

        EVBASE_ACQUIRE_LOCK(ev->ev_base, th_base_lock);

        res = event_remove_timer_nolock_(ev);

        EVBASE_RELEASE_LOCK(ev->ev_base, th_base_lock);

        return (res);
}

/* Implementation function to add an event.  Works just like event_add,
 * except: 1) it requires that we have the lock.  2) if tv_is_absolute is set,
 * we treat tv as an absolute time, not as an interval to add to the current
 * time */
int
event_add_nolock_(struct event *ev, const struct timeval *tv,
    int tv_is_absolute)
{
        struct event_base *base = ev->ev_base;
        int res = 0;
        int notify = 0;

        EVENT_BASE_ASSERT_LOCKED(base);
        event_debug_assert_is_setup_(ev);

        event_debug((
                 "event_add: event: %p (fd "EV_SOCK_FMT"), %s%s%s%scall %p",
                 ev,
                 EV_SOCK_ARG(ev->ev_fd),
                 ev->ev_events & EV_READ ? "EV_READ " : " ",
                 ev->ev_events & EV_WRITE ? "EV_WRITE " : " ",
                 ev->ev_events & EV_CLOSED ? "EV_CLOSED " : " ",
                 tv ? "EV_TIMEOUT " : " ",
                 ev->ev_callback));

        EVUTIL_ASSERT(!(ev->ev_flags & ~EVLIST_ALL));

        if (ev->ev_flags & EVLIST_FINALIZING) {
                /* XXXX debug */
                return (-1);
        }

        /*
         * prepare for timeout insertion further below, if we get a
         * failure on any step, we should not change any state.
         */
        if (tv != NULL && !(ev->ev_flags & EVLIST_TIMEOUT)) {
                if (min_heap_reserve_(&base->timeheap,
                        1 + min_heap_size_(&base->timeheap)) == -1)
                        return (-1);  /* ENOMEM == errno */
        }

        /* If the main thread is currently executing a signal event's
         * callback, and we are not the main thread, then we want to wait
         * until the callback is done before we mess with the event, or else
         * we can race on ev_ncalls and ev_pncalls below. */
#ifndef EVENT__DISABLE_THREAD_SUPPORT
        if (base->current_event == event_to_event_callback(ev) &&
            (ev->ev_events & EV_SIGNAL)
            && !EVBASE_IN_THREAD(base)) {
                ++base->current_event_waiters;
                EVTHREAD_COND_WAIT(base->current_event_cond, base->th_base_lock);
        }
#endif

        if ((ev->ev_events & (EV_READ|EV_WRITE|EV_CLOSED|EV_SIGNAL)) &&
            !(ev->ev_flags & (EVLIST_INSERTED|EVLIST_ACTIVE|EVLIST_ACTIVE_LATER))) {
                if (ev->ev_events & (EV_READ|EV_WRITE|EV_CLOSED))
                        res = evmap_io_add_(base, ev->ev_fd, ev);
                else if (ev->ev_events & EV_SIGNAL)
                        res = evmap_signal_add_(base, (int)ev->ev_fd, ev);
                if (res != -1)
                        event_queue_insert_inserted(base, ev);
                if (res == 1) {
                        /* evmap says we need to notify the main thread. */
                        notify = 1;
                        res = 0;
                }
        }

        /*
         * we should change the timeout state only if the previous event
         * addition succeeded.
         */
        if (res != -1 && tv != NULL) {
                struct timeval now;
                int common_timeout;
#ifdef USE_REINSERT_TIMEOUT
                int was_common;
                int old_timeout_idx;
#endif

                /*
                 * for persistent timeout events, we remember the
                 * timeout value and re-add the event.
                 *
                 * If tv_is_absolute, this was already set.
                 */
                if (ev->ev_closure == EV_CLOSURE_EVENT_PERSIST && !tv_is_absolute)
                        ev->ev_io_timeout = *tv;

#ifndef USE_REINSERT_TIMEOUT
                if (ev->ev_flags & EVLIST_TIMEOUT) {
                        event_queue_remove_timeout(base, ev);
                }
#endif

                /* Check if it is active due to a timeout.  Rescheduling
                 * this timeout before the callback can be executed
                 * removes it from the active list. */
                if ((ev->ev_flags & EVLIST_ACTIVE) &&
                    (ev->ev_res & EV_TIMEOUT)) {
                        if (ev->ev_events & EV_SIGNAL) {
                                /* See if we are just active executing
                                 * this event in a loop
                                 */
                                if (ev->ev_ncalls && ev->ev_pncalls) {
                                        /* Abort loop */
                                        *ev->ev_pncalls = 0;
                                }
                        }

                        event_queue_remove_active(base, event_to_event_callback(ev));
                }

                gettime(base, &now);

                common_timeout = is_common_timeout(tv, base);
#ifdef USE_REINSERT_TIMEOUT
                was_common = is_common_timeout(&ev->ev_timeout, base);
                old_timeout_idx = COMMON_TIMEOUT_IDX(&ev->ev_timeout);
#endif

                if (tv_is_absolute) {
                        ev->ev_timeout = *tv;
                } else if (common_timeout) {
                        struct timeval tmp = *tv;
                        tmp.tv_usec &= MICROSECONDS_MASK;
                        evutil_timeradd(&now, &tmp, &ev->ev_timeout);
                        ev->ev_timeout.tv_usec |=
                            (tv->tv_usec & ~MICROSECONDS_MASK);
                } else {
                        evutil_timeradd(&now, tv, &ev->ev_timeout);
                }

                event_debug((
                         "event_add: event %p, timeout in %d seconds %d useconds, call %p",
                         ev, (int)tv->tv_sec, (int)tv->tv_usec, ev->ev_callback));

#ifdef USE_REINSERT_TIMEOUT
                event_queue_reinsert_timeout(base, ev, was_common, common_timeout, old_timeout_idx);
#else
                event_queue_insert_timeout(base, ev);
#endif

                if (common_timeout) {
                        struct common_timeout_list *ctl =
                            get_common_timeout_list(base, &ev->ev_timeout);
                        if (ev == TAILQ_FIRST(&ctl->events)) {
                                common_timeout_schedule(ctl, &now, ev);
                        }
                } else {
                        struct event* top = NULL;
                        /* See if the earliest timeout is now earlier than it
                         * was before: if so, we will need to tell the main
                         * thread to wake up earlier than it would otherwise.
                         * We double check the timeout of the top element to
                         * handle time distortions due to system suspension.
                         */
                        if (min_heap_elt_is_top_(ev))
                                notify = 1;
                        else if ((top = min_heap_top_(&base->timeheap)) != NULL &&
                                         evutil_timercmp(&top->ev_timeout, &now, <))
                                notify = 1;
                }
        }

        /* if we are not in the right thread, we need to wake up the loop */
        if (res != -1 && notify && EVBASE_NEED_NOTIFY(base))
                evthread_notify_base(base);

        event_debug_note_add_(ev);

        return (res);
}

static int
event_del_(struct event *ev, int blocking)
{
        int res;

        if (EVUTIL_FAILURE_CHECK(!ev->ev_base)) {
                event_warnx("%s: event has no event_base set.", __func__);
                return -1;
        }

        EVBASE_ACQUIRE_LOCK(ev->ev_base, th_base_lock);

        res = event_del_nolock_(ev, blocking);

        EVBASE_RELEASE_LOCK(ev->ev_base, th_base_lock);

        return (res);
}

int
event_del(struct event *ev)
{
        return event_del_(ev, EVENT_DEL_AUTOBLOCK);
}

int
event_del_block(struct event *ev)
{
        return event_del_(ev, EVENT_DEL_BLOCK);
}

int
event_del_noblock(struct event *ev)
{
        return event_del_(ev, EVENT_DEL_NOBLOCK);
}

/** Helper for event_del: always called with th_base_lock held.
 *
 * "blocking" must be one of the EVENT_DEL_{BLOCK, NOBLOCK, AUTOBLOCK,
 * EVEN_IF_FINALIZING} values. See those for more information.
 */
int
event_del_nolock_(struct event *ev, int blocking)
{
        struct event_base *base;
        int res = 0, notify = 0;

        event_debug(("event_del: %p (fd "EV_SOCK_FMT"), callback %p",
                ev, EV_SOCK_ARG(ev->ev_fd), ev->ev_callback));

        /* An event without a base has not been added */
        if (ev->ev_base == NULL)
                return (-1);

        EVENT_BASE_ASSERT_LOCKED(ev->ev_base);

        if (blocking != EVENT_DEL_EVEN_IF_FINALIZING) {
                if (ev->ev_flags & EVLIST_FINALIZING) {
                        /* XXXX Debug */
                        return 0;
                }
        }

        /* If the main thread is currently executing this event's callback,
         * and we are not the main thread, then we want to wait until the
         * callback is done before we start removing the event.  That way,
         * when this function returns, it will be safe to free the
         * user-supplied argument. */
        base = ev->ev_base;
#ifndef EVENT__DISABLE_THREAD_SUPPORT
        if (blocking != EVENT_DEL_NOBLOCK &&
            base->current_event == event_to_event_callback(ev) &&
            !EVBASE_IN_THREAD(base) &&
            (blocking == EVENT_DEL_BLOCK || !(ev->ev_events & EV_FINALIZE))) {
                ++base->current_event_waiters;
                EVTHREAD_COND_WAIT(base->current_event_cond, base->th_base_lock);
        }
#endif

        EVUTIL_ASSERT(!(ev->ev_flags & ~EVLIST_ALL));

        /* See if we are just active executing this event in a loop */
        if (ev->ev_events & EV_SIGNAL) {
                if (ev->ev_ncalls && ev->ev_pncalls) {
                        /* Abort loop */
                        *ev->ev_pncalls = 0;
                }
        }

        if (ev->ev_flags & EVLIST_TIMEOUT) {
                /* NOTE: We never need to notify the main thread because of a
                 * deleted timeout event: all that could happen if we don't is
                 * that the dispatch loop might wake up too early.  But the
                 * point of notifying the main thread _is_ to wake up the
                 * dispatch loop early anyway, so we wouldn't gain anything by
                 * doing it.
                 */
                event_queue_remove_timeout(base, ev);
        }

        if (ev->ev_flags & EVLIST_ACTIVE)
                event_queue_remove_active(base, event_to_event_callback(ev));
        else if (ev->ev_flags & EVLIST_ACTIVE_LATER)
                event_queue_remove_active_later(base, event_to_event_callback(ev));

        if (ev->ev_flags & EVLIST_INSERTED) {
                event_queue_remove_inserted(base, ev);
                if (ev->ev_events & (EV_READ|EV_WRITE|EV_CLOSED))
                        res = evmap_io_del_(base, ev->ev_fd, ev);
                else
                        res = evmap_signal_del_(base, (int)ev->ev_fd, ev);
                if (res == 1) {
                        /* evmap says we need to notify the main thread. */
                        notify = 1;
                        res = 0;
                }
        }

        /* if we are not in the right thread, we need to wake up the loop */
        if (res != -1 && notify && EVBASE_NEED_NOTIFY(base))
                evthread_notify_base(base);

        event_debug_note_del_(ev);

        return (res);
}

void
event_active(struct event *ev, int res, short ncalls)
{
        if (EVUTIL_FAILURE_CHECK(!ev->ev_base)) {
                event_warnx("%s: event has no event_base set.", __func__);
                return;
        }

        EVBASE_ACQUIRE_LOCK(ev->ev_base, th_base_lock);

        event_debug_assert_is_setup_(ev);

        event_active_nolock_(ev, res, ncalls);

        EVBASE_RELEASE_LOCK(ev->ev_base, th_base_lock);
}


void
event_active_nolock_(struct event *ev, int res, short ncalls)
{
        struct event_base *base;

        event_debug(("event_active: %p (fd "EV_SOCK_FMT"), res %d, callback %p",
                ev, EV_SOCK_ARG(ev->ev_fd), (int)res, ev->ev_callback));

        base = ev->ev_base;
        EVENT_BASE_ASSERT_LOCKED(base);

        if (ev->ev_flags & EVLIST_FINALIZING) {
                /* XXXX debug */
                return;
        }

        switch ((ev->ev_flags & (EVLIST_ACTIVE|EVLIST_ACTIVE_LATER))) {
        default:
        case EVLIST_ACTIVE|EVLIST_ACTIVE_LATER:
                EVUTIL_ASSERT(0);
                break;
        case EVLIST_ACTIVE:
                /* We get different kinds of events, add them together */
                ev->ev_res |= res;
                return;
        case EVLIST_ACTIVE_LATER:
                ev->ev_res |= res;
                break;
        case 0:
                ev->ev_res = res;
                break;
        }

        if (ev->ev_pri < base->event_running_priority)
                base->event_continue = 1;

        if (ev->ev_events & EV_SIGNAL) {
#ifndef EVENT__DISABLE_THREAD_SUPPORT
                if (base->current_event == event_to_event_callback(ev) &&
                    !EVBASE_IN_THREAD(base)) {
                        ++base->current_event_waiters;
                        EVTHREAD_COND_WAIT(base->current_event_cond, base->th_base_lock);
                }
#endif
                ev->ev_ncalls = ncalls;
                ev->ev_pncalls = NULL;
        }

        event_callback_activate_nolock_(base, event_to_event_callback(ev));
}

void
event_active_later_(struct event *ev, int res)
{
        EVBASE_ACQUIRE_LOCK(ev->ev_base, th_base_lock);
        event_active_later_nolock_(ev, res);
        EVBASE_RELEASE_LOCK(ev->ev_base, th_base_lock);
}

void
event_active_later_nolock_(struct event *ev, int res)
{
        struct event_base *base = ev->ev_base;
        EVENT_BASE_ASSERT_LOCKED(base);

        if (ev->ev_flags & (EVLIST_ACTIVE|EVLIST_ACTIVE_LATER)) {
                /* We get different kinds of events, add them together */
                ev->ev_res |= res;
                return;
        }

        ev->ev_res = res;

        event_callback_activate_later_nolock_(base, event_to_event_callback(ev));
}

int
event_callback_activate_(struct event_base *base,
    struct event_callback *evcb)
{
        int r;
        EVBASE_ACQUIRE_LOCK(base, th_base_lock);
        r = event_callback_activate_nolock_(base, evcb);
        EVBASE_RELEASE_LOCK(base, th_base_lock);
        return r;
}

int
event_callback_activate_nolock_(struct event_base *base,
    struct event_callback *evcb)
{
        int r = 1;

        if (evcb->evcb_flags & EVLIST_FINALIZING)
                return 0;

        switch (evcb->evcb_flags & (EVLIST_ACTIVE|EVLIST_ACTIVE_LATER)) {
        default:
                EVUTIL_ASSERT(0);
        case EVLIST_ACTIVE_LATER:
                event_queue_remove_active_later(base, evcb);
                r = 0;
                break;
        case EVLIST_ACTIVE:
                return 0;
        case 0:
                break;
        }

        event_queue_insert_active(base, evcb);

        if (EVBASE_NEED_NOTIFY(base))
                evthread_notify_base(base);

        return r;
}

int
event_callback_activate_later_nolock_(struct event_base *base,
    struct event_callback *evcb)
{
        if (evcb->evcb_flags & (EVLIST_ACTIVE|EVLIST_ACTIVE_LATER))
                return 0;

        event_queue_insert_active_later(base, evcb);
        if (EVBASE_NEED_NOTIFY(base))
                evthread_notify_base(base);
        return 1;
}

void
event_callback_init_(struct event_base *base,
    struct event_callback *cb)
{
        memset(cb, 0, sizeof(*cb));
        cb->evcb_pri = base->nactivequeues - 1;
}

int
event_callback_cancel_(struct event_base *base,
    struct event_callback *evcb)
{
        int r;
        EVBASE_ACQUIRE_LOCK(base, th_base_lock);
        r = event_callback_cancel_nolock_(base, evcb, 0);
        EVBASE_RELEASE_LOCK(base, th_base_lock);
        return r;
}

int
event_callback_cancel_nolock_(struct event_base *base,
    struct event_callback *evcb, int even_if_finalizing)
{
        if ((evcb->evcb_flags & EVLIST_FINALIZING) && !even_if_finalizing)
                return 0;

        if (evcb->evcb_flags & EVLIST_INIT)
                return event_del_nolock_(event_callback_to_event(evcb),
                    even_if_finalizing ? EVENT_DEL_EVEN_IF_FINALIZING : EVENT_DEL_AUTOBLOCK);

        switch ((evcb->evcb_flags & (EVLIST_ACTIVE|EVLIST_ACTIVE_LATER))) {
        default:
        case EVLIST_ACTIVE|EVLIST_ACTIVE_LATER:
                EVUTIL_ASSERT(0);
                break;
        case EVLIST_ACTIVE:
                /* We get different kinds of events, add them together */
                event_queue_remove_active(base, evcb);
                return 0;
        case EVLIST_ACTIVE_LATER:
                event_queue_remove_active_later(base, evcb);
                break;
        case 0:
                break;
        }

        return 0;
}

void
event_deferred_cb_init_(struct event_callback *cb, ev_uint8_t priority, deferred_cb_fn fn, void *arg)
{
        memset(cb, 0, sizeof(*cb));
        cb->evcb_cb_union.evcb_selfcb = fn;
        cb->evcb_arg = arg;
        cb->evcb_pri = priority;
        cb->evcb_closure = EV_CLOSURE_CB_SELF;
}

void
event_deferred_cb_set_priority_(struct event_callback *cb, ev_uint8_t priority)
{
        cb->evcb_pri = priority;
}

void
event_deferred_cb_cancel_(struct event_base *base, struct event_callback *cb)
{
        if (!base)
                base = current_base;
        event_callback_cancel_(base, cb);
}

#define MAX_DEFERREDS_QUEUED 32
int
event_deferred_cb_schedule_(struct event_base *base, struct event_callback *cb)
{
        int r = 1;
        if (!base)
                base = current_base;
        EVBASE_ACQUIRE_LOCK(base, th_base_lock);
        if (base->n_deferreds_queued > MAX_DEFERREDS_QUEUED) {
                r = event_callback_activate_later_nolock_(base, cb);
        } else {
                r = event_callback_activate_nolock_(base, cb);
                if (r) {
                        ++base->n_deferreds_queued;
                }
        }
        EVBASE_RELEASE_LOCK(base, th_base_lock);
        return r;
}

static int
timeout_next(struct event_base *base, struct timeval **tv_p)
{
        /* Caller must hold th_base_lock */
        struct timeval now;
        struct event *ev;
        struct timeval *tv = *tv_p;
        int res = 0;

        ev = min_heap_top_(&base->timeheap);

        if (ev == NULL) {
                /* if no time-based events are active wait for I/O */
                *tv_p = NULL;
                goto out;
        }

        if (gettime(base, &now) == -1) {
                res = -1;
                goto out;
        }

        if (evutil_timercmp(&ev->ev_timeout, &now, <=)) {
                evutil_timerclear(tv);
                goto out;
        }

        evutil_timersub(&ev->ev_timeout, &now, tv);

        EVUTIL_ASSERT(tv->tv_sec >= 0);
        EVUTIL_ASSERT(tv->tv_usec >= 0);
        event_debug(("timeout_next: event: %p, in %d seconds, %d useconds", ev, (int)tv->tv_sec, (int)tv->tv_usec));

out:
        return (res);
}

/* Activate every event whose timeout has elapsed. */
static void
timeout_process(struct event_base *base)
{
        /* Caller must hold lock. */
        struct timeval now;
        struct event *ev;

        if (min_heap_empty_(&base->timeheap)) {
                return;
        }

        gettime(base, &now);

        while ((ev = min_heap_top_(&base->timeheap))) {
                if (evutil_timercmp(&ev->ev_timeout, &now, >))
                        break;

                /* delete this event from the I/O queues */
                event_del_nolock_(ev, EVENT_DEL_NOBLOCK);

                event_debug(("timeout_process: event: %p, call %p",
                         ev, ev->ev_callback));
                event_active_nolock_(ev, EV_TIMEOUT, 1);
        }
}

#if (EVLIST_INTERNAL >> 4) != 1
#error "Mismatch for value of EVLIST_INTERNAL"
#endif

#ifndef MAX
#define MAX(a,b) (((a)>(b))?(a):(b))
#endif

#define MAX_EVENT_COUNT(var, v) var = MAX(var, v)

/* These are a fancy way to spell
     if (flags & EVLIST_INTERNAL)
         base->event_count--/++;
*/
#define DECR_EVENT_COUNT(base,flags) \
        ((base)->event_count -= (~((flags) >> 4) & 1))
#define INCR_EVENT_COUNT(base,flags) do {                                       \
        ((base)->event_count += (~((flags) >> 4) & 1));                         \
        MAX_EVENT_COUNT((base)->event_count_max, (base)->event_count);          \
} while (0)

static void
event_queue_remove_inserted(struct event_base *base, struct event *ev)
{
        EVENT_BASE_ASSERT_LOCKED(base);
        if (EVUTIL_FAILURE_CHECK(!(ev->ev_flags & EVLIST_INSERTED))) {
                event_errx(1, "%s: %p(fd "EV_SOCK_FMT") not on queue %x", __func__,
                    ev, EV_SOCK_ARG(ev->ev_fd), EVLIST_INSERTED);
                return;
        }
        DECR_EVENT_COUNT(base, ev->ev_flags);
        ev->ev_flags &= ~EVLIST_INSERTED;
}
static void
event_queue_remove_active(struct event_base *base, struct event_callback *evcb)
{
        EVENT_BASE_ASSERT_LOCKED(base);
        if (EVUTIL_FAILURE_CHECK(!(evcb->evcb_flags & EVLIST_ACTIVE))) {
                event_errx(1, "%s: %p not on queue %x", __func__,
                           evcb, EVLIST_ACTIVE);
                return;
        }
        DECR_EVENT_COUNT(base, evcb->evcb_flags);
        evcb->evcb_flags &= ~EVLIST_ACTIVE;
        base->event_count_active--;

        TAILQ_REMOVE(&base->activequeues[evcb->evcb_pri],
            evcb, evcb_active_next);
}
static void
event_queue_remove_active_later(struct event_base *base, struct event_callback *evcb)
{
        EVENT_BASE_ASSERT_LOCKED(base);
        if (EVUTIL_FAILURE_CHECK(!(evcb->evcb_flags & EVLIST_ACTIVE_LATER))) {
                event_errx(1, "%s: %p not on queue %x", __func__,
                           evcb, EVLIST_ACTIVE_LATER);
                return;
        }
        DECR_EVENT_COUNT(base, evcb->evcb_flags);
        evcb->evcb_flags &= ~EVLIST_ACTIVE_LATER;
        base->event_count_active--;

        TAILQ_REMOVE(&base->active_later_queue, evcb, evcb_active_next);
}
static void
event_queue_remove_timeout(struct event_base *base, struct event *ev)
{
        EVENT_BASE_ASSERT_LOCKED(base);
        if (EVUTIL_FAILURE_CHECK(!(ev->ev_flags & EVLIST_TIMEOUT))) {
                event_errx(1, "%s: %p(fd "EV_SOCK_FMT") not on queue %x", __func__,
                    ev, EV_SOCK_ARG(ev->ev_fd), EVLIST_TIMEOUT);
                return;
        }
        DECR_EVENT_COUNT(base, ev->ev_flags);
        ev->ev_flags &= ~EVLIST_TIMEOUT;

        if (is_common_timeout(&ev->ev_timeout, base)) {
                struct common_timeout_list *ctl =
                    get_common_timeout_list(base, &ev->ev_timeout);
                TAILQ_REMOVE(&ctl->events, ev,
                    ev_timeout_pos.ev_next_with_common_timeout);
        } else {
                min_heap_erase_(&base->timeheap, ev);
        }
}

#ifdef USE_REINSERT_TIMEOUT
/* Remove and reinsert 'ev' into the timeout queue. */
static void
event_queue_reinsert_timeout(struct event_base *base, struct event *ev,
    int was_common, int is_common, int old_timeout_idx)
{
        struct common_timeout_list *ctl;
        if (!(ev->ev_flags & EVLIST_TIMEOUT)) {
                event_queue_insert_timeout(base, ev);
                return;
        }

        switch ((was_common<<1) | is_common) {
        case 3: /* Changing from one common timeout to another */
                ctl = base->common_timeout_queues[old_timeout_idx];
                TAILQ_REMOVE(&ctl->events, ev,
                    ev_timeout_pos.ev_next_with_common_timeout);
                ctl = get_common_timeout_list(base, &ev->ev_timeout);
                insert_common_timeout_inorder(ctl, ev);
                break;
        case 2: /* Was common; is no longer common */
                ctl = base->common_timeout_queues[old_timeout_idx];
                TAILQ_REMOVE(&ctl->events, ev,
                    ev_timeout_pos.ev_next_with_common_timeout);
                min_heap_push_(&base->timeheap, ev);
                break;
        case 1: /* Wasn't common; has become common. */
                min_heap_erase_(&base->timeheap, ev);
                ctl = get_common_timeout_list(base, &ev->ev_timeout);
                insert_common_timeout_inorder(ctl, ev);
                break;
        case 0: /* was in heap; is still on heap. */
                min_heap_adjust_(&base->timeheap, ev);
                break;
        default:
                EVUTIL_ASSERT(0); /* unreachable */
                break;
        }
}
#endif

/* Add 'ev' to the common timeout list in 'ev'. */
static void
insert_common_timeout_inorder(struct common_timeout_list *ctl,
    struct event *ev)
{
        struct event *e;
        /* By all logic, we should just be able to append 'ev' to the end of
         * ctl->events, since the timeout on each 'ev' is set to {the common
         * timeout} + {the time when we add the event}, and so the events
         * should arrive in order of their timeeouts.  But just in case
         * there's some wacky threading issue going on, we do a search from
         * the end of 'ev' to find the right insertion point.
         */
        TAILQ_FOREACH_REVERSE(e, &ctl->events,
            event_list, ev_timeout_pos.ev_next_with_common_timeout) {
                /* This timercmp is a little sneaky, since both ev and e have
                 * magic values in tv_usec.  Fortunately, they ought to have
                 * the _same_ magic values in tv_usec.  Let's assert for that.
                 */
                EVUTIL_ASSERT(
                        is_same_common_timeout(&e->ev_timeout, &ev->ev_timeout));
                if (evutil_timercmp(&ev->ev_timeout, &e->ev_timeout, >=)) {
                        TAILQ_INSERT_AFTER(&ctl->events, e, ev,
                            ev_timeout_pos.ev_next_with_common_timeout);
                        return;
                }
        }
        TAILQ_INSERT_HEAD(&ctl->events, ev,
            ev_timeout_pos.ev_next_with_common_timeout);
}

static void
event_queue_insert_inserted(struct event_base *base, struct event *ev)
{
        EVENT_BASE_ASSERT_LOCKED(base);

        if (EVUTIL_FAILURE_CHECK(ev->ev_flags & EVLIST_INSERTED)) {
                event_errx(1, "%s: %p(fd "EV_SOCK_FMT") already inserted", __func__,
                    ev, EV_SOCK_ARG(ev->ev_fd));
                return;
        }

        INCR_EVENT_COUNT(base, ev->ev_flags);

        ev->ev_flags |= EVLIST_INSERTED;
}

static void
event_queue_insert_active(struct event_base *base, struct event_callback *evcb)
{
        EVENT_BASE_ASSERT_LOCKED(base);

        if (evcb->evcb_flags & EVLIST_ACTIVE) {
                /* Double insertion is possible for active events */
                return;
        }

        INCR_EVENT_COUNT(base, evcb->evcb_flags);

        evcb->evcb_flags |= EVLIST_ACTIVE;

        base->event_count_active++;
        MAX_EVENT_COUNT(base->event_count_active_max, base->event_count_active);
        EVUTIL_ASSERT(evcb->evcb_pri < base->nactivequeues);
        TAILQ_INSERT_TAIL(&base->activequeues[evcb->evcb_pri],
            evcb, evcb_active_next);
}

static void
event_queue_insert_active_later(struct event_base *base, struct event_callback *evcb)
{
        EVENT_BASE_ASSERT_LOCKED(base);
        if (evcb->evcb_flags & (EVLIST_ACTIVE_LATER|EVLIST_ACTIVE)) {
                /* Double insertion is possible */
                return;
        }

        INCR_EVENT_COUNT(base, evcb->evcb_flags);
        evcb->evcb_flags |= EVLIST_ACTIVE_LATER;
        base->event_count_active++;
        MAX_EVENT_COUNT(base->event_count_active_max, base->event_count_active);
        EVUTIL_ASSERT(evcb->evcb_pri < base->nactivequeues);
        TAILQ_INSERT_TAIL(&base->active_later_queue, evcb, evcb_active_next);
}

static void
event_queue_insert_timeout(struct event_base *base, struct event *ev)
{
        EVENT_BASE_ASSERT_LOCKED(base);

        if (EVUTIL_FAILURE_CHECK(ev->ev_flags & EVLIST_TIMEOUT)) {
                event_errx(1, "%s: %p(fd "EV_SOCK_FMT") already on timeout", __func__,
                    ev, EV_SOCK_ARG(ev->ev_fd));
                return;
        }

        INCR_EVENT_COUNT(base, ev->ev_flags);

        ev->ev_flags |= EVLIST_TIMEOUT;

        if (is_common_timeout(&ev->ev_timeout, base)) {
                struct common_timeout_list *ctl =
                    get_common_timeout_list(base, &ev->ev_timeout);
                insert_common_timeout_inorder(ctl, ev);
        } else {
                min_heap_push_(&base->timeheap, ev);
        }
}

static void
event_queue_make_later_events_active(struct event_base *base)
{
        struct event_callback *evcb;
        EVENT_BASE_ASSERT_LOCKED(base);

        while ((evcb = TAILQ_FIRST(&base->active_later_queue))) {
                TAILQ_REMOVE(&base->active_later_queue, evcb, evcb_active_next);
                evcb->evcb_flags = (evcb->evcb_flags & ~EVLIST_ACTIVE_LATER) | EVLIST_ACTIVE;
                EVUTIL_ASSERT(evcb->evcb_pri < base->nactivequeues);
                TAILQ_INSERT_TAIL(&base->activequeues[evcb->evcb_pri], evcb, evcb_active_next);
                base->n_deferreds_queued += (evcb->evcb_closure == EV_CLOSURE_CB_SELF);
        }
}

/* Functions for debugging */

const char *
event_get_version(void)
{
        return (EVENT__VERSION);
}

ev_uint32_t
event_get_version_number(void)
{
        return (EVENT__NUMERIC_VERSION);
}

/*
 * No thread-safe interface needed - the information should be the same
 * for all threads.
 */

const char *
event_get_method(void)
{
        return (current_base->evsel->name);
}

#ifndef EVENT__DISABLE_MM_REPLACEMENT
static void *(*mm_malloc_fn_)(size_t sz) = NULL;
static void *(*mm_realloc_fn_)(void *p, size_t sz) = NULL;
static void (*mm_free_fn_)(void *p) = NULL;

void *
event_mm_malloc_(size_t sz)
{
        if (sz == 0)
                return NULL;

        if (mm_malloc_fn_)
                return mm_malloc_fn_(sz);
        else
                return malloc(sz);
}

void *
event_mm_calloc_(size_t count, size_t size)
{
        if (count == 0 || size == 0)
                return NULL;

        if (mm_malloc_fn_) {
                size_t sz = count * size;
                void *p = NULL;
                if (count > EV_SIZE_MAX / size)
                        goto error;
                p = mm_malloc_fn_(sz);
                if (p)
                        return memset(p, 0, sz);
        } else {
                void *p = calloc(count, size);
#ifdef _WIN32
                /* Windows calloc doesn't reliably set ENOMEM */
                if (p == NULL)
                        goto error;
#endif
                return p;
        }

error:
        errno = ENOMEM;
        return NULL;
}

char *
event_mm_strdup_(const char *str)
{
        if (!str) {
                errno = EINVAL;
                return NULL;
        }

        if (mm_malloc_fn_) {
                size_t ln = strlen(str);
                void *p = NULL;
                if (ln == EV_SIZE_MAX)
                        goto error;
                p = mm_malloc_fn_(ln+1);
                if (p)
                        return memcpy(p, str, ln+1);
        } else
#ifdef _WIN32
                return _strdup(str);
#else
                return strdup(str);
#endif

error:
        errno = ENOMEM;
        return NULL;
}

void *
event_mm_realloc_(void *ptr, size_t sz)
{
        if (mm_realloc_fn_)
                return mm_realloc_fn_(ptr, sz);
        else
                return realloc(ptr, sz);
}

void
event_mm_free_(void *ptr)
{
        if (mm_free_fn_)
                mm_free_fn_(ptr);
        else
                free(ptr);
}

void
event_set_mem_functions(void *(*malloc_fn)(size_t sz),
                        void *(*realloc_fn)(void *ptr, size_t sz),
                        void (*free_fn)(void *ptr))
{
        mm_malloc_fn_ = malloc_fn;
        mm_realloc_fn_ = realloc_fn;
        mm_free_fn_ = free_fn;
}
#endif

#ifdef EVENT__HAVE_EVENTFD
static void
evthread_notify_drain_eventfd(evutil_socket_t fd, short what, void *arg)
{
        ev_uint64_t msg;
        ev_ssize_t r;
        struct event_base *base = arg;

        r = read(fd, (void*) &msg, sizeof(msg));
        if (r<0 && errno != EAGAIN) {
                event_sock_warn(fd, "Error reading from eventfd");
        }
        EVBASE_ACQUIRE_LOCK(base, th_base_lock);
        base->is_notify_pending = 0;
        EVBASE_RELEASE_LOCK(base, th_base_lock);
}
#endif

static void
evthread_notify_drain_default(evutil_socket_t fd, short what, void *arg)
{
        unsigned char buf[1024];
        struct event_base *base = arg;
#ifdef _WIN32
        while (recv(fd, (char*)buf, sizeof(buf), 0) > 0)
                ;
#else
        while (read(fd, (char*)buf, sizeof(buf)) > 0)
                ;
#endif

        EVBASE_ACQUIRE_LOCK(base, th_base_lock);
        base->is_notify_pending = 0;
        EVBASE_RELEASE_LOCK(base, th_base_lock);
}

int
evthread_make_base_notifiable(struct event_base *base)
{
        int r;
        if (!base)
                return -1;

        EVBASE_ACQUIRE_LOCK(base, th_base_lock);
        r = evthread_make_base_notifiable_nolock_(base);
        EVBASE_RELEASE_LOCK(base, th_base_lock);
        return r;
}

static int
evthread_make_base_notifiable_nolock_(struct event_base *base)
{
        void (*cb)(evutil_socket_t, short, void *);
        int (*notify)(struct event_base *);

        if (base->th_notify_fn != NULL) {
                /* The base is already notifiable: we're doing fine. */
                return 0;
        }

#if defined(EVENT__HAVE_WORKING_KQUEUE)
        if (base->evsel == &kqops && event_kq_add_notify_event_(base) == 0) {
                base->th_notify_fn = event_kq_notify_base_;
                /* No need to add an event here; the backend can wake
                 * itself up just fine. */
                return 0;
        }
#endif

#ifdef EVENT__HAVE_EVENTFD
        base->th_notify_fd[0] = evutil_eventfd_(0,
            EVUTIL_EFD_CLOEXEC|EVUTIL_EFD_NONBLOCK);
        if (base->th_notify_fd[0] >= 0) {
                base->th_notify_fd[1] = -1;
                notify = evthread_notify_base_eventfd;
                cb = evthread_notify_drain_eventfd;
        } else
#endif
        if (evutil_make_internal_pipe_(base->th_notify_fd) == 0) {
                notify = evthread_notify_base_default;
                cb = evthread_notify_drain_default;
        } else {
                return -1;
        }

        base->th_notify_fn = notify;

        /* prepare an event that we can use for wakeup */
        event_assign(&base->th_notify, base, base->th_notify_fd[0],
                                 EV_READ|EV_PERSIST, cb, base);

        /* we need to mark this as internal event */
        base->th_notify.ev_flags |= EVLIST_INTERNAL;
        event_priority_set(&base->th_notify, 0);

        return event_add_nolock_(&base->th_notify, NULL, 0);
}

int
event_base_foreach_event_nolock_(struct event_base *base,
    event_base_foreach_event_cb fn, void *arg)
{
        int r, i;
        unsigned u;
        struct event *ev;

        /* Start out with all the EVLIST_INSERTED events. */
        if ((r = evmap_foreach_event_(base, fn, arg)))
                return r;

        /* Okay, now we deal with those events that have timeouts and are in
         * the min-heap. */
        for (u = 0; u < base->timeheap.n; ++u) {
                ev = base->timeheap.p[u];
                if (ev->ev_flags & EVLIST_INSERTED) {
                        /* we already processed this one */
                        continue;
                }
                if ((r = fn(base, ev, arg)))
                        return r;
        }

        /* Now for the events in one of the timeout queues.
         * the min-heap. */
        for (i = 0; i < base->n_common_timeouts; ++i) {
                struct common_timeout_list *ctl =
                    base->common_timeout_queues[i];
                TAILQ_FOREACH(ev, &ctl->events,
                    ev_timeout_pos.ev_next_with_common_timeout) {
                        if (ev->ev_flags & EVLIST_INSERTED) {
                                /* we already processed this one */
                                continue;
                        }
                        if ((r = fn(base, ev, arg)))
                                return r;
                }
        }

        /* Finally, we deal wit all the active events that we haven't touched
         * yet. */
        for (i = 0; i < base->nactivequeues; ++i) {
                struct event_callback *evcb;
                TAILQ_FOREACH(evcb, &base->activequeues[i], evcb_active_next) {
                        if ((evcb->evcb_flags & (EVLIST_INIT|EVLIST_INSERTED|EVLIST_TIMEOUT)) != EVLIST_INIT) {
                                /* This isn't an event (evlist_init clear), or
                                 * we already processed it. (inserted or
                                 * timeout set */
                                continue;
                        }
                        ev = event_callback_to_event(evcb);
                        if ((r = fn(base, ev, arg)))
                                return r;
                }
        }

        return 0;
}

/* Helper for event_base_dump_events: called on each event in the event base;
 * dumps only the inserted events. */
static int
dump_inserted_event_fn(const struct event_base *base, const struct event *e, void *arg)
{
        FILE *output = arg;
        const char *gloss = (e->ev_events & EV_SIGNAL) ?
            "sig" : "fd ";

        if (! (e->ev_flags & (EVLIST_INSERTED|EVLIST_TIMEOUT)))
                return 0;

        fprintf(output, "  %p [%s "EV_SOCK_FMT"]%s%s%s%s%s%s",
            (void*)e, gloss, EV_SOCK_ARG(e->ev_fd),
            (e->ev_events&EV_READ)?" Read":"",
            (e->ev_events&EV_WRITE)?" Write":"",
            (e->ev_events&EV_CLOSED)?" EOF":"",
            (e->ev_events&EV_SIGNAL)?" Signal":"",
            (e->ev_events&EV_PERSIST)?" Persist":"",
            (e->ev_flags&EVLIST_INTERNAL)?" Internal":"");
        if (e->ev_flags & EVLIST_TIMEOUT) {
                struct timeval tv;
                tv.tv_sec = e->ev_timeout.tv_sec;
                tv.tv_usec = e->ev_timeout.tv_usec & MICROSECONDS_MASK;
                evutil_timeradd(&tv, &base->tv_clock_diff, &tv);
                fprintf(output, " Timeout=%ld.%06d",
                    (long)tv.tv_sec, (int)(tv.tv_usec & MICROSECONDS_MASK));
        }
        fputc('\n', output);

        return 0;
}

/* Helper for event_base_dump_events: called on each event in the event base;
 * dumps only the active events. */
static int
dump_active_event_fn(const struct event_base *base, const struct event *e, void *arg)
{
        FILE *output = arg;
        const char *gloss = (e->ev_events & EV_SIGNAL) ?
            "sig" : "fd ";

        if (! (e->ev_flags & (EVLIST_ACTIVE|EVLIST_ACTIVE_LATER)))
                return 0;

        fprintf(output, "  %p [%s "EV_SOCK_FMT", priority=%d]%s%s%s%s%s active%s%s\n",
            (void*)e, gloss, EV_SOCK_ARG(e->ev_fd), e->ev_pri,
            (e->ev_res&EV_READ)?" Read":"",
            (e->ev_res&EV_WRITE)?" Write":"",
            (e->ev_res&EV_CLOSED)?" EOF":"",
            (e->ev_res&EV_SIGNAL)?" Signal":"",
            (e->ev_res&EV_TIMEOUT)?" Timeout":"",
            (e->ev_flags&EVLIST_INTERNAL)?" [Internal]":"",
            (e->ev_flags&EVLIST_ACTIVE_LATER)?" [NextTime]":"");

        return 0;
}

int
event_base_foreach_event(struct event_base *base,
    event_base_foreach_event_cb fn, void *arg)
{
        int r;
        if ((!fn) || (!base)) {
                return -1;
        }
        EVBASE_ACQUIRE_LOCK(base, th_base_lock);
        r = event_base_foreach_event_nolock_(base, fn, arg);
        EVBASE_RELEASE_LOCK(base, th_base_lock);
        return r;
}


void
event_base_dump_events(struct event_base *base, FILE *output)
{
        EVBASE_ACQUIRE_LOCK(base, th_base_lock);
        fprintf(output, "Inserted events:\n");
        event_base_foreach_event_nolock_(base, dump_inserted_event_fn, output);

        fprintf(output, "Active events:\n");
        event_base_foreach_event_nolock_(base, dump_active_event_fn, output);
        EVBASE_RELEASE_LOCK(base, th_base_lock);
}

void
event_base_active_by_fd(struct event_base *base, evutil_socket_t fd, short events)
{
        EVBASE_ACQUIRE_LOCK(base, th_base_lock);
        evmap_io_active_(base, fd, events & (EV_READ|EV_WRITE|EV_CLOSED));
        EVBASE_RELEASE_LOCK(base, th_base_lock);
}

void
event_base_active_by_signal(struct event_base *base, int sig)
{
        EVBASE_ACQUIRE_LOCK(base, th_base_lock);
        evmap_signal_active_(base, sig, 1);
        EVBASE_RELEASE_LOCK(base, th_base_lock);
}


void
event_base_add_virtual_(struct event_base *base)
{
        EVBASE_ACQUIRE_LOCK(base, th_base_lock);
        base->virtual_event_count++;
        MAX_EVENT_COUNT(base->virtual_event_count_max, base->virtual_event_count);
        EVBASE_RELEASE_LOCK(base, th_base_lock);
}

void
event_base_del_virtual_(struct event_base *base)
{
        EVBASE_ACQUIRE_LOCK(base, th_base_lock);
        EVUTIL_ASSERT(base->virtual_event_count > 0);
        base->virtual_event_count--;
        if (base->virtual_event_count == 0 && EVBASE_NEED_NOTIFY(base))
                evthread_notify_base(base);
        EVBASE_RELEASE_LOCK(base, th_base_lock);
}

static void
event_free_debug_globals_locks(void)
{
#ifndef EVENT__DISABLE_THREAD_SUPPORT
#ifndef EVENT__DISABLE_DEBUG_MODE
        if (event_debug_map_lock_ != NULL) {
                EVTHREAD_FREE_LOCK(event_debug_map_lock_, 0);
                event_debug_map_lock_ = NULL;
                evthreadimpl_disable_lock_debugging_();
        }
#endif /* EVENT__DISABLE_DEBUG_MODE */
#endif /* EVENT__DISABLE_THREAD_SUPPORT */
        return;
}

static void
event_free_debug_globals(void)
{
        event_free_debug_globals_locks();
}

static void
event_free_evsig_globals(void)
{
        evsig_free_globals_();
}

static void
event_free_evutil_globals(void)
{
        evutil_free_globals_();
}

static void
event_free_globals(void)
{
        event_free_debug_globals();
        event_free_evsig_globals();
        event_free_evutil_globals();
}

void
libevent_global_shutdown(void)
{
        event_disable_debug_mode();
        event_free_globals();
}

#ifndef EVENT__DISABLE_THREAD_SUPPORT
int
event_global_setup_locks_(const int enable_locks)
{
#ifndef EVENT__DISABLE_DEBUG_MODE
        EVTHREAD_SETUP_GLOBAL_LOCK(event_debug_map_lock_, 0);
#endif
        if (evsig_global_setup_locks_(enable_locks) < 0)
                return -1;
        if (evutil_global_setup_locks_(enable_locks) < 0)
                return -1;
        if (evutil_secure_rng_global_setup_locks_(enable_locks) < 0)
                return -1;
        return 0;
}
#endif

void
event_base_assert_ok_(struct event_base *base)
{
        EVBASE_ACQUIRE_LOCK(base, th_base_lock);
        event_base_assert_ok_nolock_(base);
        EVBASE_RELEASE_LOCK(base, th_base_lock);
}

void
event_base_assert_ok_nolock_(struct event_base *base)
{
        int i;
        int count;

        /* First do checks on the per-fd and per-signal lists */
        evmap_check_integrity_(base);

        /* Check the heap property */
        for (i = 1; i < (int)base->timeheap.n; ++i) {
                int parent = (i - 1) / 2;
                struct event *ev, *p_ev;
                ev = base->timeheap.p[i];
                p_ev = base->timeheap.p[parent];
                EVUTIL_ASSERT(ev->ev_flags & EVLIST_TIMEOUT);
                EVUTIL_ASSERT(evutil_timercmp(&p_ev->ev_timeout, &ev->ev_timeout, <=));
                EVUTIL_ASSERT(ev->ev_timeout_pos.min_heap_idx == i);
        }

        /* Check that the common timeouts are fine */
        for (i = 0; i < base->n_common_timeouts; ++i) {
                struct common_timeout_list *ctl = base->common_timeout_queues[i];
                struct event *last=NULL, *ev;

                EVUTIL_ASSERT_TAILQ_OK(&ctl->events, event, ev_timeout_pos.ev_next_with_common_timeout);

                TAILQ_FOREACH(ev, &ctl->events, ev_timeout_pos.ev_next_with_common_timeout) {
                        if (last)
                                EVUTIL_ASSERT(evutil_timercmp(&last->ev_timeout, &ev->ev_timeout, <=));
                        EVUTIL_ASSERT(ev->ev_flags & EVLIST_TIMEOUT);
                        EVUTIL_ASSERT(is_common_timeout(&ev->ev_timeout,base));
                        EVUTIL_ASSERT(COMMON_TIMEOUT_IDX(&ev->ev_timeout) == i);
                        last = ev;
                }
        }

        /* Check the active queues. */
        count = 0;
        for (i = 0; i < base->nactivequeues; ++i) {
                struct event_callback *evcb;
                EVUTIL_ASSERT_TAILQ_OK(&base->activequeues[i], event_callback, evcb_active_next);
                TAILQ_FOREACH(evcb, &base->activequeues[i], evcb_active_next) {
                        EVUTIL_ASSERT((evcb->evcb_flags & (EVLIST_ACTIVE|EVLIST_ACTIVE_LATER)) == EVLIST_ACTIVE);
                        EVUTIL_ASSERT(evcb->evcb_pri == i);
                        ++count;
                }
        }

        {
                struct event_callback *evcb;
                TAILQ_FOREACH(evcb, &base->active_later_queue, evcb_active_next) {
                        EVUTIL_ASSERT((evcb->evcb_flags & (EVLIST_ACTIVE|EVLIST_ACTIVE_LATER)) == EVLIST_ACTIVE_LATER);
                        ++count;
                }
        }
        EVUTIL_ASSERT(count == base->event_count_active);
}