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event.c
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/*
* 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 */
EVENT2_EXPORT_SYMBOL
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;
if (precise_time) {
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));
had_signal_added = 1;
base->sig.ev_signal_added = 0;
}
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]);
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