forked from libevent/libevent
/
event.c
2203 lines (1868 loc) · 50.6 KB
/
event.c
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/*
* Copyright (c) 2000-2007 Niels Provos <provos@citi.umich.edu>
* Copyright (c) 2007-2009 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 "event-config.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
#ifdef _EVENT_HAVE_SYS_EVENTFD_H
#include <sys/eventfd.h>
#endif
#include <ctype.h>
#include <errno.h>
#include <signal.h>
#include <string.h>
#include <time.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"
#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
/* 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 */
struct event_base *current_base = NULL;
extern struct event_base *evsig_base;
static int use_monotonic;
/* Prototypes */
static inline int event_add_internal(struct event *ev,
const struct timeval *tv, int tv_is_absolute);
static inline int event_del_internal(struct event *ev);
static void event_queue_insert(struct event_base *, struct event *, int);
static void event_queue_remove(struct event_base *, struct event *, int);
static int event_haveevents(struct event_base *);
static void event_process_active(struct event_base *);
static int timeout_next(struct event_base *, struct timeval **);
static void timeout_process(struct event_base *);
static void timeout_correct(struct event_base *, struct timeval *);
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
detect_monotonic(void)
{
#if defined(_EVENT_HAVE_CLOCK_GETTIME) && defined(CLOCK_MONOTONIC)
struct timespec ts;
static int use_monotonic_initialized = 0;
if (use_monotonic_initialized)
return;
if (clock_gettime(CLOCK_MONOTONIC, &ts) == 0)
use_monotonic = 1;
use_monotonic_initialized = 1;
#endif
}
static int
gettime(struct event_base *base, struct timeval *tp)
{
if (base->tv_cache.tv_sec) {
*tp = base->tv_cache;
return (0);
}
#if defined(_EVENT_HAVE_CLOCK_GETTIME) && defined(CLOCK_MONOTONIC)
if (use_monotonic) {
struct timespec ts;
if (clock_gettime(CLOCK_MONOTONIC, &ts) == -1)
return (-1);
tp->tv_sec = ts.tv_sec;
tp->tv_usec = ts.tv_nsec / 1000;
return (0);
}
#endif
return (evutil_gettimeofday(tp, NULL));
}
static inline void
clear_time_cache(struct event_base *base)
{
base->tv_cache.tv_sec = 0;
}
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);
}
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;
}
static int
event_config_is_avoided_method(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);
}
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] = toupper(environment[i]);
return (evutil_getenv(environment) != NULL);
}
int
event_base_get_features(struct event_base *base)
{
return base->evsel->features;
}
void
event_deferred_cb_queue_init(struct deferred_cb_queue *cb)
{
memset(cb, 0, sizeof(struct deferred_cb_queue));
TAILQ_INIT(&cb->deferred_cb_list);
}
static void
notify_base_cbq_callback(struct deferred_cb_queue *cb, void *baseptr)
{
struct event_base *base = baseptr;
if (!EVBASE_IN_THREAD(base))
evthread_notify_base(base);
}
struct deferred_cb_queue *
event_base_get_deferred_cb_queue(struct event_base *base)
{
return base ? &base->defer_queue : NULL;
}
struct event_base *
event_base_new_with_config(struct event_config *cfg)
{
int i;
struct event_base *base;
int should_check_environment;
if ((base = mm_calloc(1, sizeof(struct event_base))) == NULL) {
event_warn("%s: calloc", __func__);
return NULL;
}
detect_monotonic();
gettime(base, &base->event_tv);
min_heap_ctor(&base->timeheap);
TAILQ_INIT(&base->eventqueue);
base->sig.ev_signal_pair[0] = -1;
base->sig.ev_signal_pair[1] = -1;
event_deferred_cb_queue_init(&base->defer_queue);
base->defer_queue.notify_fn = notify_base_cbq_callback;
base->defer_queue.notify_arg = base;
if (cfg)
base->flags = cfg->flags;
evmap_io_initmap(&base->io);
evmap_signal_initmap(&base->sigmap);
base->evbase = NULL;
should_check_environment =
!(cfg && (cfg->flags & EVENT_BASE_FLAG_IGNORE_ENV));
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__);
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 */
base->th_notify_fd[0] = -1;
base->th_notify_fd[1] = -1;
#ifndef _EVENT_DISABLE_THREAD_SUPPORT
if (!cfg || !(cfg->flags & EVENT_BASE_FLAG_NOLOCK)) {
int r;
EVTHREAD_ALLOC_LOCK(base->th_base_lock,
EVTHREAD_LOCKTYPE_RECURSIVE);
base->defer_queue.lock = base->th_base_lock;
EVTHREAD_ALLOC_LOCK(base->current_event_lock,
EVTHREAD_LOCKTYPE_RECURSIVE);
r = evthread_make_base_notifiable(base);
if (r<0) {
event_base_free(base);
return NULL;
}
}
#endif
#ifdef WIN32
if (cfg && (cfg->flags & EVENT_BASE_FLAG_STARTUP_IOCP))
event_base_start_iocp(base);
#endif
return (base);
}
int
event_base_start_iocp(struct event_base *base)
{
#ifdef WIN32
if (base->iocp)
return 0;
base->iocp = event_iocp_port_launch();
if (!base->iocp) {
event_warnx("%s: Couldn't launch IOCP", __func__);
return -1;
}
return 0;
#else
return -1;
#endif
}
void
event_base_free(struct event_base *base)
{
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. */
if (base == NULL && current_base)
base = current_base;
if (base == current_base)
current_base = NULL;
/* XXX(niels) - check for internal events first */
EVUTIL_ASSERT(base);
/* 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]);
EVUTIL_CLOSESOCKET(base->th_notify_fd[1]);
base->th_notify_fd[0] = -1;
base->th_notify_fd[1] = -1;
}
/* Delete all non-internal events. */
for (ev = TAILQ_FIRST(&base->eventqueue); ev; ) {
struct event *next = TAILQ_NEXT(ev, ev_next);
if (!(ev->ev_flags & EVLIST_INTERNAL)) {
event_del(ev);
++n_deleted;
}
ev = next;
}
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 */
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 (i = 0; i < base->nactivequeues; ++i) {
for (ev = TAILQ_FIRST(&base->activequeues[i]); ev; ) {
struct event *next = TAILQ_NEXT(ev, ev_active_next);
if (!(ev->ev_flags & EVLIST_INTERNAL)) {
event_del(ev);
++n_deleted;
}
ev = next;
}
}
if (n_deleted)
event_debug(("%s: %d events were still set in base",
__func__, n_deleted));
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);
EVUTIL_ASSERT(TAILQ_EMPTY(&base->eventqueue));
evmap_io_clear(&base->io);
evmap_signal_clear(&base->sigmap);
EVTHREAD_FREE_LOCK(base->th_base_lock, EVTHREAD_LOCKTYPE_RECURSIVE);
EVTHREAD_FREE_LOCK(base->current_event_lock,
EVTHREAD_LOCKTYPE_RECURSIVE);
mm_free(base);
}
/* reinitialize the event base after a fork */
int
event_reinit(struct event_base *base)
{
/* XXXX We need to grab a lock here! */
const struct eventop *evsel = base->evsel;
int res = 0;
struct event *ev;
/* check if this event mechanism requires reinit */
if (!evsel->need_reinit)
return (0);
/* prevent internal delete */
if (base->sig.ev_signal_added) {
/* we cannot call event_del here because the base has
* not been reinitialized yet. */
event_queue_remove(base, &base->sig.ev_signal,
EVLIST_INSERTED);
if (base->sig.ev_signal.ev_flags & EVLIST_ACTIVE)
event_queue_remove(base, &base->sig.ev_signal,
EVLIST_ACTIVE);
base->sig.ev_signal_added = 0;
}
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__);
return (-1);
}
evmap_io_clear(&base->io);
evmap_signal_clear(&base->sigmap);
TAILQ_FOREACH(ev, &base->eventqueue, ev_next) {
if (ev->ev_events & (EV_READ|EV_WRITE)) {
if (evmap_io_add(base, ev->ev_fd, ev) == -1)
res = -1;
} else if (ev->ev_events & EV_SIGNAL) {
if (evmap_signal_add(base, ev->ev_fd, ev) == -1)
res = -1;
}
}
return (res);
}
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);
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_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;
if (N_ACTIVE_CALLBACKS(base) || npriorities < 1
|| npriorities >= EVENT_MAX_PRIORITIES)
return (-1);
if (npriorities == base->nactivequeues)
return (0);
if (base->nactivequeues) {
mm_free(base->activequeues);
base->nactivequeues = 0;
}
/* Allocate our priority queues */
base->activequeues = (struct event_list *)
mm_calloc(npriorities, sizeof(struct event_list));
if (base->activequeues == NULL) {
event_warn("%s: calloc", __func__);
return (-1);
}
base->nactivequeues = npriorities;
for (i = 0; i < base->nactivequeues; ++i) {
TAILQ_INIT(&base->activequeues[i]);
}
return (0);
}
static int
event_haveevents(struct event_base *base)
{
/* Caller must hold th_base_lock */
return (base->event_count > 0);
}
static inline void
event_signal_closure(struct event_base *base, struct event *ev)
{
short ncalls;
/* Allows deletes to work */
ncalls = ev->ev_ncalls;
ev->ev_pncalls = &ncalls;
while (ncalls) {
ncalls--;
ev->ev_ncalls = ncalls;
(*ev->ev_callback)((int)ev->ev_fd, ev->ev_res, ev->ev_arg);
if (base->event_break)
return;
}
}
#define MICROSECONDS_MASK 0x000fffff
#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)
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);
}
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)];
}
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;
}
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_internal(&ctl->timeout_event, &timeout, 1);
}
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_internal(ev);
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_warn("%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;
}
static inline void
event_persist_closure(struct event_base *base, struct event *ev)
{
/* reschedule the persistent event if we have a timeout. */
if (ev->ev_io_timeout.tv_sec || ev->ev_io_timeout.tv_usec) {
/* 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_. */
struct timeval run_at;
EVUTIL_ASSERT(is_same_common_timeout(&ev->ev_timeout,
&ev->ev_io_timeout));
if (is_common_timeout(&ev->ev_timeout, base)) {
ev_uint32_t usec_mask;
struct timeval delay, last_at;
last_at = ev->ev_timeout;
delay = ev->ev_io_timeout;
usec_mask = delay.tv_usec & ~MICROSECONDS_MASK;
last_at.tv_usec &= MICROSECONDS_MASK;
delay.tv_usec &= MICROSECONDS_MASK;
evutil_timeradd(&last_at, &delay, &run_at);
run_at.tv_usec |= usec_mask;
} else {
evutil_timeradd(&ev->ev_io_timeout, &ev->ev_timeout,
&run_at);
}
event_add_internal(ev, &run_at, 1);
}
(*ev->ev_callback)((int)ev->ev_fd, ev->ev_res, ev->ev_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 events that we processed.
*/
static int
event_process_active_single_queue(struct event_base *base,
struct event_list *activeq)
{
struct event *ev;
int count = 0;
EVUTIL_ASSERT(activeq != NULL);
for (ev = TAILQ_FIRST(activeq); ev; ev = TAILQ_FIRST(activeq)) {
if (ev->ev_events & EV_PERSIST)
event_queue_remove(base, ev, EVLIST_ACTIVE);
else
event_del_internal(ev);
if (!(ev->ev_flags & EVLIST_INTERNAL))
++count;
event_debug((
"event_process_active: event: %p, %s%scall %p",
ev,
ev->ev_res & EV_READ ? "EV_READ " : " ",
ev->ev_res & EV_WRITE ? "EV_WRITE " : " ",
ev->ev_callback));
base->current_event = ev;
EVBASE_ACQUIRE_LOCK(base, current_event_lock);
EVBASE_RELEASE_LOCK(base, th_base_lock);
switch (ev->ev_closure) {
case EV_CLOSURE_SIGNAL:
event_signal_closure(base, ev);
break;
case EV_CLOSURE_PERSIST:
event_persist_closure(base, ev);
break;
default:
case EV_CLOSURE_NONE:
(*ev->ev_callback)(
(int)ev->ev_fd, ev->ev_res, ev->ev_arg);
break;
}
EVBASE_RELEASE_LOCK(base, current_event_lock);
EVBASE_ACQUIRE_LOCK(base, th_base_lock);
base->current_event = NULL;
if (base->event_break)
return -1;
}
return count;
}
static int
event_process_deferred_callbacks(struct deferred_cb_queue *queue, int *breakptr)
{
int count = 0;
struct deferred_cb *cb;
while ((cb = TAILQ_FIRST(&queue->deferred_cb_list))) {
cb->queued = 0;
TAILQ_REMOVE(&queue->deferred_cb_list, cb, cb_next);
--queue->active_count;
UNLOCK_DEFERRED_QUEUE(queue);
cb->cb(cb, cb->arg);
++count;
if (*breakptr)
return -1;
LOCK_DEFERRED_QUEUE(queue);
}
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 void
event_process_active(struct event_base *base)
{
/* Caller must hold th_base_lock */
struct event_list *activeq = NULL;
int i, c;
for (i = 0; i < base->nactivequeues; ++i) {
if (TAILQ_FIRST(&base->activequeues[i]) != NULL) {
activeq = &base->activequeues[i];
c = event_process_active_single_queue(base, activeq);
if (c < 0)
return;
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. */
}
}
event_process_deferred_callbacks(&base->defer_queue,&base->event_break);
}
/*
* Wait continuously for events. We exit only if no events are left.
*/