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libevent/event.c

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/*
* Copyright (c) 2000-2004 Niels Provos <provos@citi.umich.edu>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#ifdef WIN32
#include <winsock2.h>
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#undef WIN32_LEAN_AND_MEAN
#endif
#include <sys/types.h>
#ifndef WIN32
#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#else
#include <sys/_time.h>
#endif
#endif
#include <sys/queue.h>
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <ctype.h>
#include <errno.h>
#include <signal.h>
#include <string.h>
#include <assert.h>
#include <time.h>
#include "event2/event.h"
#include "event2/event_struct.h"
#include "event2/event_compat.h"
#include "event-internal.h"
#include "evthread-internal.h"
#include "event2/thread.h"
#include "event2/util.h"
#include "log.h"
#ifdef HAVE_EVENT_PORTS
extern const struct eventop evportops;
#endif
#ifdef HAVE_SELECT
extern const struct eventop selectops;
#endif
#ifdef HAVE_POLL
extern const struct eventop pollops;
#endif
#ifdef HAVE_EPOLL
extern const struct eventop epollops;
#endif
#ifdef HAVE_WORKING_KQUEUE
extern const struct eventop kqops;
#endif
#ifdef HAVE_DEVPOLL
extern const struct eventop devpollops;
#endif
#ifdef WIN32
extern const struct eventop win32ops;
#endif
/* In order of preference */
const struct eventop *eventops[] = {
#ifdef HAVE_EVENT_PORTS
&evportops,
#endif
#ifdef HAVE_WORKING_KQUEUE
&kqops,
#endif
#ifdef HAVE_EPOLL
&epollops,
#endif
#ifdef HAVE_DEVPOLL
&devpollops,
#endif
#ifdef HAVE_POLL
&pollops,
#endif
#ifdef HAVE_SELECT
&selectops,
#endif
#ifdef WIN32
&win32ops,
#endif
NULL
};
/* Global state */
struct event_base *current_base = NULL;
extern struct event_base *evsignal_base;
static int use_monotonic;
/* Handle signals - This is a deprecated interface */
int (*event_sigcb)(void); /* Signal callback when gotsig is set */
volatile sig_atomic_t event_gotsig; /* Set in signal handler */
/* Prototypes */
static inline int event_add_internal(struct event *ev,
const struct timeval *tv);
static inline int event_del_internal(struct event *ev);
static inline void event_active_internal(struct event *ev, int res,short count);
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 void event_signal_closure(struct event_base *, struct event *ev);
static void event_periodic_closure(struct event_base *, struct event *ev);
static void
detect_monotonic(void)
{
#if defined(HAVE_CLOCK_GETTIME) && defined(CLOCK_MONOTONIC)
struct timespec ts;
if (clock_gettime(CLOCK_MONOTONIC, &ts) == 0)
use_monotonic = 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(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));
}
struct event_base *
event_init(void)
{
struct event_base *base = event_base_new();
if (base != NULL)
current_base = base;
return (base);
}
struct event_base *
event_base_new(void)
{
return (event_base_new_with_config(NULL));
}
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 (getenv(environment) != NULL);
}
enum event_method_feature
event_base_get_features(struct event_base *base)
{
return base->evsel->features;
}
struct event_base *
event_base_new_with_config(struct event_config *cfg)
{
int i;
struct event_base *base;
if ((base = mm_calloc(1, sizeof(struct event_base))) == NULL)
event_err(1, "%s: calloc", __func__);
event_sigcb = NULL;
event_gotsig = 0;
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;
base->evbase = NULL;
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 (event_is_method_disabled(eventops[i]->name))
continue;
base->evsel = eventops[i];
base->evbase = base->evsel->init(base);
}
if (base->evbase == NULL) {
if (cfg == NULL)
event_errx(1, "%s: no event mechanism available", __func__);
else {
event_base_free(base);
return NULL;
}
}
if (getenv("EVENT_SHOW_METHOD"))
event_msgx("libevent using: %s", base->evsel->name);
/* allocate a single active event queue */
event_base_priority_init(base, 1);
/* prepare for threading */
base->th_notify_fd[0] = -1;
base->th_notify_fd[1] = -1;
return (base);
}
void
event_base_free(struct event_base *base)
{
int i, n_deleted=0;
struct event *ev;
if (base == NULL && current_base)
base = current_base;
if (base == current_base)
current_base = NULL;
/* XXX(niels) - check for internal events first */
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]);
}
if (base->th_base_lock != NULL)
(*base->th_free)(base->th_base_lock);
/* 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->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->dealloc != NULL)
base->evsel->dealloc(base, base->evbase);
for (i = 0; i < base->nactivequeues; ++i)
assert(TAILQ_EMPTY(base->activequeues[i]));
assert(min_heap_empty(&base->timeheap));
min_heap_dtor(&base->timeheap);
for (i = 0; i < base->nactivequeues; ++i)
mm_free(base->activequeues[i]);
mm_free(base->activequeues);
assert(TAILQ_EMPTY(&base->eventqueue));
mm_free(base);
}
/* reinitialized the event base after a fork */
int
event_reinit(struct event_base *base)
{
const struct eventop *evsel = base->evsel;
void *evbase = base->evbase;
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) {
event_queue_remove(base, &base->sig.ev_signal,
EVLIST_INSERTED);
base->sig.ev_signal_added = 0;
}
if (base->evsel->dealloc != NULL)
base->evsel->dealloc(base, base->evbase);
evbase = base->evbase = evsel->init(base);
if (base->evbase == NULL)
event_errx(1, "%s: could not reinitialize event mechanism",
__func__);
TAILQ_FOREACH(ev, &base->eventqueue, ev_next) {
if (evsel->add(evbase, ev) == -1)
res = -1;
}
return (res);
}
const char **
event_get_supported_methods(void)
{
static const char **methods;
const struct eventop **method;
const char **tmp;
int i = 0, k;
/* count all methods */
for (method = &eventops[0]; *method != NULL; ++method) {
if (event_is_method_disabled((*method)->name))
continue;
++i;
}
/* allocate one more than we need for the NULL pointer */
tmp = mm_malloc((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) {
if (event_is_method_disabled(eventops[k]->name))
continue;
tmp[i++] = eventops[k]->name;
}
tmp[i] = NULL;
if (methods != NULL)
mm_free(methods);
methods = tmp;
return (methods);
}
struct event_config *
event_config_new(void)
{
struct event_config *cfg = mm_malloc(sizeof(*cfg));
if (cfg == NULL)
return (NULL);
TAILQ_INIT(&cfg->entries);
cfg->require_features = 0;
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);
}
}
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,
enum event_method_feature 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 (base->event_count_active)
return (-1);
if (base->nactivequeues && npriorities != base->nactivequeues) {
for (i = 0; i < base->nactivequeues; ++i) {
mm_free(base->activequeues[i]);
}
mm_free(base->activequeues);
}
/* Allocate our priority queues */
base->nactivequeues = npriorities;
base->activequeues = (struct event_list **)mm_calloc(
base->nactivequeues,
npriorities * sizeof(struct event_list *));
if (base->activequeues == NULL)
event_err(1, "%s: calloc", __func__);
for (i = 0; i < base->nactivequeues; ++i) {
base->activequeues[i] = mm_malloc(sizeof(struct event_list));
if (base->activequeues[i] == NULL)
event_err(1, "%s: malloc", __func__);
TAILQ_INIT(base->activequeues[i]);
}
return (0);
}
int
event_haveevents(struct event_base *base)
{
return (base->event_count > 0);
}
static void
event_periodic_closure(struct event_base *base, struct event *ev)
{
event_add(ev, &ev->_ev.ev_periodic.tv_interval);
(*ev->ev_callback)((int)ev->ev_fd, ev->ev_res, ev->ev_arg);
}
static 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 (event_gotsig || base->event_break)
return;
}
}
/*
* 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)
{
struct event *ev;
struct event_list *activeq = NULL;
int i;
EVTHREAD_ACQUIRE_LOCK(base, EVTHREAD_WRITE, th_base_lock);
for (i = 0; i < base->nactivequeues; ++i) {
if (TAILQ_FIRST(base->activequeues[i]) != NULL) {
activeq = base->activequeues[i];
break;
}
}
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);
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));
EVTHREAD_RELEASE_LOCK(base,
EVTHREAD_WRITE, th_base_lock);
if (ev->ev_closure != NULL)
(*ev->ev_closure)(base, ev);
else
(*ev->ev_callback)(
(int)ev->ev_fd, ev->ev_res, ev->ev_arg);
if (event_gotsig || base->event_break)
return;
EVTHREAD_ACQUIRE_LOCK(base, EVTHREAD_WRITE, th_base_lock);
}
EVTHREAD_RELEASE_LOCK(base, EVTHREAD_WRITE, th_base_lock);
}
/*
* Wait continously 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(struct event_base *base)
{
assert(base);
return (base->evsel->name);
}
static void
event_loopexit_cb(evutil_socket_t fd, short what, void *arg)
{
struct event_base *base = arg;
base->event_gotterm = 1;
}
/* not thread safe */
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));
}
/* not thread safe */
int
event_loopbreak(void)
{
return (event_base_loopbreak(current_base));
}
int
event_base_loopbreak(struct event_base *event_base)
{
if (event_base == NULL)
return (-1);
event_base->event_break = 1;
return (0);
}
/* 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;
void *evbase = base->evbase;
struct timeval tv;
struct timeval *tv_p;
int res, done;
if (&base->sig.ev_signal_added)
evsignal_base = base;
done = 0;
while (!done) {
/* Terminate the loop if we have been asked to */
if (base->event_gotterm) {
base->event_gotterm = 0;
break;
}
if (base->event_break) {
base->event_break = 0;
break;
}
/* You cannot use this interface for multi-threaded apps */
while (event_gotsig) {
event_gotsig = 0;
if (event_sigcb) {
res = (*event_sigcb)();
if (res == -1) {
errno = EINTR;
return (-1);
}
}
}
timeout_correct(base, &tv);
tv_p = &tv;
if (!base->event_count_active && !(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 (!event_haveevents(base)) {
event_debug(("%s: no events registered.", __func__));
return (1);
}
/* update last old time */
gettime(base, &base->event_tv);
/* clear time cache */
base->tv_cache.tv_sec = 0;
res = evsel->dispatch(base, evbase, tv_p);
if (res == -1)
return (-1);
gettime(base, &base->tv_cache);
timeout_process(base);
if (base->event_count_active) {
event_process_active(base);
if (!base->event_count_active && (flags & EVLOOP_ONCE))
done = 1;
} else if (flags & EVLOOP_NONBLOCK)
done = 1;
}
event_debug(("%s: asked to terminate loop.", __func__));
return (0);
}
/* Sets up an event for processing once */
struct event_once {
struct event ev;
void (*cb)(evutil_socket_t, short, void *);
void *arg;
};
/* One-time callback, it deletes itself */
static void
event_once_cb(evutil_socket_t fd, short events, void *arg)
{
struct event_once *eonce = arg;
(*eonce->cb)(fd, events, eonce->arg);
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;
struct timeval etv;
int res = 0;
/* We cannot support signals that just fire once */
if (events & EV_SIGNAL)
return (-1);
if ((eonce = mm_calloc(1, sizeof(struct event_once))) == NULL)
return (-1);
eonce->cb = callback;
eonce->arg = arg;
if (events == EV_TIMEOUT) {
if (tv == NULL) {
evutil_timerclear(&etv);
tv = &etv;
}
evtimer_assign(&eonce->ev, base, event_once_cb, eonce);
} else if (events & (EV_READ|EV_WRITE)) {
events &= EV_READ|EV_WRITE;
event_assign(&eonce->ev, base, fd, events, event_once_cb, eonce);
} else {
/* Bad event combination */
mm_free(eonce);
return (-1);
}
if (res == 0)
res = event_add(&eonce->ev, tv);
if (res != 0) {
mm_free(eonce);
return (res);
}
return (0);
}
void
event_set(struct event *ev, evutil_socket_t fd, short events,
void (*callback)(evutil_socket_t, short, void *), void *arg)
{
/* Take the current base - caller needs to set the real base later */
ev->ev_base = current_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)) != 0)
event_errx(1, "%s: EV_SIGNAL incompatible use",
__func__);
ev->ev_closure = event_signal_closure;
} else {
ev->ev_closure = NULL;
}
min_heap_elem_init(ev);
/* by default, we put new events into the middle priority */
if (current_base)
ev->ev_pri = current_base->nactivequeues/2;
}
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);
ev->ev_base = base;
ev->ev_pri = base->nactivequeues/2;
return (0);
}
void
event_assign(struct event *ev, struct event_base *base, evutil_socket_t fd, short events, void (*cb)(evutil_socket_t, short, void *), void *arg)
{
event_set(ev, fd, events, cb, arg);
if (base != NULL)
assert(event_base_set(base, ev) == 0);
}
void
evperiodic_assign(struct event *ev, struct event_base *base,
const struct timeval *tv,
void (*cb)(evutil_socket_t, short, void *), void *arg)
{
event_assign(ev, base, -1, EV_TIMEOUT, cb, arg);
ev->_ev.ev_periodic.tv_interval = *tv;
ev->ev_closure = event_periodic_closure;
}
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);
event_assign(ev, base, fd, events, cb, arg);
return (ev);
}
void
event_free(struct event *ev)
{
/* make sure that this event won't be coming back to haunt us. */
event_del(ev);
mm_free(ev);
}
/*
* 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)
{
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(struct event *ev, short event, struct timeval *tv)
{
struct timeval now, res;
int flags = 0;
if (ev->ev_flags & EVLIST_INSERTED)
flags |= (ev->ev_events & (EV_READ|EV_WRITE|EV_SIGNAL));
if (ev->ev_flags & EVLIST_ACTIVE)
flags |= ev->ev_res;
if (ev->ev_flags & EVLIST_TIMEOUT)
flags |= EV_TIMEOUT;
event &= (EV_TIMEOUT|EV_READ|EV_WRITE|EV_SIGNAL);
/* See if there is a timeout that we should report */
if (tv != NULL && (flags & event & EV_TIMEOUT)) {
gettime(ev->ev_base, &now);
evutil_timersub(&ev->ev_timeout, &now, &res);
/* correctly remap to real time */
evutil_gettimeofday(&now, NULL);
evutil_timeradd(&now, &res, tv);
}
return (flags & event);
}
int
_event_initialized(struct event *ev, int need_fd)
{
if (!(ev->ev_flags & EVLIST_INIT))
return 0;
#ifdef WIN32
/* XXX Is this actually a sensible thing to check? -NM */
if (need_fd && (ev)->ev_fd == (evutil_socket_t)INVALID_HANDLE_VALUE)
return 0;
#endif
return 1;
}
evutil_socket_t
event_get_fd(struct event *ev)
{
return ev->ev_fd;
}
int
event_add(struct event *ev, const struct timeval *tv)
{
int res;
EVTHREAD_ACQUIRE_LOCK(ev->ev_base, EVTHREAD_WRITE, th_base_lock);
res = event_add_internal(ev, tv);
EVTHREAD_RELEASE_LOCK(ev->ev_base, EVTHREAD_WRITE, th_base_lock);
return (res);
}
static inline int
event_add_internal(struct event *ev, const struct timeval *tv)
{
struct event_base *base = ev->ev_base;
const struct eventop *evsel = base->evsel;
void *evbase = base->evbase;
int res = 0;
event_debug((
"event_add: event: %p, %s%s%scall %p",
ev,
ev->ev_events & EV_READ ? "EV_READ " : " ",
ev->ev_events & EV_WRITE ? "EV_WRITE " : " ",
tv ? "EV_TIMEOUT " : " ",
ev->ev_callback));
assert(!(ev->ev_flags & ~EVLIST_ALL));
/*
* 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 ((ev->ev_events & (EV_READ|EV_WRITE|EV_SIGNAL)) &&
!(ev->ev_flags & (EVLIST_INSERTED|EVLIST_ACTIVE))) {
res = evsel->add(evbase, ev);
if (res != -1)
event_queue_insert(base, ev, EVLIST_INSERTED);
}
/*
* we should change the timout state only if the previous event
* addition succeeded.
*/
if (res != -1 && tv != NULL) {
struct timeval now;
/*
* we already reserved memory above for the case where we
* are not replacing an exisiting timeout.
*/
if (ev->ev_flags & EVLIST_TIMEOUT)
event_queue_remove(base, ev, EVLIST_TIMEOUT);
/* 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(base, ev, EVLIST_ACTIVE);
}
gettime(base, &now);
evutil_timeradd(&now, tv, &ev->ev_timeout);
event_debug((
"event_add: timeout in %d seconds, call %p",
(int)tv->tv_sec, ev->ev_callback));
event_queue_insert(base, ev, EVLIST_TIMEOUT);
}
/* if we are not in the right thread, we need to wake up the loop */
if (res != -1 && !EVTHREAD_IN_THREAD(base))
send(base->th_notify_fd[1], "", 1, 0);
return (res);
}
int
event_del(struct event *ev)
{
int res;
EVTHREAD_ACQUIRE_LOCK(ev->ev_base, EVTHREAD_WRITE, th_base_lock);
res = event_del_internal(ev);
EVTHREAD_RELEASE_LOCK(ev->ev_base, EVTHREAD_WRITE, th_base_lock);
return (res);
}
static inline int
event_del_internal(struct event *ev)
{
struct event_base *base;
const struct eventop *evsel;
void *evbase;
int res = 0;
event_debug(("event_del: %p, callback %p",
ev, ev->ev_callback));
/* An event without a base has not been added */
if (ev->ev_base == NULL)
return (-1);
base = ev->ev_base;
evsel = base->evsel;
evbase = base->evbase;
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)
event_queue_remove(base, ev, EVLIST_TIMEOUT);
if (ev->ev_flags & EVLIST_ACTIVE)
event_queue_remove(base, ev, EVLIST_ACTIVE);
if (ev->ev_flags & EVLIST_INSERTED) {
event_queue_remove(base, ev, EVLIST_INSERTED);
res = evsel->del(evbase, ev);
}
/* if we are not in the right thread, we need to wake up the loop */
if (res != -1 && !EVTHREAD_IN_THREAD(base))
send(base->th_notify_fd[1], "", 1, 0);
return (res);
}
void
event_active(struct event *ev, int res, short ncalls)
{
EVTHREAD_ACQUIRE_LOCK(ev->ev_base, EVTHREAD_WRITE, th_base_lock);
event_active_internal(ev, res, ncalls);
EVTHREAD_RELEASE_LOCK(ev->ev_base, EVTHREAD_WRITE, th_base_lock);
}
static inline void
event_active_internal(struct event *ev, int res, short ncalls)
{
struct event_base *base;
/* We get different kinds of events, add them together */
if (ev->ev_flags & EVLIST_ACTIVE) {
ev->ev_res |= res;
return;
}
base = ev->ev_base;
ev->ev_res = res;
if (ev->ev_events & EV_SIGNAL) {
ev->ev_ncalls = ncalls;
ev->ev_pncalls = NULL;
}
event_queue_insert(base, ev, EVLIST_ACTIVE);
}
static int
timeout_next(struct event_base *base, struct timeval **tv_p)
{
struct timeval now;
struct event *ev;
struct timeval *tv = *tv_p;
int res = 0;
EVTHREAD_ACQUIRE_LOCK(base, EVTHREAD_WRITE, th_base_lock);
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);
assert(tv->tv_sec >= 0);
assert(tv->tv_usec >= 0);
event_debug(("timeout_next: in %d seconds", (int)tv->tv_sec));
out:
EVTHREAD_RELEASE_LOCK(base, EVTHREAD_WRITE, th_base_lock);
return (res);
}
/*
* Determines if the time is running backwards by comparing the current
* time against the last time we checked. Not needed when using clock
* monotonic.
*/
static void
timeout_correct(struct event_base *base, struct timeval *tv)
{
struct event **pev;
unsigned int size;
struct timeval off;
if (use_monotonic)
return;
/* Check if time is running backwards */
gettime(base, tv);
EVTHREAD_ACQUIRE_LOCK(base, EVTHREAD_WRITE, th_base_lock);
if (evutil_timercmp(tv, &base->event_tv, >=)) {
base->event_tv = *tv;
EVTHREAD_RELEASE_LOCK(base, EVTHREAD_WRITE, th_base_lock);
return;
}
event_debug(("%s: time is running backwards, corrected",
__func__));
evutil_timersub(&base->event_tv, tv, &off);
/*
* We can modify the key element of the node without destroying
* the key, beause we apply it to all in the right order.
*/
pev = base->timeheap.p;
size = base->timeheap.n;
for (; size-- > 0; ++pev) {
struct timeval *ev_tv = &(**pev).ev_timeout;
evutil_timersub(ev_tv, &off, ev_tv);
}
EVTHREAD_RELEASE_LOCK(base, EVTHREAD_WRITE, th_base_lock);
}
void
timeout_process(struct event_base *base)
{
struct timeval now;
struct event *ev;
EVTHREAD_ACQUIRE_LOCK(base, EVTHREAD_WRITE, th_base_lock);
if (min_heap_empty(&base->timeheap)) {
EVTHREAD_RELEASE_LOCK(base, EVTHREAD_WRITE, th_base_lock);
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_internal(ev);
event_debug(("timeout_process: call %p",
ev->ev_callback));
event_active_internal(ev, EV_TIMEOUT, 1);
}
EVTHREAD_RELEASE_LOCK(base, EVTHREAD_WRITE, th_base_lock);
}
void
event_queue_remove(struct event_base *base, struct event *ev, int queue)
{
if (!(ev->ev_flags & queue))
event_errx(1, "%s: %p(fd %d) not on queue %x", __func__,
ev, ev->ev_fd, queue);
if (~ev->ev_flags & EVLIST_INTERNAL)
base->event_count--;
ev->ev_flags &= ~queue;
switch (queue) {
case EVLIST_INSERTED:
TAILQ_REMOVE(&base->eventqueue, ev, ev_next);
break;
case EVLIST_ACTIVE:
base->event_count_active--;
TAILQ_REMOVE(base->activequeues[ev->ev_pri],
ev, ev_active_next);
break;
case EVLIST_TIMEOUT:
min_heap_erase(&base->timeheap, ev);
break;
default:
event_errx(1, "%s: unknown queue %x", __func__, queue);
}
}
void
event_queue_insert(struct event_base *base, struct event *ev, int queue)
{
if (ev->ev_flags & queue) {
/* Double insertion is possible for active events */
if (queue & EVLIST_ACTIVE)
return;
event_errx(1, "%s: %p(fd %d) already on queue %x", __func__,
ev, ev->ev_fd, queue);
}
if (~ev->ev_flags & EVLIST_INTERNAL)
base->event_count++;
ev->ev_flags |= queue;
switch (queue) {
case EVLIST_INSERTED:
TAILQ_INSERT_TAIL(&base->eventqueue, ev, ev_next);
break;
case EVLIST_ACTIVE:
base->event_count_active++;
TAILQ_INSERT_TAIL(base->activequeues[ev->ev_pri],
ev,ev_active_next);
break;
case EVLIST_TIMEOUT: {
min_heap_push(&base->timeheap, ev);
break;
}
default:
event_errx(1, "%s: unknown queue %x", __func__, queue);
}
}
/* Functions for debugging */
const char *
event_get_version(void)
{
return (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);
}
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 *
mm_malloc(size_t sz)
{
if (_mm_malloc_fn)
return _mm_malloc_fn(sz);
else
return malloc(sz);
}
void *
mm_calloc(size_t count, size_t size)
{
if (_mm_malloc_fn) {
size_t sz = count * size;
void *p = _mm_malloc_fn(sz);
if (p)
memset(p, 0, sz);
return p;
} else
return calloc(count, size);
}
char *
mm_strdup(const char *str)
{
if (_mm_malloc_fn) {
size_t ln = strlen(str);
void *p = _mm_malloc_fn(ln+1);
if (p)
memcpy(p, str, ln+1);
return p;
} else
#ifdef WIN32
return _strdup(str);
#else
return strdup(str);
#endif
}
void *
mm_realloc(void *ptr, size_t sz)
{
if (_mm_realloc_fn)
return _mm_realloc_fn(ptr, sz);
else
return realloc(ptr, sz);
}
void
mm_free(void *ptr)
{
if (_mm_realloc_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;
}
/* support for threading */
void
evthread_set_locking_callback(struct event_base *base,
void (*locking_fn)(int mode, void *lock))
{
#ifdef DISABLE_THREAD_SUPPORT
event_errx(1, "%s: not compiled with thread support", __func__);
#endif
base->th_lock = locking_fn;
}
static void
evthread_ignore_fd(int fd, short what, void *arg)
{
struct event_base *base = arg;
char buf[128];
/* we're draining the socket */
while (recv(fd, buf, sizeof(buf), 0) != -1)
;
event_add(&base->th_notify, NULL);
}
void
evthread_set_id_callback(struct event_base *base,
unsigned long (*id_fn)(void))
{
#ifdef DISABLE_THREAD_SUPPORT
event_errx(1, "%s: not compiled with thread support", __func__);
#endif
#ifdef WIN32
#define LOCAL_SOCKETPAIR_AF AF_INET
#else
#define LOCAL_SOCKETPAIR_AF AF_UNIX
#endif
base->th_get_id = id_fn;
base->th_owner_id = (*id_fn)();
/*
* If another thread wants to add a new event, we need to notify
* the thread that owns the base to wakeup for rescheduling.
*/
if (evutil_socketpair(LOCAL_SOCKETPAIR_AF, SOCK_STREAM, 0,
base->th_notify_fd) == -1)
event_sock_err(1, -1, "%s: socketpair", __func__);
evutil_make_socket_nonblocking(base->th_notify_fd[0]);
evutil_make_socket_nonblocking(base->th_notify_fd[1]);
/* prepare an event that we can use for wakeup */
event_assign(&base->th_notify, base, base->th_notify_fd[0], EV_READ,
evthread_ignore_fd, base);
/* we need to mark this as internal event */
base->th_notify.ev_flags |= EVLIST_INTERNAL;
event_add(&base->th_notify, NULL);
}
void
evthread_set_lock_create_callbacks(struct event_base *base,
void *(*alloc_fn)(void), void (*free_fn)(void *))
{
#ifdef DISABLE_THREAD_SUPPORT
event_errx(1, "%s: not compiled with thread support", __func__);
#endif
base->th_alloc = alloc_fn;
base->th_free = free_fn;
/* now, let's allocate our lock */
base->th_base_lock = (*alloc_fn)();
}
void
event_base_dump_events(struct event_base *base, FILE *output)
{
struct event *e;
int i;
fprintf(output, "Inserted events:\n");
TAILQ_FOREACH(e, &base->eventqueue, ev_next) {
fprintf(output, " %p [fd %ld]%s%s%s%s%s\n",
(void*)e, (long)e->ev_fd,
(e->ev_events&EV_READ)?" Read":"",
(e->ev_events&EV_WRITE)?" Write":"",
(e->ev_events&EV_SIGNAL)?" Signal":"",
(e->ev_events&EV_TIMEOUT)?" Timeout":"",
(e->ev_events&EV_PERSIST)?" Persist":"");
}
for (i = 0; i < base->nactivequeues; ++i) {
if (TAILQ_EMPTY(base->activequeues[i]))
continue;
fprintf(output, "Active events [priority %d]:\n", i);
TAILQ_FOREACH(e, &base->eventqueue, ev_next) {
fprintf(output, " %p [fd %ld]%s%s%s%s\n",
(void*)e, (long)e->ev_fd,
(e->ev_res&EV_READ)?" Read active":"",
(e->ev_res&EV_WRITE)?" Write active":"",
(e->ev_res&EV_SIGNAL)?" Signal active":"",
(e->ev_res&EV_TIMEOUT)?" Timeout active":"");
}
}
}
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