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event.c
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event.c
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/*
* Copyright (c) 2000-2007 Niels Provos <[email protected]>
* 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"
#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"
#include "changelist-internal.h"
#include "ht-internal.h"
#include "util-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
/* 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 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 int 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);
#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;
/* 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)
/* The first time this function is called, it sets use_monotonic to 1
* if we have a clock function that supports monotonic time */
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;
//获取系统启动计时 返回秒和纳秒
if (clock_gettime(CLOCK_MONOTONIC, &ts) == 0)
use_monotonic = 1;
use_monotonic_initialized = 1;
#endif
}
/* 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 -1
/** 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)
{
//th_base_lock
EVENT_BASE_ASSERT_LOCKED(base);
//返回timeval结构体数据
if (base->tv_cache.tv_sec) {
*tp = base->tv_cache;
return (0);
}
#if defined(_EVENT_HAVE_CLOCK_GETTIME) && defined(CLOCK_MONOTONIC)
//使用系统计时
if (use_monotonic) {
struct timespec ts;
//获取计时失败的话直接返回
if (clock_gettime(CLOCK_MONOTONIC, &ts) == -1)
return (-1);
//tp时间结构体保存当前ts变量获取到的系统计时数据
tp->tv_sec = ts.tv_sec;
tp->tv_usec = ts.tv_nsec / 1000;
if (base->last_updated_clock_diff + CLOCK_SYNC_INTERVAL
< ts.tv_sec) {
struct timeval tv;
evutil_gettimeofday(&tv,NULL);
evutil_timersub(&tv, tp, &base->tv_clock_diff);
base->last_updated_clock_diff = ts.tv_sec;
}
return (0);
}
#endif
return (evutil_gettimeofday(tp, NULL));
}
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 {
#if defined(_EVENT_HAVE_CLOCK_GETTIME) && defined(CLOCK_MONOTONIC)
evutil_timeradd(&base->tv_cache, &base->tv_clock_diff, tv);
#else
*tv = base->tv_cache;
#endif
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);
}
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_deferred_cb_queue_init(struct deferred_cb_queue *cb)
{
memset(cb, 0, sizeof(struct deferred_cb_queue));
TAILQ_INIT(&cb->deferred_cb_list);
}
/** Helper for the deferred_cb queue: wake up the event base. */
static void
notify_base_cbq_callback(struct deferred_cb_queue *cb, void *baseptr)
{
struct event_base *base = baseptr;
if (EVBASE_NEED_NOTIFY(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;
}
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
}
#if 0
void
event_disable_debug_mode(void)
{
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);
}
#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
//创建event_base结构体变量
if ((base = mm_calloc(1, sizeof(struct event_base))) == NULL) {
event_warn("%s: calloc", __func__);
return NULL;
}
//检测是否要 CLOCK_MONOTONIC
detect_monotonic();
//base->event_tv timeval 结构体 含有秒和微秒
//给event_base变量赋时间初始值
gettime(base, &base->event_tv);
//给event_base->timehead事件队列优先级超时初始化
min_heap_ctor(&base->timeheap);
//给event_base事件列表初始化
TAILQ_INIT(&base->eventqueue);
//给event_base 信号事件处理器的成员初始化
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;
//给event_base延迟回调成员初始化
event_deferred_cb_queue_init(&base->defer_queue);
//给event_base 延迟队列的通知设置回调函数
base->defer_queue.notify_fn = notify_base_cbq_callback;
base->defer_queue.notify_arg = base;
//给event_base成员设置flags
if (cfg)
base->flags = cfg->flags;
//给event_base io成员初始化
evmap_io_initmap(&base->io);
evmap_signal_initmap(&base->sigmap);
event_changelist_init(&base->changelist);
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 */
//检测cfg给的配置是否与目前eventpos数组的某IO复用匹配
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];
//假设系统选择的IO复用是epoll则看epoll.c的封装
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;
}
//获取环境变量
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 */
#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,
EVTHREAD_LOCKTYPE_RECURSIVE);
base->defer_queue.lock = base->th_base_lock;
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
}
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. */
/* 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;
/* If we're freeing current_base, there won't be a current_base. */
if (base == current_base)
current_base = NULL;
/* 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. */
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 */
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 (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);
event_changelist_freemem(&base->changelist);
EVTHREAD_FREE_LOCK(base->th_base_lock, EVTHREAD_LOCKTYPE_RECURSIVE);
EVTHREAD_FREE_COND(base->current_event_cond);
mm_free(base);
}
/* reinitialize the event base after a fork */
int
event_reinit(struct event_base *base)
{
const struct eventop *evsel;
int res = 0;
struct event *ev;
int was_notifiable = 0;
EVBASE_ACQUIRE_LOCK(base, th_base_lock);
evsel = base->evsel;
#if 0
/* Right now, reinit always takes effect, since even if the
backend doesn't require it, the signal socketpair code does.
XXX
*/
/* check if this event mechanism requires reinit */
if (!evsel->need_reinit)
goto done;
#endif
/* 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);
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]);
base->sig.ev_signal_added = 0;
}
if (base->th_notify_fd[0] != -1) {
/* we cannot call event_del here because the base has
* not been reinitialized yet. */
was_notifiable = 1;
event_queue_remove(base, &base->th_notify,
EVLIST_INSERTED);
if (base->th_notify.ev_flags & EVLIST_ACTIVE)
event_queue_remove(base, &base->th_notify,
EVLIST_ACTIVE);
base->sig.ev_signal_added = 0;
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);
}
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;
}
event_changelist_freemem(&base->changelist); /* XXX */
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 (ev == &base->sig.ev_signal) {
/* If we run into the ev_signal event, it's only
* in eventqueue because some signal event was
* added, which made evsig_add re-add ev_signal.
* So don't double-add it. */
continue;
}
if (evmap_io_add(base, ev->ev_fd, ev) == -1)
res = -1;
} else if (ev->ev_events & EV_SIGNAL) {
if (evmap_signal_add(base, (int)ev->ev_fd, ev) == -1)
res = -1;
}
}
if (was_notifiable && res == 0)
res = evthread_make_base_notifiable(base);
done:
EVBASE_RELEASE_LOCK(base, th_base_lock);
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);
//该宏定义位于queue.h文件中
//是一个尾队列宏【函数】
//给
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);
}
/**
* 给event_config.flags赋值
* @param cfg
* @param flag
* @return
*/
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)
{
//申请指定大小的内存返回
struct event_config_entry *entry = mm_malloc(sizeof(*entry));
if (entry == NULL)
return (-1);
//method参数是空的话就释放掉上面申请好的内容
if ((entry->avoid_method = mm_strdup(method)) == NULL) {
mm_free(entry);
return (-1);
}