Nginnxソース分析-Eventイベント編-epollイベントモジュール
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この記事は主にepoll事件モジュールについて説明します.Nginnxは複数のイベントモジュールをサポートします.epoll/pool/select/kqueueなど.epollはよく使われています.私たちもよく知っています.
Nginnxのepollイベントモジュールは/event/module/ngx_epoll_module.
Epollモジュールのデータ構造
1.epollモジュール命令集ngx_epoll_command
1.プロファイル初期化
epoolモジュールはEventモジュールの下のサブモジュールに属しています.ファイル初期化時にEvent解析プロファイルのコア関数:ngx_events_ブロック中です
epoolモジュールはEventモジュールの下のサブモジュールですので、独立したinit_は設定されていません.processはコールバック関数を初期化します.
epollイベントモジュールの初期化は、Event大モジュールの初期化時に行われる.
初期化セット:ngx_イベントprocess.initで行う
1.ngx_epoll_process.イベント イベントインターフェースの収集、配布を実現しました.
Nginnxのepollイベントモジュールは/event/module/ngx_epoll_module.
Epollモジュールのデータ構造
1.epollモジュール命令集ngx_epoll_command
/**
* epoll
* epoll_events： epoll_wait
* worker_aio_requests： I/O io_setup I/O ， I/O
*/
static ngx_command_t ngx_epoll_commands[] = {
{ ngx_string("epoll_events"),
NGX_EVENT_CONF|NGX_CONF_TAKE1,
ngx_conf_set_num_slot,
0,
offsetof(ngx_epoll_conf_t, events),
NULL },
{ ngx_string("worker_aio_requests"),
NGX_EVENT_CONF|NGX_CONF_TAKE1,
ngx_conf_set_num_slot,
0,
offsetof(ngx_epoll_conf_t, aio_requests),
NULL },
ngx_null_command
};/**
* epoll
* ngx_epoll_create_conf ：
* ngx_epoll_init_conf ：
* ngx_event_actions_t actions ： action
*/
ngx_event_module_t ngx_epoll_module_ctx = {
&epoll_name,
ngx_epoll_create_conf, /* create configuration */
ngx_epoll_init_conf, /* init configuration */
{
ngx_epoll_add_event, /* add an event */
ngx_epoll_del_event, /* delete an event */
ngx_epoll_add_event, /* enable an event */
ngx_epoll_del_event, /* disable an event */
ngx_epoll_add_connection, /* add an connection */
ngx_epoll_del_connection, /* delete an connection */
#if (NGX_HAVE_EVENTFD)
ngx_epoll_notify, /* trigger a notify */
#else
NULL, /* trigger a notify */
#endif
ngx_epoll_process_events, /* process the events */
ngx_epoll_init, /* init the events */
ngx_epoll_done, /* done the events */
}
};/**
* epoll
* ngx_epoll_module_ctx：epoll
* ngx_epoll_commands：epoll
* epoll/kqueue
*/
ngx_module_t ngx_epoll_module = {
NGX_MODULE_V1,
&ngx_epoll_module_ctx, /* module context */
ngx_epoll_commands, /* module directives */
NGX_EVENT_MODULE, /* module type */
NULL, /* init master */
NULL, /* init module */
NULL, /* init process */
NULL, /* init thread */
NULL, /* exit thread */
NULL, /* exit process */
NULL, /* exit master */
NGX_MODULE_V1_PADDING
};1.プロファイル初期化
epoolモジュールはEventモジュールの下のサブモジュールに属しています.ファイル初期化時にEvent解析プロファイルのコア関数:ngx_events_ブロック中です
/* ， NGX_EVENT_MODULE， create_conf */
for (i = 0; cf->cycle->modules[i]; i++) {
if (cf->cycle->modules[i]->type != NGX_EVENT_MODULE) {
continue;
}
m = cf->cycle->modules[i]->ctx;
if (m->create_conf) {
(*ctx)[cf->cycle->modules[i]->ctx_index] = m->create_conf(
cf->cycle);
if ((*ctx)[cf->cycle->modules[i]->ctx_index] == NULL) {
return NGX_CONF_ERROR ;
}
}
}
/* event*/
pcf = *cf;
cf->ctx = ctx;
cf->module_type = NGX_EVENT_MODULE;
cf->cmd_type = NGX_EVENT_CONF;
/* ， ， */
rv = ngx_conf_parse(cf, NULL);
*cf = pcf;
if (rv != NGX_CONF_OK) {
return rv;
}
/* init_conf */
for (i = 0; cf->cycle->modules[i]; i++) {
if (cf->cycle->modules[i]->type != NGX_EVENT_MODULE) {
continue;
}
m = cf->cycle->modules[i]->ctx;
if (m->init_conf) {
rv = m->init_conf(cf->cycle,
(*ctx)[cf->cycle->modules[i]->ctx_index]);
if (rv != NGX_CONF_OK) {
return rv;
}
}
}/**
*
*/
static void *
ngx_epoll_create_conf(ngx_cycle_t *cycle)
{
ngx_epoll_conf_t *epcf;
epcf = ngx_palloc(cycle->pool, sizeof(ngx_epoll_conf_t));
if (epcf == NULL) {
return NULL;
}
epcf->events = NGX_CONF_UNSET;
epcf->aio_requests = NGX_CONF_UNSET;
return epcf;
}
/**
*
*/
static char *
ngx_epoll_init_conf(ngx_cycle_t *cycle, void *conf)
{
ngx_epoll_conf_t *epcf = conf;
ngx_conf_init_uint_value(epcf->events, 512);
ngx_conf_init_uint_value(epcf->aio_requests, 32);
return NGX_CONF_OK;
}epoolモジュールはEventモジュールの下のサブモジュールですので、独立したinit_は設定されていません.processはコールバック関数を初期化します.
epollイベントモジュールの初期化は、Event大モジュールの初期化時に行われる.
初期化セット:ngx_イベントprocess.initで行う
/**
* ， epoll/kqueue
*/
for (m = 0; cycle->modules[m]; m++) {
if (cycle->modules[m]->type != NGX_EVENT_MODULE) {
continue;
}
if (cycle->modules[m]->ctx_index != ecf->use) {
continue;
}
module = cycle->modules[m]->ctx;
/**
* epoll/kqueue init
* epoll ngx_epoll_init
*/
if (module->actions.init(cycle, ngx_timer_resolution) != NGX_OK) {
/* fatal */
exit(2);
}
break;
}/**
* epoll
*/
static ngx_int_t
ngx_epoll_init(ngx_cycle_t *cycle, ngx_msec_t timer)
{
/* */
ngx_epoll_conf_t *epcf;
/* */
epcf = ngx_event_get_conf(cycle->conf_ctx, ngx_epoll_module);
if (ep == -1) {
/* epoll ， Linux ， */
ep = epoll_create(cycle->connection_n / 2);
if (ep == -1) {
ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
"epoll_create() failed");
return NGX_ERROR;
}
#if (NGX_HAVE_EVENTFD)
if (ngx_epoll_notify_init(cycle->log) != NGX_OK) {
ngx_epoll_module_ctx.actions.notify = NULL;
}
#endif
#if (NGX_HAVE_FILE_AIO)
ngx_epoll_aio_init(cycle, epcf);
#endif
#if (NGX_HAVE_EPOLLRDHUP)
ngx_epoll_test_rdhup(cycle);
#endif
}
/* epoll_wait */
if (nevents < epcf->events) {
if (event_list) {
ngx_free(event_list);
}
event_list = ngx_alloc(sizeof(struct epoll_event) * epcf->events,
cycle->log);
if (event_list == NULL) {
return NGX_ERROR;
}
}
/* */
nevents = epcf->events;
ngx_io = ngx_os_io;
ngx_event_actions = ngx_epoll_module_ctx.actions;
#if (NGX_HAVE_CLEAR_EVENT)
ngx_event_flags = NGX_USE_CLEAR_EVENT
#else
ngx_event_flags = NGX_USE_LEVEL_EVENT
#endif
|NGX_USE_GREEDY_EVENT
|NGX_USE_EPOLL_EVENT;
return NGX_OK;
}
1.ngx_epoll_process.イベント イベントインターフェースの収集、配布を実現しました.
/**
* ==> ngx_process_events
* 、 (void) ngx_process_events(cycle, timer, flags);
*/
static ngx_int_t
ngx_epoll_process_events(ngx_cycle_t *cycle, ngx_msec_t timer, ngx_uint_t flags)
{
int events;
uint32_t revents;
ngx_int_t instance, i;
ngx_uint_t level;
ngx_err_t err;
ngx_event_t *rev, *wev;
ngx_queue_t *queue;
ngx_connection_t *c;
/* NGX_TIMER_INFINITE == INFTIM */
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"epoll timer: %M", timer);
/* epoll_wait */
events = epoll_wait(ep, event_list, (int) nevents, timer);
err = (events == -1) ? ngx_errno : 0;
/* */
if (flags & NGX_UPDATE_TIME || ngx_event_timer_alarm) {
ngx_time_update();
}
/* epoll_wait */
if (err) {
if (err == NGX_EINTR) {
if (ngx_event_timer_alarm) {
ngx_event_timer_alarm = 0;
return NGX_OK;
}
level = NGX_LOG_INFO;
} else {
level = NGX_LOG_ALERT;
}
ngx_log_error(level, cycle->log, err, "epoll_wait() failed");
return NGX_ERROR;
}
/* */
if (events == 0) {
if (timer != NGX_TIMER_INFINITE) {
return NGX_OK;
}
ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
"epoll_wait() returned no events without timeout");
return NGX_ERROR;
}
/* epoll_wait */
for (i = 0; i < events; i++) {
/* ngx_connection_t */
c = event_list[i].data.ptr;
instance = (uintptr_t) c & 1;
c = (ngx_connection_t *) ((uintptr_t) c & (uintptr_t) ~1);
/* */
rev = c->read;
if (c->fd == -1 || rev->instance != instance) {
/*
* the stale event from a file descriptor
* that was just closed in this iteration
*/
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"epoll: stale event %p", c);
continue;
}
/* */
revents = event_list[i].events;
ngx_log_debug3(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"epoll: fd:%d ev:%04XD d:%p",
c->fd, revents, event_list[i].data.ptr);
if (revents & (EPOLLERR|EPOLLHUP)) {
ngx_log_debug2(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"epoll_wait() error on fd:%d ev:%04XD",
c->fd, revents);
}
#if 0
if (revents & ~(EPOLLIN|EPOLLOUT|EPOLLERR|EPOLLHUP)) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
"strange epoll_wait() events fd:%d ev:%04XD",
c->fd, revents);
}
#endif
if ((revents & (EPOLLERR|EPOLLHUP))
&& (revents & (EPOLLIN|EPOLLOUT)) == 0)
{
/*
* if the error events were returned without EPOLLIN or EPOLLOUT,
* then add these flags to handle the events at least in one
* active handler
*/
revents |= EPOLLIN|EPOLLOUT;
}
/* EPOLLIN */
if ((revents & EPOLLIN) && rev->active) {
#if (NGX_HAVE_EPOLLRDHUP)
if (revents & EPOLLRDHUP) {
rev->pending_eof = 1;
}
rev->available = 1;
#endif
rev->ready = 1;
/* ， */
if (flags & NGX_POST_EVENTS) {
queue = rev->accept ? &ngx_posted_accept_events
: &ngx_posted_events;
ngx_post_event(rev, queue);
} else {
/* ， */
rev->handler(rev);
}
}
wev = c->write;
/* EPOLLOUT*/
if ((revents & EPOLLOUT) && wev->active) {
if (c->fd == -1 || wev->instance != instance) {
/*
* the stale event from a file descriptor
* that was just closed in this iteration
*/
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"epoll: stale event %p", c);
continue;
}
wev->ready = 1;
#if (NGX_THREADS)
wev->complete = 1;
#endif
if (flags & NGX_POST_EVENTS) {
ngx_post_event(wev, &ngx_posted_events);
} else {
wev->handler(wev);
}
}
}
return NGX_OK;
}/**
*
*/
static ngx_int_t
ngx_epoll_add_event(ngx_event_t *ev, ngx_int_t event, ngx_uint_t flags)
{
int op;
uint32_t events, prev;
ngx_event_t *e;
ngx_connection_t *c;
struct epoll_event ee;
/* data ngx_connection_t */
c = ev->data;
events = (uint32_t) event;
/* 。 ，c->write ，c->read*/
if (event == NGX_READ_EVENT) {
e = c->write;
prev = EPOLLOUT;
#if (NGX_READ_EVENT != EPOLLIN|EPOLLRDHUP)
events = EPOLLIN|EPOLLRDHUP;
#endif
} else {
e = c->read;
prev = EPOLLIN|EPOLLRDHUP;
#if (NGX_WRITE_EVENT != EPOLLOUT)
events = EPOLLOUT;
#endif
}
/* active */
if (e->active) {
op = EPOLL_CTL_MOD;
events |= prev;
} else {
op = EPOLL_CTL_ADD;
}
ee.events = events | (uint32_t) flags;
ee.data.ptr = (void *) ((uintptr_t) c | ev->instance);
ngx_log_debug3(NGX_LOG_DEBUG_EVENT, ev->log, 0,
"epoll add event: fd:%d op:%d ev:%08XD",
c->fd, op, ee.events);
/* */
if (epoll_ctl(ep, op, c->fd, &ee) == -1) {
ngx_log_error(NGX_LOG_ALERT, ev->log, ngx_errno,
"epoll_ctl(%d, %d) failed", op, c->fd);
return NGX_ERROR;
}
ev->active = 1;
#if 0
ev->oneshot = (flags & NGX_ONESHOT_EVENT) ? 1 : 0;
#endif
return NGX_OK;
}