/*
* Copyright (C) Igor Sysoev
* Copyright (C) Nginx, Inc.
*/
#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_event.h>
static ngx_int_t ngx_select_init(ngx_cycle_t *cycle, ngx_msec_t timer);
static void ngx_select_done(ngx_cycle_t *cycle);
static ngx_int_t ngx_select_add_event(ngx_event_t *ev, ngx_int_t event,
ngx_uint_t flags);
static ngx_int_t ngx_select_del_event(ngx_event_t *ev, ngx_int_t event,
ngx_uint_t flags);
static ngx_int_t ngx_select_process_events(ngx_cycle_t *cycle, ngx_msec_t timer,
ngx_uint_t flags);
static void ngx_select_repair_fd_sets(ngx_cycle_t *cycle);
static char *ngx_select_init_conf(ngx_cycle_t *cycle, void *conf);
static fd_set master_read_fd_set;
static fd_set master_write_fd_set;
static fd_set work_read_fd_set;
static fd_set work_write_fd_set;
static ngx_int_t max_fd;
static ngx_uint_t nevents;
static ngx_event_t **event_index;
static ngx_str_t select_name = ngx_string("select");
static ngx_event_module_t ngx_select_module_ctx = {
&select_name,
NULL, /* create configuration */
ngx_select_init_conf, /* init configuration */
{
ngx_select_add_event, /* add an event */
ngx_select_del_event, /* delete an event */
ngx_select_add_event, /* enable an event */
ngx_select_del_event, /* disable an event */
NULL, /* add an connection */
NULL, /* delete an connection */
NULL, /* trigger a notify */
ngx_select_process_events, /* process the events */
ngx_select_init, /* init the events */
ngx_select_done /* done the events */
}
};
ngx_module_t ngx_select_module = {
NGX_MODULE_V1,
&ngx_select_module_ctx, /* module context */
NULL, /* 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
};
static ngx_int_t
ngx_select_init(ngx_cycle_t *cycle, ngx_msec_t timer)
{
ngx_event_t **index;
if (event_index == NULL) {
FD_ZERO(&master_read_fd_set);
FD_ZERO(&master_write_fd_set);
nevents = 0;
}
if (ngx_process >= NGX_PROCESS_WORKER
|| cycle->old_cycle == NULL
|| cycle->old_cycle->connection_n < cycle->connection_n)
{
index = ngx_alloc(sizeof(ngx_event_t *) * 2 * cycle->connection_n,
cycle->log);
if (index == NULL) {
return NGX_ERROR;
}
if (event_index) {
ngx_memcpy(index, event_index, sizeof(ngx_event_t *) * nevents);
ngx_free(event_index);
}
event_index = index;
}
ngx_io = ngx_os_io;
ngx_event_actions = ngx_select_module_ctx.actions;
ngx_event_flags = NGX_USE_LEVEL_EVENT;
max_fd = -1;
return NGX_OK;
}
static void
ngx_select_done(ngx_cycle_t *cycle)
{
ngx_free(event_index);
event_index = NULL;
}
static ngx_int_t
ngx_select_add_event(ngx_event_t *ev, ngx_int_t event, ngx_uint_t flags)
{
ngx_connection_t *c;
c = ev->data;
ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0,
"select add event fd:%d ev:%i", c->fd, event);
if (ev->index != NGX_INVALID_INDEX) {
ngx_log_error(NGX_LOG_ALERT, ev->log, 0,
"select event fd:%d ev:%i is already set", c->fd, event);
return NGX_OK;
}
if ((event == NGX_READ_EVENT && ev->write)
|| (event == NGX_WRITE_EVENT && !ev->write))
{
ngx_log_error(NGX_LOG_ALERT, ev->log, 0,
"invalid select %s event fd:%d ev:%i",
ev->write ? "write" : "read", c->fd, event);
return NGX_ERROR;
}
if (event == NGX_READ_EVENT) {
FD_SET(c->fd, &master_read_fd_set);
} else if (event == NGX_WRITE_EVENT) {
FD_SET(c->fd, &master_write_fd_set);
}
if (max_fd != -1 && max_fd < c->fd) {
max_fd = c->fd;
}
ev->active = 1;
event_index[nevents] = ev;
ev->index = nevents;
nevents++;
return NGX_OK;
}
static ngx_int_t
ngx_select_del_event(ngx_event_t *ev, ngx_int_t event, ngx_uint_t flags)
{
ngx_event_t *e;
ngx_connection_t *c;
c = ev->data;
ev->active = 0;
if (ev->index == NGX_INVALID_INDEX) {
return NGX_OK;
}
ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0,
"select del event fd:%d ev:%i", c->fd, event);
if (event == NGX_READ_EVENT) {
FD_CLR(c->fd, &master_read_fd_set);
} else if (event == NGX_WRITE_EVENT) {
FD_CLR(c->fd, &master_write_fd_set);
}
if (max_fd == c->fd) {
max_fd = -1;
}
if (ev->index < --nevents) {
e = event_index[nevents];
event_index[ev->index] = e;
e->index = ev->index;
}
ev->index = NGX_INVALID_INDEX;
return NGX_OK;
}
static ngx_int_t
ngx_select_process_events(ngx_cycle_t *cycle, ngx_msec_t timer,
ngx_uint_t flags)
{
int ready, nready;
ngx_err_t err;
ngx_uint_t i, found;
ngx_event_t *ev;
ngx_queue_t *queue;
struct timeval tv, *tp;
ngx_connection_t *c;
if (max_fd == -1) {
for (i = 0; i < nevents; i++) {
c = event_index[i]->data;
if (max_fd < c->fd) {
max_fd = c->fd;
}
}
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"change max_fd: %i", max_fd);
}
#if (NGX_DEBUG)
if (cycle->log->log_level & NGX_LOG_DEBUG_ALL) {
for (i = 0; i < nevents; i++) {
ev = event_index[i];
c = ev->data;
ngx_log_debug2(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"select event: fd:%d wr:%d", c->fd, ev->write);
}
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"max_fd: %i", max_fd);
}
#endif
if (timer == NGX_TIMER_INFINITE) {
tp = NULL;
} else {
tv.tv_sec = (long) (timer / 1000);
tv.tv_usec = (long) ((timer % 1000) * 1000);
tp = &tv;
}
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"select timer: %M", timer);
work_read_fd_set = master_read_fd_set;
work_write_fd_set = master_write_fd_set;
ready = select(max_fd + 1, &work_read_fd_set, &work_write_fd_set, NULL, tp);
err = (ready == -1) ? ngx_errno : 0;
if (flags & NGX_UPDATE_TIME || ngx_event_timer_alarm) {
ngx_time_update();
}
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"select ready %d", ready);
if (err) {
ngx_uint_t level;
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, "select() failed");
if (err == NGX_EBADF) {
ngx_select_repair_fd_sets(cycle);
}
return NGX_ERROR;
}
if (ready == 0) {
if (timer != NGX_TIMER_INFINITE) {
return NGX_OK;
}
ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
"select() returned no events without timeout");
return NGX_ERROR;
}
nready = 0;
for (i = 0; i < nevents; i++) {
ev = event_index[i];
c = ev->data;
found = 0;
if (ev->write) {
if (FD_ISSET(c->fd, &work_write_fd_set)) {
found = 1;
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"select write %d", c->fd);
}
} else {
if (FD_ISSET(c->fd, &work_read_fd_set)) {
found = 1;
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"select read %d", c->fd);
}
}
if (found) {
ev->ready = 1;
ev->available = -1;
queue = ev->accept ? &ngx_posted_accept_events
: &ngx_posted_events;
ngx_post_event(ev, queue);
nready++;
}
}
if (ready != nready) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
"select ready != events: %d:%d", ready, nready);
ngx_select_repair_fd_sets(cycle);
}
return NGX_OK;
}
static void
ngx_select_repair_fd_sets(ngx_cycle_t *cycle)
{
int n;
socklen_t len;
ngx_err_t err;
ngx_socket_t s;
for (s = 0; s <= max_fd; s++) {
if (FD_ISSET(s, &master_read_fd_set) == 0) {
continue;
}
len = sizeof(int);
if (getsockopt(s, SOL_SOCKET, SO_TYPE, &n, &len) == -1) {
err = ngx_socket_errno;
ngx_log_error(NGX_LOG_ALERT, cycle->log, err,
"invalid descriptor #%d in read fd_set", s);
FD_CLR(s, &master_read_fd_set);
}
}
for (s = 0; s <= max_fd; s++) {
if (FD_ISSET(s, &master_write_fd_set) == 0) {
continue;
}
len = sizeof(int);
if (getsockopt(s, SOL_SOCKET, SO_TYPE, &n, &len) == -1) {
err = ngx_socket_errno;
ngx_log_error(NGX_LOG_ALERT, cycle->log, err,
"invalid descriptor #%d in write fd_set", s);
FD_CLR(s, &master_write_fd_set);
}
}
max_fd = -1;
}
static char *
ngx_select_init_conf(ngx_cycle_t *cycle, void *conf)
{
ngx_event_conf_t *ecf;
ecf = ngx_event_get_conf(cycle->conf_ctx, ngx_event_core_module);
if (ecf->use != ngx_select_module.ctx_index) {
return NGX_CONF_OK;
}
/* disable warning: the default FD_SETSIZE is 1024U in FreeBSD 5.x */
if (cycle->connection_n > FD_SETSIZE) {
ngx_log_error(NGX_LOG_EMERG, cycle->log, 0,
"the maximum number of files "
"supported by select() is %ud", FD_SETSIZE);
return NGX_CONF_ERROR;
}
return NGX_CONF_OK;
}
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