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/*
* Copyright (C) Igor Sysoev
*/
#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_event.h>
static ngx_int_t ngx_select_init(ngx_cycle_t *cycle);
static void ngx_select_done(ngx_cycle_t *cycle);
static ngx_int_t ngx_select_add_event(ngx_event_t *ev, int event, u_int flags);
static ngx_int_t ngx_select_del_event(ngx_event_t *ev, int event, u_int flags);
static ngx_int_t ngx_select_process_events(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;
#if (NGX_WIN32)
static int max_read;
static int max_write;
#else
static int max_fd;
#endif
static ngx_uint_t nevents;
static ngx_event_t **event_index;
#if 0
static ngx_event_t **ready_index;
#endif
static ngx_event_t *accept_events;
static ngx_str_t select_name = ngx_string("select");
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, /* process the changes */
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,
&ngx_select_module_ctx, /* module context */
NULL, /* module directives */
NGX_EVENT_MODULE, /* module type */
NULL, /* init module */
NULL /* init process */
};
static ngx_int_t
ngx_select_init(ngx_cycle_t *cycle)
{
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;
#if 0
if (ready_index) {
ngx_free(ready_index);
}
ready_index = ngx_alloc(sizeof(ngx_event_t *) * 2 * cycle->connection_n,
cycle->log);
if (ready_index == NULL) {
return NGX_ERROR;
}
#endif
}
ngx_io = ngx_os_io;
ngx_event_actions = ngx_select_module_ctx.actions;
ngx_event_flags = NGX_USE_LEVEL_EVENT|NGX_USE_ONESHOT_EVENT;
#if (NGX_WIN32)
max_read = max_write = 0;
#else
max_fd = -1;
#endif
return NGX_OK;
}
static void
ngx_select_done(ngx_cycle_t *cycle)
{
ngx_free(event_index);
#if 0
ngx_free(ready_index);
#endif
event_index = NULL;
}
static ngx_int_t
ngx_select_add_event(ngx_event_t *ev, int event, u_int flags)
{
ngx_connection_t *c;
c = ev->data;
ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0,
"select add event fd:%d ev:%d", c->fd, event);
if (ev->index != NGX_INVALID_INDEX) {
ngx_log_error(NGX_LOG_ALERT, ev->log, 0,
"select event fd:%d ev:%d is already set", c->fd, event);
return NGX_OK;
}
#if (NGX_WIN32)
if ((event == NGX_READ_EVENT) && (max_read >= FD_SETSIZE)
|| (event == NGX_WRITE_EVENT) && (max_write >= FD_SETSIZE))
{
ngx_log_error(NGX_LOG_ERR, ev->log, 0,
"maximum number of descriptors "
"supported by select() is %d", FD_SETSIZE);
return NGX_ERROR;
}
if (event == NGX_READ_EVENT) {
FD_SET(c->fd, &master_read_fd_set);
max_read++;
} else if (event == NGX_WRITE_EVENT) {
FD_SET(c->fd, &master_write_fd_set);
max_write++;
}
#else
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;
}
#endif
ev->active = 1;
ev->oneshot = (u_char) ((flags & NGX_ONESHOT_EVENT) ? 1 : 0);
event_index[nevents] = ev;
ev->index = nevents;
nevents++;
return NGX_OK;
}
static ngx_int_t
ngx_select_del_event(ngx_event_t *ev, int event, u_int flags)
{
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:%d", c->fd, event);
#if (NGX_WIN32)
if (event == NGX_READ_EVENT) {
FD_CLR(c->fd, &master_read_fd_set);
max_read--;
} else if (event == NGX_WRITE_EVENT) {
FD_CLR(c->fd, &master_write_fd_set);
max_write--;
}
#else
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;
}
#endif
if (ev->index < (u_int) --nevents) {
event_index[ev->index] = event_index[nevents];
event_index[ev->index]->index = ev->index;
}
ev->index = NGX_INVALID_INDEX;
return NGX_OK;
}
static ngx_int_t
ngx_select_process_events(ngx_cycle_t *cycle)
{
int ready, nready;
ngx_uint_t i, found, lock, expire;
ngx_err_t err;
ngx_msec_t timer;
ngx_event_t *ev;
ngx_connection_t *c;
ngx_epoch_msec_t delta;
struct timeval tv, *tp;
#if (NGX_HAVE_SELECT_CHANGE_TIMEOUT)
static ngx_epoch_msec_t deltas = 0;
#endif
for ( ;; ) {
timer = ngx_event_find_timer();
if (timer != 0) {
break;
}
ngx_log_debug0(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"select expired timer");
ngx_event_expire_timers((ngx_msec_t)
(ngx_elapsed_msec - ngx_old_elapsed_msec));
}
ngx_old_elapsed_msec = ngx_elapsed_msec;
expire = 1;
#if !(NGX_WIN32)
if (ngx_accept_mutex) {
if (ngx_accept_disabled > 0) {
ngx_accept_disabled--;
} else {
if (ngx_trylock_accept_mutex(cycle) == NGX_ERROR) {
return NGX_ERROR;
}
if (ngx_accept_mutex_held == 0
&& (timer == NGX_TIMER_INFINITE
|| timer > ngx_accept_mutex_delay))
{
timer = ngx_accept_mutex_delay;
expire = 0;
}
}
}
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: %d", max_fd);
}
#endif
#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);
}
#if !(NGX_WIN32)
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"max_fd: %d", max_fd);
#endif
}
#endif
if (timer == NGX_TIMER_INFINITE) {
tp = NULL;
expire = 0;
} else {
tv.tv_sec = timer / 1000;
tv.tv_usec = (timer % 1000) * 1000;
tp = &tv;
}
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"select timer: %d", timer);
work_read_fd_set = master_read_fd_set;
work_write_fd_set = master_write_fd_set;
#if 1
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
/*
* (void *) disables "dereferencing type-punned
* pointer will break strict-aliasing rules
*/
"select read fd_set: %08Xd",
*(int *) (void *) &work_read_fd_set);
#endif
#if (NGX_WIN32)
ready = select(0, &work_read_fd_set, &work_write_fd_set, NULL, tp);
#else
ready = select(max_fd + 1, &work_read_fd_set, &work_write_fd_set, NULL, tp);
#endif
if (ready == -1) {
err = ngx_socket_errno;
} else {
err = 0;
}
#if (NGX_HAVE_SELECT_CHANGE_TIMEOUT)
if (timer != NGX_TIMER_INFINITE) {
delta = timer - (tv.tv_sec * 1000 + tv.tv_usec / 1000);
/*
* learn the real time and update the cached time
* if the sum of the last deltas overcomes 1 second
*/
deltas += delta;
if (deltas > 1000) {
ngx_gettimeofday(&tv);
ngx_time_update(tv.tv_sec);
deltas = tv.tv_usec / 1000;
ngx_elapsed_msec = (ngx_epoch_msec_t) tv.tv_sec * 1000
+ tv.tv_usec / 1000 - ngx_start_msec;
} else {
ngx_elapsed_msec += delta;
}
ngx_log_debug2(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"select timer: %d, delta: %d", timer, (int) delta);
} else {
delta = 0;
ngx_gettimeofday(&tv);
ngx_time_update(tv.tv_sec);
ngx_elapsed_msec = (ngx_epoch_msec_t) tv.tv_sec * 1000
+ tv.tv_usec / 1000 - ngx_start_msec;
if (ready == 0) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
"select() returned no events without timeout");
ngx_accept_mutex_unlock();
return NGX_ERROR;
}
}
#else /* !(NGX_HAVE_SELECT_CHANGE_TIMEOUT) */
ngx_gettimeofday(&tv);
ngx_time_update(tv.tv_sec);
delta = ngx_elapsed_msec;
ngx_elapsed_msec = (ngx_epoch_msec_t) tv.tv_sec * 1000
+ tv.tv_usec / 1000 - ngx_start_msec;
if (timer != NGX_TIMER_INFINITE) {
delta = ngx_elapsed_msec - delta;
ngx_log_debug2(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"select timer: %d, delta: %d", timer, (int) delta);
} else {
if (ready == 0) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
"select() returned no events without timeout");
ngx_accept_mutex_unlock();
return NGX_ERROR;
}
}
#endif /* NGX_HAVE_SELECT_CHANGE_TIMEOUT */
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"select ready %d", ready);
if (err) {
#if (NGX_WIN32)
ngx_log_error(NGX_LOG_ALERT, cycle->log, err, "select() failed");
#else
ngx_log_error((err == NGX_EINTR) ? NGX_LOG_INFO : NGX_LOG_ALERT,
cycle->log, err, "select() failed");
#endif
ngx_accept_mutex_unlock();
return NGX_ERROR;
}
if (ngx_mutex_lock(ngx_posted_events_mutex) == NGX_ERROR) {
ngx_accept_mutex_unlock();
return NGX_ERROR;
}
lock = 1;
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;
if (ev->oneshot) {
if (ev->timer_set) {
ngx_del_timer(ev);
}
if (ev->write) {
ngx_select_del_event(ev, NGX_WRITE_EVENT, 0);
} else {
ngx_select_del_event(ev, NGX_READ_EVENT, 0);
}
}
if (ev->accept) {
ev->next = accept_events;
accept_events = ev;
} else {
ngx_post_event(ev);
}
nready++;
#if 0
ready_index[nready++] = ev;
#endif
}
}
#if 0
for (i = 0; i < nready; i++) {
ev = ready_index[i];
ready--;
if (!ev->active) {
continue;
}
ev->ready = 1;
if (ev->oneshot) {
if (ev->timer_set) {
ngx_del_timer(ev);
}
if (ev->write) {
ngx_select_del_event(ev, NGX_WRITE_EVENT, 0);
} else {
ngx_select_del_event(ev, NGX_READ_EVENT, 0);
}
}
ev->event_handler(ev);
}
#endif
ev = accept_events;
for ( ;; ) {
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"accept event %p", ev);
if (ev == NULL) {
break;
}
ngx_mutex_unlock(ngx_posted_events_mutex);
ev->event_handler(ev);
if (ngx_accept_disabled > 0) {
lock = 0;
break;
}
ev = ev->next;
if (ev == NULL) {
lock = 0;
break;
}
if (ngx_mutex_lock(ngx_posted_events_mutex) == NGX_ERROR) {
ngx_accept_mutex_unlock();
return NGX_ERROR;
}
}
ngx_accept_mutex_unlock();
accept_events = NULL;
if (lock) {
ngx_mutex_unlock(ngx_posted_events_mutex);
}
if (ready != nready) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, 0, "select ready != events");
}
if (expire && delta) {
ngx_event_expire_timers((ngx_msec_t) delta);
}
if (!ngx_threaded) {
ngx_event_process_posted(cycle);
}
return NGX_OK;
}
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 !(NGX_WIN32)
if ((unsigned) ecf->connections > FD_SETSIZE) {
ngx_log_error(NGX_LOG_EMERG, cycle->log, 0,
"the maximum number of files "
"supported by select() is " ngx_value(FD_SETSIZE));
return NGX_CONF_ERROR;
}
#endif
#if (NGX_THREADS) && !(NGX_WIN32)
ngx_log_error(NGX_LOG_EMERG, cycle->log, 0,
"select() is not supported in the threaded mode");
return NGX_CONF_ERROR;
#else
return NGX_CONF_OK;
#endif
}
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