/*
* Copyright (C) Igor Sysoev
* Copyright (C) Nginx, Inc.
*/
#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_event.h>
#if (NGX_TEST_BUILD_RTSIG)
#if (NGX_DARWIN)
#define SIGRTMIN 33
#define si_fd __pad[0]
#else
#ifdef SIGRTMIN
#define si_fd _reason.__spare__.__spare2__[0]
#else
#define SIGRTMIN 33
#define si_fd __spare__[0]
#endif
#endif
#define F_SETSIG 10
#define KERN_RTSIGNR 30
#define KERN_RTSIGMAX 31
int sigtimedwait(const sigset_t *set, siginfo_t *info,
const struct timespec *timeout);
int sigtimedwait(const sigset_t *set, siginfo_t *info,
const struct timespec *timeout)
{
return -1;
}
int ngx_linux_rtsig_max;
#endif
typedef struct {
ngx_uint_t signo;
ngx_uint_t overflow_events;
ngx_uint_t overflow_test;
ngx_uint_t overflow_threshold;
} ngx_rtsig_conf_t;
extern ngx_event_module_t ngx_poll_module_ctx;
static ngx_int_t ngx_rtsig_init(ngx_cycle_t *cycle, ngx_msec_t timer);
static void ngx_rtsig_done(ngx_cycle_t *cycle);
static ngx_int_t ngx_rtsig_add_connection(ngx_connection_t *c);
static ngx_int_t ngx_rtsig_del_connection(ngx_connection_t *c,
ngx_uint_t flags);
static ngx_int_t ngx_rtsig_process_events(ngx_cycle_t *cycle,
ngx_msec_t timer, ngx_uint_t flags);
static ngx_int_t ngx_rtsig_process_overflow(ngx_cycle_t *cycle,
ngx_msec_t timer, ngx_uint_t flags);
static void *ngx_rtsig_create_conf(ngx_cycle_t *cycle);
static char *ngx_rtsig_init_conf(ngx_cycle_t *cycle, void *conf);
static char *ngx_check_ngx_overflow_threshold_bounds(ngx_conf_t *cf,
void *post, void *data);
static sigset_t set;
static ngx_uint_t overflow, overflow_current;
static struct pollfd *overflow_list;
static ngx_str_t rtsig_name = ngx_string("rtsig");
static ngx_conf_num_bounds_t ngx_overflow_threshold_bounds = {
ngx_check_ngx_overflow_threshold_bounds, 2, 10
};
static ngx_command_t ngx_rtsig_commands[] = {
{ ngx_string("rtsig_signo"),
NGX_EVENT_CONF|NGX_CONF_TAKE1,
ngx_conf_set_num_slot,
0,
offsetof(ngx_rtsig_conf_t, signo),
NULL },
{ ngx_string("rtsig_overflow_events"),
NGX_EVENT_CONF|NGX_CONF_TAKE1,
ngx_conf_set_num_slot,
0,
offsetof(ngx_rtsig_conf_t, overflow_events),
NULL },
{ ngx_string("rtsig_overflow_test"),
NGX_EVENT_CONF|NGX_CONF_TAKE1,
ngx_conf_set_num_slot,
0,
offsetof(ngx_rtsig_conf_t, overflow_test),
NULL },
{ ngx_string("rtsig_overflow_threshold"),
NGX_EVENT_CONF|NGX_CONF_TAKE1,
ngx_conf_set_num_slot,
0,
offsetof(ngx_rtsig_conf_t, overflow_threshold),
&ngx_overflow_threshold_bounds },
ngx_null_command
};
ngx_event_module_t ngx_rtsig_module_ctx = {
&rtsig_name,
ngx_rtsig_create_conf, /* create configuration */
ngx_rtsig_init_conf, /* init configuration */
{
NULL, /* add an event */
NULL, /* delete an event */
NULL, /* enable an event */
NULL, /* disable an event */
ngx_rtsig_add_connection, /* add an connection */
ngx_rtsig_del_connection, /* delete an connection */
NULL, /* process the changes */
ngx_rtsig_process_events, /* process the events */
ngx_rtsig_init, /* init the events */
ngx_rtsig_done, /* done the events */
}
};
ngx_module_t ngx_rtsig_module = {
NGX_MODULE_V1,
&ngx_rtsig_module_ctx, /* module context */
ngx_rtsig_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
};
static ngx_int_t
ngx_rtsig_init(ngx_cycle_t *cycle, ngx_msec_t timer)
{
ngx_rtsig_conf_t *rtscf;
rtscf = ngx_event_get_conf(cycle->conf_ctx, ngx_rtsig_module);
sigemptyset(&set);
sigaddset(&set, (int) rtscf->signo);
sigaddset(&set, (int) rtscf->signo + 1);
sigaddset(&set, SIGIO);
sigaddset(&set, SIGALRM);
if (sigprocmask(SIG_BLOCK, &set, NULL) == -1) {
ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
"sigprocmask() failed");
return NGX_ERROR;
}
if (overflow_list) {
ngx_free(overflow_list);
}
overflow_list = ngx_alloc(sizeof(struct pollfd) * rtscf->overflow_events,
cycle->log);
if (overflow_list == NULL) {
return NGX_ERROR;
}
ngx_io = ngx_os_io;
ngx_event_actions = ngx_rtsig_module_ctx.actions;
ngx_event_flags = NGX_USE_RTSIG_EVENT
|NGX_USE_GREEDY_EVENT
|NGX_USE_FD_EVENT;
return NGX_OK;
}
static void
ngx_rtsig_done(ngx_cycle_t *cycle)
{
ngx_free(overflow_list);
overflow_list = NULL;
}
static ngx_int_t
ngx_rtsig_add_connection(ngx_connection_t *c)
{
ngx_uint_t signo;
ngx_rtsig_conf_t *rtscf;
if (c->read->accept && c->read->disabled) {
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0,
"rtsig enable connection: fd:%d", c->fd);
if (fcntl(c->fd, F_SETOWN, ngx_pid) == -1) {
ngx_log_error(NGX_LOG_ALERT, c->log, ngx_errno,
"fcntl(F_SETOWN) failed");
return NGX_ERROR;
}
c->read->active = 1;
c->read->disabled = 0;
}
rtscf = ngx_event_get_conf(ngx_cycle->conf_ctx, ngx_rtsig_module);
signo = rtscf->signo + c->read->instance;
ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0,
"rtsig add connection: fd:%d signo:%ui", c->fd, signo);
if (fcntl(c->fd, F_SETFL, O_RDWR|O_NONBLOCK|O_ASYNC) == -1) {
ngx_log_error(NGX_LOG_ALERT, c->log, ngx_errno,
"fcntl(O_RDWR|O_NONBLOCK|O_ASYNC) failed");
return NGX_ERROR;
}
if (fcntl(c->fd, F_SETSIG, (int) signo) == -1) {
ngx_log_error(NGX_LOG_ALERT, c->log, ngx_errno,
"fcntl(F_SETSIG) failed");
return NGX_ERROR;
}
if (fcntl(c->fd, F_SETOWN, ngx_pid) == -1) {
ngx_log_error(NGX_LOG_ALERT, c->log, ngx_errno,
"fcntl(F_SETOWN) failed");
return NGX_ERROR;
}
#if (NGX_HAVE_ONESIGFD)
if (fcntl(c->fd, F_SETAUXFL, O_ONESIGFD) == -1) {
ngx_log_error(NGX_LOG_ALERT, c->log, ngx_errno,
"fcntl(F_SETAUXFL) failed");
return NGX_ERROR;
}
#endif
c->read->active = 1;
c->write->active = 1;
return NGX_OK;
}
static ngx_int_t
ngx_rtsig_del_connection(ngx_connection_t *c, ngx_uint_t flags)
{
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0,
"rtsig del connection: fd:%d", c->fd);
if ((flags & NGX_DISABLE_EVENT) && c->read->accept) {
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0,
"rtsig disable connection: fd:%d", c->fd);
c->read->active = 0;
c->read->disabled = 1;
return NGX_OK;
}
if (flags & NGX_CLOSE_EVENT) {
c->read->active = 0;
c->write->active = 0;
return NGX_OK;
}
if (fcntl(c->fd, F_SETFL, O_RDWR|O_NONBLOCK) == -1) {
ngx_log_error(NGX_LOG_ALERT, c->log, ngx_errno,
"fcntl(O_RDWR|O_NONBLOCK) failed");
return NGX_ERROR;
}
c->read->active = 0;
c->write->active = 0;
return NGX_OK;
}
static ngx_int_t
ngx_rtsig_process_events(ngx_cycle_t *cycle, ngx_msec_t timer, ngx_uint_t flags)
{
int signo;
ngx_int_t instance;
ngx_err_t err;
siginfo_t si;
ngx_event_t *rev, *wev, **queue;
struct timespec ts, *tp;
struct sigaction sa;
ngx_connection_t *c;
ngx_rtsig_conf_t *rtscf;
if (timer == NGX_TIMER_INFINITE) {
tp = NULL;
} else {
ts.tv_sec = timer / 1000;
ts.tv_nsec = (timer % 1000) * 1000000;
tp = &ts;
}
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"rtsig timer: %M", timer);
/* Linux's sigwaitinfo() is sigtimedwait() with the NULL timeout pointer */
signo = sigtimedwait(&set, &si, tp);
if (signo == -1) {
err = ngx_errno;
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, err,
"rtsig signo:%d", signo);
if (flags & NGX_UPDATE_TIME) {
ngx_time_update();
}
if (err == NGX_EAGAIN) {
/* timeout */
if (timer != NGX_TIMER_INFINITE) {
return NGX_AGAIN;
}
ngx_log_error(NGX_LOG_ALERT, cycle->log, err,
"sigtimedwait() returned EAGAIN without timeout");
return NGX_ERROR;
}
ngx_log_error((err == NGX_EINTR) ? NGX_LOG_INFO : NGX_LOG_ALERT,
cycle->log, err, "sigtimedwait() failed");
return NGX_ERROR;
}
ngx_log_debug3(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"rtsig signo:%d fd:%d band:%04Xd",
signo, si.si_fd, si.si_band);
if (flags & NGX_UPDATE_TIME) {
ngx_time_update();
}
rtscf = ngx_event_get_conf(ngx_cycle->conf_ctx, ngx_rtsig_module);
if (signo == (int) rtscf->signo || signo == (int) rtscf->signo + 1) {
if (overflow && (ngx_uint_t) si.si_fd > overflow_current) {
return NGX_OK;
}
c = ngx_cycle->files[si.si_fd];
if (c == NULL) {
/* the stale event */
return NGX_OK;
}
instance = signo - (int) rtscf->signo;
rev = c->read;
if (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,
"rtsig: stale event %p", c);
return NGX_OK;
}
if ((si.si_band & (POLLIN|POLLHUP|POLLERR)) && rev->active) {
rev->ready = 1;
if (flags & NGX_POST_EVENTS) {
queue = (ngx_event_t **) (rev->accept ?
&ngx_posted_accept_events : &ngx_posted_events);
ngx_locked_post_event(rev, queue);
} else {
rev->handler(rev);
}
}
wev = c->write;
if ((si.si_band & (POLLOUT|POLLHUP|POLLERR)) && wev->active) {
wev->ready = 1;
if (flags & NGX_POST_EVENTS) {
ngx_locked_post_event(wev, &ngx_posted_events);
} else {
wev->handler(wev);
}
}
return NGX_OK;
} else if (signo == SIGALRM) {
ngx_time_update();
return NGX_OK;
} else if (signo == SIGIO) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
"rt signal queue overflowed");
/* flush the RT signal queue */
ngx_memzero(&sa, sizeof(struct sigaction));
sa.sa_handler = SIG_DFL;
sigemptyset(&sa.sa_mask);
if (sigaction(rtscf->signo, &sa, NULL) == -1) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
"sigaction(%d, SIG_DFL) failed", rtscf->signo);
}
if (sigaction(rtscf->signo + 1, &sa, NULL) == -1) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
"sigaction(%d, SIG_DFL) failed", rtscf->signo + 1);
}
overflow = 1;
overflow_current = 0;
ngx_event_actions.process_events = ngx_rtsig_process_overflow;
return NGX_ERROR;
}
ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
"sigtimedwait() returned unexpected signal: %d", signo);
return NGX_ERROR;
}
static ngx_int_t
ngx_rtsig_process_overflow(ngx_cycle_t *cycle, ngx_msec_t timer,
ngx_uint_t flags)
{
int name[2], rtsig_max, rtsig_nr, events, ready;
size_t len;
ngx_err_t err;
ngx_uint_t tested, n, i;
ngx_event_t *rev, *wev, **queue;
ngx_connection_t *c;
ngx_rtsig_conf_t *rtscf;
ngx_log_debug0(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"rtsig process overflow");
rtscf = ngx_event_get_conf(ngx_cycle->conf_ctx, ngx_rtsig_module);
tested = 0;
for ( ;; ) {
n = 0;
while (n < rtscf->overflow_events) {
if (overflow_current == cycle->connection_n) {
break;
}
c = cycle->files[overflow_current++];
if (c == NULL || c->fd == -1) {
continue;
}
events = 0;
if (c->read->active && c->read->handler) {
events |= POLLIN;
}
if (c->write->active && c->write->handler) {
events |= POLLOUT;
}
if (events == 0) {
continue;
}
overflow_list[n].fd = c->fd;
overflow_list[n].events = events;
overflow_list[n].revents = 0;
n++;
}
if (n == 0) {
break;
}
for ( ;; ) {
ready = poll(overflow_list, n, 0);
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"rtsig overflow poll:%d", ready);
if (ready == -1) {
err = ngx_errno;
ngx_log_error((err == NGX_EINTR) ? NGX_LOG_INFO : NGX_LOG_ALERT,
cycle->log, 0,
"poll() failed while the overflow recover");
if (err == NGX_EINTR) {
continue;
}
}
break;
}
if (ready <= 0) {
continue;
}
ngx_mutex_lock(ngx_posted_events_mutex);
for (i = 0; i < n; i++) {
c = cycle->files[overflow_list[i].fd];
if (c == NULL) {
continue;
}
rev = c->read;
if (rev->active
&& !rev->closed
&& rev->handler
&& (overflow_list[i].revents
& (POLLIN|POLLERR|POLLHUP|POLLNVAL)))
{
tested++;
if ((flags & NGX_POST_THREAD_EVENTS) && !rev->accept) {
rev->posted_ready = 1;
} else {
rev->ready = 1;
}
if (flags & NGX_POST_EVENTS) {
queue = (ngx_event_t **) (rev->accept ?
&ngx_posted_accept_events : &ngx_posted_events);
ngx_locked_post_event(rev, queue);
} else {
rev->handler(rev);
}
}
wev = c->write;
if (wev->active
&& !wev->closed
&& wev->handler
&& (overflow_list[i].revents
& (POLLOUT|POLLERR|POLLHUP|POLLNVAL)))
{
tested++;
if (flags & NGX_POST_THREAD_EVENTS) {
wev->posted_ready = 1;
} else {
wev->ready = 1;
}
if (flags & NGX_POST_EVENTS) {
ngx_locked_post_event(wev, &ngx_posted_events);
} else {
wev->handler(wev);
}
}
}
ngx_mutex_unlock(ngx_posted_events_mutex);
if (tested >= rtscf->overflow_test) {
if (ngx_linux_rtsig_max) {
/*
* Check the current rt queue length to prevent
* the new overflow.
*
* learn the "/proc/sys/kernel/rtsig-max" value because
* it can be changed since the last checking
*/
name[0] = CTL_KERN;
name[1] = KERN_RTSIGMAX;
len = sizeof(rtsig_max);
if (sysctl(name, 2, &rtsig_max, &len, NULL, 0) == -1) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, errno,
"sysctl(KERN_RTSIGMAX) failed");
return NGX_ERROR;
}
/* name[0] = CTL_KERN; */
name[1] = KERN_RTSIGNR;
len = sizeof(rtsig_nr);
if (sysctl(name, 2, &rtsig_nr, &len, NULL, 0) == -1) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, errno,
"sysctl(KERN_RTSIGNR) failed");
return NGX_ERROR;
}
/*
* drain the rt signal queue if the /"proc/sys/kernel/rtsig-nr"
* is bigger than
* "/proc/sys/kernel/rtsig-max" / "rtsig_overflow_threshold"
*/
if (rtsig_max / (int) rtscf->overflow_threshold < rtsig_nr) {
ngx_log_debug2(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"rtsig queue state: %d/%d",
rtsig_nr, rtsig_max);
while (ngx_rtsig_process_events(cycle, 0, flags) == NGX_OK)
{
/* void */
}
}
} else {
/*
* Linux has not KERN_RTSIGMAX since 2.6.6-mm2
* so drain the rt signal queue unconditionally
*/
while (ngx_rtsig_process_events(cycle, 0, flags) == NGX_OK) {
/* void */
}
}
tested = 0;
}
}
if (flags & NGX_UPDATE_TIME) {
ngx_time_update();
}
ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
"rt signal queue overflow recovered");
overflow = 0;
ngx_event_actions.process_events = ngx_rtsig_process_events;
return NGX_OK;
}
static void *
ngx_rtsig_create_conf(ngx_cycle_t *cycle)
{
ngx_rtsig_conf_t *rtscf;
rtscf = ngx_palloc(cycle->pool, sizeof(ngx_rtsig_conf_t));
if (rtscf == NULL) {
return NULL;
}
rtscf->signo = NGX_CONF_UNSET;
rtscf->overflow_events = NGX_CONF_UNSET;
rtscf->overflow_test = NGX_CONF_UNSET;
rtscf->overflow_threshold = NGX_CONF_UNSET;
return rtscf;
}
static char *
ngx_rtsig_init_conf(ngx_cycle_t *cycle, void *conf)
{
ngx_rtsig_conf_t *rtscf = conf;
/* LinuxThreads use the first 3 RT signals */
ngx_conf_init_uint_value(rtscf->signo, SIGRTMIN + 10);
ngx_conf_init_uint_value(rtscf->overflow_events, 16);
ngx_conf_init_uint_value(rtscf->overflow_test, 32);
ngx_conf_init_uint_value(rtscf->overflow_threshold, 10);
return NGX_CONF_OK;
}
static char *
ngx_check_ngx_overflow_threshold_bounds(ngx_conf_t *cf, void *post, void *data)
{
if (ngx_linux_rtsig_max) {
return ngx_conf_check_num_bounds(cf, post, data);
}
ngx_conf_log_error(NGX_LOG_WARN, cf, 0,
"\"rtsig_overflow_threshold\" is not supported "
"since Linux 2.6.6-mm2, ignored");
return NGX_CONF_OK;
}
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