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;
}
ngx_int_t
ngx_devpoll_process_events(ngx_cycle_t *cycle, ngx_msec_t timer,
ngx_uint_t flags)
{
int events, revents, rc;
size_t n;
ngx_fd_t fd;
ngx_err_t err;
ngx_int_t i;
ngx_uint_t level, instance;
ngx_event_t *rev, *wev, **queue;
ngx_connection_t *c;
struct pollfd pfd;
struct dvpoll dvp;
/* NGX_TIMER_INFINITE == INFTIM */
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"devpoll timer: %M", timer);
if (nchanges) {
n = nchanges * sizeof(struct pollfd);
if (write(dp, change_list, n) != (ssize_t) n) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
"write(/dev/poll) failed");
return NGX_ERROR;
}
nchanges = 0;
}
dvp.dp_fds = event_list;
dvp.dp_nfds = (int) nevents;
dvp.dp_timeout = timer;
events = ioctl(dp, DP_POLL, &dvp);
err = (events == -1) ? ngx_errno : 0;
if (flags & NGX_UPDATE_TIME || ngx_event_timer_alarm) {
ngx_time_update();
}
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, "ioctl(DP_POLL) failed");
return NGX_ERROR;
}
if (events == 0) {
if (timer != NGX_TIMER_INFINITE) {
return NGX_OK;
}
ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
"ioctl(DP_POLL) returned no events without timeout");
return NGX_ERROR;
}
ngx_mutex_lock(ngx_posted_events_mutex);
for (i = 0; i < events; i++) {
fd = event_list[i].fd;
revents = event_list[i].revents;
c = ngx_cycle->files[fd];
if (c == NULL || c->fd == -1) {
pfd.fd = fd;
pfd.events = 0;
pfd.revents = 0;
rc = ioctl(dp, DP_ISPOLLED, &pfd);
switch (rc) {
case -1:
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
"ioctl(DP_ISPOLLED) failed for socket %d, event %04Xd",
fd, revents);
break;
case 0:
ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
"phantom event %04Xd for closed and removed socket %d",
revents, fd);
break;
default:
ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
"unexpected event %04Xd for closed and removed socket %d, ",
"ioctl(DP_ISPOLLED) returned rc:%d, fd:%d, event %04Xd",
revents, fd, rc, pfd.fd, pfd.revents);
pfd.fd = fd;
pfd.events = POLLREMOVE;
pfd.revents = 0;
if (write(dp, &pfd, sizeof(struct pollfd))
!= (ssize_t) sizeof(struct pollfd))
{
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
"write(/dev/poll) for %d failed", fd);
}
if (close(fd) == -1) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
"close(%d) failed", fd);
}
break;
}
continue;
}
ngx_log_debug3(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"devpoll: fd:%d, ev:%04Xd, rev:%04Xd",
fd, event_list[i].events, revents);
if (revents & (POLLERR|POLLHUP|POLLNVAL)) {
ngx_log_debug3(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"ioctl(DP_POLL) error fd:%d ev:%04Xd rev:%04Xd",
fd, event_list[i].events, revents);
}
if (revents & ~(POLLIN|POLLOUT|POLLERR|POLLHUP|POLLNVAL)) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
"strange ioctl(DP_POLL) events "
"fd:%d ev:%04Xd rev:%04Xd",
fd, event_list[i].events, revents);
}
if ((revents & (POLLERR|POLLHUP|POLLNVAL))
&& (revents & (POLLIN|POLLOUT)) == 0)
{
/*
* if the error events were returned without POLLIN or POLLOUT,
* then add these flags to handle the events at least in one
* active handler
*/
revents |= POLLIN|POLLOUT;
}
rev = c->read;
if ((revents & POLLIN) && rev->active) {
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 {
instance = rev->instance;
rev->handler(rev);
if (c->fd == -1 || rev->instance != instance) {
continue;
}
}
}
wev = c->write;
if ((revents & POLLOUT) && wev->active) {
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);
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_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, **queue;
ngx_connection_t *c;
/* NGX_TIMER_INFINITE == INFTIM */
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "epoll timer: %M", timer);
//Here,we start to 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();
}
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;
}
ngx_mutex_lock(ngx_posted_events_mutex);
for (i = 0; i < events; i++) {//Here,traverse all the events!!!
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;
}
//------------------------------------->Test Isn't read event ready!!!
if ((revents & EPOLLIN) && rev->active) {
if ((flags & NGX_POST_THREAD_EVENTS) && !rev->accept) {
rev->posted_ready = 1;
} else {
rev->ready = 1;//Set we the read_event has been ready!!!
}
if (flags & NGX_POST_EVENTS) {//Here,If the read_event is used for accept,we should push the event to ngx_posted_accept_events queue!!!
queue = (ngx_event_t **) (rev->accept ? &ngx_posted_accept_events : &ngx_posted_events);
ngx_locked_post_event(rev, queue);//Here,post the readly event to ngx_posted_events list!!we will desposit it lately!!
} else {
rev->handler(rev);
}
}
wev = c->write;
//------------------------------------->Test Isn't write event ready!!!
if ((revents & EPOLLOUT) && wev->active) {
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);//Here,we post the events!!!
} else {
wev->handler(wev);
}
}
}
ngx_mutex_unlock(ngx_posted_events_mutex);
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_uint_t i, found;
ngx_err_t err;
ngx_event_t *ev, **queue;
ngx_connection_t *c;
struct timeval tv, *tp;
#if !(NGX_WIN32)
ngx_uint_t level;
#endif
#if !(NGX_WIN32)
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;
} 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;
#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 (flags & NGX_UPDATE_TIME) {
ngx_time_update(0, 0);
}
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"select ready %d", ready);
#if (NGX_WIN32)
if (err) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, err, "select() failed");
return NGX_ERROR;
}
#else
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, "select() failed");
return NGX_ERROR;
}
#endif
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;
}
ngx_mutex_lock(ngx_posted_events_mutex);
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;
queue = (ngx_event_t **) (ev->accept ? &ngx_posted_accept_events:
&ngx_posted_events);
ngx_locked_post_event(ev, queue);
nready++;
}
}
ngx_mutex_unlock(ngx_posted_events_mutex);
if (ready != nready) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, 0, "select ready != events");
}
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, **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: %d", 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: %d", 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;
}
ngx_mutex_lock(ngx_posted_events_mutex);
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;
queue = (ngx_event_t **) (ev->accept ? &ngx_posted_accept_events:
&ngx_posted_events);
ngx_locked_post_event(ev, queue);
nready++;
}
}
ngx_mutex_unlock(ngx_posted_events_mutex);
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;
}
/* called ngx_process_events_and_timers */
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_log_t *log;
ngx_event_t *rev, *wev, **queue;
ngx_connection_t *c;
/* NGX_TIMER_INFINITE == INFTIM */
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"epoll timer: %M", timer);
events = epoll_wait(ep, event_list, (int) nevents, timer);
err = (events == -1) ? ngx_errno : 0;
if (flags & NGX_UPDATE_TIME || ngx_event_timer_alarm) { /* 这里判断是否需要更新系统时间变量 ngx_current_msec */
ngx_time_update(); /* 更新系统时间变量 ngx_current_msec */
}
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;
}
ngx_mutex_lock(ngx_posted_events_mutex);
log = cycle->log;
for (i = 0; i < events; i++) {
c = event_list[i].data.ptr;
instance = (uintptr_t) c & 1; //获取stale的标识
c = (ngx_connection_t *) ((uintptr_t) c & (uintptr_t) ~1);//获取链接的指针
rev = c->read;
/*如果c-fd为－1则说明fd被关闭，如果rev->instance != instance则表示当前的fd已经被重新使用过了，
也就是说这个event已经是stale的了，所以跳过这个事件，然后进行下一个*/
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;
}
#if (NGX_DEBUG0)
log = c->log ? c->log : cycle->log;
#endif
revents = event_list[i].events;
ngx_log_debug3(NGX_LOG_DEBUG_EVENT, 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, 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, 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;
}
if ((revents & EPOLLIN) && rev->active) { /* 这里需要判断是否connection是否激活了读事件，如果没有这里不需要进行处理 */
if ((flags & NGX_POST_THREAD_EVENTS) && !rev->accept) {
rev->posted_ready = 1;
} else {
rev->ready = 1;
}
if (flags & NGX_POST_EVENTS) { /* event 是否需要POSTED */
queue = (ngx_event_t **) (rev->accept ?
&ngx_posted_accept_events : &ngx_posted_events);/* 根据 accept 来判断，将事件放入到哪个事件队列 */
ngx_locked_post_event(rev, queue);/* 将事件添加队列中*/
} else {
rev->handler(rev); /* 调用事件处理函数 */
}
}
wev = c->write;
/* 这里需要判断是否connection是否激活了读事件，如果没有这里不需要进行处理
fd本身的状态变化可能在没有关注EPOLLIN的情况下由于缓冲区的状态变化触发写事件
*/
if ((revents & EPOLLOUT) && wev->active) {
if (flags & NGX_POST_THREAD_EVENTS) {
wev->posted_ready = 1;
} else {
wev->ready = 1;
}
if (flags & NGX_POST_EVENTS) { /* 写事件只有ngx_posted_events 事件队列 */
ngx_locked_post_event(wev, &ngx_posted_events);
} else {
wev->handler(wev);
}
}
}
ngx_mutex_unlock(ngx_posted_events_mutex);
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, **queue;
struct timeval tv, *tp;
ngx_connection_t *c;
#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);
}
}
#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;
if (max_read || max_write) {
ready = select(0, &work_read_fd_set, &work_write_fd_set, NULL, tp);
} else {
/*
* Winsock select() requires that at least one descriptor set must be
* be non-null, and any non-null descriptor set must contain at least
* one handle to a socket. Otherwise select() returns WSAEINVAL.
*/
ngx_msleep(timer);
ready = 0;
}
err = (ready == -1) ? ngx_socket_errno : 0;
if (flags & NGX_UPDATE_TIME) {
ngx_time_update();
}
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"select ready %d", ready);
if (err) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, err, "select() failed");
if (err == WSAENOTSOCK) {
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;
}
ngx_mutex_lock(ngx_posted_events_mutex);
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;
queue = (ngx_event_t **) (ev->accept ? &ngx_posted_accept_events:
&ngx_posted_events);
ngx_locked_post_event(ev, queue);
nready++;
}
}
ngx_mutex_unlock(ngx_posted_events_mutex);
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;
}
ngx_int_t
ngx_eventport_process_events(ngx_cycle_t *cycle, ngx_msec_t timer,
ngx_uint_t flags)
{
int n, revents;
u_int events;
ngx_err_t err;
ngx_int_t instance;
ngx_uint_t i, level;
ngx_event_t *ev, *rev, *wev, **queue;
ngx_connection_t *c;
struct timespec ts, *tp;
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,
"eventport timer: %M", timer);
events = 1;
n = port_getn(ep, event_list, (u_int) nevents, &events, tp);
err = ngx_errno;
if (flags & NGX_UPDATE_TIME) {
ngx_time_update();
}
if (n == -1) {
if (err == ETIME) {
if (timer != NGX_TIMER_INFINITE) {
return NGX_OK;
}
ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
"port_getn() returned no events without timeout");
return NGX_ERROR;
}
level = (err == NGX_EINTR) ? NGX_LOG_INFO : NGX_LOG_ALERT;
ngx_log_error(level, cycle->log, err, "port_getn() failed");
return NGX_ERROR;
}
if (events == 0) {
if (timer != NGX_TIMER_INFINITE) {
return NGX_OK;
}
ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
"port_getn() returned no events without timeout");
return NGX_ERROR;
}
ngx_mutex_lock(ngx_posted_events_mutex);
for (i = 0; i < events; i++) {
if (event_list[i].portev_source == PORT_SOURCE_TIMER) {
ngx_time_update();
continue;
}
ev = event_list[i].portev_user;
switch (event_list[i].portev_source) {
case PORT_SOURCE_FD:
instance = (uintptr_t) ev & 1;
ev = (ngx_event_t *) ((uintptr_t) ev & (uintptr_t) ~1);
if (ev->closed || ev->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,
"eventport: stale event %p", ev);
continue;
}
revents = event_list[i].portev_events;
ngx_log_debug2(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"eventport: fd:%d, ev:%04Xd",
event_list[i].portev_object, revents);
if (revents & (POLLERR|POLLHUP|POLLNVAL)) {
ngx_log_debug2(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"port_getn() error fd:%d ev:%04Xd",
event_list[i].portev_object, revents);
}
if (revents & ~(POLLIN|POLLOUT|POLLERR|POLLHUP|POLLNVAL)) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
"strange port_getn() events fd:%d ev:%04Xd",
event_list[i].portev_object, revents);
}
if ((revents & (POLLERR|POLLHUP|POLLNVAL))
&& (revents & (POLLIN|POLLOUT)) == 0)
{
/*
* if the error events were returned without POLLIN or POLLOUT,
* then add these flags to handle the events at least in one
* active handler
*/
revents |= POLLIN|POLLOUT;
}
c = ev->data;
rev = c->read;
wev = c->write;
rev->active = 0;
wev->active = 0;
if (revents & POLLIN) {
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);
if (ev->closed) {
continue;
}
}
if (rev->accept) {
if (ngx_use_accept_mutex) {
ngx_accept_events = 1;
continue;
}
if (port_associate(ep, PORT_SOURCE_FD, c->fd, POLLIN,
(void *) ((uintptr_t) ev | ev->instance))
== -1)
{
ngx_log_error(NGX_LOG_ALERT, ev->log, ngx_errno,
"port_associate() failed");
return NGX_ERROR;
}
}
}
if (revents & POLLOUT) {
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);
}
}
continue;
default:
ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
"unexpected even_port object %d",
event_list[i].portev_object);
continue;
}
}
ngx_mutex_unlock(ngx_posted_events_mutex);
return NGX_OK;
}
static ngx_int_t
ngx_kqueue_process_events(ngx_cycle_t *cycle, ngx_msec_t timer,
ngx_uint_t flags)
{
int events, n;
ngx_int_t i, instance;
ngx_uint_t level;
ngx_err_t err;
ngx_event_t *ev, **queue;
struct timespec ts, *tp;
if (ngx_threaded) {
if (ngx_kqueue_process_changes(cycle, 0) == NGX_ERROR) {
return NGX_ERROR;
}
n = 0;
} else {
n = (int) nchanges;
nchanges = 0;
}
if (timer == NGX_TIMER_INFINITE) {
tp = NULL;
} else {
ts.tv_sec = timer / 1000;
ts.tv_nsec = (timer % 1000) * 1000000;
/*
* 64-bit Darwin kernel has the bug: kernel level ts.tv_nsec is
* the int32_t while user level ts.tv_nsec is the long (64-bit),
* so on the big endian PowerPC all nanoseconds are lost.
*/
#if (NGX_DARWIN_KEVENT_BUG)
ts.tv_nsec <<= 32;
#endif
tp = &ts;
}
ngx_log_debug2(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"kevent timer: %M, changes: %d", timer, n);
events = kevent(ngx_kqueue, change_list, n, event_list, (int) nevents, tp);
err = (events == -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,
"kevent events: %d", events);
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, "kevent() failed");
return NGX_ERROR;
}
if (events == 0) {
if (timer != NGX_TIMER_INFINITE) {
return NGX_OK;
}
ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
"kevent() returned no events without timeout");
return NGX_ERROR;
}
ngx_mutex_lock(ngx_posted_events_mutex);
for (i = 0; i < events; i++) {
ngx_kqueue_dump_event(cycle->log, &event_list[i]);
if (event_list[i].flags & EV_ERROR) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, event_list[i].data,
"kevent() error on %d filter:%d flags:%04Xd",
event_list[i].ident, event_list[i].filter,
event_list[i].flags);
continue;
}
#if (NGX_HAVE_TIMER_EVENT)
if (event_list[i].filter == EVFILT_TIMER) {
ngx_time_update();
continue;
}
#endif
ev = (ngx_event_t *) event_list[i].udata;
switch (event_list[i].filter) {
case EVFILT_READ:
case EVFILT_WRITE:
instance = (uintptr_t) ev & 1;
ev = (ngx_event_t *) ((uintptr_t) ev & (uintptr_t) ~1);
if (ev->closed || ev->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,
"kevent: stale event %p", ev);
continue;
}
if (ev->log && (ev->log->log_level & NGX_LOG_DEBUG_CONNECTION)) {
ngx_kqueue_dump_event(ev->log, &event_list[i]);
}
if (ev->oneshot) {
ev->active = 0;
}
#if (NGX_THREADS)
if ((flags & NGX_POST_THREAD_EVENTS) && !ev->accept) {
ev->posted_ready = 1;
ev->posted_available = event_list[i].data;
if (event_list[i].flags & EV_EOF) {
ev->posted_eof = 1;
ev->posted_errno = event_list[i].fflags;
}
ngx_locked_post_event(ev, &ngx_posted_events);
continue;
}
#endif
ev->available = event_list[i].data;
if (event_list[i].flags & EV_EOF) {
ev->pending_eof = 1;
ev->kq_errno = event_list[i].fflags;
}
ev->ready = 1;
break;
case EVFILT_VNODE:
ev->kq_vnode = 1;
break;
case EVFILT_AIO:
ev->complete = 1;
ev->ready = 1;
break;
default:
ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
"unexpected kevent() filter %d",
event_list[i].filter);
continue;
}
if (flags & NGX_POST_EVENTS) {
queue = (ngx_event_t **) (ev->accept ? &ngx_posted_accept_events:
&ngx_posted_events);
ngx_locked_post_event(ev, queue);
continue;
}
ev->handler(ev);
}
ngx_mutex_unlock(ngx_posted_events_mutex);
return NGX_OK;
}
static ngx_int_t
ngx_poll_process_events(ngx_cycle_t *cycle, ngx_msec_t timer, ngx_uint_t flags)
{
int ready, revents;
ngx_err_t err;
ngx_int_t i, nready;
ngx_uint_t found, level;
ngx_event_t *ev, **queue;
ngx_connection_t *c;
/* NGX_TIMER_INFINITE == INFTIM */
#if (NGX_DEBUG0)
if (cycle->log->log_level & NGX_LOG_DEBUG_ALL) {
for (i = 0; i < nevents; i++) {
ngx_log_debug3(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"poll: %d: fd:%d ev:%04Xd",
i, event_list[i].fd, event_list[i].events);
}
}
#endif
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "poll timer: %M", timer);
ready = poll(event_list, (u_int) nevents, (int) timer);
if (ready == -1) {
err = ngx_errno;
} else {
err = 0;
}
if (flags & NGX_UPDATE_TIME) {
ngx_time_update(0, 0);
}
ngx_log_debug2(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"poll ready %d of %d", ready, nevents);
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, "poll() failed");
return NGX_ERROR;
}
if (ready == 0) {
if (timer != NGX_TIMER_INFINITE) {
return NGX_OK;
}
ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
"poll() returned no events without timeout");
return NGX_ERROR;
}
ngx_mutex_lock(ngx_posted_events_mutex);
nready = 0;
for (i = 0; i < nevents && ready; i++) {
revents = event_list[i].revents;
#if 1
ngx_log_debug4(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"poll: %d: fd:%d ev:%04Xd rev:%04Xd",
i, event_list[i].fd, event_list[i].events, revents);
#else
if (revents) {
ngx_log_debug4(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"poll: %d: fd:%d ev:%04Xd rev:%04Xd",
i, event_list[i].fd, event_list[i].events, revents);
}
#endif
if (revents & POLLNVAL) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
"poll() error fd:%d ev:%04Xd rev:%04Xd",
event_list[i].fd, event_list[i].events, revents);
}
if (revents & ~(POLLIN|POLLOUT|POLLERR|POLLHUP|POLLNVAL)) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
"strange poll() events fd:%d ev:%04Xd rev:%04Xd",
event_list[i].fd, event_list[i].events, revents);
}
if (event_list[i].fd == -1) {
/*
* the disabled event, a workaround for our possible bug,
* see the comment below
*/
continue;
}
c = ngx_cycle->files[event_list[i].fd];
if (c->fd == -1) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, 0, "unexpected event");
/*
* it is certainly our fault and it should be investigated,
* in the meantime we disable this event to avoid a CPU spinning
*/
if (i == nevents - 1) {
nevents--;
} else {
event_list[i].fd = -1;
}
continue;
}
if ((revents & (POLLERR|POLLHUP|POLLNVAL))
&& (revents & (POLLIN|POLLOUT)) == 0)
{
/*
* if the error events were returned without POLLIN or POLLOUT,
* then add these flags to handle the events at least in one
* active handler
*/
revents |= POLLIN|POLLOUT;
}
found = 0;
if (revents & POLLIN) {
found = 1;
ev = c->read;
if ((flags & NGX_POST_THREAD_EVENTS) && !ev->accept) {
ev->posted_ready = 1;
} else {
ev->ready = 1;
}
queue = (ngx_event_t **) (ev->accept ? &ngx_posted_accept_events:
&ngx_posted_events);
ngx_locked_post_event(ev, queue);
}
if (revents & POLLOUT) {
found = 1;
ev = c->write;
if (flags & NGX_POST_THREAD_EVENTS) {
ev->posted_ready = 1;
} else {
ev->ready = 1;
}
ngx_locked_post_event(ev, &ngx_posted_events);
}
if (found) {
ready--;
continue;
}
}
ngx_mutex_unlock(ngx_posted_events_mutex);
if (ready != 0) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, 0, "poll ready != events");
}
return nready;
}
/*epoll事件驱动模型的实现*/
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, **queue;
ngx_connection_t *c;
/* NGX_TIMER_INFINITE == INFTIM */
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"epoll timer: %M", timer);
//一开始就是等待事件，最长等待时间为timer；nginx为事件专门用红黑树维护了一个计时器
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(); //执行一次时间更新，nginx将时间缓存到一组全局变量中，方便程序高效的获取事件
}
//处理wait错误
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;
}
//wait返回事件数0，可能是timeout返回，也可能是非timeout返回，非timeout返回则是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;
}
ngx_mutex_lock(ngx_posted_events_mutex);
//循环开始处理收到的所有事件
for (i = 0; i < events; i++) {
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;
}
//取得发生一个事件
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);
//记录wait的错误返回状态
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
//该事件是一个读事件，并该连接上注册的读事件是active的
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;
}
if ((revents & EPOLLIN) && rev->active) {
if ((flags & NGX_POST_THREAD_EVENTS) && !rev->accept) {
rev->posted_ready = 1;
} else {
rev->ready = 1;
}
//事件放入到相应的队列中
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 ((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;
}
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);
return NGX_OK;
}
