blob: 09a48a4d986ddccf8a348352037fc51b261df342 [file] [log] [blame]
/*
* FD polling functions for SunOS event ports.
*
* Copyright 2018 Joyent, Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <unistd.h>
#include <sys/time.h>
#include <sys/types.h>
#include <poll.h>
#include <port.h>
#include <errno.h>
#include <syslog.h>
#include <haproxy/activity.h>
#include <haproxy/api.h>
#include <haproxy/fd.h>
#include <haproxy/global.h>
#include <haproxy/signal.h>
#include <haproxy/ticks.h>
#include <haproxy/time.h>
/*
* Private data:
*/
static int evports_fd[MAX_THREADS]; // per-thread evports_fd
static THREAD_LOCAL port_event_t *evports_evlist = NULL;
static THREAD_LOCAL int evports_evlist_max = 0;
/*
* Convert the "state" member of "fdtab" into an event ports event mask.
*/
static inline int evports_state_to_events(int state)
{
int events = 0;
if (state & FD_EV_ACTIVE_W)
events |= POLLOUT;
if (state & FD_EV_ACTIVE_R)
events |= POLLIN;
return (events);
}
/*
* Associate or dissociate this file descriptor with the event port, using the
* specified event mask.
*/
static inline void evports_resync_fd(int fd, int events)
{
if (events == 0)
port_dissociate(evports_fd[tid], PORT_SOURCE_FD, fd);
else
port_associate(evports_fd[tid], PORT_SOURCE_FD, fd, events, NULL);
}
static void _update_fd(int fd)
{
int en;
int events;
en = fdtab[fd].state;
if (!(fdtab[fd].thread_mask & tid_bit) || !(en & FD_EV_ACTIVE_RW)) {
if (!(polled_mask[fd].poll_recv & tid_bit) &&
!(polled_mask[fd].poll_send & tid_bit)) {
/* fd was not watched, it's still not */
return;
}
/* fd totally removed from poll list */
events = 0;
if (polled_mask[fd].poll_recv & tid_bit)
_HA_ATOMIC_AND(&polled_mask[fd].poll_recv, ~tid_bit);
if (polled_mask[fd].poll_send & tid_bit)
_HA_ATOMIC_AND(&polled_mask[fd].poll_send, ~tid_bit);
}
else {
/* OK fd has to be monitored, it was either added or changed */
events = evports_state_to_events(en);
if (en & FD_EV_ACTIVE_R) {
if (!(polled_mask[fd].poll_recv & tid_bit))
_HA_ATOMIC_OR(&polled_mask[fd].poll_recv, tid_bit);
} else {
if (polled_mask[fd].poll_recv & tid_bit)
_HA_ATOMIC_AND(&polled_mask[fd].poll_recv, ~tid_bit);
}
if (en & FD_EV_ACTIVE_W) {
if (!(polled_mask[fd].poll_send & tid_bit))
_HA_ATOMIC_OR(&polled_mask[fd].poll_send, tid_bit);
} else {
if (polled_mask[fd].poll_send & tid_bit)
_HA_ATOMIC_AND(&polled_mask[fd].poll_send, ~tid_bit);
}
}
evports_resync_fd(fd, events);
}
/*
* Event Ports poller. This routine interacts with the file descriptor
* management data structures and routines; see the large block comment in
* "src/fd.c" for more information.
*/
static void _do_poll(struct poller *p, int exp, int wake)
{
int i;
int wait_time;
struct timespec timeout_ts;
unsigned int nevlist;
int fd, old_fd;
int status;
/*
* Scan the list of file descriptors with an updated status:
*/
for (i = 0; i < fd_nbupdt; i++) {
fd = fd_updt[i];
_HA_ATOMIC_AND(&fdtab[fd].update_mask, ~tid_bit);
if (fdtab[fd].owner == NULL) {
activity[tid].poll_drop_fd++;
continue;
}
_update_fd(fd);
}
fd_nbupdt = 0;
/* Scan the global update list */
for (old_fd = fd = update_list.first; fd != -1; fd = fdtab[fd].update.next) {
if (fd == -2) {
fd = old_fd;
continue;
}
else if (fd <= -3)
fd = -fd -4;
if (fd == -1)
break;
if (fdtab[fd].update_mask & tid_bit)
done_update_polling(fd);
else
continue;
if (!fdtab[fd].owner)
continue;
_update_fd(fd);
}
thread_harmless_now();
if (sleeping_thread_mask & tid_bit)
_HA_ATOMIC_AND(&sleeping_thread_mask, ~tid_bit);
/*
* Determine how long to wait for events to materialise on the port.
*/
wait_time = wake ? 0 : compute_poll_timeout(exp);
tv_entering_poll();
activity_count_runtime();
do {
int timeout = (global.tune.options & GTUNE_BUSY_POLLING) ? 0 : wait_time;
int interrupted = 0;
nevlist = 1; /* desired number of events to be retrieved */
timeout_ts.tv_sec = (timeout / 1000);
timeout_ts.tv_nsec = (timeout % 1000) * 1000000;
status = port_getn(evports_fd[tid],
evports_evlist,
evports_evlist_max,
&nevlist, /* updated to the number of events retrieved */
&timeout_ts);
if (status != 0) {
int e = errno;
switch (e) {
case ETIME:
/*
* Though the manual page has not historically made it
* clear, port_getn() can return -1 with an errno of
* ETIME and still have returned some number of events.
*/
/* nevlist >= 0 */
break;
default:
nevlist = 0;
interrupted = 1;
break;
}
}
tv_update_date(timeout, nevlist);
if (nevlist || interrupted)
break;
if (timeout || !wait_time)
break;
if (signal_queue_len || wake)
break;
if (tick_isset(exp) && tick_is_expired(exp, now_ms))
break;
} while(1);
tv_leaving_poll(wait_time, nevlist);
thread_harmless_end();
if (nevlist > 0)
activity[tid].poll_io++;
for (i = 0; i < nevlist; i++) {
unsigned int n = 0;
int events, rebind_events;
fd = evports_evlist[i].portev_object;
events = evports_evlist[i].portev_events;
#ifdef DEBUG_FD
_HA_ATOMIC_INC(&fdtab[fd].event_count);
#endif
if (fdtab[fd].owner == NULL) {
activity[tid].poll_dead_fd++;
continue;
}
if (!(fdtab[fd].thread_mask & tid_bit)) {
activity[tid].poll_skip_fd++;
continue;
}
/*
* By virtue of receiving an event for this file descriptor, it
* is no longer associated with the port in question. Store
* the previous event mask so that we may reassociate after
* processing is complete.
*/
rebind_events = evports_state_to_events(fdtab[fd].state);
/* rebind_events != 0 */
/*
* Set bits based on the events we received from the port:
*/
n = ((events & POLLIN) ? FD_EV_READY_R : 0) |
((events & POLLOUT) ? FD_EV_READY_W : 0) |
((events & POLLHUP) ? FD_EV_SHUT_RW : 0) |
((events & POLLERR) ? FD_EV_ERR_RW : 0);
/*
* Call connection processing callbacks. Note that it's
* possible for this processing to alter the required event
* port association; i.e., the "state" member of the "fdtab"
* entry. If it changes, the fd will be placed on the updated
* list for processing the next time we are called.
*/
fd_update_events(fd, n);
/*
* This file descriptor was closed during the processing of
* polled events. No need to reassociate.
*/
if (fdtab[fd].owner == NULL)
continue;
/*
* Reassociate with the port, using the same event mask as
* before. This call will not result in a dissociation as we
* asserted that _some_ events needed to be rebound above.
*
* Reassociating with the same mask allows us to mimic the
* level-triggered behaviour of poll(2). In the event that we
* are interested in the same events on the next turn of the
* loop, this represents no extra work.
*
* If this additional port_associate(3C) call becomes a
* performance problem, we would need to verify that we can
* correctly interact with the file descriptor cache and update
* list (see "src/fd.c") to avoid reassociating here, or to use
* a different events mask.
*/
evports_resync_fd(fd, rebind_events);
}
}
static int init_evports_per_thread()
{
int fd;
evports_evlist_max = global.tune.maxpollevents;
evports_evlist = calloc(evports_evlist_max, sizeof (port_event_t));
if (evports_evlist == NULL) {
goto fail_alloc;
}
if (MAX_THREADS > 1 && tid) {
if ((evports_fd[tid] = port_create()) == -1) {
goto fail_fd;
}
}
/* we may have to unregister some events initially registered on the
* original fd when it was alone, and/or to register events on the new
* fd for this thread. Let's just mark them as updated, the poller will
* do the rest.
*/
for (fd = 0; fd < global.maxsock; fd++)
updt_fd_polling(fd);
return 1;
fail_fd:
ha_free(&evports_evlist);
evports_evlist_max = 0;
fail_alloc:
return 0;
}
static void deinit_evports_per_thread()
{
if (MAX_THREADS > 1 && tid)
close(evports_fd[tid]);
ha_free(&evports_evlist);
evports_evlist_max = 0;
}
/*
* Initialisation of the event ports poller.
* Returns 0 in case of failure, non-zero in case of success.
*/
static int _do_init(struct poller *p)
{
p->private = NULL;
if ((evports_fd[tid] = port_create()) == -1) {
goto fail;
}
hap_register_per_thread_init(init_evports_per_thread);
hap_register_per_thread_deinit(deinit_evports_per_thread);
return 1;
fail:
p->pref = 0;
return 0;
}
/*
* Termination of the event ports poller.
* All resources are released and the poller is marked as inoperative.
*/
static void _do_term(struct poller *p)
{
if (evports_fd[tid] != -1) {
close(evports_fd[tid]);
evports_fd[tid] = -1;
}
p->private = NULL;
p->pref = 0;
ha_free(&evports_evlist);
evports_evlist_max = 0;
}
/*
* Run-time check to make sure we can allocate the resources needed for
* the poller to function correctly.
* Returns 1 on success, otherwise 0.
*/
static int _do_test(struct poller *p)
{
int fd;
if ((fd = port_create()) == -1) {
return 0;
}
close(fd);
return 1;
}
/*
* Close and recreate the event port after fork(). Returns 1 on success,
* otherwise 0. If this function fails, "_do_term()" must be called to
* clean up the poller.
*/
static int _do_fork(struct poller *p)
{
if (evports_fd[tid] != -1) {
close(evports_fd[tid]);
}
if ((evports_fd[tid] = port_create()) == -1) {
return 0;
}
return 1;
}
/*
* This constructor must be called before main() to register the event ports
* poller.
*/
__attribute__((constructor))
static void _do_register(void)
{
struct poller *p;
int i;
if (nbpollers >= MAX_POLLERS)
return;
for (i = 0; i < MAX_THREADS; i++)
evports_fd[i] = -1;
p = &pollers[nbpollers++];
p->name = "evports";
p->pref = 300;
p->flags = HAP_POLL_F_ERRHUP;
p->private = NULL;
p->clo = NULL;
p->test = _do_test;
p->init = _do_init;
p->term = _do_term;
p->poll = _do_poll;
p->fork = _do_fork;
}