blob: efd56ee1914c8861b11e3303ccbbddfeb57ed5ad [file] [log] [blame]
/*
* FD polling functions for generic poll()
*
* Copyright 2000-2014 Willy Tarreau <w@1wt.eu>
*
* 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.
*
*/
#define _GNU_SOURCE // for POLLRDHUP on Linux
#include <unistd.h>
#include <poll.h>
#include <sys/time.h>
#include <sys/types.h>
#include <common/compat.h>
#include <common/config.h>
#include <common/ticks.h>
#include <common/time.h>
#include <types/global.h>
#include <proto/fd.h>
#ifndef POLLRDHUP
/* POLLRDHUP was defined late in libc, and it appeared in kernel 2.6.17 */
#define POLLRDHUP 0
#endif
static unsigned int *fd_evts[2];
/* private data */
static THREAD_LOCAL int nbfd = 0;
static THREAD_LOCAL struct pollfd *poll_events = NULL;
static inline void hap_fd_set(int fd, unsigned int *evts)
{
evts[fd / (8*sizeof(*evts))] |= 1U << (fd & (8*sizeof(*evts) - 1));
}
static inline void hap_fd_clr(int fd, unsigned int *evts)
{
evts[fd / (8*sizeof(*evts))] &= ~(1U << (fd & (8*sizeof(*evts) - 1)));
}
REGPRM1 static void __fd_clo(int fd)
{
HA_SPIN_LOCK(POLL_LOCK, &poll_lock);
hap_fd_clr(fd, fd_evts[DIR_RD]);
hap_fd_clr(fd, fd_evts[DIR_WR]);
HA_SPIN_UNLOCK(POLL_LOCK, &poll_lock);
}
/*
* Poll() poller
*/
REGPRM2 static void _do_poll(struct poller *p, int exp)
{
int status;
int fd;
int wait_time;
int updt_idx, en, eo;
int fds, count;
int sr, sw;
unsigned rn, wn; /* read new, write new */
/* first, scan the update list to find changes */
for (updt_idx = 0; updt_idx < fd_nbupdt; updt_idx++) {
fd = fd_updt[updt_idx];
if (!fdtab[fd].owner) {
activity[tid].poll_drop++;
continue;
}
HA_SPIN_LOCK(FD_LOCK, &fdtab[fd].lock);
fdtab[fd].updated = 0;
fdtab[fd].new = 0;
eo = fdtab[fd].state;
en = fd_compute_new_polled_status(eo);
fdtab[fd].state = en;
HA_SPIN_UNLOCK(FD_LOCK, &fdtab[fd].lock);
if ((eo ^ en) & FD_EV_POLLED_RW) {
/* poll status changed, update the lists */
HA_SPIN_LOCK(POLL_LOCK, &poll_lock);
if ((eo & ~en) & FD_EV_POLLED_R)
hap_fd_clr(fd, fd_evts[DIR_RD]);
else if ((en & ~eo) & FD_EV_POLLED_R)
hap_fd_set(fd, fd_evts[DIR_RD]);
if ((eo & ~en) & FD_EV_POLLED_W)
hap_fd_clr(fd, fd_evts[DIR_WR]);
else if ((en & ~eo) & FD_EV_POLLED_W)
hap_fd_set(fd, fd_evts[DIR_WR]);
HA_SPIN_UNLOCK(POLL_LOCK, &poll_lock);
}
}
fd_nbupdt = 0;
nbfd = 0;
for (fds = 0; (fds * 8*sizeof(**fd_evts)) < maxfd; fds++) {
rn = fd_evts[DIR_RD][fds];
wn = fd_evts[DIR_WR][fds];
if (!(rn|wn))
continue;
for (count = 0, fd = fds * 8*sizeof(**fd_evts); count < 8*sizeof(**fd_evts) && fd < maxfd; count++, fd++) {
sr = (rn >> count) & 1;
sw = (wn >> count) & 1;
if ((sr|sw)) {
if (!fdtab[fd].owner) {
/* should normally not happen here except
* due to rare thread concurrency
*/
continue;
}
if (!(fdtab[fd].thread_mask & tid_bit)) {
activity[tid].poll_skip++;
continue;
}
poll_events[nbfd].fd = fd;
poll_events[nbfd].events = (sr ? (POLLIN | POLLRDHUP) : 0) | (sw ? POLLOUT : 0);
nbfd++;
}
}
}
/* now let's wait for events */
if (!exp)
wait_time = MAX_DELAY_MS;
else if (tick_is_expired(exp, now_ms)) {
activity[tid].poll_exp++;
wait_time = 0;
}
else {
wait_time = TICKS_TO_MS(tick_remain(now_ms, exp)) + 1;
if (wait_time > MAX_DELAY_MS)
wait_time = MAX_DELAY_MS;
}
gettimeofday(&before_poll, NULL);
status = poll(poll_events, nbfd, wait_time);
tv_update_date(wait_time, status);
measure_idle();
for (count = 0; status > 0 && count < nbfd; count++) {
unsigned int n;
int e = poll_events[count].revents;
fd = poll_events[count].fd;
if (!(e & ( POLLOUT | POLLIN | POLLERR | POLLHUP | POLLRDHUP )))
continue;
/* ok, we found one active fd */
status--;
if (!fdtab[fd].owner) {
activity[tid].poll_dead++;
continue;
}
/* it looks complicated but gcc can optimize it away when constants
* have same values... In fact it depends on gcc :-(
*/
if (POLLIN == FD_POLL_IN && POLLOUT == FD_POLL_OUT &&
POLLERR == FD_POLL_ERR && POLLHUP == FD_POLL_HUP) {
n = e & (POLLIN|POLLOUT|POLLERR|POLLHUP);
}
else {
n = ((e & POLLIN ) ? FD_POLL_IN : 0) |
((e & POLLOUT) ? FD_POLL_OUT : 0) |
((e & POLLERR) ? FD_POLL_ERR : 0) |
((e & POLLHUP) ? FD_POLL_HUP : 0);
}
/* always remap RDHUP to HUP as they're used similarly */
if (e & POLLRDHUP) {
HA_ATOMIC_OR(&cur_poller.flags, HAP_POLL_F_RDHUP);
n |= FD_POLL_HUP;
}
fd_update_events(fd, n);
}
}
static int init_poll_per_thread()
{
poll_events = calloc(1, sizeof(struct pollfd) * global.maxsock);
if (poll_events == NULL)
return 0;
return 1;
}
static void deinit_poll_per_thread()
{
free(poll_events);
poll_events = NULL;
}
/*
* Initialization of the poll() poller.
* Returns 0 in case of failure, non-zero in case of success. If it fails, it
* disables the poller by setting its pref to 0.
*/
REGPRM1 static int _do_init(struct poller *p)
{
__label__ fail_swevt, fail_srevt;
int fd_evts_bytes;
p->private = NULL;
fd_evts_bytes = (global.maxsock + sizeof(**fd_evts) * 8 - 1) / (sizeof(**fd_evts) * 8) * sizeof(**fd_evts);
if ((fd_evts[DIR_RD] = calloc(1, fd_evts_bytes)) == NULL)
goto fail_srevt;
if ((fd_evts[DIR_WR] = calloc(1, fd_evts_bytes)) == NULL)
goto fail_swevt;
hap_register_per_thread_init(init_poll_per_thread);
hap_register_per_thread_deinit(deinit_poll_per_thread);
return 1;
fail_swevt:
free(fd_evts[DIR_RD]);
fail_srevt:
free(poll_events);
p->pref = 0;
return 0;
}
/*
* Termination of the poll() poller.
* Memory is released and the poller is marked as unselectable.
*/
REGPRM1 static void _do_term(struct poller *p)
{
free(fd_evts[DIR_WR]);
free(fd_evts[DIR_RD]);
p->private = NULL;
p->pref = 0;
}
/*
* Check that the poller works.
* Returns 1 if OK, otherwise 0.
*/
REGPRM1 static int _do_test(struct poller *p)
{
return 1;
}
/*
* It is a constructor, which means that it will automatically be called before
* main(). This is GCC-specific but it works at least since 2.95.
* Special care must be taken so that it does not need any uninitialized data.
*/
__attribute__((constructor))
static void _do_register(void)
{
struct poller *p;
if (nbpollers >= MAX_POLLERS)
return;
p = &pollers[nbpollers++];
p->name = "poll";
p->pref = 200;
p->flags = 0;
p->private = NULL;
p->clo = __fd_clo;
p->test = _do_test;
p->init = _do_init;
p->term = _do_term;
p->poll = _do_poll;
}
/*
* Local variables:
* c-indent-level: 8
* c-basic-offset: 8
* End:
*/