haproxy/src/ev_kqueue.c

288 lines
6.2 KiB
C

/*
* FD polling functions for FreeBSD kqueue()
*
* Copyright 2000-2008 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.
*
* Note: not knowing much about kqueue, I had to rely on OpenBSD's detailed man
* page and to check how it was implemented in lighttpd to understand it better.
* But it is possible that I got things wrong.
*
*/
#include <unistd.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/event.h>
#include <sys/time.h>
#include <common/compat.h>
#include <common/config.h>
#include <common/ticks.h>
#include <common/time.h>
#include <common/tools.h>
#include <types/global.h>
#include <proto/fd.h>
#include <proto/signal.h>
#include <proto/task.h>
/* private data */
static fd_set *fd_evts[2];
static int kqueue_fd;
static struct kevent *kev = NULL;
/* speeds up conversion of DIR_RD/DIR_WR to EVFILT* */
static const int dir2filt[2] = { EVFILT_READ, EVFILT_WRITE };
/* completes a change list for deletion */
REGPRM3 static int kqev_del(struct kevent *kev, const int fd, const int dir)
{
if (FD_ISSET(fd, fd_evts[dir])) {
FD_CLR(fd, fd_evts[dir]);
EV_SET(kev, fd, dir2filt[dir], EV_DELETE, 0, 0, NULL);
return 1;
}
return 0;
}
/*
* Returns non-zero if direction <dir> is already set for <fd>.
*/
REGPRM2 static int __fd_is_set(const int fd, int dir)
{
return FD_ISSET(fd, fd_evts[dir]);
}
REGPRM2 static int __fd_set(const int fd, int dir)
{
/* if the value was set, do nothing */
if (FD_ISSET(fd, fd_evts[dir]))
return 0;
FD_SET(fd, fd_evts[dir]);
EV_SET(kev, fd, dir2filt[dir], EV_ADD, 0, 0, NULL);
kevent(kqueue_fd, kev, 1, NULL, 0, NULL);
return 1;
}
REGPRM2 static int __fd_clr(const int fd, int dir)
{
if (!kqev_del(kev, fd, dir))
return 0;
kevent(kqueue_fd, kev, 1, NULL, 0, NULL);
return 1;
}
REGPRM1 static void __fd_rem(int fd)
{
int changes = 0;
changes += kqev_del(&kev[changes], fd, DIR_RD);
changes += kqev_del(&kev[changes], fd, DIR_WR);
if (changes)
kevent(kqueue_fd, kev, changes, NULL, 0, NULL);
}
REGPRM1 static void __fd_clo(int fd)
{
FD_CLR(fd, fd_evts[DIR_RD]);
FD_CLR(fd, fd_evts[DIR_WR]);
}
/*
* kqueue() poller
*/
REGPRM2 static void _do_poll(struct poller *p, int exp)
{
int status;
int count, fd, delta_ms;
struct timespec timeout;
delta_ms = 0;
timeout.tv_sec = 0;
timeout.tv_nsec = 0;
if (!run_queue && !signal_queue_len) {
if (!exp) {
delta_ms = MAX_DELAY_MS;
timeout.tv_sec = (MAX_DELAY_MS / 1000);
timeout.tv_nsec = (MAX_DELAY_MS % 1000) * 1000000;
}
else if (!tick_is_expired(exp, now_ms)) {
delta_ms = TICKS_TO_MS(tick_remain(now_ms, exp)) + 1;
if (delta_ms > MAX_DELAY_MS)
delta_ms = MAX_DELAY_MS;
timeout.tv_sec = (delta_ms / 1000);
timeout.tv_nsec = (delta_ms % 1000) * 1000000;
}
}
fd = MIN(maxfd, global.tune.maxpollevents);
gettimeofday(&before_poll, NULL);
status = kevent(kqueue_fd, // int kq
NULL, // const struct kevent *changelist
0, // int nchanges
kev, // struct kevent *eventlist
fd, // int nevents
&timeout); // const struct timespec *timeout
tv_update_date(delta_ms, status);
measure_idle();
for (count = 0; count < status; count++) {
fd = kev[count].ident;
if (kev[count].filter == EVFILT_READ) {
if (FD_ISSET(fd, fd_evts[DIR_RD])) {
if (fdtab[fd].state == FD_STCLOSE)
continue;
fdtab[fd].cb[DIR_RD].f(fd);
}
} else if (kev[count].filter == EVFILT_WRITE) {
if (FD_ISSET(fd, fd_evts[DIR_WR])) {
if (fdtab[fd].state == FD_STCLOSE)
continue;
fdtab[fd].cb[DIR_WR].f(fd);
}
}
}
}
/*
* Initialization of the kqueue() 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_wevt, fail_revt, fail_fd;
int fd_set_bytes;
p->private = NULL;
fd_set_bytes = sizeof(fd_set) * (global.maxsock + FD_SETSIZE - 1) / FD_SETSIZE;
kqueue_fd = kqueue();
if (kqueue_fd < 0)
goto fail_fd;
kev = (struct kevent*)calloc(1, sizeof(struct kevent) * global.tune.maxpollevents);
if (kev == NULL)
goto fail_kev;
if ((fd_evts[DIR_RD] = (fd_set *)calloc(1, fd_set_bytes)) == NULL)
goto fail_revt;
if ((fd_evts[DIR_WR] = (fd_set *)calloc(1, fd_set_bytes)) == NULL)
goto fail_wevt;
return 1;
fail_wevt:
free(fd_evts[DIR_RD]);
fail_revt:
free(kev);
fail_kev:
close(kqueue_fd);
kqueue_fd = -1;
fail_fd:
p->pref = 0;
return 0;
}
/*
* Termination of the kqueue() 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]);
free(kev);
if (kqueue_fd >= 0) {
close(kqueue_fd);
kqueue_fd = -1;
}
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)
{
int fd;
fd = kqueue();
if (fd < 0)
return 0;
close(fd);
return 1;
}
/*
* Recreate the kqueue file descriptor after a fork(). Returns 1 if OK,
* otherwise 0. Note that some pollers need to be reopened after a fork()
* (such as kqueue), and some others may fail to do so in a chroot.
*/
REGPRM1 static int _do_fork(struct poller *p)
{
if (kqueue_fd >= 0)
close(kqueue_fd);
kqueue_fd = kqueue();
if (kqueue_fd < 0)
return 0;
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;
kqueue_fd = -1;
p = &pollers[nbpollers++];
p->name = "kqueue";
p->pref = 300;
p->private = NULL;
p->test = _do_test;
p->init = _do_init;
p->term = _do_term;
p->poll = _do_poll;
p->fork = _do_fork;
p->is_set = __fd_is_set;
p->cond_s = p->set = __fd_set;
p->cond_c = p->clr = __fd_clr;
p->rem = __fd_rem;
p->clo = __fd_clo;
}
/*
* Local variables:
* c-indent-level: 8
* c-basic-offset: 8
* End:
*/