elemental-ircd/libcharybdis/devpoll.c

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/*
* ircd-ratbox: A slightly useful ircd.
* s_bsd_devpoll.c: /dev/poll compatible network routines.
*
* Copyright (C) 1990 Jarkko Oikarinen and University of Oulu, Co Center
* Copyright (C) 1996-2002 Hybrid Development Team
* Copyright (C) 2001 Adrian Chadd <adrian@creative.net.au>
* Copyright (C) 2002-2005 ircd-ratbox development team
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
* USA
*
* $Id: devpoll.c 3229 2007-03-05 17:23:07Z nenolod $
*/
#include "config.h"
#include "stdinc.h"
#include <sys/devpoll.h>
#include "libcharybdis.h"
#define POLL_LENGTH HARD_FDLIMIT
static void devpoll_update_events(int, short, PF *);
static int dpfd;
static short fdmask[POLL_LENGTH];
static void devpoll_update_events(int, short, PF *);
static void devpoll_write_update(int, int);
/* #define NOTYET 1 */
/* XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX */
/* Private functions */
/*
* Write an update to the devpoll filter.
* See, we end up having to do a seperate (?) remove before we do an
* add of a new polltype, so we have to have this function seperate from
* the others.
*/
static void
devpoll_write_update(int fd, int events)
{
struct pollfd pollfds[1]; /* Just to be careful */
int retval;
/* Build the pollfd entry */
pollfds[0].revents = 0;
pollfds[0].fd = fd;
pollfds[0].events = events;
/* Write the thing to our poll fd */
retval = write(dpfd, &pollfds[0], sizeof(struct pollfd));
if(retval != sizeof(struct pollfd))
libcharybdis_log("devpoll_write_update: dpfd write failed %d: %s", errno, strerror(errno));
/* Done! */
}
void
devpoll_update_events(int fd, short filter, PF * handler)
{
int update_required = 0;
int cur_mask = fdmask[fd];
PF *cur_handler;
fdmask[fd] = 0;
fde_t *F = comm_locate_fd(fd);
switch (filter)
{
case COMM_SELECT_READ:
cur_handler = F->read_handler;
if(handler)
fdmask[fd] |= POLLRDNORM;
else
fdmask[fd] &= ~POLLRDNORM;
if(F->write_handler)
fdmask[fd] |= POLLWRNORM;
break;
case COMM_SELECT_WRITE:
cur_handler = F->write_handler;
if(handler)
fdmask[fd] |= POLLWRNORM;
else
fdmask[fd] &= ~POLLWRNORM;
if(F->read_handler)
fdmask[fd] |= POLLRDNORM;
break;
default:
#ifdef NOTYET
libcharybdis_log("devpoll_update_events called with unknown filter: %hd", filter);
#endif
return;
break;
}
if(cur_handler == NULL && handler != NULL)
update_required++;
else if(cur_handler != NULL && handler == NULL)
update_required++;
if(cur_mask != fdmask[fd])
update_required++;
if(update_required)
{
/*
* Ok, we can call devpoll_write_update() here now to re-build the
* fd struct. If we end up with nothing on this fd, it won't write
* anything.
*/
if(fdmask[fd])
{
devpoll_write_update(fd, POLLREMOVE);
devpoll_write_update(fd, fdmask[fd]);
}
else
devpoll_write_update(fd, POLLREMOVE);
}
}
/* XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX */
/* Public functions */
/*
* init_netio
*
* This is a needed exported function which will be called to initialise
* the network loop code.
*/
void
init_netio(void)
{
memset(&fdmask, 0, sizeof(fdmask));
dpfd = open("/dev/poll", O_RDWR);
if(dpfd < 0)
{
fprintf(stderr,
"init_netio: Couldn't open /dev/poll - %d: %s\n",
errno, strerror(errno));
exit(115); /* Whee! */
}
}
/*
* comm_setselect
*
* This is a needed exported function which will be called to register
* and deregister interest in a pending IO state for a given FD.
*/
void
comm_setselect(int fd, fdlist_t list, unsigned int type, PF * handler,
void *client_data, time_t timeout)
{
fde_t *F = comm_locate_fd(fd);
s_assert(fd >= 0);
s_assert(F->flags.open);
/* Update the list, even though we're not using it .. */
F->list = list;
if(type & COMM_SELECT_READ)
{
devpoll_update_events(fd, COMM_SELECT_READ, handler);
F->read_handler = handler;
F->read_data = client_data;
}
if(type & COMM_SELECT_WRITE)
{
devpoll_update_events(fd, COMM_SELECT_WRITE, handler);
F->write_handler = handler;
F->write_data = client_data;
}
if(timeout)
F->timeout = CurrentTime + (timeout / 1000);
}
/*
* Check all connections for new connections and input data that is to be
* processed. Also check for connections with data queued and whether we can
* write it out.
*/
/*
* comm_select
*
* Called to do the new-style IO, courtesy of squid (like most of this
* new IO code). This routine handles the stuff we've hidden in
* comm_setselect and fd_table[] and calls callbacks for IO ready
* events.
*/
int
comm_select(unsigned long delay)
{
int num, i;
struct pollfd pollfds[POLL_LENGTH];
struct dvpoll dopoll;
do
{
for (;;)
{
dopoll.dp_timeout = delay;
dopoll.dp_nfds = POLL_LENGTH;
dopoll.dp_fds = &pollfds[0];
num = ioctl(dpfd, DP_POLL, &dopoll);
if(num >= 0)
break;
if(ignoreErrno(errno))
break;
set_time();
return COMM_ERROR;
}
set_time();
if(num == 0)
continue;
for (i = 0; i < num; i++)
{
int fd = dopoll.dp_fds[i].fd;
PF *hdl = NULL;
fde_t *F = comm_locate_fd(fd);
if((dopoll.dp_fds[i].
revents & (POLLRDNORM | POLLIN | POLLHUP |
POLLERR))
&& (dopoll.dp_fds[i].events & (POLLRDNORM | POLLIN)))
{
if((hdl = F->read_handler) != NULL)
{
F->read_handler = NULL;
hdl(fd, F->read_data);
/*
* this call used to be with a NULL pointer, BUT
* in the devpoll case we only want to update the
* poll set *if* the handler changes state (active ->
* NULL or vice versa.)
*/
devpoll_update_events(fd,
COMM_SELECT_READ, F->read_handler);
}
else
libcharybdis_log("comm_select: Unhandled read event: fdmask: %x",
fdmask[fd]);
}
if(F->flags.open == 0)
continue; /* Read handler closed us..go on to do something more useful */
if((dopoll.dp_fds[i].
revents & (POLLWRNORM | POLLOUT | POLLHUP |
POLLERR))
&& (dopoll.dp_fds[i].events & (POLLWRNORM | POLLOUT)))
{
if((hdl = F->write_handler) != NULL)
{
F->write_handler = NULL;
hdl(fd, F->write_data);
/* See above similar code in the read case */
devpoll_update_events(fd,
COMM_SELECT_WRITE, F->write_handler);
}
else
libcharybdis_log("comm_select: Unhandled write event: fdmask: %x",
fdmask[fd]);
}
if(dopoll.dp_fds[i].revents & POLLNVAL)
{
libcharybdis_log("revents was Invalid for %d", fd);
}
}
return COMM_OK;
}
while (0);
/* XXX Get here, we broke! */
return 0;
}