1
0
mirror of git://sourceware.org/git/lvm2.git synced 2024-12-22 17:35:59 +03:00
lvm2/daemons/cmirrord/link_mon.c

152 lines
3.0 KiB
C
Raw Normal View History

/*
* Copyright (C) 2004-2009 Red Hat, Inc. All rights reserved.
*
* This copyrighted material is made available to anyone wishing to use,
* modify, copy, or redistribute it subject to the terms and conditions
* of the GNU Lesser General Public License v.2.1.
*
* You should have received a copy of the GNU Lesser 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
*/
#include "logging.h"
2010-01-18 23:08:44 +03:00
#include "link_mon.h"
2010-01-19 00:07:24 +03:00
#include <errno.h>
#include <poll.h>
#include <stdlib.h>
struct link_callback {
int fd;
2010-01-18 23:08:44 +03:00
const char *name;
void *data;
int (*callback)(void *data);
struct link_callback *next;
};
static unsigned used_pfds = 0;
static unsigned free_pfds = 0;
static struct pollfd *pfds = NULL;
static struct link_callback *callbacks = NULL;
2010-01-18 23:08:44 +03:00
int links_register(int fd, const char *name, int (*callback)(void *data), void *data)
{
unsigned i;
struct link_callback *lc;
for (i = 0; i < used_pfds; i++) {
if (fd == pfds[i].fd) {
LOG_ERROR("links_register: Duplicate file descriptor");
return -EINVAL;
}
}
lc = malloc(sizeof(*lc));
if (!lc)
return -ENOMEM;
lc->fd = fd;
lc->name = name;
lc->data = data;
lc->callback = callback;
if (!free_pfds) {
struct pollfd *tmp;
tmp = realloc(pfds, sizeof(struct pollfd) * ((used_pfds*2) + 1));
if (!tmp) {
free(lc);
return -ENOMEM;
}
pfds = tmp;
free_pfds = used_pfds + 1;
}
free_pfds--;
pfds[used_pfds].fd = fd;
pfds[used_pfds].events = POLLIN;
pfds[used_pfds].revents = 0;
used_pfds++;
lc->next = callbacks;
callbacks = lc;
LOG_DBG("Adding %s/%d", lc->name, lc->fd);
LOG_DBG(" used_pfds = %u, free_pfds = %u",
used_pfds, free_pfds);
return 0;
}
int links_unregister(int fd)
{
unsigned i;
struct link_callback *p, *c;
for (i = 0; i < used_pfds; i++)
if (fd == pfds[i].fd) {
/* entire struct is copied (overwritten) */
pfds[i] = pfds[used_pfds - 1];
used_pfds--;
free_pfds++;
}
for (p = NULL, c = callbacks; c; p = c, c = c->next)
if (fd == c->fd) {
LOG_DBG("Freeing up %s/%d", c->name, c->fd);
LOG_DBG(" used_pfds = %u, free_pfds = %u",
used_pfds, free_pfds);
if (p)
p->next = c->next;
else
callbacks = c->next;
free(c);
break;
}
return 0;
}
int links_monitor(void)
{
unsigned i;
int r;
for (i = 0; i < used_pfds; i++) {
pfds[i].revents = 0;
}
r = poll(pfds, used_pfds, -1);
if (r <= 0)
return r;
r = 0;
/* FIXME: handle POLLHUP */
for (i = 0; i < used_pfds; i++)
if (pfds[i].revents & POLLIN) {
LOG_DBG("Data ready on %d", pfds[i].fd);
/* FIXME: Add this back return 1;*/
r++;
}
return r;
}
int links_issue_callbacks(void)
{
unsigned i;
struct link_callback *lc;
for (i = 0; i < used_pfds; i++)
if (pfds[i].revents & POLLIN)
for (lc = callbacks; lc; lc = lc->next)
if (pfds[i].fd == lc->fd) {
LOG_DBG("Issuing callback on %s/%d",
lc->name, lc->fd);
lc->callback(lc->data);
break;
}
return 0;
}