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|
/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
/* dir-watch-kqueue.c OS specific directory change notification for message bus
*
* Copyright (C) 2003 Red Hat, Inc.
*
* Licensed under the Academic Free License version 2.1
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include <config.h>
#include <sys/types.h>
#include <sys/event.h>
#include <sys/time.h>
#include <signal.h>
#include <fcntl.h>
#include <unistd.h>
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#include "bus.h"
#include <dbus/dbus-watch.h>
#include <dbus/dbus-internals.h>
#include <dbus/dbus-list.h>
#include "dir-watch.h"
#define MAX_DIRS_TO_WATCH 128
static int kq = -1;
static int fds[MAX_DIRS_TO_WATCH];
static char *dirs[MAX_DIRS_TO_WATCH];
static int num_fds = 0;
static DBusWatch *watch = NULL;
static DBusLoop *loop = NULL;
static dbus_bool_t
_kqueue_watch_callback (DBusWatch *watch, unsigned int condition, void *data)
{
return dbus_watch_handle (watch, condition);
}
static dbus_bool_t
_handle_kqueue_watch (DBusWatch *watch, unsigned int flags, void *data)
{
struct kevent ev;
struct timespec nullts = { 0, 0 };
int res;
pid_t pid;
res = kevent (kq, NULL, 0, &ev, 1, &nullts);
/* Sleep for half a second to avoid a race when files are install(1)'d
* to system.d. */
usleep(500000);
if (res > 0)
{
pid = getpid ();
_dbus_verbose ("Sending SIGHUP signal on reception of a kevent\n");
(void) kill (pid, SIGHUP);
}
else if (res < 0 && errno == EBADF)
{
kq = -1;
if (watch != NULL)
{
_dbus_loop_remove_watch (loop, watch, _kqueue_watch_callback, NULL);
_dbus_watch_unref (watch);
watch = NULL;
}
pid = getpid ();
_dbus_verbose ("Sending SIGHUP signal since kqueue has been closed\n");
(void) kill (pid, SIGHUP);
}
return TRUE;
}
static int
_init_kqueue (BusContext *context)
{
int ret = 0;
if (kq < 0)
{
kq = kqueue ();
if (kq < 0)
{
_dbus_warn ("Cannot create kqueue; error '%s'\n", _dbus_strerror (errno));
goto out;
}
loop = bus_context_get_loop (context);
watch = _dbus_watch_new (kq, DBUS_WATCH_READABLE, TRUE,
_handle_kqueue_watch, NULL, NULL);
if (watch == NULL)
{
_dbus_warn ("Unable to create kqueue watch\n");
close (kq);
kq = -1;
goto out;
}
if (!_dbus_loop_add_watch (loop, watch, _kqueue_watch_callback,
NULL, NULL))
{
_dbus_warn ("Unable to add reload watch to main loop");
close (kq);
kq = -1;
_dbus_watch_unref (watch);
watch = NULL;
goto out;
}
}
ret = 1;
out:
return ret;
}
void
bus_set_watched_dirs (BusContext *context, DBusList **directories)
{
int new_fds[MAX_DIRS_TO_WATCH];
char *new_dirs[MAX_DIRS_TO_WATCH];
DBusList *link;
int i, j, f, fd;
struct kevent ev;
if (!_init_kqueue (context))
goto out;
for (i = 0; i < MAX_DIRS_TO_WATCH; i++)
{
new_fds[i] = -1;
new_dirs[i] = NULL;
}
i = 0;
link = _dbus_list_get_first_link (directories);
while (link != NULL)
{
new_dirs[i++] = (char *)link->data;
link = _dbus_list_get_next_link (directories, link);
}
/* Look for directories in both the old and new sets, if
* we find one, move its data into the new set.
*/
for (i = 0; new_dirs[i]; i++)
{
for (j = 0; j < num_fds; j++)
{
if (dirs[j] && strcmp (new_dirs[i], dirs[j]) == 0)
{
new_fds[i] = fds[j];
new_dirs[i] = dirs[j];
fds[j] = -1;
dirs[j] = NULL;
break;
}
}
}
/* Any directory we find in "fds" with a nonzero fd must
* not be in the new set, so perform cleanup now.
*/
for (j = 0; j < num_fds; j++)
{
if (fds[j] != -1)
{
close (fds[j]);
dbus_free (dirs[j]);
fds[j] = -1;
dirs[j] = NULL;
}
}
for (i = 0; new_dirs[i]; i++)
{
if (new_fds[i] == -1)
{
/* FIXME - less lame error handling for failing to add a watch;
* we may need to sleep.
*/
fd = open (new_dirs[i], O_RDONLY);
if (fd < 0)
{
if (errno != ENOENT)
{
_dbus_warn ("Cannot open directory '%s'; error '%s'\n", new_dirs[i], _dbus_strerror (errno));
goto out;
}
else
{
new_fds[i] = -1;
new_dirs[i] = NULL;
continue;
}
}
EV_SET (&ev, fd, EVFILT_VNODE, EV_ADD | EV_ENABLE | EV_CLEAR,
NOTE_DELETE | NOTE_EXTEND | NOTE_WRITE | NOTE_RENAME, 0, 0);
if (kevent (kq, &ev, 1, NULL, 0, NULL) == -1)
{
_dbus_warn ("Cannot setup a kevent for '%s'; error '%s'\n", new_dirs[i], _dbus_strerror (errno));
close (fd);
goto out;
}
new_fds[i] = fd;
new_dirs[i] = _dbus_strdup (new_dirs[i]);
if (!new_dirs[i])
{
/* FIXME have less lame handling for OOM, we just silently fail to
* watch. (In reality though, the whole OOM handling in dbus is
* stupid but we won't go into that in this comment =) )
*/
close (fd);
new_fds[i] = -1;
}
}
}
num_fds = i;
for (i = 0; i < MAX_DIRS_TO_WATCH; i++)
{
fds[i] = new_fds[i];
dirs[i] = new_dirs[i];
}
out:
;
}
|
