/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
/* expirelist.c List of items that expire
*
* 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 "expirelist.h"
#include "test.h"
#include <dbus/dbus-internals.h>
#include <dbus/dbus-mainloop.h>
#include <dbus/dbus-timeout.h>
struct BusExpireList
{
DBusList *items; /**< List of BusExpireItem */
DBusTimeout *timeout;
DBusLoop *loop;
BusExpireFunc expire_func;
void *data;
int expire_after; /**< Expire after milliseconds (thousandths) */
};
static dbus_bool_t expire_timeout_handler (void *data);
static void
call_timeout_callback (DBusTimeout *timeout,
void *data)
{
/* can return FALSE on OOM but we just let it fire again later */
dbus_timeout_handle (timeout);
}
BusExpireList*
bus_expire_list_new (DBusLoop *loop,
int expire_after,
BusExpireFunc expire_func,
void *data)
{
BusExpireList *list;
list = dbus_new0 (BusExpireList, 1);
if (list == NULL)
return NULL;
list->expire_func = expire_func;
list->data = data;
list->loop = loop;
list->expire_after = expire_after;
list->timeout = _dbus_timeout_new (100, /* irrelevant */
expire_timeout_handler,
list, NULL);
if (list->timeout == NULL)
goto failed;
_dbus_timeout_set_enabled (list->timeout, FALSE);
if (!_dbus_loop_add_timeout (list->loop,
list->timeout,
call_timeout_callback, NULL, NULL))
goto failed;
return list;
failed:
if (list->timeout)
_dbus_timeout_unref (list->timeout);
dbus_free (list);
return NULL;
}
void
bus_expire_list_free (BusExpireList *list)
{
_dbus_assert (list->items == NULL);
_dbus_loop_remove_timeout (list->loop, list->timeout,
call_timeout_callback, NULL);
_dbus_timeout_unref (list->timeout);
dbus_free (list);
}
void
bus_expire_timeout_set_interval (DBusTimeout *timeout,
int next_interval)
{
if (next_interval >= 0)
{
_dbus_timeout_set_interval (timeout,
next_interval);
_dbus_timeout_set_enabled (timeout, TRUE);
_dbus_verbose ("Enabled an expire timeout with interval %d\n",
next_interval);
}
else if (dbus_timeout_get_enabled (timeout))
{
_dbus_timeout_set_enabled (timeout, FALSE);
_dbus_verbose ("Disabled an expire timeout\n");
}
else
_dbus_verbose ("No need to disable this expire timeout\n");
}
void
bus_expire_list_recheck_immediately (BusExpireList *list)
{
_dbus_verbose ("setting interval on expire list to 0 for immediate recheck\n");
bus_expire_timeout_set_interval (list->timeout, 0);
}
static int
do_expiration_with_current_time (BusExpireList *list,
long tv_sec,
long tv_usec)
{
DBusList *link;
int next_interval, min_wait_time, items_to_expire;
next_interval = -1;
min_wait_time = 3600 * 1000; /* this is reset anyway if used */
items_to_expire = 0;
link = _dbus_list_get_first_link (&list->items);
while (link != NULL)
{
DBusList *next = _dbus_list_get_next_link (&list->items, link);
double elapsed;
BusExpireItem *item;
item = link->data;
elapsed = ELAPSED_MILLISECONDS_SINCE (item->added_tv_sec,
item->added_tv_usec,
tv_sec, tv_usec);
if (((item->added_tv_sec == 0) && (item->added_tv_usec == 0)) ||
((list->expire_after > 0) && (elapsed >= (double) list->expire_after)))
{
_dbus_verbose ("Expiring an item %p\n", item);
/* If the expire function fails, we just end up expiring
* this item next time we walk through the list. This would
* be an indeterminate time normally, so we set up the
* next_interval to be "shortly" (just enough to avoid
* a busy loop)
*/
if (!(* list->expire_func) (list, link, list->data))
{
next_interval = _dbus_get_oom_wait ();
break;
}
}
else if (list->expire_after > 0)
{
double to_wait;
items_to_expire = 1;
to_wait = (double) list->expire_after - elapsed;
if (min_wait_time > to_wait)
min_wait_time = to_wait;
}
link = next;
}
if (next_interval < 0 && items_to_expire)
next_interval = min_wait_time;
return next_interval;
}
static void
bus_expirelist_expire (BusExpireList *list)
{
int next_interval;
next_interval = -1;
if (list->items != NULL)
{
long tv_sec, tv_usec;
_dbus_get_current_time (&tv_sec, &tv_usec);
next_interval = do_expiration_with_current_time (list, tv_sec, tv_usec);
}
bus_expire_timeout_set_interval (list->timeout, next_interval);
}
static dbus_bool_t
expire_timeout_handler (void *data)
{
BusExpireList *list = data;
_dbus_verbose ("Running\n");
/* note that this may remove the timeout */
bus_expirelist_expire (list);
return TRUE;
}
void
bus_expire_list_remove_link (BusExpireList *list,
DBusList *link)
{
_dbus_list_remove_link (&list->items, link);
}
dbus_bool_t
bus_expire_list_remove (BusExpireList *list,
BusExpireItem *item)
{
return _dbus_list_remove (&list->items, item);
}
void
bus_expire_list_unlink (BusExpireList *list,
DBusList *link)
{
_dbus_list_unlink (&list->items, link);
}
dbus_bool_t
bus_expire_list_add (BusExpireList *list,
BusExpireItem *item)
{
dbus_bool_t ret;
ret = _dbus_list_prepend (&list->items, item);
if (ret && !dbus_timeout_get_enabled (list->timeout))
bus_expire_timeout_set_interval (list->timeout, 0);
return ret;
}
void
bus_expire_list_add_link (BusExpireList *list,
DBusList *link)
{
_dbus_assert (link->data != NULL);
_dbus_list_prepend_link (&list->items, link);
if (!dbus_timeout_get_enabled (list->timeout))
bus_expire_timeout_set_interval (list->timeout, 0);
}
DBusList*
bus_expire_list_get_first_link (BusExpireList *list)
{
return _dbus_list_get_first_link (&list->items);
}
DBusList*
bus_expire_list_get_next_link (BusExpireList *list,
DBusList *link)
{
return _dbus_list_get_next_link (&list->items, link);
}
dbus_bool_t
bus_expire_list_contains_item (BusExpireList *list,
BusExpireItem *item)
{
return _dbus_list_find_last (&list->items, item) != NULL;
}
#ifdef DBUS_BUILD_TESTS
typedef struct
{
BusExpireItem item;
int expire_count;
} TestExpireItem;
static dbus_bool_t
test_expire_func (BusExpireList *list,
DBusList *link,
void *data)
{
TestExpireItem *t;
t = (TestExpireItem*) link->data;
t->expire_count += 1;
return TRUE;
}
static void
time_add_milliseconds (long *tv_sec,
long *tv_usec,
int milliseconds)
{
*tv_sec = *tv_sec + milliseconds / 1000;
*tv_usec = *tv_usec + milliseconds * 1000;
if (*tv_usec >= 1000000)
{
*tv_usec -= 1000000;
*tv_sec += 1;
}
}
dbus_bool_t
bus_expire_list_test (const DBusString *test_data_dir)
{
DBusLoop *loop;
BusExpireList *list;
long tv_sec, tv_usec;
long tv_sec_not_expired, tv_usec_not_expired;
long tv_sec_expired, tv_usec_expired;
long tv_sec_past, tv_usec_past;
TestExpireItem *item;
int next_interval;
dbus_bool_t result = FALSE;
loop = _dbus_loop_new ();
_dbus_assert (loop != NULL);
#define EXPIRE_AFTER 100
list = bus_expire_list_new (loop, EXPIRE_AFTER,
test_expire_func, NULL);
_dbus_assert (list != NULL);
_dbus_get_current_time (&tv_sec, &tv_usec);
tv_sec_not_expired = tv_sec;
tv_usec_not_expired = tv_usec;
time_add_milliseconds (&tv_sec_not_expired,
&tv_usec_not_expired, EXPIRE_AFTER - 1);
tv_sec_expired = tv_sec;
tv_usec_expired = tv_usec;
time_add_milliseconds (&tv_sec_expired,
&tv_usec_expired, EXPIRE_AFTER);
tv_sec_past = tv_sec - 1;
tv_usec_past = tv_usec;
item = dbus_new0 (TestExpireItem, 1);
if (item == NULL)
goto oom;
item->item.added_tv_sec = tv_sec;
item->item.added_tv_usec = tv_usec;
if (!bus_expire_list_add (list, &item->item))
_dbus_assert_not_reached ("out of memory");
next_interval =
do_expiration_with_current_time (list, tv_sec_not_expired,
tv_usec_not_expired);
_dbus_assert (item->expire_count == 0);
_dbus_verbose ("next_interval = %d\n", next_interval);
_dbus_assert (next_interval == 1);
next_interval =
do_expiration_with_current_time (list, tv_sec_expired,
tv_usec_expired);
_dbus_assert (item->expire_count == 1);
_dbus_verbose ("next_interval = %d\n", next_interval);
_dbus_assert (next_interval == -1);
next_interval =
do_expiration_with_current_time (list, tv_sec_past,
tv_usec_past);
_dbus_assert (item->expire_count == 1);
_dbus_verbose ("next_interval = %d\n", next_interval);
_dbus_assert (next_interval == 1000 + EXPIRE_AFTER);
bus_expire_list_remove (list, &item->item);
dbus_free (item);
bus_expire_list_free (list);
_dbus_loop_unref (loop);
result = TRUE;
oom:
return result;
}
#endif /* DBUS_BUILD_TESTS */