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/* -*- mode: C; c-file-style: "gnu" -*- */
/* dbus-resources.c Resource tracking/limits
*
* Copyright (C) 2003 Red Hat Inc.
*
* Licensed under the Academic Free License version 1.2
*
* 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
*
*/
#include <dbus/dbus-resources.h>
#include <dbus/dbus-internals.h>
/**
* @defgroup DBusResources Resource limits related code
* @ingroup DBusInternals
* @brief DBusCounter and other stuff related to resource limits
*
* Types and functions related to tracking resource limits,
* such as the maximum amount of memory a connection can use
* for messages, etc.
*/
/**
* @defgroup DBusResourcesInternals Resource limits implementation details
* @ingroup DBusInternals
* @brief Resource limits implementation details
*
* Implementation details of resource limits code.
*
* @{
*/
/**
* @brief Internals of DBusCounter.
*
* DBusCounter internals. DBusCounter is an opaque object, it must be
* used via accessor functions.
*/
struct DBusCounter
{
int refcount; /**< reference count */
long value; /**< current counter value */
long notify_guard_value; /**< call notify function when crossing this value */
DBusCounterNotifyFunction notify_function; /**< notify function */
void *notify_data; /**< data for notify function */
};
/** @} */ /* end of resource limits internals docs */
/**
* @addtogroup DBusResources
* @{
*/
/**
* Creates a new DBusCounter. DBusCounter is used
* to count usage of some resource such as memory.
*
* @returns new counter or #NULL on failure
*/
DBusCounter*
_dbus_counter_new (void)
{
DBusCounter *counter;
counter = dbus_new (DBusCounter, 1);
if (counter == NULL)
return NULL;
counter->refcount = 1;
counter->value = 0;
counter->notify_guard_value = 0;
counter->notify_function = NULL;
counter->notify_data = NULL;
return counter;
}
/**
* Increments refcount of the counter
*
* @param counter the counter
*/
void
_dbus_counter_ref (DBusCounter *counter)
{
_dbus_assert (counter->refcount > 0);
counter->refcount += 1;
}
/**
* Decrements refcount of the counter and possibly
* finalizes the counter.
*
* @param counter the counter
*/
void
_dbus_counter_unref (DBusCounter *counter)
{
_dbus_assert (counter->refcount > 0);
counter->refcount -= 1;
if (counter->refcount == 0)
{
dbus_free (counter);
}
}
/**
* Adjusts the value of the counter by the given
* delta which may be positive or negative.
* Calls the notify function from _dbus_counter_set_notify()
* if that function has been specified.
*
* @param counter the counter
* @param delta value to add to the counter's current value
*/
void
_dbus_counter_adjust (DBusCounter *counter,
long delta)
{
long old = counter->value;
counter->value += delta;
#if 0
_dbus_verbose ("Adjusting counter %ld by %ld = %ld\n",
old, delta, counter->value);
#endif
if (counter->notify_function != NULL &&
((old < counter->notify_guard_value &&
counter->value >= counter->notify_guard_value) ||
(old >= counter->notify_guard_value &&
counter->value < counter->notify_guard_value)))
(* counter->notify_function) (counter, counter->notify_data);
}
/**
* Gets the current value of the counter.
*
* @param counter the counter
* @returns its current value
*/
long
_dbus_counter_get_value (DBusCounter *counter)
{
return counter->value;
}
/**
* Sets the notify function for this counter; the notify function is
* called whenever the counter's value crosses the guard value in
* either direction (moving up, or moving down).
*
* @param counter the counter
* @param guard_value the value we're notified if the counter crosses
* @param function function to call in order to notify
* @param user_data data to pass to the function
*/
void
_dbus_counter_set_notify (DBusCounter *counter,
long guard_value,
DBusCounterNotifyFunction function,
void *user_data)
{
counter->notify_guard_value = guard_value;
counter->notify_function = function;
counter->notify_data = user_data;
}
/** @} */ /* end of resource limits exported API */
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