dbus-resources.c

/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
/* dbus-resources.c Resource tracking/limits
 *
 * Copyright (C) 2003  Red Hat Inc.
 *
 * SPDX-License-Identifier: AFL-2.1 OR GPL-2.0-or-later
 *
 * 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 <dbus/dbus-resources.h>
#include <dbus/dbus-internals.h>
 
struct DBusCounter
{
  int refcount;  
  long size_value;       
  long unix_fd_value;    
#ifdef DBUS_ENABLE_STATS
  long peak_size_value;     
  long peak_unix_fd_value;  
#endif
 
  long notify_size_guard_value;    
  long notify_unix_fd_guard_value; 
  DBusCounterNotifyFunction notify_function; 
  void *notify_data; 
  dbus_bool_t notify_pending : 1; 
  DBusRMutex *mutex;    
};
  /* end of resource limits internals docs */
 
DBusCounter*
_dbus_counter_new (void)
{
  DBusCounter *counter;
 
  counter = dbus_new0 (DBusCounter, 1);
  if (counter == NULL)
    return NULL;
 
  counter->refcount = 1;
 
  _dbus_rmutex_new_at_location (&counter->mutex);
  if (counter->mutex == NULL)
  {
    dbus_free (counter);
    counter = NULL;
  }
 
  return counter;
}
 
DBusCounter *
_dbus_counter_ref (DBusCounter *counter)
{
  _dbus_rmutex_lock (counter->mutex);
 
  _dbus_assert (counter->refcount > 0);
  
  counter->refcount += 1;
 
  _dbus_rmutex_unlock (counter->mutex);
 
  return counter;
}
 
void
_dbus_counter_unref (DBusCounter *counter)
{
  dbus_bool_t last_ref = FALSE;
 
  _dbus_rmutex_lock (counter->mutex);
 
  _dbus_assert (counter->refcount > 0);
 
  counter->refcount -= 1;
  last_ref = (counter->refcount == 0);
 
  _dbus_rmutex_unlock (counter->mutex);
 
  if (last_ref)
    {
      _dbus_rmutex_free_at_location (&counter->mutex);
      dbus_free (counter);
    }
}
 
void
_dbus_counter_adjust_size (DBusCounter *counter,
                           long         delta)
{
  long old = 0;
 
  _dbus_rmutex_lock (counter->mutex);
 
  old = counter->size_value;
 
  counter->size_value += delta;
 
#ifdef DBUS_ENABLE_STATS
  if (counter->peak_size_value < counter->size_value)
    counter->peak_size_value = counter->size_value;
#endif
 
#if 0
  _dbus_verbose ("Adjusting counter %ld by %ld = %ld\n",
                 old, delta, counter->size_value);
#endif
 
  if (counter->notify_function != NULL &&
      ((old < counter->notify_size_guard_value &&
        counter->size_value >= counter->notify_size_guard_value) ||
       (old >= counter->notify_size_guard_value &&
        counter->size_value < counter->notify_size_guard_value)))
    counter->notify_pending = TRUE;
 
  _dbus_rmutex_unlock (counter->mutex);
}
 
void
_dbus_counter_notify (DBusCounter *counter)
{
  DBusCounterNotifyFunction notify_function = NULL;
  void *notify_data = NULL;
 
  _dbus_rmutex_lock (counter->mutex);
  if (counter->notify_pending)
    {
      counter->notify_pending = FALSE;
      notify_function = counter->notify_function;
      notify_data = counter->notify_data;
    }
  _dbus_rmutex_unlock (counter->mutex);
 
  if (notify_function != NULL)
    (* notify_function) (counter, notify_data);
}
 
void
_dbus_counter_adjust_unix_fd (DBusCounter *counter,
                              long         delta)
{
  long old = 0;
 
  _dbus_rmutex_lock (counter->mutex);
 
  old = counter->unix_fd_value;
  
  counter->unix_fd_value += delta;
 
#ifdef DBUS_ENABLE_STATS
  if (counter->peak_unix_fd_value < counter->unix_fd_value)
    counter->peak_unix_fd_value = counter->unix_fd_value;
#endif
 
#if 0
  _dbus_verbose ("Adjusting counter %ld by %ld = %ld\n",
                 old, delta, counter->unix_fd_value);
#endif
  
  if (counter->notify_function != NULL &&
      ((old < counter->notify_unix_fd_guard_value &&
        counter->unix_fd_value >= counter->notify_unix_fd_guard_value) ||
       (old >= counter->notify_unix_fd_guard_value &&
        counter->unix_fd_value < counter->notify_unix_fd_guard_value)))
    counter->notify_pending = TRUE;
 
  _dbus_rmutex_unlock (counter->mutex);
}
 
long
_dbus_counter_get_size_value (DBusCounter *counter)
{
  long result;
  _dbus_rmutex_lock (counter->mutex);
  result = counter->size_value;
  _dbus_rmutex_unlock (counter->mutex);
  return result;
}
 
long
_dbus_counter_get_unix_fd_value (DBusCounter *counter)
{
  long result;
  _dbus_rmutex_lock (counter->mutex);
  result = counter->unix_fd_value;
  _dbus_rmutex_unlock (counter->mutex);
  return result;
}
 
void
_dbus_counter_set_notify (DBusCounter               *counter,
                          long                       size_guard_value,
                          long                       unix_fd_guard_value,
                          DBusCounterNotifyFunction  function,
                          void                      *user_data)
{
  _dbus_rmutex_lock (counter->mutex);
  counter->notify_size_guard_value = size_guard_value;
  counter->notify_unix_fd_guard_value = unix_fd_guard_value;
  counter->notify_function = function;
  counter->notify_data = user_data;
  counter->notify_pending = FALSE;
  _dbus_rmutex_unlock (counter->mutex);
}
 
#ifdef DBUS_ENABLE_STATS
long
_dbus_counter_get_peak_size_value (DBusCounter *counter)
{
  return counter->peak_size_value;
}
 
long
_dbus_counter_get_peak_unix_fd_value (DBusCounter *counter)
{
  return counter->peak_unix_fd_value;
}
#endif
  /* end of resource limits exported API */