1 /* -*- mode: C; c-file-style: "gnu" -*- */ 2 /* dbus-resources.c Resource tracking/limits 3 * 4 * Copyright (C) 2003 Red Hat Inc. 5 * 6 * Licensed under the Academic Free License version 2.1 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; either version 2 of the License, or 11 * (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public License 19 * along with this program; if not, write to the Free Software 20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 21 * 22 */ 23 #include <dbus/dbus-resources.h> 24 #include <dbus/dbus-internals.h> 25 26 /** 27 * @defgroup DBusResources Resource limits related code 28 * @ingroup DBusInternals 29 * @brief DBusCounter and other stuff related to resource limits 30 * 31 * Types and functions related to tracking resource limits, 32 * such as the maximum amount of memory a connection can use 33 * for messages, etc. 34 */ 35 36 /** 37 * @defgroup DBusResourcesInternals Resource limits implementation details 38 * @ingroup DBusInternals 39 * @brief Resource limits implementation details 40 * 41 * Implementation details of resource limits code. 42 * 43 * @{ 44 */ 45 46 /** 47 * @brief Internals of DBusCounter. 48 * 49 * DBusCounter internals. DBusCounter is an opaque object, it must be 50 * used via accessor functions. 51 */ 52 struct DBusCounter 53 { 54 int refcount; /**< reference count */ 55 56 long value; /**< current counter value */ 57 58 long notify_guard_value; /**< call notify function when crossing this value */ 59 DBusCounterNotifyFunction notify_function; /**< notify function */ 60 void *notify_data; /**< data for notify function */ 61 }; 62 63 /** @} */ /* end of resource limits internals docs */ 64 65 /** 66 * @addtogroup DBusResources 67 * @{ 68 */ 69 70 /** 71 * Creates a new DBusCounter. DBusCounter is used 72 * to count usage of some resource such as memory. 73 * 74 * @returns new counter or #NULL on failure 75 */ 76 DBusCounter* 77 _dbus_counter_new (void) 78 { 79 DBusCounter *counter; 80 81 counter = dbus_new (DBusCounter, 1); 82 if (counter == NULL) 83 return NULL; 84 85 counter->refcount = 1; 86 counter->value = 0; 87 88 counter->notify_guard_value = 0; 89 counter->notify_function = NULL; 90 counter->notify_data = NULL; 91 92 return counter; 93 } 94 95 /** 96 * Increments refcount of the counter 97 * 98 * @param counter the counter 99 * @returns the counter 100 */ 101 DBusCounter * 102 _dbus_counter_ref (DBusCounter *counter) 103 { 104 _dbus_assert (counter->refcount > 0); 105 106 counter->refcount += 1; 107 108 return counter; 109 } 110 111 /** 112 * Decrements refcount of the counter and possibly 113 * finalizes the counter. 114 * 115 * @param counter the counter 116 */ 117 void 118 _dbus_counter_unref (DBusCounter *counter) 119 { 120 _dbus_assert (counter->refcount > 0); 121 122 counter->refcount -= 1; 123 124 if (counter->refcount == 0) 125 { 126 127 dbus_free (counter); 128 } 129 } 130 131 /** 132 * Adjusts the value of the counter by the given 133 * delta which may be positive or negative. 134 * Calls the notify function from _dbus_counter_set_notify() 135 * if that function has been specified. 136 * 137 * @param counter the counter 138 * @param delta value to add to the counter's current value 139 */ 140 void 141 _dbus_counter_adjust (DBusCounter *counter, 142 long delta) 143 { 144 long old = counter->value; 145 146 counter->value += delta; 147 148 #if 0 149 _dbus_verbose ("Adjusting counter %ld by %ld = %ld\n", 150 old, delta, counter->value); 151 #endif 152 153 if (counter->notify_function != NULL && 154 ((old < counter->notify_guard_value && 155 counter->value >= counter->notify_guard_value) || 156 (old >= counter->notify_guard_value && 157 counter->value < counter->notify_guard_value))) 158 (* counter->notify_function) (counter, counter->notify_data); 159 } 160 161 /** 162 * Gets the current value of the counter. 163 * 164 * @param counter the counter 165 * @returns its current value 166 */ 167 long 168 _dbus_counter_get_value (DBusCounter *counter) 169 { 170 return counter->value; 171 } 172 173 /** 174 * Sets the notify function for this counter; the notify function is 175 * called whenever the counter's value crosses the guard value in 176 * either direction (moving up, or moving down). 177 * 178 * @param counter the counter 179 * @param guard_value the value we're notified if the counter crosses 180 * @param function function to call in order to notify 181 * @param user_data data to pass to the function 182 */ 183 void 184 _dbus_counter_set_notify (DBusCounter *counter, 185 long guard_value, 186 DBusCounterNotifyFunction function, 187 void *user_data) 188 { 189 counter->notify_guard_value = guard_value; 190 counter->notify_function = function; 191 counter->notify_data = user_data; 192 } 193 194 /** @} */ /* end of resource limits exported API */ 195
