doubango/tinySAK/src/tsk_list.c
c732d49e
 #if HAVE_CRT
 #define _CRTDBG_MAP_ALLOC 
 #include <stdlib.h> 
 #include <crtdbg.h>
 #endif //HAVE_CRT
 /*
 * Copyright (C) 2017, University of the Basque Country (UPV/EHU)
 * Contact for licensing options: <licensing-mcpttclient(at)mcopenplatform(dot)com>
 *
 * The original file was part of Open Source Doubango Framework
 * Copyright (C) 2010-2011 Mamadou Diop.
 * Copyright (C) 2012 Doubango Telecom <http://doubango.org>
 *
 * This file is part of Open Source Doubango Framework.
 *
 * DOUBANGO 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 3 of the License, or
 * (at your option) any later version.
 *
 * DOUBANGO 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 DOUBANGO.
 *
 */
 
 /**@file tsk_list.c
  * @brief Linked list.
  *
  */
 #include "tsk_list.h"
 #include "tsk_memory.h"
 #include "tsk_debug.h"
 
 #include <string.h>
 
 /**@defgroup tsk_list_group Linked list.
 * @brief Linked list. For more information about linked list you can check @ref _Page_TinySAK_AnsiC_Linked_List "this page".
 */
 
 /* Predicate function to find item using memory address comparison.
 */
 static int tsk_list_find_by_item(const tsk_list_item_t* item, const void* _item)
 {
 	return (item == (const tsk_list_item_t*)_item) ? 0 : -1;
 }
 
 /**@ingroup tsk_list_group
 * Creates a @ref _Page_TinySAK_AnsiC_Linked_List "linked-list"  object. <br />
 * You <b>MUST</b> use @ref TSK_OBJECT_SAFE_FREE() to safely free the returned @ref _Page_TinySAK_AnsiC_Object_Programming "well-defined" object.
 * @return The newly created list object.
 */
 tsk_list_t* tsk_list_create()
 {
 	return (tsk_list_t*)tsk_object_new(tsk_list_def_t);
 }
 
 /**@ingroup tsk_list_group
 * Create and initialize an item to be added to a @ref tsk_list_t "linked list". 
 * You should not need to call this function by yourself. See @ref _Anchor_TinySAK_Linked_List_Add_Remove "here" for more information on how to add items.<br />
 * You <b>MUST</b> use @ref TSK_OBJECT_SAFE_FREE() to safely free the returned @ref _Page_TinySAK_AnsiC_Object_Programming "well-defined" object. <br />
 * @return The newly created @ref tsk_list_item_t "item" object.
 */
 tsk_list_item_t* tsk_list_item_create()
 {
 	return (tsk_list_item_t*)tsk_object_new(tsk_list_item_def_t);
 }
 
 /**@ingroup tsk_list_group
 * Locks the @ref tsk_list_t "list" to avoid concurrent access. The @ref tsk_list_t "list" must be unlocked using @ref tsk_list_unlock(). <br />
 * For more information about thread-safety see @ref _Anchor_TinySAK_Linked_List_Thread_Safety "here".
 * @param list The list to lock.
 * @return 0 if succeed and non-zero error code otherwise.
 * @sa @ref tsk_list_unlock
 */
 int tsk_list_lock(tsk_list_t* list)
 {
 	if(list){
 		if(!list->mutex){
 			list->mutex = tsk_mutex_create();
 		}
 		return tsk_mutex_lock(list->mutex);
 	}
 	else{
 		TSK_DEBUG_ERROR("Invalid parameter");
 		return -1;
 	}
 }
 
 /**@ingroup tsk_list_group
 * UnLocks a previously locked @ref tsk_list_t "list". The @ref tsk_list_t "list" must be previously locked using @ref tsk_list_lock().<br />
 * For more information about thread-safety see @ref _Anchor_TinySAK_Linked_List_Thread_Safety "here".
 * @param list The @ref tsk_list_t "list" to unlock. <br />
 * @return 0 if succeed and non-zero error code otherwise.
 * @sa @ref tsk_list_lock
 */
 int tsk_list_unlock(tsk_list_t* list)
 {
 	if(list && list->mutex){
 		return tsk_mutex_unlock(list->mutex); 
 	}
 	else{
 		TSK_DEBUG_ERROR("Invalid parameter");
 		return -1;
 	}
 }
 
 /**@ingroup tsk_list_group
 * Removes an item from the @ref tsk_list_t "list". The reference counter value of the object held by the item will be decremented. <br />
 * You should not need to call this function by yourself. See @ref _Anchor_TinySAK_Linked_List_Add_Remove "here" for more information on how to remove items.<br />
 * @param list the @ref tsk_list_t "list" from which to remove the @a item.
 * @param item the @ref tsk_list_item_t "item" to remove from the @a list.
 * @return @ref tsk_true if @a item exists and have been removed; @ref tsk_false otherwise.
 */
 tsk_bool_t tsk_list_remove_item(tsk_list_t* list, tsk_list_item_t* item)
 {
 	if(item){
 		return tsk_list_remove_item_by_pred(list, tsk_list_find_by_item, (const void*)item);
 	}
 	return tsk_false;
 }
 
 /**@ingroup tsk_list_group
 * Pops an object from the @ref tsk_list_t "list". The item will be removed from the list but the refrence counter will not change.
 * @param list The @ref tsk_list_t "list" from which to pop the item.
 * @param tskobj Any @ref _Page_TinySAK_AnsiC_Object_Programming "well-defined" object to pop.
 * @return The item holding @ref tskobj or any equivalent object. @ref tsk_object_cmp(item->data, tskobj) == 0. <br />
 * @ref tsk_null will be returned if no matching object could be found.
 */
 tsk_list_item_t* tsk_list_pop_item_by_data(tsk_list_t* list, const tsk_object_t *tskobj)
 {
 	if(list){
 		tsk_list_item_t *prev = tsk_null;
 		tsk_list_item_t *curr = prev = list->head;
 
 		while(curr){
 			if(!tsk_object_cmp(curr->data, tskobj)){
 				if(prev == curr){
 					/* Found at first position. */
 					if(list->head == list->tail){
 						/* There was only one item */
 						list->head = list->tail = tsk_null;
 					}
 					else{
 						list->head = curr->next;
 					}
 				}
 				else {
 					if(curr == list->tail){
 						/* Found at last position */
 						list->tail = prev;
 						list->tail->next = tsk_null;
 					}
 					else{
 						prev->next = curr->next;
 					}
 				}
 
 				return curr;
 			}
 			
 			prev = curr;
 			curr = curr->next;
 		}
 	}
 
 	return tsk_null;
 }
 
 /**@ingroup tsk_list_group
 * Removes an object from the @ref tsk_list_t "list". The reference counter value of the @ref _Page_TinySAK_AnsiC_Object_Programming "well-defined" object held by the item will be decremented.
 * @param list The @ref tsk_list_t "list" from which to remove the object.
 * @param tskobj Any valid @ref _Page_TinySAK_AnsiC_Object_Programming "well-defined" object to remove.
 * @return @ref tsk_true if an item have been removed; @ref tsk_false otherwise.
 */
 tsk_bool_t tsk_list_remove_item_by_data(tsk_list_t* list, const tsk_object_t * tskobj)
 {
 	tsk_list_item_t* item;
 	if((item = tsk_list_pop_item_by_data(list, tskobj))){
 		tsk_object_unref(item);
 		return tsk_true;
 	}
 	return tsk_false;
 }
 
 /**@ingroup tsk_list_group
 * Pops an item from the @ref tsk_list_t "list" using a @ref _Anchor_TinySAK_Linked_List_Predicates "predicate". The item will be completely removed from the list but the reference counter value will <b>not</b> be decremented.<br />
 * See @ref _Anchor_TinySAK_Linked_List_Add_Remove "here" for more information on how to use this function.
 * @param list The list from which to pop the item.
 * @param predicate The @ref _Anchor_TinySAK_Linked_List_Predicates "predicate" used to match the item.
 * @param data Arbitrary data to pass to the predicate function.
 * @return An @ref tsk_list_item_t "item" matching the @ref _Anchor_TinySAK_Linked_List_Predicates "predicate" or @ref tsk_null if none match. <br />
 * You <b>must</b> free the returned item using @ref TSK_OBJECT_SAFE_FREE.
 */
 tsk_list_item_t* tsk_list_pop_item_by_pred(tsk_list_t* list, tsk_list_func_predicate predicate, const void * data)
 {
 	if(list){
 		tsk_list_item_t *prev = tsk_null;
 		tsk_list_item_t *curr = prev = list->head;
 
 		while(curr){
 			if(!predicate(curr, data)){
 				if(prev == curr){
 					/* Found at first position. */
 					if(list->head == list->tail){
 						/* There was only one item */
 						list->head = list->tail = tsk_null;
 					}
 					else{
 						list->head = curr->next;
 					}
 				}
 				else {
 					if(curr == list->tail){
 						/* Found at last position */
 						list->tail = prev;
 						list->tail->next = tsk_null;
 					}
 					else{
 						prev->next = curr->next;
 					}
 				}
 
 				return curr;
 			}
 			
 			prev = curr;
 			curr = curr->next;
 		}
 	}
 
 	return 0;
 }
 
 /**@ingroup tsk_list_group
 * Removes an item from the @ref tsk_list_t "list" using a @ref _Anchor_TinySAK_Linked_List_Predicates "predicate".
 * @param list The list from which to remove the @ref tsk_list_item_t "item".
 * @param predicate The @ref _Anchor_TinySAK_Linked_List_Predicates "predicate" used to match the item to remove.
 * @param data Arbitrary data to pass to the @ref _Anchor_TinySAK_Linked_List_Predicates "predicate".
 * @return @ref tsk_true if an item have been removed and @ref tsk_false otherwise.
 */
 tsk_bool_t tsk_list_remove_item_by_pred(tsk_list_t* list, tsk_list_func_predicate predicate, const void * data)
 {
 	tsk_list_item_t* item;
 	if((item = tsk_list_pop_item_by_pred(list, predicate, data))){
 		tsk_object_unref(item);
 		return tsk_true;
 	}
 	return tsk_false;
 }
 
 /**@ingroup tsk_list_group
 * Cleans up and remove all items from the @ref tsk_list_t "list". The reference counter for each item will be decremented. An item will be freed only if its new reference counter value is equal to 0.
 * @param list The list to clean up.
 */
 void tsk_list_clear_items(tsk_list_t* list)
 {
 	if(list){
 		tsk_list_item_t* next = tsk_null;
 		tsk_list_item_t* curr = list->head;
 
 		while(curr){
 			next = curr->next;
 			tsk_object_unref(curr);
 			curr = next;
 		}
 		list->head = tsk_null;
 		list->tail = tsk_null;
 	}
 }
 
 /**@ingroup tsk_list_group
 * Pops the first item from the @ref tsk_list_t "list". The item will be definitely removed from the list but its reference counter will not be decremented.
 * @param list The list from which to pop the item.
 * @return The first item from the lit. It's up to you to free the returned item using @ref TSK_OBJECT_SAFE_FREE.
 */
 tsk_list_item_t* tsk_list_pop_first_item(tsk_list_t* list)
 {
 	tsk_list_item_t* item = tsk_null;
 	if(list){
 		item = list->head;
 		if(list->head){
 			if(list->head->next){
 				list->head = list->head->next;
 			}
 			else{
 				list->head = list->tail = tsk_null;
 			}
 		}
 	}
 
 	return item;
 }
 
 /**@ingroup tsk_list_group
 * Adds an item to the @ref tsk_list_t "list". You should using @ref tsk_list_push_data instead of this function.
 * @param list The destination @a list.
 * @param item The @a item to add. The reference to the item will be stolen(set to @ref tsk_null) instead of incrementing its reference counter.
 * @param back Indicates whether to put the item back or not (first).
 */
 void tsk_list_push_item(tsk_list_t* list, tsk_list_item_t** item, tsk_bool_t back)
 {
 	// do not test
 	tsk_bool_t first = !list->head;
 	
 	if(back && list->tail){
175b478c
 		//TODO: . This instruction crash in Android aplication
c732d49e
 		list->tail->next = *item, list->tail = *item, (*item)->next = tsk_null;
 	}
 	else {
 		(*item)->next = list->head, list->head = *item;
 	}
 	
 	if(first){
 		list->tail = list->head = *item, list->tail->next = tsk_null;
 	}
 	(*item) = tsk_null;
 }
 
 /**@ingroup tsk_list_group
 * Add an item to the list in ascending or descending order. <br />
 * See @ref _Anchor_TinySAK_Linked_List_Sort_Items "here" for more information.
 * @param list The destination @a list.
 * @param item The  @a item to add. The reference to the @a item will be stolen(set to @ref tsk_null) instead of incrementing its reference counter.
 * @param ascending Indicates whether to put the @a item in ascending order or not.
 */
 void tsk_list_push_filtered_item(tsk_list_t* list, tsk_list_item_t** item, tsk_bool_t ascending)
 {
 	if (list && item && *item) {
 		tsk_list_item_t *prev = tsk_null;
 		tsk_list_item_t *curr = prev = list->head;
 		int diff;
 		
 		while (curr) {
 			diff = tsk_object_cmp((*item), curr);
 			if (diff == 0 || (diff </*=*/ 0 && ascending) || (diff >/*=*/0 && !ascending)) {
 				int after = (diff == 0); // push_after(match) -> backward compatibility
 				int back = (after && (curr == list->tail));
 				int front = !back && (curr == list->head);
 
 				if (back) {
 					tsk_list_push_back_item(list, item);
 				}
 				else if (front) {
 					tsk_list_push_front_item(list, item);
 				}
 				else {
 					if (after) {
 						// push_after(match)
 						(*item)->next = curr->next;
 						curr->next = (*item);
 					}
 					else {
 						// push_before(match)
 						(*item)->next = curr;
 						prev->next = (*item);
 					}
 				}				
 				(*item) = tsk_null;
 				return;
 			}
 			prev = curr;
 			curr = curr->next;
 		}
 		tsk_list_push_back_item(list, item);
 	}
 }
 
 /**@ingroup tsk_list_group
 * Add all items in @a src into @a dest. Each item will have its reference counter incremented before being added.
 * @param dest The destination list.
 * @param src The source list.
 * @param back Indicates whether to put the list back or not.
 * @return 0 if succeed and non-zero error code otherwise.
 **/
 int tsk_list_push_list(tsk_list_t* dest, const tsk_list_t* src, tsk_bool_t back)
 {
 	const tsk_list_item_t* curr = (src)->head;
 	tsk_object_t* copy;
 	
 	if(!dest || !src){
 		TSK_DEBUG_ERROR("Invalid parameter");
 		return -1;
 	}
 
 	while(curr){
 		copy = tsk_object_ref(curr->data);
 		tsk_list_push_data(dest, (void**)&copy, back);
 				
 		curr = curr->next;
 	}
 	return 0;
 }
 
 /**@ingroup tsk_list_group
 * Adds a @ref _Page_TinySAK_AnsiC_Object_Programming "well-defined" object to the @a list. 
 * The reference to the @a object will be stolen(set to @ref tsk_null) instead of incrementing its reference counter.
 * @param list The destination @a list.
 * @param tskobj The @a object to add.
 * @param back Indicates whether to put the item back or not.
 * @return 0 if succeed and non-zero error code otherwise.
 * @sa @ref tsk_list_push_back_data @ref tsk_list_push_front_data
 */
 int tsk_list_push_data(tsk_list_t* list, tsk_object_t** tskobj, tsk_bool_t back)
 {
 	if(list && tskobj && *tskobj){
 		tsk_list_item_t *item = tsk_list_item_create();
 		item->data = *tskobj; // stolen
 		
 		tsk_list_push_item(list, &item, back);
 		(*tskobj) = tsk_null;
 
 		return 0;
 	}
 	else{
 		TSK_DEBUG_ERROR("Invalid parameter");
 		return -1;
 	}
 }
 
 /**@ingroup tsk_list_group
 * Adds a @ref _Page_TinySAK_AnsiC_Object_Programming "well-defined" object to the @a list in ascending or descending order.
 * The reference to the @a object will be stolen(set to @ref tsk_null) instead of incrementing its reference counter. <br />
 * See @ref @ref _Anchor_TinySAK_Linked_List_Sort_Items "here" for more information on how to use this function.
 * @param list The destination @a list.
 * @param tskobj The @a tskobj to add.
 * @param ascending Indicates whether to put the object in ascending order or not.
 */
 int tsk_list_push_filtered_data(tsk_list_t* list, tsk_object_t** tskobj, tsk_bool_t ascending)
 {
 	if(list && tskobj && *tskobj){
 		tsk_list_item_t *item = tsk_list_item_create();
 		item->data = *tskobj;
 		
 		tsk_list_push_filtered_item(list, &item, ascending);
 		(*tskobj) = tsk_null;
 
 		return 0;
 	}
 	else{
 		TSK_DEBUG_ERROR("Invalid parameter");
 		return -1;
 	}
 }
 
 /**@ingroup tsk_list_group
 * Finds an item helding same object as @a tskobj from a list. A matching item will be: <i>tsk_object_cmp(item->data, tskobj) == 0</i> <br />
 * See @ref _Anchor_TinySAK_Linked_List_Find_Items "here" for more information on how to use this function.
 * @param list The @a list holding the item to find.
 * @param tskobj The @a object to use for comparison to find the item.
 * @return A @ref tsk_list_item_t "item" if found and @ref tsk_null otherwize. <br />
 * Because the returned object is a constant, you <b>must</b> not try to free or decrement its reference counter.
 * @sa @ref tsk_list_find_item_by_pred
 */
 const tsk_list_item_t* tsk_list_find_item_by_data(const tsk_list_t* list, const tsk_object_t* tskobj)
 {
 	if(list && tskobj){
 		tsk_list_item_t *item;
 		tsk_list_foreach(item, list){
 			if(!tsk_object_cmp(item->data, tskobj)){
 				return item;
 			}
 		}
 	}
 	
 	return 0;
 }
 
 /**@ingroup tsk_list_group
 * Finds an item from a list using a @ref _Anchor_TinySAK_Linked_List_Predicates "predicate".
 * See @ref _Anchor_TinySAK_Linked_List_Find_Items "here" for more information on how to use this function.
 * @param list the list from which to find the item.
 * @param predicate the @ref _Anchor_TinySAK_Linked_List_Predicates "predicate" against which to test each item
 * @param data data passed to the predicate function for comparison
 * @return the item which match the criteria and @ref tsk_null otherwise. <br />
 * Because the returned object is a constant, you <b>must</b> not try to free or decrement its reference counter.
 * @sa @ref tsk_list_find_item_by_data
 */
 const tsk_list_item_t* tsk_list_find_item_by_pred(const tsk_list_t* list, tsk_list_func_predicate predicate, const void* data)
 {
 	if(predicate && list){
 		const tsk_list_item_t *item;
 		tsk_list_foreach(item, list){
 			if(predicate(item, data) == 0){
 				return item;
 			}
 		}
 	}
 	else{
 		TSK_DEBUG_WARN("Cannot use a null predicate function");
 	}
 	return tsk_null;
 }
 
 /**@ingroup tsk_list_group
 * Finds a @ref _Page_TinySAK_AnsiC_Object_Programming "well-defined" object (held by an item) from a list using a @ref _Anchor_TinySAK_Linked_List_Predicates "predicate".
 * @param list the list from which to find the object.
 * @param predicate the @ref _Anchor_TinySAK_Linked_List_Predicates "predicate" against which to test each item
 * @param data data passed to the predicate function for comparaison
 * @return The @ref _Page_TinySAK_AnsiC_Object_Programming "well-defined" object held by the item which match the criteria and @ref tsk_null otherwise. <br />
 * Because the returned object is a constant, you <b>must</b> not try to free or decrement its reference counter.
 * @sa @ref tsk_list_find_item_by_pred
 */
 const tsk_object_t* tsk_list_find_object_by_pred(const tsk_list_t* list, tsk_list_func_predicate predicate, const void* data)
 {
 	return tsk_list_find_object_by_pred_at_index(list, predicate, data, 0);
 }
 
 const tsk_object_t* tsk_list_find_object_by_data(const tsk_list_t* list, const tsk_object_t* tskobj)
 {
 	const tsk_list_item_t* item = tsk_list_find_item_by_data(list, tskobj);
 	if(item) {
 		return (const tsk_object_t*)item->data;
 	}
 	return tsk_null;
 }
 
 /**@ingroup tsk_list_group */
 const tsk_object_t* tsk_list_find_object_by_pred_at_index(const tsk_list_t* list, tsk_list_func_predicate predicate, const void* data, tsk_size_t index)
 {
 	tsk_size_t pos = 0;
 	const tsk_list_item_t *item;
 	
 	tsk_list_foreach(item, list){
 		if((!predicate || predicate(item, data) == 0) && pos++ >= index){
 			return item->data;
 		}
 	}
 	
 	return tsk_null;
 }
 
 /**@ingroup tsk_list_group */
 int tsk_list_find_index_by_pred(const tsk_list_t* list, tsk_list_func_predicate predicate, const void* data)
 { 
 	if(list && predicate){
 		int index = 0;
 		const tsk_list_item_t *item;
 		tsk_list_foreach(item, list){
 			if(predicate(item, data) == 0){
 				return index;
 			}
 			++index;
 		}
 	}
 	return -1;
 }
 
 /**@ingroup tsk_list_group
 * Counts the number of item matching the predicate.
 * @param list The list containing the items to count
 * @param predicate The predicate to use to match the items. Set to null to count all items
 * @param data Data passed to the predicate function for comparaison
 * @return The number of item matching the predicate
 */
 tsk_size_t tsk_list_count(const tsk_list_t* list, tsk_list_func_predicate predicate, const void* data)
 {
 	tsk_size_t count = 0;
 	if(list){
 		const tsk_list_item_t *item;
 		tsk_list_foreach(item, list){
 			if(!predicate || (predicate(item, data) == 0)){
 				++count;
 			}
 		}
 	}
 	else{
 		TSK_DEBUG_ERROR("Invalid parameter");
 	}
 
 	return count;
 }
 
 /**@ingroup tsk_list_group
 */
 tsk_list_t* tsk_list_clone(const tsk_list_t* list)
 {
 	if (list) {
 		tsk_list_t*clone = tsk_list_create();
 		if (clone) {
 			tsk_list_pushback_list(clone, list);
 		}
 		return clone;
 	}
 	return tsk_null;
 }
 
 
 
 
 
 
 
 
 
 //=================================================================================================
 //	Item object definition
 //
 static tsk_object_t* tsk_list_item_ctor(tsk_object_t * self, va_list * app)
 {
 	tsk_list_item_t *item = (tsk_list_item_t*)self;
 	if(item){
 	}
 	return self;
 }
 
 static tsk_object_t* tsk_list_item_dtor(tsk_object_t *self)
 {
 	tsk_list_item_t *item = (tsk_list_item_t*)self;
 	if(item){
 		item->data = tsk_object_unref(item->data);
 	}
 	else{
 		TSK_DEBUG_WARN("Cannot free an uninitialized item");
 	}
 	return item;
 }
 
 static int tsk_list_item_cmp(const tsk_object_t *_item1, const tsk_object_t *_item2)
 {	
 	const tsk_list_item_t* item1 = (const tsk_list_item_t*)_item1;
 	const tsk_list_item_t* item2 = (const tsk_list_item_t*)_item2;
 	
 	if(item1 && item2){
 		return tsk_object_cmp(item1->data, item2->data);
 	}
 	else return -1;
 }
 
 static const tsk_object_def_t tsk_list_item_def_s =
 {
 	sizeof(tsk_list_item_t),	
 	tsk_list_item_ctor,
 	tsk_list_item_dtor,
 	tsk_list_item_cmp,
 };
 const tsk_object_def_t *tsk_list_item_def_t = &tsk_list_item_def_s;
 
 //=================================================================================================
 //	List object definition
 //
 static tsk_object_t* tsk_list_ctor(tsk_object_t *self, va_list *app)
 {
 	tsk_list_t *list = (tsk_list_t *)self;
 	if(list){
 	}
 
 	return self;
 }
 
 static tsk_object_t* tsk_list_dtor(tsk_object_t *self)
 { 
 	tsk_list_t *list = (tsk_list_t *)self;
 	if(list){
 #if 0
 		/* Not thread-safe */
 		tsk_list_item_t* next = tsk_null;
 		tsk_list_item_t* curr = list->head;
 
 		while(curr){
 			next = curr->next;
 			/*curr =*/ tsk_object_unref(curr);
 			curr = next;
 		}
 #else
 		/* Thread-safe method */
 		tsk_list_item_t* item;
 		while((item = tsk_list_pop_first_item(list))){
 			tsk_object_unref(item);
 		}
 #endif
 
 		/* destroy the on-demand mutex */
 		if(list->mutex){
 			tsk_mutex_destroy(&list->mutex);
 		}
 	}
 	else{
 		TSK_DEBUG_WARN("Cannot free an uninitialized list");
 	}
 	return list;
 }
 
 static const tsk_object_def_t tsk_list_def_s =
 {
 	sizeof(tsk_list_t),
 	tsk_list_ctor,
 	tsk_list_dtor,
 	tsk_null,
 };
 const tsk_object_def_t *tsk_list_def_t = &tsk_list_def_s;
 
 
 
 /**@page _Page_TinySAK_AnsiC_Linked_List Linked list
 *
 * - @ref _Anchor_TinySAK_Linked_List_Well_Defined_Object "Our \"well-defined\" object"
 * - @ref _Anchor_TinySAK_Linked_List_Predicates "Predicates"
 * - @ref _Anchor_TinySAK_Linked_List_Create_Destroy "Create and destroy the list"
 * - @ref _Anchor_TinySAK_Linked_List_Thread_Safety "Thread safety"
 * - @ref _Anchor_TinySAK_Linked_List_Add_Remove "Add and remove items"
 * - @ref _Anchor_TinySAK_Linked_List_Dump_Items "Dump items"
 * - @ref _Anchor_TinySAK_Linked_List_Sort_Items "Sort items"
 * - @ref _Anchor_TinySAK_Linked_List_Find_Items "Find items"
 * - @ref _Anchor_TinySAK_Linked_List_Public_Functions "Public functions"
 * - @ref _Anchor_TinySAK_Linked_List_Helper_Macros "Helper macros"
 *
 * <hr />
 *
 * A linked-list is a @ref _Page_TinySAK_AnsiC_Object_Programming "well defined" object and must contain only @ref _Page_TinySAK_AnsiC_Object_Programming "well defined" objects. <br />
 * A linked-list is a @ref tsk_list_t object and contains @ref tsk_list_item_t objects which holds @ref _Anchor_TinySAK_Linked_List_Well_Defined_Object "our well defined object" in its <i>data</i> field. <br />
 * 
 * <h2>@anchor _Anchor_TinySAK_Linked_List_Well_Defined_Object Our "well-defined" object</h2>
 * Our linked-list will hold a "well defined" object defined like this:
 *
 *@code
 // (well-defined object declaration)
 typedef struct student_s 
 {	
 	TSK_DECLARE_OBJECT;
 
 	char *id;
 	char *name;
 } 
 student_t;
 
 // (constructor)
 static tsk_object_t* student_ctor(tsk_object_t* self, va_list * app)
 {
 	student_t* student = (tsk_object_t*)self;
 	if(student){
 	}
 	return self;
 }
 
 // (destructor)
 static tsk_object_t* student_dtor(tsk_object_t* self)
 {
 	student_t* student = (tsk_object_t*)self;
 	TSK_FREE(student->id);
 	TSK_FREE(student->name);
 	return self;
 }
 
 // (case insensitive comparator)
 static int student_icmp(const tsk_object_t *self, const tsk_object_t *object)
 {	
 	const student_t* student1 = (const tsk_object_t*)self;
 	const student_t* student2 = (const tsk_object_t*)object;
 
 	if(!student1 || !student2){
 		return 0;// must never happen
 	}
 
 	return tsk_stricmp(student1->id, student2->id);
 }
 
 // (well-defined object declaration)
 static const tsk_object_def_t student_def_s =
 {
 	sizeof(student_t),	
 	student_ctor,
 	student_dtor,
 	student_icmp
 };
 
 // create a student object
 static student_t* student_create(const char* id, const char* name)
 {
 	student_t* student;
 	if((student = (student_t*)tsk_object_new(&student_def_s))){
 		student->id = tsk_strdup(id);
 		student->name = tsk_strdup(name);
 	}
 	return student;
 }
 *@endcode
 *
 *
 * <h2>@anchor _Anchor_TinySAK_Linked_List_Predicates Predicates</h2>
 * A predicate is a function pointer. <br />
 * In the next sections we will need some predicates defined like this:
 *@code
 // predicate to find a student by name
 static int pred_find_student_by_name(const tsk_list_item_t *item, const void *name)
 {
 	if(item && item->data){
 		const student_t *student = (const student_t *)item->data;
 		return tsk_striequals(student->name, name);
 	}
 	return -1;
 }
 // predicate to find a student by id
 static int pred_find_student_by_id(const tsk_list_item_t *item, const void *id)
 {
 	if(item && item->data){
 		const student_t *student = (const student_t *)item->data;
 		return tsk_striequals(student->id, id);
 	}
 	return -1;
 }
 *@endcode
 *
 *
 * <h2>@anchor _Anchor_TinySAK_Linked_List_Create_Destroy Create and destroy the list</h2>
 * To create the list:
 * @code
 * tsk_list_t *list = tsk_list_create();
 * @endcode
 * To destroy the list:
 * @code
 * TSK_OBJECT_SAFE_FREE(list);
 * @endcode
 * To increment the reference counting:
 * @code
 * tsk_object_ref(list);
 * @endcode
 * To decrement the reference counting:
 * @code
 * tsk_object_unref(list);
 * @endcode
 *
 ** <h2>@anchor _Anchor_TinySAK_Linked_List_Thread_Safety Thread safety</h2>
 * A linked-list is not thread-safe. It's up to you to use @ref tsk_list_lock() and @ref tsk_list_unlock() to make it thread-safe. <br />
 * @ref tsk_list_lock() and @ref tsk_list_unlock() internally use a <a target=_blank href="http://en.wikipedia.org/wiki/Reentrant_mutex">reentrant mutex</a>.
 *
 * <h2>@anchor _Anchor_TinySAK_Linked_List_Add_Remove Add and remove items</h2>
 * There are two ways to add items to the list: <br />
 * First way:
 * @code
 * // create the well-defined object 
 * student_t *student = student_create("0", "student-0");
 * // push the object at the end of the list
 * tsk_list_push_back_data(list, (void**)&student);
 * @endcode
 * Second way:
 * @code
 * // create an item
 * tsk_list_item_t* item = tsk_list_item_create();
 * // fill the data field of the item
 * item->data = (void*)student_create("0", "student-0");
 * // push the item at the end of the list
 * tsk_list_push_back_item(list, (void**)&item);
 * @endcode
 * You can also add a list to another list using @ref tsk_list_pushback_list() or @ref tsk_list_pushfront_list(). All items will be retained (reference counting incremented).<br />
 * There are many ways to remove items. <br />
 * Remove item using default comparison function:
 * @code
 * tsk_list_remove_item_by_data(list, student);
 * @endcode
 * Remove item using predicate:
 * @code
 * tsk_list_remove_item_by_pred(list, pred_find_student_by_id, "2"); // remove student with id equal to "2"
 * @endcode
 *
 * Checks @ref _Anchor_TinySAK_Linked_List_Public_Functions "the public functions" for more ways to add or remove items.
 *
 * <h2>@anchor _Anchor_TinySAK_Linked_List_Dump_Items Dump items</h2>
 * To dump the content of all items:
 * @code
 * const tsk_list_item_t* item;
 * const student_t *student;
 * tsk_list_foreach(item, list) {
 *	student = (const student_t *)item->data;
 *	TSK_DEBUG_INFO("id = %s, name = %s", student->id, student->name);
 * }
 * @endcode
 * 
 * <h2>@anchor _Anchor_TinySAK_Linked_List_Sort_Items Sort items</h2>
 * You can sort the list in ascending or descending order. The default function used for comparison is the one defined in the well-defined object (see @ref _Anchor_TinySAK_Object_Comparator "here" for more information). <br />
 * An item is sorted when it's being added to the list. It's not possible to sort items later once they are added. <br />
 * Sorting items using default comparison function:
 * @code
 // ascending order
 * tsk_list_push_ascending_data(list, (void**)&student); // comparision function will be student_icmp() defined above.
 // or descending order
 * tsk_list_push_descending_data(list, (void**)&student); // comparision function will be student_icmp() defined above.
 * @endcode
 *
 * Checks @ref _Anchor_TinySAK_Linked_List_Public_Functions "the public functions" for more ways to sort items.
 *
 * <h2>@anchor _Anchor_TinySAK_Linked_List_Find_Items Find items</h2>
 * @code
 * // find student with same id 
 * const student_t* _student = tsk_list_find_object_by_data(list, student);// comparision function will be student_icmp() defined above.
 * // find an item containing a student with name equal to "student-2"
 * const tsk_list_item_t *item = tsk_list_find_item_by_pred(list, pred_find_student_by_name, "student-2");
 * // find a student with id equal to "2"
 * const student_t *student = tsk_list_find_object_by_pred(list, pred_find_student_by_id, "2");
 * @endcode
 *
 * Checks @ref _Anchor_TinySAK_Linked_List_Public_Functions "the public functions" for more ways to find items.
 *
 * <h2>@anchor _Anchor_TinySAK_Linked_List_Public_Functions Public functions </h2>
 * - @ref tsk_list_count
 * - @ref tsk_list_create
 * - @ref tsk_list_find_index_by_pred
 * - @ref tsk_list_find_item_by_data
 * - @ref tsk_list_find_item_by_pred
 * - @ref tsk_list_find_object_by_pred
 * - @ref tsk_list_find_object_by_pred_at_index
 * - @ref tsk_list_foreach
 * - @ref tsk_list_item_create
 * - @ref tsk_list_lock
 * - @ref tsk_list_pop_first_item
 * - @ref tsk_list_pop_item_by_data
 * - @ref tsk_list_pop_item_by_pred
 * - @ref tsk_list_push_ascending_data
 * - @ref tsk_list_push_ascending_item
 * - @ref tsk_list_push_back_data
 * - @ref tsk_list_push_back_item
 * - @ref tsk_list_push_data
 * - @ref tsk_list_push_descending_data
 * - @ref tsk_list_push_descending_item
 * - @ref tsk_list_push_filtered_data
 * - @ref tsk_list_push_filtered_item
 * - @ref tsk_list_push_front_data
 * - @ref tsk_list_push_front_item
 * - @ref tsk_list_push_item
 * - @ref tsk_list_push_list
 * - @ref tsk_list_pushback_list
 * - @ref tsk_list_pushfront_list
 * - @ref tsk_list_remove_first_item
 * - @ref tsk_list_remove_item
 * - @ref tsk_list_remove_item_by_data
 * - @ref tsk_list_remove_item_by_pred
 * - @ref tsk_list_remove_last_item
 * - @ref tsk_list_unlock
 *
 * <h2>@anchor _Anchor_TinySAK_Linked_List_Helper_Macros Helper macros </h2>
 * - @ref TSK_LIST_IS_EMPTY
 * - @ref TSK_LIST_IS_FIRST
 * - @ref TSK_LIST_IS_LAST
 * - @ref TSK_LIST_FIRST_DATA
 * - @ref TSK_LIST_LAST_DATA
 */