풋악을 올려라

/**
 * 
 * I grub it from linux kernel source code and fix it for user space
 * program. Of course, this is a GPL licensed header file.
 *
 * Here is a recipe to cook list.h for user space program
 *
 * 1. copy list.h from linux/include/list.h
 * 2. remove 
 *     - #ifdef __KERNE__ and its #endif
 *     - all #include line
 *     - prefetch() and rcu related functions
 * 3. add macro offsetof() and container_of
 *
 * - kazutomo@mcs.anl.gov
 */
#ifndef _LINUX_LIST_H
#define _LINUX_LIST_H

/**
 * @name from other kernel headers
 */
/*@{*/

/**
 * Get offset of a member
 */
#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)

/**
 * Casts a member of a structure out to the containing structure
 * @param ptr        the pointer to the member.
 * @param type       the type of the container struct this is embedded in.
 * @param member     the name of the member within the struct.
 *
 */
#define container_of(ptr, type, member) ({                      \
        const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
        (type *)( (char *)__mptr - offsetof(type,member) );})
/*@}*/


/*
 * These are non-NULL pointers that will result in page faults
 * under normal circumstances, used to verify that nobody uses
 * non-initialized list entries.
 */
#define LIST_POISON1  ((void *) 0x00100100)
#define LIST_POISON2  ((void *) 0x00200200)

/**
 * Simple doubly linked list implementation.
 *
 * Some of the internal functions ("__xxx") are useful when
 * manipulating whole lists rather than single entries, as
 * sometimes we already know the next/prev entries and we can
 * generate better code by using them directly rather than
 * using the generic single-entry routines.
 */
struct list_head {
	struct list_head *next, *prev;
};

#define LIST_HEAD_INIT(name) { &(name), &(name) }

#define LIST_HEAD(name) \
	struct list_head name = LIST_HEAD_INIT(name)

#define INIT_LIST_HEAD(ptr) do { \
	(ptr)->next = (ptr); (ptr)->prev = (ptr); \
} while (0)

/*
 * Insert a new entry between two known consecutive entries.
 *
 * This is only for internal list manipulation where we know
 * the prev/next entries already!
 */
static inline void __list_add(struct list_head *new,
			      struct list_head *prev,
			      struct list_head *next)
{
	next->prev = new;
	new->next = next;
	new->prev = prev;
	prev->next = new;
}

/**
 * list_add - add a new entry
 * @new: new entry to be added
 * @head: list head to add it after
 *
 * Insert a new entry after the specified head.
 * This is good for implementing stacks.
 */
static inline void list_add(struct list_head *new, struct list_head *head)
{
	__list_add(new, head, head->next);
}

/**
 * list_add_tail - add a new entry
 * @new: new entry to be added
 * @head: list head to add it before
 *
 * Insert a new entry before the specified head.
 * This is useful for implementing queues.
 */
static inline void list_add_tail(struct list_head *new, struct list_head *head)
{
	__list_add(new, head->prev, head);
}


/*
 * Delete a list entry by making the prev/next entries
 * point to each other.
 *
 * This is only for internal list manipulation where we know
 * the prev/next entries already!
 */
static inline void __list_del(struct list_head * prev, struct list_head * next)
{
	next->prev = prev;
	prev->next = next;
}

/**
 * list_del - deletes entry from list.
 * @entry: the element to delete from the list.
 * Note: list_empty on entry does not return true after this, the entry is
 * in an undefined state.
 */
static inline void list_del(struct list_head *entry)
{
	__list_del(entry->prev, entry->next);
	entry->next = LIST_POISON1;
	entry->prev = LIST_POISON2;
}



/**
 * list_del_init - deletes entry from list and reinitialize it.
 * @entry: the element to delete from the list.
 */
static inline void list_del_init(struct list_head *entry)
{
	__list_del(entry->prev, entry->next);
	INIT_LIST_HEAD(entry);
}

/**
 * list_move - delete from one list and add as another's head
 * @list: the entry to move
 * @head: the head that will precede our entry
 */
static inline void list_move(struct list_head *list, struct list_head *head)
{
        __list_del(list->prev, list->next);
        list_add(list, head);
}

/**
 * list_move_tail - delete from one list and add as another's tail
 * @list: the entry to move
 * @head: the head that will follow our entry
 */
static inline void list_move_tail(struct list_head *list,
				  struct list_head *head)
{
        __list_del(list->prev, list->next);
        list_add_tail(list, head);
}

/**
 * list_empty - tests whether a list is empty
 * @head: the list to test.
 */
static inline int list_empty(const struct list_head *head)
{
	return head->next == head;
}

static inline void __list_splice(struct list_head *list,
				 struct list_head *head)
{
	struct list_head *first = list->next;
	struct list_head *last = list->prev;
	struct list_head *at = head->next;

	first->prev = head;
	head->next = first;

	last->next = at;
	at->prev = last;
}

/**
 * list_splice - join two lists
 * @list: the new list to add.
 * @head: the place to add it in the first list.
 */
static inline void list_splice(struct list_head *list, struct list_head *head)
{
	if (!list_empty(list))
		__list_splice(list, head);
}

/**
 * list_splice_init - join two lists and reinitialise the emptied list.
 * @list: the new list to add.
 * @head: the place to add it in the first list.
 *
 * The list at @list is reinitialised
 */
static inline void list_splice_init(struct list_head *list,
				    struct list_head *head)
{
	if (!list_empty(list)) {
		__list_splice(list, head);
		INIT_LIST_HEAD(list);
	}
}

/**
 * list_entry - get the struct for this entry
 * @ptr:	the &struct list_head pointer.
 * @type:	the type of the struct this is embedded in.
 * @member:	the name of the list_struct within the struct.
 */
#define list_entry(ptr, type, member) \
	container_of(ptr, type, member)

/**
 * list_for_each	-	iterate over a list
 * @pos:	the &struct list_head to use as a loop counter.
 * @head:	the head for your list.
 */

#define list_for_each(pos, head) \
  for (pos = (head)->next; pos != (head);	\
       pos = pos->next)

/**
 * __list_for_each	-	iterate over a list
 * @pos:	the &struct list_head to use as a loop counter.
 * @head:	the head for your list.
 *
 * This variant differs from list_for_each() in that it's the
 * simplest possible list iteration code, no prefetching is done.
 * Use this for code that knows the list to be very short (empty
 * or 1 entry) most of the time.
 */
#define __list_for_each(pos, head) \
	for (pos = (head)->next; pos != (head); pos = pos->next)

/**
 * list_for_each_prev	-	iterate over a list backwards
 * @pos:	the &struct list_head to use as a loop counter.
 * @head:	the head for your list.
 */
#define list_for_each_prev(pos, head) \
	for (pos = (head)->prev; prefetch(pos->prev), pos != (head); \
        	pos = pos->prev)

/**
 * list_for_each_safe	-	iterate over a list safe against removal of list entry
 * @pos:	the &struct list_head to use as a loop counter.
 * @n:		another &struct list_head to use as temporary storage
 * @head:	the head for your list.
 */
#define list_for_each_safe(pos, n, head) \
	for (pos = (head)->next, n = pos->next; pos != (head); \
		pos = n, n = pos->next)

/**
 * list_for_each_entry	-	iterate over list of given type
 * @pos:	the type * to use as a loop counter.
 * @head:	the head for your list.
 * @member:	the name of the list_struct within the struct.
 */
#define list_for_each_entry(pos, head, member)				\
	for (pos = list_entry((head)->next, typeof(*pos), member);	\
	     &pos->member != (head);					\
	     pos = list_entry(pos->member.next, typeof(*pos), member))

/**
 * list_for_each_entry_reverse - iterate backwards over list of given type.
 * @pos:	the type * to use as a loop counter.
 * @head:	the head for your list.
 * @member:	the name of the list_struct within the struct.
 */
#define list_for_each_entry_reverse(pos, head, member)			\
	for (pos = list_entry((head)->prev, typeof(*pos), member);	\
	     &pos->member != (head); 	\
	     pos = list_entry(pos->member.prev, typeof(*pos), member))

/**
 * list_prepare_entry - prepare a pos entry for use as a start point in
 *			list_for_each_entry_continue
 * @pos:	the type * to use as a start point
 * @head:	the head of the list
 * @member:	the name of the list_struct within the struct.
 */
#define list_prepare_entry(pos, head, member) \
	((pos) ? : list_entry(head, typeof(*pos), member))

/**
 * list_for_each_entry_continue -	iterate over list of given type
 *			continuing after existing point
 * @pos:	the type * to use as a loop counter.
 * @head:	the head for your list.
 * @member:	the name of the list_struct within the struct.
 */
#define list_for_each_entry_continue(pos, head, member) 		\
	for (pos = list_entry(pos->member.next, typeof(*pos), member);	\
	     &pos->member != (head);	\
	     pos = list_entry(pos->member.next, typeof(*pos), member))

/**
 * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry
 * @pos:	the type * to use as a loop counter.
 * @n:		another type * to use as temporary storage
 * @head:	the head for your list.
 * @member:	the name of the list_struct within the struct.
 */
#define list_for_each_entry_safe(pos, n, head, member)			\
	for (pos = list_entry((head)->next, typeof(*pos), member),	\
		n = list_entry(pos->member.next, typeof(*pos), member);	\
	     &pos->member != (head); 					\
	     pos = n, n = list_entry(n->member.next, typeof(*n), member))

/**
 * list_for_each_entry_safe_continue -	iterate over list of given type
 *			continuing after existing point safe against removal of list entry
 * @pos:	the type * to use as a loop counter.
 * @n:		another type * to use as temporary storage
 * @head:	the head for your list.
 * @member:	the name of the list_struct within the struct.
 */
#define list_for_each_entry_safe_continue(pos, n, head, member) 		\
	for (pos = list_entry(pos->member.next, typeof(*pos), member), 		\
		n = list_entry(pos->member.next, typeof(*pos), member);		\
	     &pos->member != (head);						\
	     pos = n, n = list_entry(n->member.next, typeof(*n), member))

/**
 * list_for_each_entry_safe_reverse - iterate backwards over list of given type safe against
 *				      removal of list entry
 * @pos:	the type * to use as a loop counter.
 * @n:		another type * to use as temporary storage
 * @head:	the head for your list.
 * @member:	the name of the list_struct within the struct.
 */
#define list_for_each_entry_safe_reverse(pos, n, head, member)		\
	for (pos = list_entry((head)->prev, typeof(*pos), member),	\
		n = list_entry(pos->member.prev, typeof(*pos), member);	\
	     &pos->member != (head); 					\
	     pos = n, n = list_entry(n->member.prev, typeof(*n), member))




/*
 * Double linked lists with a single pointer list head.
 * Mostly useful for hash tables where the two pointer list head is
 * too wasteful.
 * You lose the ability to access the tail in O(1).
 */

struct hlist_head {
	struct hlist_node *first;
};

struct hlist_node {
	struct hlist_node *next, **pprev;
};

#define HLIST_HEAD_INIT { .first = NULL }
#define HLIST_HEAD(name) struct hlist_head name = {  .first = NULL }
#define INIT_HLIST_HEAD(ptr) ((ptr)->first = NULL)
#define INIT_HLIST_NODE(ptr) ((ptr)->next = NULL, (ptr)->pprev = NULL)

static inline int hlist_unhashed(const struct hlist_node *h)
{
	return !h->pprev;
}

static inline int hlist_empty(const struct hlist_head *h)
{
	return !h->first;
}

static inline void __hlist_del(struct hlist_node *n)
{
	struct hlist_node *next = n->next;
	struct hlist_node **pprev = n->pprev;
	*pprev = next;
	if (next)
		next->pprev = pprev;
}

static inline void hlist_del(struct hlist_node *n)
{
	__hlist_del(n);
	n->next = LIST_POISON1;
	n->pprev = LIST_POISON2;
}


static inline void hlist_del_init(struct hlist_node *n)
{
	if (n->pprev)  {
		__hlist_del(n);
		INIT_HLIST_NODE(n);
	}
}

static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h)
{
	struct hlist_node *first = h->first;
	n->next = first;
	if (first)
		first->pprev = &n->next;
	h->first = n;
	n->pprev = &h->first;
}



/* next must be != NULL */
static inline void hlist_add_before(struct hlist_node *n,
					struct hlist_node *next)
{
	n->pprev = next->pprev;
	n->next = next;
	next->pprev = &n->next;
	*(n->pprev) = n;
}

static inline void hlist_add_after(struct hlist_node *n,
					struct hlist_node *next)
{
	next->next = n->next;
	n->next = next;
	next->pprev = &n->next;

	if(next->next)
		next->next->pprev  = &next->next;
}



#define hlist_entry(ptr, type, member) container_of(ptr,type,member)

#define hlist_for_each(pos, head) \
	for (pos = (head)->first; pos && ({ prefetch(pos->next); 1; }); \
	     pos = pos->next)

#define hlist_for_each_safe(pos, n, head) \
	for (pos = (head)->first; pos && ({ n = pos->next; 1; }); \
	     pos = n)

/**
 * hlist_for_each_entry	- iterate over list of given type
 * @tpos:	the type * to use as a loop counter.
 * @pos:	the &struct hlist_node to use as a loop counter.
 * @head:	the head for your list.
 * @member:	the name of the hlist_node within the struct.
 */
#define hlist_for_each_entry(tpos, pos, head, member)			 \
	for (pos = (head)->first;					 \
	     pos && ({ prefetch(pos->next); 1;}) &&			 \
		({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
	     pos = pos->next)

/**
 * hlist_for_each_entry_continue - iterate over a hlist continuing after existing point
 * @tpos:	the type * to use as a loop counter.
 * @pos:	the &struct hlist_node to use as a loop counter.
 * @member:	the name of the hlist_node within the struct.
 */
#define hlist_for_each_entry_continue(tpos, pos, member)		 \
	for (pos = (pos)->next;						 \
	     pos && ({ prefetch(pos->next); 1;}) &&			 \
		({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
	     pos = pos->next)

/**
 * hlist_for_each_entry_from - iterate over a hlist continuing from existing point
 * @tpos:	the type * to use as a loop counter.
 * @pos:	the &struct hlist_node to use as a loop counter.
 * @member:	the name of the hlist_node within the struct.
 */
#define hlist_for_each_entry_from(tpos, pos, member)			 \
	for (; pos && ({ prefetch(pos->next); 1;}) &&			 \
		({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
	     pos = pos->next)

/**
 * hlist_for_each_entry_safe - iterate over list of given type safe against removal of list entry
 * @tpos:	the type * to use as a loop counter.
 * @pos:	the &struct hlist_node to use as a loop counter.
 * @n:		another &struct hlist_node to use as temporary storage
 * @head:	the head for your list.
 * @member:	the name of the hlist_node within the struct.
 */
#define hlist_for_each_entry_safe(tpos, pos, n, head, member) 		 \
	for (pos = (head)->first;					 \
	     pos && ({ n = pos->next; 1; }) && 				 \
		({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
	     pos = n)


#endif

#include <stdio.h>
#include <stdlib.h>
#include "list.h"

//
// Define a data structure that contains a list_head
//

typedef struct queue_s {
  struct list_head next;
  int data;
} queue_t;

//
// Define a list of structures
//

struct list_head request_q;

//
// Add an element to the end of the list, so it will be the last one popped
//

queue_t * queue_add_fifo(int data) 
{
  queue_t * next;

  next = (queue_t *) malloc(sizeof(queue_t));
  next->data = data;
  
  //
  //  Add to the tail for FIFO queueing
  //

  list_add_tail(&next->next, &request_q );

  return(next);
}

//
// Add an element to the head of the list, so it will be the next one popped
//

queue_t * queue_add_lifo(int data) 
{
  queue_t * next;

  next = (queue_t *) malloc(sizeof(queue_t));
  next->data = data;
  
  //
  //  Add to the head for LIFO (stack) queueing
  //

  list_add(&next->next, &request_q );

  return(next);
}

//
// Pop an element off the head of the queue
//

queue_t * queue_pop(void)
{
  //
  // Check if the queue is empty
  //
  if (!list_empty(&request_q)) {
    queue_t * next;
    
    // 
    // Get the first entry on the list. This is the one that request_q.next points to.
    // 
    next = list_entry(request_q.next,queue_t,next);
    list_del(&next->next);
    return(next);
  } else {
    return(NULL);
  }
}

//
// Pop an element off the tail of the queue
//

queue_t * queue_pop_tail(void)
{
  //
  // Check if the queue is empty
  //
  if (!list_empty(&request_q)) {
    queue_t * next;
    
    // 
    // Get the last entry on the list. This is the one that request_q.prev points to.
    // 
    next = list_entry(request_q.prev,queue_t,next);
    list_del(&next->next);
    return(next);
  } else {
    return(NULL);
  }
}

//
// Find the first entry in the list with a matching data value
//

queue_t * find_queue_entry(int data) 
{
  struct list_head * next;

  //
  // Iterate over the list
  //

  list_for_each(next, &request_q) {
    queue_t * elem;

    //
    // Get a pointer to the element on the list
    //
    elem = list_entry(next, queue_t, next);
    if (elem->data == data) {
      return(elem);
    }
  }
  return(NULL);
    
}

//
// Delete all entries from the queue that match the data value
//
void del_queue_entry(int data) 
{
  struct list_head * next;
  struct list_head * temp;

  //
  // Iterate over the list. We need to use the safe iterator because we may want to 
  // remove things.
  //

  list_for_each_safe(next, temp, &request_q) {
    queue_t * elem;

    //
    // Get a pointer to the element on the list
    //
    elem = list_entry(next, queue_t, next);
    
    //
    // Delete the element if the data field matches
    //

    if (elem->data == data) {
      list_del(&elem->next);
    }
  }
    
}

void print_queue(void) 
{
  struct list_head * next;

  //
  // Iterate over the list
  //

  printf("Queue:\n");
  list_for_each(next, &request_q) {
    queue_t * elem;

    //
    // Get a pointer to the element on the list
    //

    elem = list_entry(next, queue_t, next);

    printf("\t%d\n",elem->data);
  }

}

int main(int argc, char * argv[])
{
    INIT_LIST_HEAD(&request_q);
    queue_t * elem;

    queue_add_fifo(1);
    queue_add_fifo(2);
    queue_add_fifo(3);
    queue_add_fifo(4);
    queue_add_fifo(5);

    printf("Should be 1,2,3,4,5\n");
    print_queue(); 
    
    elem =queue_pop(); // should be 1

    printf("Should be 1: %d\n",elem->data);
    
    elem = queue_pop_tail();

    printf("Should be 5: %d\n",elem->data);
    
    printf("Should be 2,3,4\n");
    print_queue(); 

    queue_pop();
    queue_pop();
    queue_pop();

    printf("Should be empty\n");
    print_queue();

    queue_add_lifo(10);
    queue_add_lifo(20);
    queue_add_lifo(30);
    queue_add_lifo(40);

    printf("Should be 40,30,20,10\n");
    print_queue();

    elem = find_queue_entry(20);
    printf("Should be non-NULL: %p\n",elem);

    elem = find_queue_entry(50);
    printf("Should be NULL: %p\n",elem);

    del_queue_entry(20);
    
    printf("Should be 40,30,10\n");
    print_queue();

    del_queue_entry(40);
    del_queue_entry(10);
    del_queue_entry(30);
    
    printf("Should be empty\n");
    print_queue();


}

#include <stdio.h>
#include <stdlib.h>
#include "list.h"

struct a_list
{
  struct list_head list;
  int   val;
  const char* str;
};

static void append(struct a_list* ptr,const char* str, int val)           
{
  struct a_list* tmp;
  tmp = (struct a_list*)malloc(sizeof(struct a_list));
  if(!tmp) {
    perror("malloc");
    exit(1);
  }
  tmp->str = str;
  tmp->val = val;
  list_add_tail( &(tmp->list), &(ptr->list) );
}

int main()
{
  struct a_list  blist;
  struct a_list* iter; 

  INIT_LIST_HEAD(&blist.list);
  
  /* add item to list */
  append(&blist, "NM", 87501);
  append(&blist, "CA", 94041);
  append(&blist, "IL", 60561);

  /* iterates list */
  list_for_each_entry(iter,&blist.list,list) {
    printf("%s %d\n", iter->str, iter->val);
  }

  /* remove all items in the list */
  while( !list_empty(&blist.list) ) {
    iter = list_entry(blist.list.next,struct a_list,list);
    list_del(&iter->list);
    free(iter);
  }
  
  return 0;
}