linux list.h for userspace

• list.h

/**
 * http://www.mcs.anl.gov/~kazutomo/list/list.h
 *
 * 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

#include <stdio.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

• userspace_list.c

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


typedef struct episode {
    int epid;
    struct list_head list;
} episode_t;


typedef struct program {
    int pid;
    struct list_head list;
    struct list_head episode_list;
} program_t;


int main(void)
{
    LIST_HEAD(program_list);

    program_t* ptr;
    int i;

    for (i = 0; i < 5; i++) {
        ptr = malloc(sizeof(*ptr));
        ptr->pid = i;
        INIT_LIST_HEAD(&ptr->list);
        INIT_LIST_HEAD(&ptr->episode_list);
        list_add_tail(&ptr->list, &program_list);

        int j;
        episode_t* eptr;

        for (j = 10; j < 15; j++) {
            eptr = malloc(sizeof(*eptr));
            eptr->epid = j;
            INIT_LIST_HEAD(&eptr->list);
            list_add_tail(&eptr->list, &ptr->episode_list);

        }
    }

    //traverse list
    list_for_each_entry(ptr, &program_list, list) {
        printf("pid: %d\n", ptr->pid);

        episode_t* eptr;
        list_for_each_entry(eptr, &ptr->episode_list, list) {
            printf("epid: %d\n", eptr->epid);
        }
    }


    //delete node
    program_t* next;
    list_for_each_entry_safe(ptr, next, &program_list, list) {
        printf("Removing – pid: %d\n", ptr->pid);

        episode_t* enext, *eptr;
        list_for_each_entry_safe(eptr, enext, &ptr->episode_list, list) {
            printf("Removing – epid: %d\n", eptr->epid);
            list_del(&eptr->list);
            free(eptr);
        }

        list_del(&ptr->list);
        free(ptr);
    }

    printf("list\n");

    //traverse list
    list_for_each_entry(ptr, &program_list, list) {
        printf("pid: %d\n", ptr->pid);

        episode_t* eptr;
        list_for_each_entry(eptr, &ptr->episode_list, list) {
            printf("epid: %d\n", eptr->epid);
        }
    }

    return 0;
}