rculist_bl.h

Go to the documentation of this file.

#ifndef _LINUX_RCULIST_BL_H
#define _LINUX_RCULIST_BL_H

/*
 * RCU-protected bl list version. See include/linux/list_bl.h.
 */
#include <linux/list_bl.h>
#include <linux/rcupdate.h>

static inline void hlist_bl_set_first_rcu(struct hlist_bl_head *h,
                    struct hlist_bl_node *n)
{
    LIST_BL_BUG_ON((unsigned long)n & LIST_BL_LOCKMASK);
    LIST_BL_BUG_ON(((unsigned long)h->first & LIST_BL_LOCKMASK) !=
                            LIST_BL_LOCKMASK);
    rcu_assign_pointer(h->first,
        (struct hlist_bl_node *)((unsigned long)n | LIST_BL_LOCKMASK));
}

static inline struct hlist_bl_node *hlist_bl_first_rcu(struct hlist_bl_head *h)
{
    return (struct hlist_bl_node *)
        ((unsigned long)rcu_dereference(h->first) & ~LIST_BL_LOCKMASK);
}

static inline void hlist_bl_del_init_rcu(struct hlist_bl_node *n)
{
    if (!hlist_bl_unhashed(n)) {
        __hlist_bl_del(n);
        n->pprev = NULL;
    }
}

static inline void hlist_bl_del_rcu(struct hlist_bl_node *n)
{
    __hlist_bl_del(n);
    n->pprev = LIST_POISON2;
}

static inline void hlist_bl_add_head_rcu(struct hlist_bl_node *n,
                    struct hlist_bl_head *h)
{
    struct hlist_bl_node *first;

    /* don't need hlist_bl_first_rcu because we're under lock */
    first = hlist_bl_first(h);

    n->next = first;
    if (first)
        first->pprev = &n->next;
    n->pprev = &h->first;

    /* need _rcu because we can have concurrent lock free readers */
    hlist_bl_set_first_rcu(h, n);
}
#define hlist_bl_for_each_entry_rcu(tpos, pos, head, member)        \
    for (pos = hlist_bl_first_rcu(head);                \
        pos &&                          \
        ({ tpos = hlist_bl_entry(pos, typeof(*tpos), member); 1; }); \
        pos = rcu_dereference_raw(pos->next))

#endif