C++ INIT_HLIST_HEAD函数代码示例

void perf_evlist__init(struct perf_evlist *evlist, struct cpu_map *cpus,
		       struct thread_map *threads)
{
	int i;

	for (i = 0; i < PERF_EVLIST__HLIST_SIZE; ++i)
		INIT_HLIST_HEAD(&evlist->heads[i]);
	INIT_LIST_HEAD(&evlist->entries);
	perf_evlist__set_maps(evlist, cpus, threads);
	fdarray__init(&evlist->pollfd, 64);
	evlist->workload.pid = -1;
	evlist->bkw_mmap_state = BKW_MMAP_NOTREADY;
}

static void
vnlayer_destroy_inode_callback(struct rcu_head *head)
{
    struct inode *inode_p = container_of(head, struct inode, i_rcu);

#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,6,0)
    INIT_HLIST_HEAD(&inode_p->i_dentry);
#else
    INIT_LIST_HEAD(&inode_p->i_dentry);
#endif
    ASSERT(I_COUNT(inode_p) == 0);
    ASSERT(inode_p->i_state & I_FREEING);
    kmem_cache_free(vnlayer_vnode_cache, (vnlayer_vnode_t *) ITOV(inode_p));
}

/**
 * avc_init - Initialize the AVC.
 *
 * Initialize the access vector cache.
 */
void __init avc_init(void)
{
    int i;

    for ( i = 0; i < AVC_CACHE_SLOTS; i++ )
    {
        INIT_HLIST_HEAD(&avc_cache.slots[i]);
        spin_lock_init(&avc_cache.slots_lock[i]);
    }
    atomic_set(&avc_cache.active_nodes, 0);
    atomic_set(&avc_cache.lru_hint, 0);

    printk("AVC INITIALIZED\n");
}

/*
 * Allocate and initialize a new local port bind bucket.
 * The bindhash mutex for snum's hash chain must be held here.
 */
struct inet_bind_bucket *inet_bind_bucket_create(struct kmem_cache *cachep,
						 struct inet_bind_hashbucket *head,
						 const unsigned short snum)
{
	struct inet_bind_bucket *tb = kmem_cache_alloc(cachep, GFP_ATOMIC);

	if (tb != NULL) {
		tb->port      = snum;
		tb->fastreuse = 0;
		INIT_HLIST_HEAD(&tb->owners);
		hlist_add_head(&tb->node, &head->chain);
	}
	return tb;
}

static int khashmap_alloc(struct khashmap *hlist)
{
	size_t size = khashmap_size_in_bytes(hlist);
	int i;

	if (size < PAGE_SIZE)
		hlist->hash = kmalloc(size, GFP_KERNEL);
	else
		hlist->hash = vmalloc(size);
	if (unlikely(!hlist->hash))
		return -ENOMEM;
	for (i = 0; i < khashmap_size(hlist); i++)
		INIT_HLIST_HEAD(&hlist->hash[i]);
	return 0;
}

/*
* Expand the size of the hash table to @size.
* @ht: the hash table to expand
* @size: the size we expand to
*/
static int uproc_htable_expand(uproc_htable_t *ht, int size){
    int new_len, new_idx, new_load_limit,  i;
    struct hlist_head *new_buckets, *head;
    struct hlist_node *p, *q;
    unsigned h;
    new_load_limit = ht->load_limit;
    new_len = ht->len;
    new_idx = ht->p_index;
    while(new_load_limit < size && new_idx < uproc_htable_nprimes){
        new_len = uproc_htable_primes[++new_idx];
        new_load_limit = ht->load_factor * new_len;
    }

    if((new_buckets = malloc(new_len * sizeof(struct hlist_head))) == NULL){
        fprintf(stderr, "failed to malloc: %s", strerror(errno));
        return -ENOMEM;
    }

    for(i = 0; i < new_len; ++i){
        INIT_HLIST_HEAD(&new_buckets[i]);
    }

    /*
    * Rehash and move all event to new_buckets.
    */
    for(i = 0; i < ht->len; ++i){
        head = &(ht->buckets[i]);
        if(!hlist_empty(head)){
            p = head->first;
            while(p){
                q = p->next;
                hlist_del(p);
                h = ht->hf(p) % new_len;
                hlist_add_head(&new_buckets[h], p);
                p = q;
            }
        }
    }

    free(ht->buckets);

    ht->p_index = new_idx;
    ht->buckets = new_buckets;
    ht->len = new_len;
    ht->load_limit = new_load_limit;

    return 0;
}

struct pid *alloc_pid(struct pid_namespace *ns)
{
	struct pid *pid;
	enum pid_type type;
	int i, nr;
	struct pid_namespace *tmp;
	struct upid *upid;

	pid = kmem_cache_alloc(ns->pid_cachep, GFP_KERNEL);
	if (!pid)
		goto out;

	tmp = ns;
	for (i = ns->level; i >= 0; i--) {
		nr = alloc_pidmap(tmp);
		if (nr < 0)
			goto out_free;

		pid->numbers[i].nr = nr;
		pid->numbers[i].ns = tmp;
		tmp = tmp->parent;
	}

	get_pid_ns(ns);
	pid->level = ns->level;
	atomic_set(&pid->count, 1);
	for (type = 0; type < PIDTYPE_MAX; ++type)
		INIT_HLIST_HEAD(&pid->tasks[type]);

	spin_lock_irq(&pidmap_lock);
	for (i = ns->level; i >= 0; i--) {
		upid = &pid->numbers[i];
		hlist_add_head_rcu(&upid->pid_chain,
				&pid_hash[pid_hashfn(upid->nr, upid->ns)]);
	}
	spin_unlock_irq(&pidmap_lock);

out:
	return pid;

out_free:
	for (i++; i <= ns->level; i++)
		free_pidmap(pid->numbers[i].ns, pid->numbers[i].nr);

	kmem_cache_free(ns->pid_cachep, pid);
	pid = NULL;
	goto out;
}

/*
 * the allocated memory has to be freed by
 * au_nhash_wh_free() or au_nhash_de_free().
 */
int au_nhash_alloc(struct au_nhash *nhash, unsigned int num_hash, gfp_t gfp)
{
    struct hlist_head *head;
    unsigned int u;

    head = kmalloc(sizeof(*nhash->nh_head) * num_hash, gfp);
    if (head) {
        nhash->nh_num = num_hash;
        nhash->nh_head = head;
        for (u = 0; u < num_hash; u++)
            INIT_HLIST_HEAD(head++);
        return 0; /* success */
    }

    return -ENOMEM;
}

/**
 * avc_init - Initialize the AVC.
 *
 * Initialize the access vector cache.
 */
void __init avc_init(void)
{
	int i;

	for (i = 0; i < AVC_CACHE_SLOTS; i++) {
		INIT_HLIST_HEAD(&avc_cache.slots[i]);
		spin_lock_init(&avc_cache.slots_lock[i]);
	}
	atomic_set(&avc_cache.active_nodes, 0);
	atomic_set(&avc_cache.lru_hint, 0);

	avc_node_cachep = kmem_cache_create("avc_node", sizeof(struct avc_node),
					     0, SLAB_PANIC, NULL);

	audit_log(current->audit_context, GFP_KERNEL, AUDIT_KERNEL, "AVC INITIALIZED\n");
}

static struct hlist_head *alloc_rmtperm_hash(void)
{
	struct hlist_head *hash;
	int i;

	OBD_SLAB_ALLOC_GFP(hash, ll_rmtperm_hash_cachep,
			   REMOTE_PERM_HASHSIZE * sizeof(*hash),
			   GFP_IOFS);
	if (!hash)
		return NULL;

	for (i = 0; i < REMOTE_PERM_HASHSIZE; i++)
		INIT_HLIST_HEAD(hash + i);

	return hash;
}

static int pep_init(struct sock *sk)
{
	struct pep_sock *pn = pep_sk(sk);

	sk->sk_destruct = pipe_destruct;
	INIT_HLIST_HEAD(&pn->hlist);
	pn->listener = NULL;
	skb_queue_head_init(&pn->ctrlreq_queue);
	atomic_set(&pn->tx_credits, 0);
	pn->ifindex = 0;
	pn->peer_type = 0;
	pn->pipe_handle = PN_PIPE_INVALID_HANDLE;
	pn->rx_credits = 0;
	pn->rx_fc = pn->tx_fc = PN_LEGACY_FLOW_CONTROL;
	pn->init_enable = 1;
	pn->aligned = 0;
	return 0;
}

int nilfs_init_gccache(struct the_nilfs *nilfs)
{
	int loop;

	BUG_ON(nilfs->ns_gc_inodes_h);

	INIT_LIST_HEAD(&nilfs->ns_gc_inodes);

	nilfs->ns_gc_inodes_h =
		kmalloc(sizeof(struct hlist_head) * NILFS_GCINODE_HASH_SIZE,
			GFP_NOFS);
	if (nilfs->ns_gc_inodes_h == NULL)
		return -ENOMEM;

	for (loop = 0; loop < NILFS_GCINODE_HASH_SIZE; loop++)
		INIT_HLIST_HEAD(&nilfs->ns_gc_inodes_h[loop]);
	return 0;
}

void nhash_move(struct aufs_nhash *dst, struct aufs_nhash *src)
{
	int i;

	TraceEnter();

	//DbgWhlist(src);
	*dst = *src;
	for (i = 0; i < AUFS_NHASH_SIZE; i++) {
		struct hlist_head *h;
		h = dst->heads + i;
		if (h->first)
			h->first->pprev = &h->first;
		INIT_HLIST_HEAD(src->heads + i);
	}
	//DbgWhlist(src);
	//DbgWhlist(dst);
	//smp_mb();
}

void *slab_alloc(ohc_slab_t *slab)
{
	slab_block_t *sblock;
	uintptr_t leader;
	struct hlist_node *p;
	int buckets;
	int i;

	if(hlist_empty(&slab->block_head)) {
		buckets = slab_buckets(slab);
		sblock = malloc(sizeof(slab_block_t) + slab->item_size * buckets);
		if(sblock == NULL) {
			return NULL;
		}

		sblock->slab = slab;
		sblock->frees = buckets;
		hlist_add_head(&sblock->block_node, &slab->block_head);
		INIT_HLIST_HEAD(&sblock->item_head);

		leader = (uintptr_t)sblock + sizeof(slab_block_t);
		for(i = 0; i < buckets; i++) {
			*((slab_block_t **)leader) = sblock;
			p = (struct hlist_node *)(leader + sizeof(slab_block_t *));
			hlist_add_head(p, &sblock->item_head);
			leader += slab->item_size;
		}

	} else {
		sblock = list_entry(slab->block_head.first, slab_block_t, block_node);
	}

	p = sblock->item_head.first;
	hlist_del(p);

	sblock->frees--;
	if(sblock->frees == 0) {
		/* if no free items, we throw the block away */
		hlist_del(&sblock->block_node);
	}

	return p;
}

/*
 * Allocate space for the hash table.  The size is 2^bits.
 */
int virt_hash_table_init(struct virt_hash_table *table, unsigned bits)
{
    const unsigned table_size = 1u << bits;
    int i;

    table->head = kmalloc(table_size * sizeof(struct virt_hash_head), GFP_KERNEL);
    if(!table->head)
        return -ENOMEM;

    for(i = 0; i < table_size; i++) {
        struct virt_hash_head *head = &table->head[i];
        spin_lock_init(&head->lock);
        INIT_HLIST_HEAD(&head->list);
    }

    table->bits = bits;
    table->size = table_size;

    return 0;
}