[ltt-dev] [PATCH 5/5] rculfhash: add CDS_LFHT_ACCOUNTING flag

[Mathieu Desnoyers]

* Lai Jiangshan (laijs at cn.fujitsu.com) wrote:
> Signed-off-by: Lai Jiangshan <laijs at cn.fujitsu.com>
> ---
>  rculfhash.c            |   22 ++++++++++++++--------
>  tests/test_urcu_hash.c |    3 ++-
>  urcu/rculfhash.h       |    1 +
>  3 files changed, 17 insertions(+), 9 deletions(-)
> 
> diff --git a/rculfhash.c b/rculfhash.c
> index c0c452c..411cb34 100644
> --- a/rculfhash.c
> +++ b/rculfhash.c
> @@ -533,7 +533,7 @@ static void ht_init_nr_cpus_mask(void)
>  #endif /* #else #if defined(HAVE_SYSCONF) */
>  
>  static
> -struct ht_items_count *alloc_split_items_count(void)
> +void alloc_split_items_count(struct cds_lfht *ht)
>  {
>  	struct ht_items_count *count;
>  
> @@ -546,13 +546,19 @@ struct ht_items_count *alloc_split_items_count(void)
>  	}
>  
>  	assert(split_count_mask >= 0);
> -	return calloc(split_count_mask + 1, sizeof(*count));
> +
> +	if (ht->flags & CDS_LFHT_ACCOUNTING) {
> +		ht->split_count = calloc(split_count_mask + 1, sizeof(*count));
> +		assert(ht->split_count);
> +	} else {
> +		ht->split_count = NULL;
> +	}
>  }
>  
>  static
> -void free_split_items_count(struct ht_items_count *count)
> +void free_split_items_count(struct cds_lfht *ht)
>  {
> -	poison_free(count);

If ht->split_count can be null, we should check for it either here or
within the #ifdef POISON_FREE  poison_free implementation, else the
memset will dereference a NULL pointer.

Thanks,

Mathieu

> +	poison_free(ht->split_count);
>  }
>  
>  #if defined(HAVE_SCHED_GETCPU)
> @@ -1345,7 +1351,7 @@ struct cds_lfht *_cds_lfht_new(cds_lfht_hash_fct hash_fct,
>  	ht->cds_lfht_rcu_register_thread = cds_lfht_rcu_register_thread;
>  	ht->cds_lfht_rcu_unregister_thread = cds_lfht_rcu_unregister_thread;
>  	ht->resize_attr = attr;
> -	ht->split_count = alloc_split_items_count();
> +	alloc_split_items_count(ht);
>  	/* this mutex should not nest in read-side C.S. */
>  	pthread_mutex_init(&ht->resize_mutex, NULL);
>  	ht->flags = flags;
> @@ -1599,7 +1605,7 @@ int cds_lfht_destroy(struct cds_lfht *ht, pthread_attr_t **attr)
>  	ret = cds_lfht_delete_dummy(ht);
>  	if (ret)
>  		return ret;
> -	free_split_items_count(ht->split_count);
> +	free_split_items_count(ht);
>  	if (attr)
>  		*attr = ht->resize_attr;
>  	poison_free(ht);
> @@ -1617,7 +1623,7 @@ void cds_lfht_count_nodes(struct cds_lfht *ht,
>  	unsigned long nr_dummy = 0;
>  
>  	*approx_before = 0;
> -	if (split_count_mask >= 0) {
> +	if (ht->split_count) {
>  		int i;
>  
>  		for (i = 0; i < split_count_mask + 1; i++) {
> @@ -1647,7 +1653,7 @@ void cds_lfht_count_nodes(struct cds_lfht *ht,
>  	} while (!is_end(node));
>  	dbg_printf("number of dummy nodes: %lu\n", nr_dummy);
>  	*approx_after = 0;
> -	if (split_count_mask >= 0) {
> +	if (ht->split_count) {
>  		int i;
>  
>  		for (i = 0; i < split_count_mask + 1; i++) {
> diff --git a/tests/test_urcu_hash.c b/tests/test_urcu_hash.c
> index 70db8b3..9ae1fa0 100644
> --- a/tests/test_urcu_hash.c
> +++ b/tests/test_urcu_hash.c
> @@ -889,7 +889,8 @@ int main(int argc, char **argv)
>  	rcu_register_thread();
>  	test_ht = cds_lfht_new(test_hash, test_compare, 0x42UL,
>  			init_hash_size, 1,
> -			opt_auto_resize ? CDS_LFHT_AUTO_RESIZE : 0, NULL);
> +			(opt_auto_resize ? CDS_LFHT_AUTO_RESIZE : 0) |
> +			CDS_LFHT_ACCOUNTING, NULL);
>        	ret = populate_hash();
>  	assert(!ret);
>  
> diff --git a/urcu/rculfhash.h b/urcu/rculfhash.h
> index fd67b6b..9b96104 100644
> --- a/urcu/rculfhash.h
> +++ b/urcu/rculfhash.h
> @@ -94,6 +94,7 @@ void cds_lfht_node_init(struct cds_lfht_node *node, void *key,
>   */
>  enum {
>  	CDS_LFHT_AUTO_RESIZE = (1U << 0),
> +	CDS_LFHT_ACCOUNTING = (1U << 1),
>  };
>  
>  /*
> -- 
> 1.7.4.4
> 

-- 
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com