Re: [Tarantool-patches] [PATCH v2 3/6] txn_limbo: introduce txn_limbo_last_synchro_entry method

[Vladislav Shpilevoy <v.shpilevoy@tarantool.org>]

Thanks for the patch!

On 23.12.2020 12:59, Serge Petrenko via Tarantool-patches wrote:
> It'll be useful for box_clear_synchro_queue rework.
> 
> Prerequisite #5435
> ---
>  src/box/txn_limbo.c | 12 ++++++++++++
>  src/box/txn_limbo.h |  7 +++++++
>  2 files changed, 19 insertions(+)
> 
> diff --git a/src/box/txn_limbo.c b/src/box/txn_limbo.c
> index c406ed4c8..9272f5227 100644
> --- a/src/box/txn_limbo.c
> +++ b/src/box/txn_limbo.c
> @@ -55,6 +55,18 @@ txn_limbo_is_ro(struct txn_limbo *limbo)
>  	return limbo->owner_id != instance_id && !txn_limbo_is_empty(limbo);
>  }
>  
> +struct txn_limbo_entry *
> +txn_limbo_last_synchro_entry(struct txn_limbo *limbo)
> +{
> +	struct txn_limbo_entry *entry = NULL;
> +	rlist_foreach_entry_reverse(entry, &limbo->queue, in_queue) {
> +		if (txn_has_flag(entry->txn, TXN_WAIT_ACK))
> +			break;
> +	}
> +	assert(entry == NULL || txn_has_flag(entry->txn, TXN_WAIT_ACK));
> +	return entry;
> +}

This could be a little simpler, but up to you:

====================
@@ -58,13 +58,12 @@ txn_limbo_is_ro(struct txn_limbo *limbo)
 struct txn_limbo_entry *
 txn_limbo_last_synchro_entry(struct txn_limbo *limbo)
 {
-	struct txn_limbo_entry *entry = NULL;
+	struct txn_limbo_entry *entry;
 	rlist_foreach_entry_reverse(entry, &limbo->queue, in_queue) {
 		if (txn_has_flag(entry->txn, TXN_WAIT_ACK))
-			break;
+			return entry;
 	}
-	assert(entry == NULL || txn_has_flag(entry->txn, TXN_WAIT_ACK));
-	return entry;
+	return NULL;
 }
 
 struct txn_limbo_entry *