From: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Date: Tue, 11 Sep 2018 00:09:15 +0000 (-0400)
Subject: Fix: perform local data pending before checking data pending with relayd
X-Git-Tag: v2.9.11~11
X-Git-Url: http://git.liburcu.org/?p=lttng-tools.git;a=commitdiff_plain;h=52a799c0f07e50d56280a4cf19731102b0a24658

Fix: perform local data pending before checking data pending with relayd

Performing the data pending check in two phases, local and network,
reduces the total number network operations needed.

Doing the local check first enable early return in cases where data is
still pending locally.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
---

diff --git a/src/common/consumer/consumer.c b/src/common/consumer/consumer.c
index 7b87a85fe..53a50efbb 100644
--- a/src/common/consumer/consumer.c
+++ b/src/common/consumer/consumer.c
@@ -3604,21 +3604,6 @@ int consumer_data_pending(uint64_t id)
 	/* Ease our life a bit */
 	ht = consumer_data.stream_list_ht;
 
-	relayd = find_relayd_by_session_id(id);
-	if (relayd) {
-		/* Send init command for data pending. */
-		pthread_mutex_lock(&relayd->ctrl_sock_mutex);
-		ret = relayd_begin_data_pending(&relayd->control_sock,
-				relayd->relayd_session_id);
-		pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
-		if (ret < 0) {
-			/* Communication error thus the relayd so no data pending. */
-			ERR("Relayd begin data pending failed. Cleaning up relayd %" PRIu64".", relayd->net_seq_idx);
-			lttng_consumer_cleanup_relayd(relayd);
-			goto data_not_pending;
-		}
-	}
-
 	cds_lfht_for_each_entry_duplicate(ht->ht,
 			ht->hash_fct(&id, lttng_ht_seed),
 			ht->match_fct, &id,
@@ -3641,9 +3626,27 @@ int consumer_data_pending(uint64_t id)
 			}
 		}
 
-		/* Relayd check */
-		if (relayd) {
-			pthread_mutex_lock(&relayd->ctrl_sock_mutex);
+		pthread_mutex_unlock(&stream->lock);
+	}
+
+	relayd = find_relayd_by_session_id(id);
+	if (relayd) {
+		unsigned int is_data_inflight = 0;
+
+		/* Send init command for data pending. */
+		pthread_mutex_lock(&relayd->ctrl_sock_mutex);
+		ret = relayd_begin_data_pending(&relayd->control_sock,
+				relayd->relayd_session_id);
+		if (ret < 0) {
+			pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
+			/* Communication error thus the relayd so no data pending. */
+			goto data_not_pending;
+		}
+
+		cds_lfht_for_each_entry_duplicate(ht->ht,
+				ht->hash_fct(&id, lttng_ht_seed),
+				ht->match_fct, &id,
+				&iter.iter, stream, node_session_id.node) {
 			if (stream->metadata_flag) {
 				ret = relayd_quiescent_control(&relayd->control_sock,
 						stream->relayd_stream_id);
@@ -3652,27 +3655,19 @@ int consumer_data_pending(uint64_t id)
 						stream->relayd_stream_id,
 						stream->next_net_seq_num - 1);
 			}
-			if (ret < 0) {
+
+			if (ret == 1) {
+				pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
+				goto data_pending;
+			} else if (ret < 0) {
 				ERR("Relayd data pending failed. Cleaning up relayd %" PRIu64".", relayd->net_seq_idx);
 				lttng_consumer_cleanup_relayd(relayd);
 				pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
-				pthread_mutex_unlock(&stream->lock);
 				goto data_not_pending;
 			}
-			pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
-			if (ret == 1) {
-				pthread_mutex_unlock(&stream->lock);
-				goto data_pending;
-			}
 		}
-		pthread_mutex_unlock(&stream->lock);
-	}
-
-	if (relayd) {
-		unsigned int is_data_inflight = 0;
 
-		/* Send init command for data pending. */
-		pthread_mutex_lock(&relayd->ctrl_sock_mutex);
+		/* Send end command for data pending. */
 		ret = relayd_end_data_pending(&relayd->control_sock,
 				relayd->relayd_session_id, &is_data_inflight);
 		pthread_mutex_unlock(&relayd->ctrl_sock_mutex);