X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Fust-consumer%2Fust-consumer.c;h=89109b919a85231615fdb7f86a3c98518a9d422a;hp=4d1e7f155abd0af1474b32eeb9fdc49905127f4c;hb=d4d80f770fc0b0762b18b482381418f01aeb69db;hpb=beb5945802e0598b04d41b4ad41fb49d701fa0f5

diff --git a/src/common/ust-consumer/ust-consumer.c b/src/common/ust-consumer/ust-consumer.c
index 4d1e7f155..89109b919 100644
--- a/src/common/ust-consumer/ust-consumer.c
+++ b/src/common/ust-consumer/ust-consumer.c
@@ -767,7 +767,54 @@ static int flush_channel(uint64_t chan_key)
 
 		health_code_update();
 
-		ustctl_flush_buffer(stream->ustream, 1);
+		pthread_mutex_lock(&stream->lock);
+		if (!stream->quiescent) {
+			ustctl_flush_buffer(stream->ustream, 0);
+			stream->quiescent = true;
+		}
+		pthread_mutex_unlock(&stream->lock);
+	}
+error:
+	rcu_read_unlock();
+	return ret;
+}
+
+/*
+ * Clear quiescent state from channel's streams using the given key to
+ * retrieve the channel.
+ *
+ * Return 0 on success else an LTTng error code.
+ */
+static int clear_quiescent_channel(uint64_t chan_key)
+{
+	int ret = 0;
+	struct lttng_consumer_channel *channel;
+	struct lttng_consumer_stream *stream;
+	struct lttng_ht *ht;
+	struct lttng_ht_iter iter;
+
+	DBG("UST consumer clear quiescent channel key %" PRIu64, chan_key);
+
+	rcu_read_lock();
+	channel = consumer_find_channel(chan_key);
+	if (!channel) {
+		ERR("UST consumer clear quiescent channel %" PRIu64 " not found", chan_key);
+		ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
+		goto error;
+	}
+
+	ht = consumer_data.stream_per_chan_id_ht;
+
+	/* For each stream of the channel id, clear quiescent state. */
+	cds_lfht_for_each_entry_duplicate(ht->ht,
+			ht->hash_fct(&channel->key, lttng_ht_seed), ht->match_fct,
+			&channel->key, &iter.iter, stream, node_channel_id.node) {
+
+		health_code_update();
+
+		pthread_mutex_lock(&stream->lock);
+		stream->quiescent = false;
+		pthread_mutex_unlock(&stream->lock);
 	}
 error:
 	rcu_read_unlock();
@@ -1064,7 +1111,13 @@ static int snapshot_channel(uint64_t key, char *path, uint64_t relayd_id,
 			}
 		}
 
-		ustctl_flush_buffer(stream->ustream, 1);
+		/*
+		 * If tracing is active, we want to perform a "full" buffer flush.
+		 * Else, if quiescent, it has already been done by the prior stop.
+		 */
+		if (!stream->quiescent) {
+			ustctl_flush_buffer(stream->ustream, 0);
+		}
 
 		ret = lttng_ustconsumer_take_snapshot(stream);
 		if (ret < 0) {
@@ -1582,6 +1635,18 @@ int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 
 		goto end_msg_sessiond;
 	}
+	case LTTNG_CONSUMER_CLEAR_QUIESCENT_CHANNEL:
+	{
+		int ret;
+
+		ret = clear_quiescent_channel(
+				msg.u.clear_quiescent_channel.key);
+		if (ret != 0) {
+			ret_code = ret;
+		}
+
+		goto end_msg_sessiond;
+	}
 	case LTTNG_CONSUMER_PUSH_METADATA:
 	{
 		int ret;
@@ -1945,14 +2010,19 @@ int lttng_ustconsumer_get_sequence_number(
 }
 
 /*
- * Called when the stream signal the consumer that it has hang up.
+ * Called when the stream signals the consumer that it has hung up.
  */
 void lttng_ustconsumer_on_stream_hangup(struct lttng_consumer_stream *stream)
 {
 	assert(stream);
 	assert(stream->ustream);
 
-	ustctl_flush_buffer(stream->ustream, 0);
+	pthread_mutex_lock(&stream->lock);
+	if (!stream->quiescent) {
+		ustctl_flush_buffer(stream->ustream, 0);
+		stream->quiescent = true;
+	}
+	pthread_mutex_unlock(&stream->lock);
 	stream->hangup_flush_done = 1;
 }