X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fsession.c;h=0da2058fdf28dbbef05f0d2490cfbf49a089a294;hp=6c10aaeba9259286cdac4a43db72619d8a4e8f51;hb=ccbdaca404a66cf124ec7e4926b1507327f6d165;hpb=82b69413fa2d05d8643c4fb900b88f5d41206cfc

diff --git a/src/bin/lttng-sessiond/session.c b/src/bin/lttng-sessiond/session.c
index 6c10aaeba..0da2058fd 100644
--- a/src/bin/lttng-sessiond/session.c
+++ b/src/bin/lttng-sessiond/session.c
@@ -39,6 +39,17 @@
 #include "utils.h"
 #include "trace-ust.h"
 #include "timer.h"
+#include "cmd.h"
+
+struct ltt_session_destroy_notifier_element {
+	ltt_session_destroy_notifier notifier;
+	void *user_data;
+};
+
+struct ltt_session_clear_notifier_element {
+	ltt_session_clear_notifier notifier;
+	void *user_data;
+};
 
 /*
  * NOTES:
@@ -67,13 +78,6 @@ static const char *forbidden_name_chars = "/";
 /* Global hash table to keep the sessions, indexed by id. */
 static struct lttng_ht *ltt_sessions_ht_by_id = NULL;
 
-struct consumer_create_chunk_transaction {
-	struct consumer_socket *socket;
-	struct lttng_trace_chunk *new_chunk;
-	struct lttng_trace_chunk *previous_chunk;
-	bool new_chunk_created;
-};
-
 /*
  * Validate the session name for forbidden characters.
  *
@@ -252,18 +256,28 @@ void session_get_net_consumer_ports(const struct ltt_session *session,
  * The caller must hold the session lock.
  */
 struct lttng_trace_archive_location *session_get_trace_archive_location(
-		struct ltt_session *session)
+		const struct ltt_session *session)
 {
+	int ret;
 	struct lttng_trace_archive_location *location = NULL;
+	char *chunk_path = NULL;
 
-	if (session->rotation_state != LTTNG_ROTATION_STATE_COMPLETED) {
+	if (session->rotation_state != LTTNG_ROTATION_STATE_COMPLETED ||
+			!session->last_archived_chunk_name) {
 		goto end;
 	}
 
 	switch (session_get_consumer_destination_type(session)) {
 	case CONSUMER_DST_LOCAL:
+		ret = asprintf(&chunk_path,
+				"%s/" DEFAULT_ARCHIVED_TRACE_CHUNKS_DIRECTORY "/%s",
+				session_get_base_path(session),
+				session->last_archived_chunk_name);
+		if (ret == -1) {
+			goto end;
+		}
 		location = lttng_trace_archive_location_local_create(
-				session->rotation_chunk.current_rotate_path);
+				chunk_path);
 		break;
 	case CONSUMER_DST_NET:
 	{
@@ -277,14 +291,14 @@ struct lttng_trace_archive_location *session_get_trace_archive_location(
 		location = lttng_trace_archive_location_relay_create(
 				hostname,
 				LTTNG_TRACE_ARCHIVE_LOCATION_RELAY_PROTOCOL_TYPE_TCP,
-				control_port, data_port,
-				session->rotation_chunk.current_rotate_path);
+				control_port, data_port, session->last_chunk_path);
 		break;
 	}
 	default:
 		abort();
 	}
 end:
+	free(chunk_path);
 	return location;
 }
 
@@ -293,7 +307,7 @@ end:
  *
  * The session list lock must be held.
  */
-int ltt_sessions_ht_alloc(void)
+static int ltt_sessions_ht_alloc(void)
 {
 	int ret = 0;
 
@@ -411,150 +425,140 @@ void session_unlock(struct ltt_session *session)
 
 static
 int _session_set_trace_chunk_no_lock_check(struct ltt_session *session,
-		struct lttng_trace_chunk *new_trace_chunk)
+		struct lttng_trace_chunk *new_trace_chunk,
+		struct lttng_trace_chunk **_current_trace_chunk)
 {
-	int ret;
+	int ret = 0;
 	unsigned int i, refs_to_acquire = 0, refs_acquired = 0, refs_to_release = 0;
-	unsigned int consumer_count = 0;
-	/*
-	 * The maximum amount of consumers to reach is 3
-	 * (32/64 userspace + kernel).
-	 */
-	struct consumer_create_chunk_transaction transactions[3] = {};
 	struct cds_lfht_iter iter;
 	struct consumer_socket *socket;
-	bool close_error_occured = false;
-
-	if (new_trace_chunk) {
-		uint64_t chunk_id;
-		enum lttng_trace_chunk_status chunk_status =
-				lttng_trace_chunk_get_id(new_trace_chunk,
-					&chunk_id);
-
-		assert(chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK);
-		LTTNG_OPTIONAL_SET(&session->last_trace_chunk_id, chunk_id)
-	}
-
-	if (new_trace_chunk) {
-		refs_to_acquire = 1;
-		refs_to_acquire += !!session->ust_session;
-		refs_to_acquire += !!session->kernel_session;
-	}
+	struct lttng_trace_chunk *current_trace_chunk;
+	uint64_t chunk_id;
+	enum lttng_trace_chunk_status chunk_status;
 
+	rcu_read_lock();
 	/*
-	 * Build a list of consumers to reach to announce the new trace chunk.
-	 *
-	 * Rolling back the annoucement in case of an error is important since
-	 * not doing so would result in a leak; the chunk will not be
-	 * "reclaimed" by the consumer(s) since they have no concept of the
-	 * lifetime of a session.
+	 * Ownership of current trace chunk is transferred to
+	 * `current_trace_chunk`.
 	 */
+	current_trace_chunk = session->current_trace_chunk;
+	session->current_trace_chunk = NULL;
 	if (session->ust_session) {
-		cds_lfht_for_each_entry(
-				session->ust_session->consumer->socks->ht,
-				&iter, socket, node.node) {
-			transactions[consumer_count].socket = socket;
-			transactions[consumer_count].new_chunk = new_trace_chunk;
-			transactions[consumer_count].previous_chunk =
-					session->current_trace_chunk;
-			consumer_count++;
-			assert(consumer_count <= 3);
-		}
+		lttng_trace_chunk_put(
+				session->ust_session->current_trace_chunk);
+		session->ust_session->current_trace_chunk = NULL;
 	}
 	if (session->kernel_session) {
-		cds_lfht_for_each_entry(
-				session->kernel_session->consumer->socks->ht,
-				&iter, socket, node.node) {
-			transactions[consumer_count].socket = socket;
-			transactions[consumer_count].new_chunk = new_trace_chunk;
-			transactions[consumer_count].previous_chunk =
-					session->current_trace_chunk;
-			consumer_count++;
-			assert(consumer_count <= 3);
-		}
+		lttng_trace_chunk_put(
+				session->kernel_session->current_trace_chunk);
+		session->kernel_session->current_trace_chunk = NULL;
 	}
-	for (refs_acquired = 0; refs_acquired < refs_to_acquire; refs_acquired++) {
-		if (new_trace_chunk && !lttng_trace_chunk_get(new_trace_chunk)) {
-			ERR("Failed to acquire reference to new current trace chunk of session \"%s\"",
+	if (!new_trace_chunk) {
+		ret = 0;
+		goto end;
+	}
+	chunk_status = lttng_trace_chunk_get_id(new_trace_chunk, &chunk_id);
+	assert(chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK);
+
+	refs_to_acquire = 1;
+	refs_to_acquire += !!session->ust_session;
+	refs_to_acquire += !!session->kernel_session;
+
+	for (refs_acquired = 0; refs_acquired < refs_to_acquire;
+			refs_acquired++) {
+		if (!lttng_trace_chunk_get(new_trace_chunk)) {
+			ERR("Failed to acquire reference to new trace chunk of session \"%s\"",
 					session->name);
 			goto error;
 		}
 	}
 
-	/*
-	 * Close the previous chunk on remote peers (consumers and relayd).
-	 */
-	for (i = 0; i < consumer_count; i++) {
-		if (!transactions[i].previous_chunk) {
-			continue;
-		}
-		pthread_mutex_lock(transactions[i].socket->lock);
-		ret = consumer_close_trace_chunk(transactions[i].socket,
-				session->consumer->net_seq_index,
-				session->id,
-				transactions[i].previous_chunk);
-		pthread_mutex_unlock(transactions[i].socket->lock);
-		if (ret) {
-			ERR("Failed to close trace chunk on consumer");
-			close_error_occured = true;
-		}
-	}
+	if (session->ust_session) {
+		const uint64_t relayd_id =
+				session->ust_session->consumer->net_seq_index;
+		const bool is_local_trace =
+				session->ust_session->consumer->type ==
+				CONSUMER_DST_LOCAL;
 
-	if (close_error_occured) {
-		/*
-		 * Skip the creation of the new trace chunk and report the
-		 * error.
-		 */
-		goto error;
-	}
+		session->ust_session->current_trace_chunk = new_trace_chunk;
+                if (is_local_trace) {
+			enum lttng_error_code ret_error_code;
 
-	/* Create the new chunk on remote peers (consumers and relayd) */
-	if (new_trace_chunk) {
-		for (i = 0; i < consumer_count; i++) {
-			pthread_mutex_lock(transactions[i].socket->lock);
-			ret = consumer_create_trace_chunk(transactions[i].socket,
-					session->consumer->net_seq_index,
-					session->id,
-					transactions[i].new_chunk);
-			pthread_mutex_unlock(transactions[i].socket->lock);
-			if (ret) {
-				ERR("Failed to create trace chunk on consumer");
+			ret_error_code = ust_app_create_channel_subdirectories(
+					session->ust_session);
+			if (ret_error_code != LTTNG_OK) {
 				goto error;
 			}
-			/* This will have to be rolled-back on error. */
-			transactions[i].new_chunk_created = true;
-		}
-	}
-
-	lttng_trace_chunk_put(session->current_trace_chunk);
-	session->current_trace_chunk = NULL;
-	if (session->ust_session) {
-		lttng_trace_chunk_put(
-				session->ust_session->current_trace_chunk);
-		session->ust_session->current_trace_chunk = NULL;
-	}
+                }
+		cds_lfht_for_each_entry(
+				session->ust_session->consumer->socks->ht,
+				&iter, socket, node.node) {
+			pthread_mutex_lock(socket->lock);
+			ret = consumer_create_trace_chunk(socket,
+					relayd_id,
+					session->id, new_trace_chunk,
+					DEFAULT_UST_TRACE_DIR);
+			pthread_mutex_unlock(socket->lock);
+                        if (ret) {
+				goto error;
+                        }
+                }
+        }
 	if (session->kernel_session) {
-		lttng_trace_chunk_put(
-				session->kernel_session->current_trace_chunk);
-		session->kernel_session->current_trace_chunk = NULL;
-	}
+		const uint64_t relayd_id =
+				session->kernel_session->consumer->net_seq_index;
+		const bool is_local_trace =
+				session->kernel_session->consumer->type ==
+				CONSUMER_DST_LOCAL;
+
+		session->kernel_session->current_trace_chunk = new_trace_chunk;
+		if (is_local_trace) {
+			enum lttng_error_code ret_error_code;
+
+			ret_error_code = kernel_create_channel_subdirectories(
+					session->kernel_session);
+			if (ret_error_code != LTTNG_OK) {
+				goto error;
+			}
+                }
+		cds_lfht_for_each_entry(
+				session->kernel_session->consumer->socks->ht,
+				&iter, socket, node.node) {
+			pthread_mutex_lock(socket->lock);
+			ret = consumer_create_trace_chunk(socket,
+					relayd_id,
+					session->id, new_trace_chunk,
+					DEFAULT_KERNEL_TRACE_DIR);
+			pthread_mutex_unlock(socket->lock);
+                        if (ret) {
+				goto error;
+                        }
+                }
+        }
 
 	/*
 	 * Update local current trace chunk state last, only if all remote
-	 * annoucements succeeded.
+	 * creations succeeded.
 	 */
 	session->current_trace_chunk = new_trace_chunk;
+	LTTNG_OPTIONAL_SET(&session->most_recent_chunk_id, chunk_id);
+end:
+	if (_current_trace_chunk) {
+		*_current_trace_chunk = current_trace_chunk;
+		current_trace_chunk = NULL;
+	}
+end_no_move:
+	rcu_read_unlock();
+	lttng_trace_chunk_put(current_trace_chunk);
+	return ret;
+error:
 	if (session->ust_session) {
-		session->ust_session->current_trace_chunk = new_trace_chunk;
+		session->ust_session->current_trace_chunk = NULL;
 	}
 	if (session->kernel_session) {
-		session->kernel_session->current_trace_chunk =
-				new_trace_chunk;
+		session->kernel_session->current_trace_chunk = NULL;
 	}
-
-	return 0;
-error:
-	/*
+        /*
 	 * Release references taken in the case where all references could not
 	 * be acquired.
 	 */
@@ -562,109 +566,62 @@ error:
 	for (i = 0; i < refs_to_release; i++) {
 		lttng_trace_chunk_put(new_trace_chunk);
 	}
-
-	/*
-	 * Close the newly-created chunk from remote peers (consumers and
-	 * relayd).
-	 */
-	DBG("Rolling back the creation of the new trace chunk on consumers");
-	for (i = 0; i < consumer_count; i++) {
-		if (!transactions[i].new_chunk_created) {
-			continue;
-		}
-
-		pthread_mutex_lock(transactions[i].socket->lock);
-		ret = consumer_close_trace_chunk(transactions[i].socket,
-				session->consumer->net_seq_index,
-				session->id,
-				transactions[i].new_chunk);
-		pthread_mutex_unlock(transactions[i].socket->lock);
-		if (ret) {
-			ERR("Failed to close trace chunk on consumer");
-			close_error_occured = true;
-		}
-	}
-
-	return -1;
-}
-
-static
-bool output_supports_chunks(const struct ltt_session *session)
-{
-	if (session->consumer->type == CONSUMER_DST_LOCAL) {
-		return true;
-	} else {
-		struct consumer_output *output;
-
-		if (session->ust_session) {
-			output = session->ust_session->consumer;
-		} else if (session->kernel_session) {
-			output = session->kernel_session->consumer;
-		} else {
-			abort();
-		}
-
-		if (output->relay_major_version > 2) {
-			return true;
-		} else if (output->relay_major_version == 2 &&
-				output->relay_minor_version >= 11) {
-			return true;
-		}
-	}
-	return false;
+	ret = -1;
+	goto end_no_move;
 }
 
-enum lttng_error_code session_switch_trace_chunk(struct ltt_session *session,
+struct lttng_trace_chunk *session_create_new_trace_chunk(
+		const struct ltt_session *session,
+		const struct consumer_output *consumer_output_override,
 		const char *session_base_path_override,
 		const char *chunk_name_override)
 {
 	int ret;
-	enum lttng_error_code ret_code = LTTNG_OK;
 	struct lttng_trace_chunk *trace_chunk = NULL;
 	enum lttng_trace_chunk_status chunk_status;
-	const time_t timestamp_begin = time(NULL);
-	const bool is_local_trace =
-			session->consumer->type == CONSUMER_DST_LOCAL;
-	const char *base_path = session_base_path_override ? :
-			session_get_base_path(session);
-	struct lttng_directory_handle session_output_directory;
+	const time_t chunk_creation_ts = time(NULL);
+	bool is_local_trace;
+	const char *base_path;
+	struct lttng_directory_handle *session_output_directory = NULL;
 	const struct lttng_credentials session_credentials = {
 		.uid = session->uid,
 		.gid = session->gid,
 	};
 	uint64_t next_chunk_id;
+	const struct consumer_output *output;
 
-	if (timestamp_begin == (time_t) -1) {
-		PERROR("Failed to sample time while changing session \"%s\" trace chunk",
+	if (consumer_output_override) {
+		output = consumer_output_override;
+	} else {
+		assert(session->ust_session || session->kernel_session);
+		output = session->ust_session ?
+					 session->ust_session->consumer :
+					 session->kernel_session->consumer;
+	}
+
+	is_local_trace = output->type == CONSUMER_DST_LOCAL;
+	base_path = session_base_path_override ? :
+			consumer_output_get_base_path(output);
+
+	if (chunk_creation_ts == (time_t) -1) {
+		PERROR("Failed to sample time while creation session \"%s\" trace chunk",
 				session->name);
-		ret_code = LTTNG_ERR_FATAL;
 		goto error;
 	}
-	session->current_chunk_start_ts = timestamp_begin;
 
-	if (!output_supports_chunks(session)) {
-		goto end;
-	}
-	next_chunk_id = session->last_trace_chunk_id.is_set ?
-			session->last_trace_chunk_id.value + 1 : 0;
+	next_chunk_id = session->most_recent_chunk_id.is_set ?
+			session->most_recent_chunk_id.value + 1 : 0;
 
-	trace_chunk = lttng_trace_chunk_create(next_chunk_id, timestamp_begin);
+	trace_chunk = lttng_trace_chunk_create(next_chunk_id,
+			chunk_creation_ts);
 	if (!trace_chunk) {
-		ret_code = LTTNG_ERR_FATAL;
 		goto error;
 	}
 
 	if (chunk_name_override) {
 		chunk_status = lttng_trace_chunk_override_name(trace_chunk,
 				chunk_name_override);
-		switch (chunk_status) {
-		case LTTNG_TRACE_CHUNK_STATUS_OK:
-			break;
-		case LTTNG_TRACE_CHUNK_STATUS_INVALID_ARGUMENT:
-			ret_code = LTTNG_ERR_INVALID;
-			goto error;
-		default:
-			ret_code = LTTNG_ERR_NOMEM;
+		if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
 			goto error;
 		}
 	}
@@ -674,49 +631,117 @@ enum lttng_error_code session_switch_trace_chunk(struct ltt_session *session,
 		 * No need to set crendentials and output directory
 		 * for remote trace chunks.
 		 */
-		goto publish;
+		goto end;
 	}
 
 	chunk_status = lttng_trace_chunk_set_credentials(trace_chunk,
 			&session_credentials);
 	if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
-		ret_code = LTTNG_ERR_FATAL;
 		goto error;
 	}
 
-	if (!session->current_trace_chunk) {
-		DBG("Creating base output directory of session \"%s\" at %s",
-				session->name, base_path);
-	}
+	DBG("Creating base output directory of session \"%s\" at %s",
+			session->name, base_path);
 	ret = utils_mkdir_recursive(base_path, S_IRWXU | S_IRWXG,
 			session->uid, session->gid);
 	if (ret) {
-		ret = LTTNG_ERR_FATAL;
 		goto error;
 	}
-	ret = lttng_directory_handle_init(&session_output_directory,
-			base_path);
-	if (ret) {
-		ret = LTTNG_ERR_FATAL;
+	session_output_directory = lttng_directory_handle_create(base_path);
+	if (!session_output_directory) {
 		goto error;
 	}
 	chunk_status = lttng_trace_chunk_set_as_owner(trace_chunk,
-			&session_output_directory);
-	lttng_directory_handle_fini(&session_output_directory);
+			session_output_directory);
+	lttng_directory_handle_put(session_output_directory);
+	session_output_directory = NULL;
 	if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
-		ret = LTTNG_ERR_CREATE_DIR_FAIL;
-		goto error;
-	}
-publish:
-	ret = session_set_trace_chunk(session, trace_chunk);
-	if (ret) {
-		ret_code = LTTNG_ERR_FATAL;
 		goto error;
 	}
+end:
+	return trace_chunk;
 error:
+	lttng_directory_handle_put(session_output_directory);
 	lttng_trace_chunk_put(trace_chunk);
+	trace_chunk = NULL;
+	goto end;
+}
+
+int session_close_trace_chunk(struct ltt_session *session,
+		struct lttng_trace_chunk *trace_chunk,
+		enum lttng_trace_chunk_command_type close_command,
+		char *closed_trace_chunk_path)
+{
+	int ret = 0;
+	bool error_occurred = false;
+	struct cds_lfht_iter iter;
+	struct consumer_socket *socket;
+	enum lttng_trace_chunk_status chunk_status;
+	const time_t chunk_close_timestamp = time(NULL);
+
+	chunk_status = lttng_trace_chunk_set_close_command(
+			trace_chunk, close_command);
+	if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
+		ret = -1;
+		goto end;
+	}
+
+	if (chunk_close_timestamp == (time_t) -1) {
+		ERR("Failed to sample the close timestamp of the current trace chunk of session \"%s\"",
+				session->name);
+		ret = -1;
+		goto end;
+	}
+	chunk_status = lttng_trace_chunk_set_close_timestamp(trace_chunk,
+			chunk_close_timestamp);
+	if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
+		ERR("Failed to set the close timestamp of the current trace chunk of session \"%s\"",
+				session->name);
+		ret = -1;
+		goto end;
+	}
+
+	if (session->ust_session) {
+		const uint64_t relayd_id =
+				session->ust_session->consumer->net_seq_index;
+
+		cds_lfht_for_each_entry(
+				session->ust_session->consumer->socks->ht,
+				&iter, socket, node.node) {
+			pthread_mutex_lock(socket->lock);
+			ret = consumer_close_trace_chunk(socket,
+					relayd_id,
+					session->id,
+					trace_chunk, closed_trace_chunk_path);
+			pthread_mutex_unlock(socket->lock);
+			if (ret) {
+				ERR("Failed to close trace chunk on user space consumer");
+				error_occurred = true;
+			}
+		}
+	}
+	if (session->kernel_session) {
+		const uint64_t relayd_id =
+				session->kernel_session->consumer->net_seq_index;
+
+		cds_lfht_for_each_entry(
+				session->kernel_session->consumer->socks->ht,
+				&iter, socket, node.node) {
+			pthread_mutex_lock(socket->lock);
+			ret = consumer_close_trace_chunk(socket,
+					relayd_id,
+					session->id,
+					trace_chunk, closed_trace_chunk_path);
+			pthread_mutex_unlock(socket->lock);
+			if (ret) {
+				ERR("Failed to close trace chunk on kernel consumer");
+				error_occurred = true;
+			}
+		}
+	}
+	ret = error_occurred ? -1 : 0;
 end:
-	return ret_code;
+	return ret;
 }
 
 /*
@@ -725,10 +750,47 @@ end:
  * Must be called with the session lock held.
  */
 int session_set_trace_chunk(struct ltt_session *session,
-		struct lttng_trace_chunk *new_trace_chunk)
+		struct lttng_trace_chunk *new_trace_chunk,
+		struct lttng_trace_chunk **current_trace_chunk)
 {
 	ASSERT_LOCKED(session->lock);
-	return _session_set_trace_chunk_no_lock_check(session, new_trace_chunk);
+	return _session_set_trace_chunk_no_lock_check(session, new_trace_chunk,
+			current_trace_chunk);
+}
+
+static
+void session_notify_destruction(const struct ltt_session *session)
+{
+	size_t i;
+	const size_t count = lttng_dynamic_array_get_count(
+			&session->destroy_notifiers);
+
+	for (i = 0; i < count; i++) {
+		const struct ltt_session_destroy_notifier_element *element =
+			lttng_dynamic_array_get_element(
+					&session->destroy_notifiers, i);
+
+		element->notifier(session, element->user_data);
+	}
+}
+
+/*
+ * Fire each clear notifier once, and remove them from the array.
+ */
+void session_notify_clear(struct ltt_session *session)
+{
+	size_t i;
+	const size_t count = lttng_dynamic_array_get_count(
+			&session->clear_notifiers);
+
+	for (i = 0; i < count; i++) {
+		const struct ltt_session_clear_notifier_element *element =
+			lttng_dynamic_array_get_element(
+					&session->clear_notifiers, i);
+
+		element->notifier(session, element->user_data);
+	}
+	lttng_dynamic_array_clear(&session->clear_notifiers);
 }
 
 static
@@ -738,16 +800,17 @@ void session_release(struct urcu_ref *ref)
 	struct ltt_ust_session *usess;
 	struct ltt_kernel_session *ksess;
 	struct ltt_session *session = container_of(ref, typeof(*session), ref);
+	const bool session_published = session->published;
+
+	assert(!session->chunk_being_archived);
 
 	usess = session->ust_session;
 	ksess = session->kernel_session;
-	(void) _session_set_trace_chunk_no_lock_check(session, NULL);
 
-	/* Clean kernel session teardown */
+        /* Clean kernel session teardown, keeping data for destroy notifier. */
 	kernel_destroy_session(ksess);
-	session->kernel_session = NULL;
 
-	/* UST session teardown */
+	/* UST session teardown, keeping data for destroy notifier. */
 	if (usess) {
 		/* Close any relayd session */
 		consumer_output_send_destroy_relayd(usess->consumer);
@@ -758,9 +821,8 @@ void session_release(struct urcu_ref *ref)
 			ERR("Error in ust_app_destroy_trace_all");
 		}
 
-		/* Clean up the rest. */
+		/* Clean up the rest, keeping destroy notifier data. */
 		trace_ust_destroy_session(usess);
-		session->ust_session = NULL;
 	}
 
 	/*
@@ -774,18 +836,36 @@ void session_release(struct urcu_ref *ref)
 
 	DBG("Destroying session %s (id %" PRIu64 ")", session->name, session->id);
 
-	consumer_output_put(session->consumer);
 	snapshot_destroy(&session->snapshot);
 
 	pthread_mutex_destroy(&session->lock);
 
-	if (session->published) {
+	if (session_published) {
 		ASSERT_LOCKED(ltt_session_list.lock);
 		del_session_list(session);
 		del_session_ht(session);
-		pthread_cond_broadcast(&ltt_session_list.removal_cond);
 	}
+	session_notify_destruction(session);
+
+	consumer_output_put(session->consumer);
+	kernel_free_session(ksess);
+	session->kernel_session = NULL;
+	if (usess) {
+		trace_ust_free_session(usess);
+		session->ust_session = NULL;
+	}
+	lttng_dynamic_array_reset(&session->destroy_notifiers);
+	lttng_dynamic_array_reset(&session->clear_notifiers);
+	free(session->last_archived_chunk_name);
+	free(session->base_path);
 	free(session);
+	if (session_published) {
+		/*
+		 * Broadcast after free-ing to ensure the memory is
+		 * reclaimed before the main thread exits.
+		 */
+		pthread_cond_broadcast(&ltt_session_list.removal_cond);
+	}
 }
 
 /*
@@ -832,6 +912,30 @@ void session_destroy(struct ltt_session *session)
 	session_put(session);
 }
 
+int session_add_destroy_notifier(struct ltt_session *session,
+		ltt_session_destroy_notifier notifier, void *user_data)
+{
+	const struct ltt_session_destroy_notifier_element element = {
+		.notifier = notifier,
+		.user_data = user_data
+	};
+
+	return lttng_dynamic_array_add_element(&session->destroy_notifiers,
+			&element);
+}
+
+int session_add_clear_notifier(struct ltt_session *session,
+		ltt_session_clear_notifier notifier, void *user_data)
+{
+	const struct ltt_session_clear_notifier_element element = {
+		.notifier = notifier,
+		.user_data = user_data
+	};
+
+	return lttng_dynamic_array_add_element(&session->clear_notifiers,
+			&element);
+}
+
 /*
  * Return a ltt_session structure ptr that matches name. If no session found,
  * NULL is returned. This must be called with the session list lock held using
@@ -920,6 +1024,12 @@ enum lttng_error_code session_create(const char *name, uid_t uid, gid_t gid,
 		goto error;
 	}
 
+	lttng_dynamic_array_init(&new_session->destroy_notifiers,
+			sizeof(struct ltt_session_destroy_notifier_element),
+			NULL);
+	lttng_dynamic_array_init(&new_session->clear_notifiers,
+			sizeof(struct ltt_session_clear_notifier_element),
+			NULL);
 	urcu_ref_init(&new_session->ref);
 	pthread_mutex_init(&new_session->lock, NULL);
 
@@ -976,6 +1086,7 @@ enum lttng_error_code session_create(const char *name, uid_t uid, gid_t gid,
 						DEFAULT_SESSION_NAME, i,
 						datetime);
 			}
+			new_session->name_contains_creation_time = true;
 			if (ret == -1 || ret >= sizeof(new_session->name)) {
 				/*
 				 * Null-terminate in case the name is used
@@ -1083,7 +1194,7 @@ int session_access_ok(struct ltt_session *session, uid_t uid, gid_t gid)
  *
  * Be careful of the result passed to this function. For instance,
  * on failure to launch a rotation, a client will expect the rotation
- * state to be set to "NO_ROTATION". If an error occured while the
+ * state to be set to "NO_ROTATION". If an error occurred while the
  * rotation was "ONGOING", result should be set to "ERROR", which will
  * allow a client to report it.
  *
@@ -1097,12 +1208,27 @@ int session_reset_rotation_state(struct ltt_session *session,
 	ASSERT_LOCKED(ltt_session_list.lock);
 	ASSERT_LOCKED(session->lock);
 
-	session->rotation_pending_local = false;
-	session->rotation_pending_relay = false;
-	session->rotated_after_last_stop = false;
 	session->rotation_state = result;
 	if (session->rotation_pending_check_timer_enabled) {
 		ret = timer_session_rotation_pending_check_stop(session);
 	}
+	if (session->chunk_being_archived) {
+		uint64_t chunk_id;
+		enum lttng_trace_chunk_status chunk_status;
+
+		chunk_status = lttng_trace_chunk_get_id(
+				session->chunk_being_archived,
+				&chunk_id);
+		assert(chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK);
+		LTTNG_OPTIONAL_SET(&session->last_archived_chunk_id,
+				chunk_id);
+		lttng_trace_chunk_put(session->chunk_being_archived);
+		session->chunk_being_archived = NULL;
+		/*
+		 * Fire the clear reply notifiers if we are completing a clear
+		 * rotation.
+		 */
+		session_notify_clear(session);
+	}
 	return ret;
 }