X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Frotation-thread.c;h=fcbd83fb37b53e60c0bfe7fa47133b09b4f70d48;hp=3256a1e9b6581899380cb47f16cb35b10a90b32c;hb=8c9211169fda5c183b0cf1f94c01721fdb5ccba5;hpb=ed1e52a3cc41925b701cd1343ace4c450ff836d9

diff --git a/src/bin/lttng-sessiond/rotation-thread.c b/src/bin/lttng-sessiond/rotation-thread.c
index 3256a1e9b..fcbd83fb3 100644
--- a/src/bin/lttng-sessiond/rotation-thread.c
+++ b/src/bin/lttng-sessiond/rotation-thread.c
@@ -44,6 +44,8 @@
 #include "session.h"
 #include "timer.h"
 #include "notification-thread-commands.h"
+#include "utils.h"
+#include "thread.h"
 
 #include <urcu.h>
 #include <urcu/list.h>
@@ -56,7 +58,7 @@ struct rotation_thread {
 
 struct rotation_thread_job {
 	enum rotation_thread_job_type type;
-	uint64_t session_id;
+	struct ltt_session *session;
 	/* List member in struct rotation_thread_timer_queue. */
 	struct cds_list_head head;
 };
@@ -75,7 +77,8 @@ struct rotation_thread_handle {
 	struct rotation_thread_timer_queue *rotation_timer_queue;
 	/* Access to the notification thread cmd_queue */
 	struct notification_thread_handle *notification_thread_handle;
-	sem_t *notification_thread_ready;
+	/* Thread-specific quit pipe. */
+	struct lttng_pipe *quit_pipe;
 };
 
 static
@@ -131,15 +134,13 @@ void log_job_destruction(const struct rotation_thread_job *job)
 		abort();
 	}
 
-	LOG(log_level, "Rotation thread timer queue still contains job of type %s targeting session %" PRIu64 " on destruction",
-			job_type_str, job->session_id);
+	LOG(log_level, "Rotation thread timer queue still contains job of type %s targeting session \"%s\" on destruction",
+			job_type_str, job->session->name);
 }
 
 void rotation_thread_timer_queue_destroy(
 		struct rotation_thread_timer_queue *queue)
 {
-	struct rotation_thread_job *job, *tmp_job;
-
 	if (!queue) {
 		return;
 	}
@@ -147,12 +148,7 @@ void rotation_thread_timer_queue_destroy(
 	lttng_pipe_destroy(queue->event_pipe);
 
 	pthread_mutex_lock(&queue->lock);
-	/* Empty wait queue. */
-	cds_list_for_each_entry_safe(job, tmp_job, &queue->list, head) {
-		log_job_destruction(job);
-		cds_list_del(&job->head);
-		free(job);
-	}
+	assert(cds_list_empty(&queue->list));
 	pthread_mutex_unlock(&queue->lock);
 	pthread_mutex_destroy(&queue->lock);
 	free(queue);
@@ -164,13 +160,13 @@ void rotation_thread_timer_queue_destroy(
 void rotation_thread_handle_destroy(
 		struct rotation_thread_handle *handle)
 {
+	lttng_pipe_destroy(handle->quit_pipe);
 	free(handle);
 }
 
 struct rotation_thread_handle *rotation_thread_handle_create(
 		struct rotation_thread_timer_queue *rotation_timer_queue,
-		struct notification_thread_handle *notification_thread_handle,
-		sem_t *notification_thread_ready)
+		struct notification_thread_handle *notification_thread_handle)
 {
 	struct rotation_thread_handle *handle;
 
@@ -181,10 +177,16 @@ struct rotation_thread_handle *rotation_thread_handle_create(
 
 	handle->rotation_timer_queue = rotation_timer_queue;
 	handle->notification_thread_handle = notification_thread_handle;
-	handle->notification_thread_ready = notification_thread_ready;
+	handle->quit_pipe = lttng_pipe_open(FD_CLOEXEC);
+	if (!handle->quit_pipe) {
+		goto error;
+	}
 
 end:
 	return handle;
+error:
+	rotation_thread_handle_destroy(handle);
+	return NULL;
 }
 
 /*
@@ -193,13 +195,14 @@ end:
  */
 static
 bool timer_job_exists(const struct rotation_thread_timer_queue *queue,
-		enum rotation_thread_job_type job_type, uint64_t session_id)
+		enum rotation_thread_job_type job_type,
+		struct ltt_session *session)
 {
 	bool exists = false;
 	struct rotation_thread_job *job;
 
 	cds_list_for_each_entry(job, &queue->list, head) {
-		if (job->session_id == session_id && job->type == job_type) {
+		if (job->session == session && job->type == job_type) {
 			exists = true;
 			goto end;
 		}
@@ -209,15 +212,16 @@ end:
 }
 
 void rotation_thread_enqueue_job(struct rotation_thread_timer_queue *queue,
-		enum rotation_thread_job_type job_type, uint64_t session_id)
+		enum rotation_thread_job_type job_type,
+		struct ltt_session *session)
 {
 	int ret;
-	const char * const dummy = "!";
+	const char dummy = '!';
 	struct rotation_thread_job *job = NULL;
 	const char *job_type_str = get_job_type_str(job_type);
 
 	pthread_mutex_lock(&queue->lock);
-	if (timer_job_exists(queue, session_id, job_type)) {
+	if (timer_job_exists(queue, job_type, session)) {
 		/*
 		 * This timer job is already pending, we don't need to add
 		 * it.
@@ -227,16 +231,19 @@ void rotation_thread_enqueue_job(struct rotation_thread_timer_queue *queue,
 
 	job = zmalloc(sizeof(struct rotation_thread_job));
 	if (!job) {
-		PERROR("Failed to allocate rotation thread job of type \"%s\" for session id %" PRIu64,
-				job_type_str, session_id);
+		PERROR("Failed to allocate rotation thread job of type \"%s\" for session \"%s\"",
+				job_type_str, session->name);
 		goto end;
 	}
+	/* No reason for this to fail as the caller must hold a reference. */
+	(void) session_get(session);
+
+	job->session = session;
 	job->type = job_type;
-	job->session_id = session_id;
 	cds_list_add_tail(&job->head, &queue->list);
 
-	ret = lttng_write(lttng_pipe_get_writefd(queue->event_pipe), dummy,
-			1);
+	ret = lttng_write(lttng_pipe_get_writefd(queue->event_pipe), &dummy,
+			sizeof(dummy));
 	if (ret < 0) {
 		/*
 		 * We do not want to block in the timer handler, the job has
@@ -253,8 +260,8 @@ void rotation_thread_enqueue_job(struct rotation_thread_timer_queue *queue,
 			DBG("Wake-up pipe of rotation thread job queue is full");
 			goto end;
 		}
-		PERROR("Failed to wake-up the rotation thread after pushing a job of type \"%s\" for session id %" PRIu64,
-				job_type_str, session_id);
+		PERROR("Failed to wake-up the rotation thread after pushing a job of type \"%s\" for session \"%s\"",
+				job_type_str, session->name);
 		goto end;
 	}
 
@@ -269,19 +276,29 @@ int init_poll_set(struct lttng_poll_event *poll_set,
 	int ret;
 
 	/*
-	 * Create pollset with size 2:
-	 *	- quit pipe,
+	 * Create pollset with size 3:
+	 *	- rotation thread quit pipe,
 	 *	- rotation thread timer queue pipe,
+	 *	- notification channel sock,
 	 */
-	ret = sessiond_set_thread_pollset(poll_set, 2);
-	if (ret) {
+	ret = lttng_poll_create(poll_set, 5, LTTNG_CLOEXEC);
+	if (ret < 0) {
+		goto error;
+	}
+
+	ret = lttng_poll_add(poll_set,
+			lttng_pipe_get_readfd(handle->quit_pipe),
+			LPOLLIN | LPOLLERR);
+	if (ret < 0) {
+		ERR("[rotation-thread] Failed to add quit pipe read fd to poll set");
 		goto error;
 	}
+
 	ret = lttng_poll_add(poll_set,
 			lttng_pipe_get_readfd(handle->rotation_timer_queue->event_pipe),
 			LPOLLIN | LPOLLERR);
 	if (ret < 0) {
-		ERR("[rotation-thread] Failed to add rotate_pending fd to pollset");
+		ERR("[rotation-thread] Failed to add rotate_pending fd to poll set");
 		goto error;
 	}
 
@@ -315,11 +332,6 @@ int init_thread_state(struct rotation_thread_handle *handle,
 		goto end;
 	}
 
-	/*
-	 * We wait until the notification thread is ready to create the
-	 * notification channel and add it to the poll_set.
-	 */
-	sem_wait(handle->notification_thread_ready);
 	rotate_notification_channel = lttng_notification_channel_create(
 			lttng_session_daemon_notification_endpoint);
 	if (!rotate_notification_channel) {
@@ -339,74 +351,51 @@ end:
 }
 
 static
-int check_session_rotation_pending_local_on_consumer(
-		const struct ltt_session *session,
-		struct consumer_socket *socket, bool *rotation_completed)
-{
-	int ret;
-
-	pthread_mutex_lock(socket->lock);
-	DBG("[rotation-thread] Checking for locally pending rotation on the %s consumer for session %s",
-			lttng_consumer_type_str(socket->type),
-			session->name);
-	ret = consumer_check_rotation_pending_local(socket,
-			session->id,
-			session->current_archive_id - 1);
-	pthread_mutex_unlock(socket->lock);
-
-	if (ret == 0) {
-		/* Rotation was completed on this consumer. */
-		DBG("[rotation-thread] Local rotation of trace archive %" PRIu64 " of session \"%s\" was completed on the %s consumer",
-				session->current_archive_id - 1,
-				session->name,
-				lttng_consumer_type_str(socket->type));
-		*rotation_completed = true;
-	} else if (ret == 1) {
-		/* Rotation pending on this consumer. */
-		DBG("[rotation-thread] Local rotation of trace archive %" PRIu64 " of session \"%s\" is pending on the %s consumer",
-				session->current_archive_id - 1,
-				session->name,
-				lttng_consumer_type_str(socket->type));
-		*rotation_completed = false;
-		ret = 0;
-	} else {
-		/* Not a fatal error. */
-		ERR("[rotation-thread] Encountered an error when checking if local rotation of trace archive %" PRIu64 " of session \"%s\" is pending on the %s consumer",
-				session->current_archive_id - 1,
-				session->name,
-				lttng_consumer_type_str(socket->type));
-		*rotation_completed = false;
-	}
-	return ret;
-}
-
-static
-int check_session_rotation_pending_local(struct ltt_session *session)
+void check_session_rotation_pending_on_consumers(struct ltt_session *session,
+		bool *_rotation_completed)
 {
 	int ret = 0;
 	struct consumer_socket *socket;
 	struct cds_lfht_iter iter;
-	bool rotation_completed = true;
+	enum consumer_trace_chunk_exists_status exists_status;
+	uint64_t relayd_id;
+	bool chunk_exists_on_peer = false;
+	enum lttng_trace_chunk_status chunk_status;
+
+	assert(session->chunk_being_archived);
 
 	/*
 	 * Check for a local pending rotation on all consumers (32-bit
 	 * user space, 64-bit user space, and kernel).
 	 */
-	DBG("[rotation-thread] Checking for pending local rotation on session \"%s\", trace archive %" PRIu64,
-			session->name, session->current_archive_id - 1);
-
 	rcu_read_lock();
 	if (!session->ust_session) {
 		goto skip_ust;
 	}
 	cds_lfht_for_each_entry(session->ust_session->consumer->socks->ht,
 			&iter, socket, node.node) {
-		ret = check_session_rotation_pending_local_on_consumer(session,
-				socket, &rotation_completed);
-		if (ret || !rotation_completed) {
+		relayd_id = session->ust_session->consumer->type == CONSUMER_DST_LOCAL ?
+				-1ULL :
+				session->ust_session->consumer->net_seq_index;
+
+		pthread_mutex_lock(socket->lock);
+		ret = consumer_trace_chunk_exists(socket,
+				relayd_id,
+				session->id, session->chunk_being_archived,
+				&exists_status);
+		if (ret) {
+			pthread_mutex_unlock(socket->lock);
+			ERR("Error occurred while checking rotation status on consumer daemon");
 			goto end;
 		}
-	}
+
+                if (exists_status != CONSUMER_TRACE_CHUNK_EXISTS_STATUS_UNKNOWN_CHUNK) {
+			pthread_mutex_unlock(socket->lock);
+			chunk_exists_on_peer = true;
+			goto end;
+                }
+		pthread_mutex_unlock(socket->lock);
+        }
 
 skip_ust:
 	if (!session->kernel_session) {
@@ -414,100 +403,58 @@ skip_ust:
 	}
 	cds_lfht_for_each_entry(session->kernel_session->consumer->socks->ht,
 				&iter, socket, node.node) {
-		ret = check_session_rotation_pending_local_on_consumer(session,
-				socket, &rotation_completed);
-		if (ret || !rotation_completed) {
+		pthread_mutex_lock(socket->lock);
+		relayd_id = session->kernel_session->consumer->type == CONSUMER_DST_LOCAL ?
+				-1ULL :
+				session->kernel_session->consumer->net_seq_index;
+
+		ret = consumer_trace_chunk_exists(socket,
+				relayd_id,
+				session->id, session->chunk_being_archived,
+				&exists_status);
+		if (ret) {
+			pthread_mutex_unlock(socket->lock);
+			ERR("Error occurred while checking rotation status on consumer daemon");
 			goto end;
 		}
+
+                if (exists_status != CONSUMER_TRACE_CHUNK_EXISTS_STATUS_UNKNOWN_CHUNK) {
+			pthread_mutex_unlock(socket->lock);
+			chunk_exists_on_peer = true;
+			goto end;
+                }
+		pthread_mutex_unlock(socket->lock);
 	}
 skip_kernel:
 end:
 	rcu_read_unlock();
 
-	if (rotation_completed) {
-		DBG("[rotation-thread] Local rotation of trace archive %" PRIu64 " of session \"%s\" is complete on all consumers",
-				session->current_archive_id - 1,
-				session->name);
-		session->rotation_pending_local = false;
-	}
-	if (ret) {
-		session->rotation_state = LTTNG_ROTATION_STATE_ERROR;
-	}
-	return 0;
-}
+	if (!chunk_exists_on_peer) {
+		uint64_t chunk_being_archived_id;
 
-static
-int check_session_rotation_pending_relay(struct ltt_session *session)
-{
-	int ret;
-	struct consumer_socket *socket;
-	struct cds_lfht_iter iter;
-	bool rotation_completed = true;
-	const struct consumer_output *output;
-
-	/*
-	 * Check for a pending rotation on any consumer as we only use
-	 * it as a "tunnel" to the relayd.
-	 */
-
-	rcu_read_lock();
-	if (session->ust_session) {
-		cds_lfht_first(session->ust_session->consumer->socks->ht,
-				&iter);
-		output = session->ust_session->consumer;
-	} else {
-		cds_lfht_first(session->kernel_session->consumer->socks->ht,
-				&iter);
-		output = session->kernel_session->consumer;
-	}
-	assert(cds_lfht_iter_get_node(&iter));
-
-	socket = caa_container_of(cds_lfht_iter_get_node(&iter),
-			typeof(*socket), node.node);
-
-	pthread_mutex_lock(socket->lock);
-	DBG("[rotation-thread] Checking for pending relay rotation on session \"%s\", trace archive %" PRIu64 " through the %s consumer",
-			session->name, session->current_archive_id - 1,
-			lttng_consumer_type_str(socket->type));
-	ret = consumer_check_rotation_pending_relay(socket,
-			output,
-			session->id,
-			session->current_archive_id - 1);
-	pthread_mutex_unlock(socket->lock);
-
-	if (ret == 0) {
-		/* Rotation was completed on the relay. */
-		DBG("[rotation-thread] Relay rotation of trace archive %" PRIu64 " of session \"%s\" was completed",
-				session->current_archive_id - 1,
-				session->name);
-	} else if (ret == 1) {
-		/* Rotation pending on relay. */
-		DBG("[rotation-thread] Relay rotation of trace archive %" PRIu64 " of session \"%s\" is pending",
-				session->current_archive_id - 1,
+		chunk_status = lttng_trace_chunk_get_id(
+				session->chunk_being_archived,
+				&chunk_being_archived_id);
+		assert(chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK);
+		DBG("[rotation-thread] Rotation of trace archive %" PRIu64 " of session \"%s\" is complete on all consumers",
+				chunk_being_archived_id,
 				session->name);
-		rotation_completed = false;
-	} else {
-		/* Not a fatal error. */
-		ERR("[rotation-thread] Encountered an error when checking if rotation of trace archive %" PRIu64 " of session \"%s\" is pending on the relay",
-				session->current_archive_id - 1,
-				session->name);
-		session->rotation_state = LTTNG_ROTATION_STATE_ERROR;
-		rotation_completed = false;
 	}
-
-	rcu_read_unlock();
-
-	if (rotation_completed) {
-		DBG("[rotation-thread] Totation of trace archive %" PRIu64 " of session \"%s\" is complete on the relay",
-				session->current_archive_id - 1,
-				session->name);
-		session->rotation_pending_relay = false;
+	*_rotation_completed = !chunk_exists_on_peer;
+	if (ret) {
+		ret = session_reset_rotation_state(session,
+				LTTNG_ROTATION_STATE_ERROR);
+		if (ret) {
+			ERR("Failed to reset rotation state of session \"%s\"",
+					session->name);
+		}
 	}
-	return 0;
 }
 
 /*
  * Check if the last rotation was completed, called with session lock held.
+ * Should only return non-zero in the event of a fatal error. Doing so will
+ * shutdown the thread.
  */
 static
 int check_session_rotation_pending(struct ltt_session *session,
@@ -515,109 +462,66 @@ int check_session_rotation_pending(struct ltt_session *session,
 {
 	int ret;
 	struct lttng_trace_archive_location *location;
-	time_t now;
-
-	DBG("[rotation-thread] Checking for pending rotation on session \"%s\", trace archive %" PRIu64,
-			session->name, session->current_archive_id - 1);
-
-	if (session->rotation_pending_local) {
-		/* Updates session->rotation_pending_local as needed. */
-		ret = check_session_rotation_pending_local(session);
-		if (ret) {
-			goto end;
-		}
+	enum lttng_trace_chunk_status chunk_status;
+	bool rotation_completed = false;
+	const char *archived_chunk_name;
+	uint64_t chunk_being_archived_id;
 
-		/*
-		 * No need to check for a pending rotation on the relay
-		 * since the rotation is not even completed locally yet.
-		 */
-		if (session->rotation_pending_local) {
-			goto end;
-		}
+	if (!session->chunk_being_archived) {
+		ret = 0;
+		goto end;
 	}
 
-	if (session->rotation_pending_relay) {
-		/* Updates session->rotation_pending_relay as needed. */
-		ret = check_session_rotation_pending_relay(session);
-		if (ret) {
-			goto end;
-		}
+	chunk_status = lttng_trace_chunk_get_id(session->chunk_being_archived,
+			&chunk_being_archived_id);
+	assert(chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK);
 
-		if (session->rotation_pending_relay) {
-			goto end;
-		}
-	}
-
-	DBG("[rotation-thread] Rotation of trace archive %" PRIu64 " completed for "
-			"session %s", session->current_archive_id - 1,
-			session->name);
+	DBG("[rotation-thread] Checking for pending rotation on session \"%s\", trace archive %" PRIu64,
+			session->name, chunk_being_archived_id);
 
-	/* Rename the completed trace archive's location. */
-	now = time(NULL);
-	if (now == (time_t) -1) {
-		session->rotation_state = LTTNG_ROTATION_STATE_ERROR;
-		ret = LTTNG_ERR_UNK;
-		goto end;
+	/*
+	 * The rotation-pending check timer of a session is launched in
+	 * one-shot mode. If the rotation is incomplete, the rotation
+	 * thread will re-enable the pending-check timer.
+	 *
+	 * The timer thread can't stop the timer itself since it is involved
+	 * in the check for the timer's quiescence.
+	 */
+	ret = timer_session_rotation_pending_check_stop(session);
+	if (ret) {
+		goto check_ongoing_rotation;
 	}
 
-	ret = rename_completed_chunk(session, now);
-	if (ret < 0) {
-		ERR("Failed to rename completed rotation chunk");
-		goto end;
+	check_session_rotation_pending_on_consumers(session,
+			&rotation_completed);
+	if (!rotation_completed ||
+			session->rotation_state == LTTNG_ROTATION_STATE_ERROR) {
+		goto check_ongoing_rotation;
 	}
-	session->last_chunk_start_ts = session->current_chunk_start_ts;
 
 	/*
 	 * Now we can clear the "ONGOING" state in the session. New
 	 * rotations can start now.
 	 */
-	session->rotation_state = LTTNG_ROTATION_STATE_COMPLETED;
-
-	/* Ownership of location is transferred. */
-	location = session_get_trace_archive_location(session);
-	ret = notification_thread_command_session_rotation_completed(
-			notification_thread_handle,
-			session->name,
-			session->uid,
-			session->gid,
-			session->current_archive_id,
-			location);
-	if (ret != LTTNG_OK) {
-		ERR("[rotation-thread] Failed to notify notification thread of completed rotation for session %s",
-				session->name);
+	chunk_status = lttng_trace_chunk_get_name(session->chunk_being_archived,
+			&archived_chunk_name, NULL);
+	assert(chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK);
+	free(session->last_archived_chunk_name);
+	session->last_archived_chunk_name = strdup(archived_chunk_name);
+	if (!session->last_archived_chunk_name) {
+		PERROR("Failed to duplicate archived chunk name");
 	}
+	session_reset_rotation_state(session, LTTNG_ROTATION_STATE_COMPLETED);
 
-	if (!session->active) {
-		/*
-		 * A stop command was issued during the rotation, it is
-		 * up to the rotation completion check to perform the
-		 * renaming of the last chunk that was produced.
-		 */
-		ret = notification_thread_command_session_rotation_ongoing(
-				notification_thread_handle,
-				session->name,
-				session->uid,
-				session->gid,
-				session->current_archive_id);
-		if (ret != LTTNG_OK) {
-			ERR("[rotation-thread] Failed to notify notification thread of completed rotation for session %s",
-					session->name);
-		}
-
-		ret = rename_active_chunk(session);
-		if (ret < 0) {
-			ERR("[rotation-thread] Failed to rename active rotation chunk");
-			goto end;
-		}
-
-		/* Ownership of location is transferred. */
+	if (!session->quiet_rotation) {
 		location = session_get_trace_archive_location(session);
+		/* Ownership of location is transferred. */
 		ret = notification_thread_command_session_rotation_completed(
 				notification_thread_handle,
 				session->name,
 				session->uid,
 				session->gid,
-				session->current_archive_id,
+				session->last_archived_chunk_id.value,
 				location);
 		if (ret != LTTNG_OK) {
 			ERR("[rotation-thread] Failed to notify notification thread of completed rotation for session %s",
@@ -626,19 +530,27 @@ int check_session_rotation_pending(struct ltt_session *session,
 	}
 
 	ret = 0;
-end:
+check_ongoing_rotation:
 	if (session->rotation_state == LTTNG_ROTATION_STATE_ONGOING) {
+		uint64_t chunk_being_archived_id;
+
+		chunk_status = lttng_trace_chunk_get_id(
+				session->chunk_being_archived,
+				&chunk_being_archived_id);
+		assert(chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK);
+
 		DBG("[rotation-thread] Rotation of trace archive %" PRIu64 " is still pending for session %s",
-				session->current_archive_id - 1, session->name);
+				chunk_being_archived_id, session->name);
 		ret = timer_session_rotation_pending_check_start(session,
 				DEFAULT_ROTATE_PENDING_TIMER);
 		if (ret) {
-			ERR("Re-enabling rotate pending timer");
+			ERR("Failed to re-enable rotation pending timer");
 			ret = -1;
 			goto end;
 		}
 	}
 
+end:
 	return ret;
 }
 
@@ -652,7 +564,7 @@ int launch_session_rotation(struct ltt_session *session)
 	DBG("[rotation-thread] Launching scheduled time-based rotation on session \"%s\"",
 			session->name);
 
-	ret = cmd_rotate_session(session, &rotation_return);
+	ret = cmd_rotate_session(session, &rotation_return, false);
 	if (ret == LTTNG_OK) {
 		DBG("[rotation-thread] Scheduled time-based rotation successfully launched on session \"%s\"",
 				session->name);
@@ -690,18 +602,9 @@ int handle_job_queue(struct rotation_thread_handle *handle,
 		struct rotation_thread_timer_queue *queue)
 {
 	int ret = 0;
-	int fd = lttng_pipe_get_readfd(queue->event_pipe);
-	struct ltt_session *session;
-	char buf;
-
-	ret = lttng_read(fd, &buf, 1);
-	if (ret != 1) {
-		ERR("[rotation-thread] Failed to read from wakeup pipe (fd = %i)", fd);
-		ret = -1;
-		goto end;
-	}
 
 	for (;;) {
+		struct ltt_session *session;
 		struct rotation_thread_job *job;
 
 		/* Take the queue lock only to pop an element from the list. */
@@ -716,10 +619,10 @@ int handle_job_queue(struct rotation_thread_handle *handle,
 		pthread_mutex_unlock(&queue->lock);
 
 		session_lock_list();
-		session = session_find_by_id(job->session_id);
+		session = job->session;
 		if (!session) {
-			DBG("[rotation-thread] Session %" PRIu64 " not found",
-					job->session_id);
+			DBG("[rotation-thread] Session \"%s\" not found",
+					session->name);
 			/*
 			 * This is a non-fatal error, and we cannot report it to
 			 * the user (timer), so just print the error and
@@ -730,14 +633,17 @@ int handle_job_queue(struct rotation_thread_handle *handle,
 			 * possible for a job targeting that session to have
 			 * already been queued before it was destroyed.
 			 */
-			session_unlock_list();
 			free(job);
+			session_put(session);
+			session_unlock_list();
 			continue;
 		}
 
 		session_lock(session);
 	        ret = run_job(job, session, handle->notification_thread_handle);
 		session_unlock(session);
+		/* Release reference held by the job. */
+		session_put(session);
 		session_unlock_list();
 		free(job);
 		if (ret) {
@@ -798,7 +704,6 @@ int handle_condition(const struct lttng_condition *condition,
 		goto end;
 	}
 	session_lock(session);
-	session_unlock_list();
 
 	ret = unsubscribe_session_consumed_size_rotation(session,
 			notification_thread_handle);
@@ -806,7 +711,7 @@ int handle_condition(const struct lttng_condition *condition,
 		goto end_unlock;
 	}
 
-	ret = cmd_rotate_session(session, NULL);
+	ret = cmd_rotate_session(session, NULL, false);
 	if (ret == -LTTNG_ERR_ROTATION_PENDING) {
 		DBG("Rotate already pending, subscribe to the next threshold value");
 	} else if (ret != LTTNG_OK) {
@@ -826,6 +731,8 @@ int handle_condition(const struct lttng_condition *condition,
 
 end_unlock:
 	session_unlock(session);
+	session_put(session);
+	session_unlock_list();
 end:
 	return ret;
 }
@@ -845,7 +752,7 @@ int handle_notification_channel(int fd,
 	status = lttng_notification_channel_has_pending_notification(
 			rotate_notification_channel, &notification_pending);
 	if (status != LTTNG_NOTIFICATION_CHANNEL_STATUS_OK) {
-		ERR("[rotation-thread ]Error occured while checking for pending notification");
+		ERR("[rotation-thread ]Error occurred while checking for pending notification");
 		ret = -1;
 		goto end;
 	}
@@ -894,28 +801,28 @@ void *thread_rotation(void *data)
 	int ret;
 	struct rotation_thread_handle *handle = data;
 	struct rotation_thread thread;
+	int queue_pipe_fd;
 
 	DBG("[rotation-thread] Started rotation thread");
+	rcu_register_thread();
+	rcu_thread_online();
+	health_register(health_sessiond, HEALTH_SESSIOND_TYPE_ROTATION);
+	health_code_update();
 
 	if (!handle) {
 		ERR("[rotation-thread] Invalid thread context provided");
 		goto end;
 	}
 
-	rcu_register_thread();
-	rcu_thread_online();
+	queue_pipe_fd = lttng_pipe_get_readfd(
+			handle->rotation_timer_queue->event_pipe);
 
-	health_register(health_sessiond, HEALTH_SESSIOND_TYPE_ROTATION);
-	health_code_update();
 
 	ret = init_thread_state(handle, &thread);
 	if (ret) {
 		goto error;
 	}
 
-	/* Ready to handle client connections. */
-	sessiond_notify_ready();
-
 	while (true) {
 		int fd_count, i;
 
@@ -948,23 +855,40 @@ void *thread_rotation(void *data)
 				goto error;
 			}
 
-			if (sessiond_check_thread_quit_pipe(fd, revents)) {
-				DBG("[rotation-thread] Quit pipe activity");
-				/* TODO flush the queue. */
-				goto exit;
-			} else if (fd == lttng_pipe_get_readfd(handle->rotation_timer_queue->event_pipe)) {
+			if (fd == rotate_notification_channel->socket) {
+				ret = handle_notification_channel(fd, handle,
+						&thread);
+				if (ret) {
+					ERR("[rotation-thread] Error occurred while handling activity on notification channel socket");
+					goto error;
+				}
+			} else {
+				/* Job queue or quit pipe activity. */
+
+				/*
+				 * The job queue is serviced if there is
+				 * activity on the quit pipe to ensure it is
+				 * flushed and all references held in the queue
+				 * are released.
+				 */
 				ret = handle_job_queue(handle, &thread,
 						handle->rotation_timer_queue);
 				if (ret) {
 					ERR("[rotation-thread] Failed to handle rotation timer pipe event");
 					goto error;
 				}
-			} else if (fd == rotate_notification_channel->socket) {
-				ret = handle_notification_channel(fd, handle,
-						&thread);
-				if (ret) {
-					ERR("[rotation-thread] Error occured while handling activity on notification channel socket");
-					goto error;
+
+				if (fd == queue_pipe_fd) {
+					char buf;
+
+					ret = lttng_read(fd, &buf, 1);
+					if (ret != 1) {
+						ERR("[rotation-thread] Failed to read from wakeup pipe (fd = %i)", fd);
+						goto error;
+					}
+				} else {
+					DBG("[rotation-thread] Quit pipe activity");
+					goto exit;
 				}
 			}
 		}
@@ -973,9 +897,36 @@ exit:
 error:
 	DBG("[rotation-thread] Exit");
 	fini_thread_state(&thread);
+end:
 	health_unregister(health_sessiond);
 	rcu_thread_offline();
 	rcu_unregister_thread();
-end:
 	return NULL;
 }
+
+static
+bool shutdown_rotation_thread(void *thread_data)
+{
+	struct rotation_thread_handle *handle = thread_data;
+	const int write_fd = lttng_pipe_get_writefd(handle->quit_pipe);
+
+	return notify_thread_pipe(write_fd) == 1;
+}
+
+bool launch_rotation_thread(struct rotation_thread_handle *handle)
+{
+	struct lttng_thread *thread;
+
+	thread = lttng_thread_create("Rotation",
+			thread_rotation,
+			shutdown_rotation_thread,
+			NULL,
+			handle);
+	if (!thread) {
+		goto error;
+	}
+	lttng_thread_put(thread);
+	return true;
+error:
+	return false;
+}