Wait for the destruction of sessions before tearing down main thread

[lttng-tools.git] / src / bin / lttng-sessiond / session.h

diff --git a/src/bin/lttng-sessiond/session.h b/src/bin/lttng-sessiond/session.h
index abbf9ece04a1a1b438287fda61f2f73f39a65f91..ec03029205163cd5e230337850fed5a88edcad63 100644 (file)
--- a/src/bin/lttng-sessiond/session.h
+++ b/src/bin/lttng-sessiond/session.h
@@ -47,6 +47,11 @@ struct ltt_session_list {
         * iterate or/and do any actions on that list.
         */
        pthread_mutex_t lock;
+       /*
+        * This condition variable is signaled on every removal from
+        * the session list.
+        */
+       pthread_cond_t removal_cond;
 
        /*
         * Session unique ID generator. The session list lock MUST be
@@ -67,6 +72,7 @@ struct ltt_session {
        char hostname[HOST_NAME_MAX]; /* Local hostname. */
        struct ltt_kernel_session *kernel_session;
        struct ltt_ust_session *ust_session;
+       struct urcu_ref ref;
        /*
         * Protect any read/write on this session data structure. This lock must be
         * acquired *before* using any public functions declared below. Use
@@ -75,6 +81,8 @@ struct ltt_session {
        pthread_mutex_t lock;
        struct cds_list_head list;
        uint64_t id;            /* session unique identifier */
+       /* Indicates if a destroy command has been applied to this session. */
+       bool destroyed;
        /* UID/GID of the user owning the session */
        uid_t uid;
        gid_t gid;
@@ -123,7 +131,7 @@ struct ltt_session {
        struct lttng_ht_node_u64 node;
        /*
         * The current archive id corresponds to the number of session rotations
-        * that have occured for this session. The archive id
+        * that have occurred for this session. The archive id
         * is used to tag the "generation" of a stream. This tag allows the
         * consumer and relay daemons to track when a given stream was created
         * during the lifetime of a session.
@@ -136,24 +144,19 @@ struct ltt_session {
         */
        uint64_t current_archive_id;
        /*
-        * Rotation is pending between the time it starts until the consumer has
-        * finished extracting the data. If the session uses a relay, data related
-        * to a rotation can still be in flight after that, see
-        * rotate_pending_relay.
-        */
-       bool rotate_pending;
-       /*
-        * True until the relay has finished the rotation of all the streams.
+        * Rotation is considered pending between the time it is launched up
+        * until the moment when the data has been writen at the destination
+        * and the trace archive has been renamed.
+        *
+        * When tracing locally, only 'rotation_pending_local' is used since
+        * no remote checks are needed. However, when tracing to a relay daemon,
+        * a second check is needed to ensure that the data has been
+        * commited at the remote destination.
         */
-       bool rotate_pending_relay;
+       bool rotation_pending_local;
+       bool rotation_pending_relay;
        /* Current state of a rotation. */
        enum lttng_rotation_state rotation_state;
-       /*
-        * Number of channels waiting for a rotation.
-        * When this number reaches 0, we can handle the rename of the chunk
-        * folder and inform the client that the rotate is finished.
-        */
-       unsigned int nr_chan_rotate_pending;
        struct {
                /*
                 * When the rotation is in progress, the temporary path name is
@@ -182,14 +185,14 @@ struct ltt_session {
         */
        time_t current_chunk_start_ts;
        /*
-        * Timer to check periodically if a relay has completed the last
-        * rotation.
+        * Timer to check periodically if a relay and/or consumer has completed
+        * the last rotation.
         */
-       bool rotate_relay_pending_timer_enabled;
-       timer_t rotate_relay_pending_timer;
+       bool rotation_pending_check_timer_enabled;
+       timer_t rotation_pending_check_timer;
        /* Timer to periodically rotate a session. */
-       bool rotate_timer_enabled;
-       timer_t rotate_timer;
+       bool rotation_schedule_timer_enabled;
+       timer_t rotation_schedule_timer;
        /* Value for periodic rotations, 0 if disabled. */
        uint64_t rotate_timer_period;
        /* Value for size-based rotations, 0 if disabled. */
@@ -197,7 +200,7 @@ struct ltt_session {
        /*
         * Keep a state if this session was rotated after the last stop command.
         * We only allow one rotation after a stop. At destroy, we also need to
-        * know if a rotation occured since the last stop to rename the current
+        * know if a rotation occurred since the last stop to rename the current
         * chunk.
         */
        bool rotated_after_last_stop;
@@ -210,7 +213,6 @@ struct ltt_session {
 
 /* Prototypes */
 int session_create(char *name, uid_t uid, gid_t gid);
-int session_destroy(struct ltt_session *session);
 
 void session_lock(struct ltt_session *session);
 void session_lock_list(void);
@@ -218,6 +220,11 @@ int session_trylock_list(void);
 void session_unlock(struct ltt_session *session);
 void session_unlock_list(void);
 
+void session_destroy(struct ltt_session *session);
+
+bool session_get(struct ltt_session *session);
+void session_put(struct ltt_session *session);
+
 enum consumer_dst_type session_get_consumer_destination_type(
                const struct ltt_session *session);
 const char *session_get_net_consumer_hostname(
@@ -230,8 +237,13 @@ struct lttng_trace_archive_location *session_get_trace_archive_location(
 
 struct ltt_session *session_find_by_name(const char *name);
 struct ltt_session *session_find_by_id(uint64_t id);
+
 struct ltt_session_list *session_get_list(void);
+void session_list_wait_empty(void);
 
 int session_access_ok(struct ltt_session *session, uid_t uid, gid_t gid);
 
+int session_reset_rotation_state(struct ltt_session *session,
+               enum lttng_rotation_state result);
+
 #endif /* _LTT_SESSION_H */