Docs: clarify the meaning of the snapshot_mode flag in ltt_session

[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 6a059798d925afbd681f07a898f866e7dc8374f2..82e409521c440c621f06d5d46a86d8cc380e6d6c 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
@@ -76,6 +81,8 @@ struct ltt_session {
        pthread_mutex_t lock;
        struct cds_list_head list;
        uint64_t id;            /* session unique identifier */
+       /* Indicates if the session has been added to the session list and ht.*/
+       bool published;
        /* Indicates if a destroy command has been applied to this session. */
        bool destroyed;
        /* UID/GID of the user owning the session */
@@ -107,9 +114,11 @@ struct ltt_session {
        /* Indicate if the session has to output the traces or not. */
        unsigned int output_traces;
        /*
-        * This session is in snapshot mode. This means that every channel enabled
-        * will be set in overwrite mode and mmap. It is considered exclusively for
-        * snapshot purposes.
+        * This session is in snapshot mode. This means that channels enabled
+        * will be set in overwrite mode by default and must be in mmap
+        * output mode. Note that snapshots can be taken on a session that
+        * is not in "snapshot_mode". This parameter only affects channel
+        * creation defaults.
         */
        unsigned int snapshot_mode;
        /*
@@ -232,7 +241,9 @@ 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);