Fix: snapshot with multiple UIDs

[lttng-tools.git] / src / common / consumer.h

diff --git a/src/common/consumer.h b/src/common/consumer.h
index 5a11950084bce1f36625ff0ce7809c31ca5eae71..2003cbe43003f304c7bf60387416b9a5c8a1da76 100644 (file)
--- a/src/common/consumer.h
+++ b/src/common/consumer.h
@@ -115,7 +115,7 @@ struct lttng_consumer_channel {
        char pathname[PATH_MAX];
        /* Channel name. */
        char name[LTTNG_SYMBOL_NAME_LEN];
-       /* UID and GID of the channel. */
+       /* UID and GID of the session owning this channel. */
        uid_t uid;
        gid_t gid;
        /* Relayd id of the channel. -1ULL if it does not apply. */
@@ -131,6 +131,7 @@ struct lttng_consumer_channel {
        enum consumer_channel_type type;
 
        /* For UST */
+       uid_t ust_app_uid;      /* Application UID. */
        struct ustctl_consumer_channel *uchan;
        unsigned char uuid[UUID_STR_LEN];
        /*
@@ -172,12 +173,29 @@ struct lttng_consumer_channel {
        /*
         * Channel lock.
         *
+        * This lock protects against concurrent update of channel.
+        *
         * This is nested INSIDE the consumer data lock.
+        * This is nested OUTSIDE the channel timer lock.
         * This is nested OUTSIDE the metadata cache lock.
         * This is nested OUTSIDE stream lock.
         * This is nested OUTSIDE consumer_relayd_sock_pair lock.
         */
        pthread_mutex_t lock;
+
+       /*
+        * Channel teardown lock.
+        *
+        * This lock protect against teardown of channel. It is _never_
+        * taken by the timer handler.
+        *
+        * This is nested INSIDE the consumer data lock.
+        * This is nested INSIDE the channel lock.
+        * This is nested OUTSIDE the metadata cache lock.
+        * This is nested OUTSIDE stream lock.
+        * This is nested OUTSIDE consumer_relayd_sock_pair lock.
+        */
+       pthread_mutex_t timer_lock;
 };
 
 /*
@@ -258,6 +276,7 @@ struct lttng_consumer_stream {
         * This is nested INSIDE the consumer_data lock.
         * This is nested INSIDE the metadata cache lock.
         * This is nested INSIDE the channel lock.
+        * This is nested INSIDE the channel timer lock.
         * This is nested OUTSIDE consumer_relayd_sock_pair lock.
         */
        pthread_mutex_t lock;
@@ -398,7 +417,11 @@ struct lttng_consumer_local_data {
        int consumer_error_socket;
        /* socket to ask metadata to sessiond. */
        int consumer_metadata_socket;
-       /* Protect consumer_metadata_socket. */
+       /*
+        * Protect consumer_metadata_socket.
+        *
+        * This is nested OUTSIDE the metadata cache lock.
+        */
        pthread_mutex_t metadata_socket_lock;
        /* socket to exchange commands with sessiond */
        char *consumer_command_sock_path;
@@ -598,5 +621,9 @@ void notify_thread_del_channel(struct lttng_consumer_local_data *ctx,
 void consumer_destroy_relayd(struct consumer_relayd_sock_pair *relayd);
 unsigned long consumer_get_consumed_maxsize(unsigned long consumed_pos,
                unsigned long produced_pos, uint64_t max_stream_size);
+int consumer_add_data_stream(struct lttng_consumer_stream *stream);
+void consumer_del_stream_for_data(struct lttng_consumer_stream *stream);
+int consumer_add_metadata_stream(struct lttng_consumer_stream *stream);
+void consumer_del_stream_for_metadata(struct lttng_consumer_stream *stream);
 
 #endif /* LIB_CONSUMER_H */