Add stream lock comment for nesting

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

diff --git a/src/common/consumer.h b/src/common/consumer.h
index 9981856feeca8734a428951418c34c7e2f380e96..53b6151822ba36102b6b6df5a53878ac35b714a7 100644 (file)
--- a/src/common/consumer.h
+++ b/src/common/consumer.h
@@ -141,7 +141,12 @@ struct lttng_consumer_stream {
        uint64_t relayd_stream_id;
        /* Next sequence number to use for trace packet */
        uint64_t next_net_seq_num;
-       /* Lock to use the stream FDs since they are used between threads. */
+       /*
+        * Lock to use the stream FDs since they are used between threads. Using
+        * this lock with network streaming, when using the control mutex of a
+        * consumer_relayd_sock_pair, make sure to acquire this lock BEFORE locking
+        * it and releasing it AFTER the control mutex unlock.
+        */
        pthread_mutex_t lock;
        /* Tracing session id */
        uint64_t session_id;
@@ -414,5 +419,6 @@ int consumer_add_relayd_socket(int net_seq_idx, int sock_type,
                struct pollfd *consumer_sockpoll, struct lttcomm_sock *relayd_sock);
 void consumer_flag_relayd_for_destroy(
                struct consumer_relayd_sock_pair *relayd);
+int consumer_data_available(uint64_t id);
 
 #endif /* LIB_CONSUMER_H */