X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=libringbuffer%2Ffrontend.h;h=a2f74596eb9c06f319236309d2f36cdae2eaca99;hb=c7667bfebfa1d054ad8d54fd98ada3c86184e327;hp=8c8517086828d1fc5c9cf2bf2c780b8a933fc653;hpb=5ea386c3b8e3566ec0b6710c82aae433de4d944a;p=lttng-ust.git

diff --git a/libringbuffer/frontend.h b/libringbuffer/frontend.h
index 8c851708..a2f74596 100644
--- a/libringbuffer/frontend.h
+++ b/libringbuffer/frontend.h
@@ -131,6 +131,11 @@ extern int lib_ring_buffer_snapshot(struct lttng_ust_lib_ring_buffer *buf,
 				    unsigned long *consumed,
 				    unsigned long *produced,
 				    struct lttng_ust_shm_handle *handle);
+extern int lib_ring_buffer_snapshot_sample_positions(
+				    struct lttng_ust_lib_ring_buffer *buf,
+				    unsigned long *consumed,
+				    unsigned long *produced,
+				    struct lttng_ust_shm_handle *handle);
 extern void lib_ring_buffer_move_consumer(struct lttng_ust_lib_ring_buffer *buf,
 					  unsigned long consumed_new,
 					  struct lttng_ust_shm_handle *handle);
@@ -162,9 +167,14 @@ static inline
 void lib_ring_buffer_put_next_subbuf(struct lttng_ust_lib_ring_buffer *buf,
 				     struct lttng_ust_shm_handle *handle)
 {
+	struct channel *chan;
+
+	chan = shmp(handle, buf->backend.chan);
+	if (!chan)
+		return;
 	lib_ring_buffer_put_subbuf(buf, handle);
-	lib_ring_buffer_move_consumer(buf, subbuf_align(buf->cons_snapshot,
-							shmp(handle, buf->backend.chan)), handle);
+	lib_ring_buffer_move_consumer(buf, subbuf_align(buf->cons_snapshot, chan),
+			handle);
 }
 
 extern void channel_reset(struct channel *chan);