From bb1dcf019b7b1c2057cc34afde9172d12fc3981e Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Fri, 19 Nov 2021 11:08:15 -0500 Subject: [PATCH] relayd: clarify viewer_get_next_index no rotation condition MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The condition identifying cases where a viewer_get_next_index must not perform a viewer stream rotation is relatively tricky to comprehend. Split it in two intermediate variables, and use those variables to print debugging statements when conditions for not performing a rotation match. Signed-off-by: Mathieu Desnoyers Signed-off-by: Jérémie Galarneau Change-Id: Ieca2fbf879c8ed45c0b3aa6035ac32679b12dcdc --- src/bin/lttng-relayd/live.cpp | 53 +++++++++++++++++++++++++++++++---- 1 file changed, 47 insertions(+), 6 deletions(-) diff --git a/src/bin/lttng-relayd/live.cpp b/src/bin/lttng-relayd/live.cpp index 9cdc1c8d7..96ec11efc 100644 --- a/src/bin/lttng-relayd/live.cpp +++ b/src/bin/lttng-relayd/live.cpp @@ -29,6 +29,7 @@ #include #include #include +#include #include #include @@ -1602,6 +1603,9 @@ int viewer_get_next_index(struct relay_connection *conn) struct relay_stream *rstream = NULL; struct ctf_trace *ctf_trace = NULL; struct relay_viewer_stream *metadata_viewer_stream = NULL; + bool viewer_stream_and_session_in_same_chunk, viewer_stream_one_rotation_behind; + uint64_t stream_file_chunk_id = -1ULL, viewer_session_chunk_id = -1ULL; + enum lttng_trace_chunk_status status; LTTNG_ASSERT(conn); @@ -1682,12 +1686,50 @@ int viewer_get_next_index(struct relay_connection *conn) * This allows clients to consume all the packets of a trace chunk * after a session's destruction. */ - if (!lttng_trace_chunk_ids_equal(conn->viewer_session->current_trace_chunk, vstream->stream_file.trace_chunk) && - !(rstream->completed_rotation_count == vstream->last_seen_rotation_count + 1 && !rstream->trace_chunk)) { - DBG("Viewer session and viewer stream chunk IDs differ: " - "vsession chunk %p vstream chunk %p", + if (vstream->stream_file.trace_chunk) { + status = lttng_trace_chunk_get_id( + vstream->stream_file.trace_chunk, + &stream_file_chunk_id); + LTTNG_ASSERT(status == LTTNG_TRACE_CHUNK_STATUS_OK); + } + if (conn->viewer_session->current_trace_chunk) { + status = lttng_trace_chunk_get_id( conn->viewer_session->current_trace_chunk, - vstream->stream_file.trace_chunk); + &viewer_session_chunk_id); + LTTNG_ASSERT(status == LTTNG_TRACE_CHUNK_STATUS_OK); + } + + viewer_stream_and_session_in_same_chunk = lttng_trace_chunk_ids_equal( + conn->viewer_session->current_trace_chunk, + vstream->stream_file.trace_chunk); + viewer_stream_one_rotation_behind = rstream->completed_rotation_count == + vstream->last_seen_rotation_count + 1; + + if (viewer_stream_and_session_in_same_chunk) { + DBG("Transition to latest chunk check (%s -> %s): Same chunk, no need to rotate", + vstream->stream_file.trace_chunk ? + std::to_string(stream_file_chunk_id).c_str() : + "None", + conn->viewer_session->current_trace_chunk ? + std::to_string(viewer_session_chunk_id).c_str() : + "None"); + } else if (viewer_stream_one_rotation_behind && !rstream->trace_chunk) { + DBG("Transition to latest chunk check (%s -> %s): One chunk behind relay stream which is being destroyed, no need to rotate", + vstream->stream_file.trace_chunk ? + std::to_string(stream_file_chunk_id).c_str() : + "None", + conn->viewer_session->current_trace_chunk ? + std::to_string(viewer_session_chunk_id).c_str() : + "None"); + } else { + DBG("Transition to latest chunk check (%s -> %s): Viewer stream chunk ID and viewer session chunk ID differ, rotating viewer stream", + vstream->stream_file.trace_chunk ? + std::to_string(stream_file_chunk_id).c_str() : + "None", + conn->viewer_session->current_trace_chunk ? + std::to_string(viewer_session_chunk_id).c_str() : + "None"); + viewer_stream_rotate_to_trace_chunk(vstream, conn->viewer_session->current_trace_chunk); vstream->last_seen_rotation_count = @@ -1732,7 +1774,6 @@ int viewer_get_next_index(struct relay_connection *conn) */ if (!vstream->stream_file.handle) { char file_path[LTTNG_PATH_MAX]; - enum lttng_trace_chunk_status status; struct fs_handle *fs_handle; ret = utils_stream_file_path(rstream->path_name, -- 2.34.1