-- Copyright 2023 The Chromium Authors
-- Use of this source code is governed by a BSD-style license that can be
-- found in the LICENSE file.
INCLUDE PERFETTO MODULE chrome.chrome_scrolls;
INCLUDE PERFETTO MODULE chrome.scroll_jank.scroll_jank_v3;
-- Selects EventLatency slices that correspond with janks in a scroll. This is
-- based on the V3 version of scroll jank metrics.
CREATE PERFETTO TABLE chrome_janky_event_latencies_v3(
-- The slice id.
id INT,
-- The start timestamp of the slice.
ts INT,
-- The duration of the slice.
dur INT,
-- The track_id for the slice.
track_id INT,
-- The name of the slice (EventLatency).
name STRING,
-- The stage of EventLatency that the caused the jank.
cause_of_jank STRING,
-- The stage of cause_of_jank that caused the jank.
sub_cause_of_jank STRING,
-- How many vsyncs this frame missed its deadline by.
delayed_frame_count INT,
-- The start timestamp where frame presentation was delayed.
frame_jank_ts INT,
-- The duration in ms of the delay in frame presentation.
frame_jank_dur INT
) AS
SELECT
s.id,
s.ts,
s.dur,
s.track_id,
s.name,
e.cause_of_jank,
e.sub_cause_of_jank,
CAST((e.delay_since_last_frame/e.vsync_interval) - 1 AS INT)
AS delayed_frame_count,
CAST(s.ts + s.dur - ((e.delay_since_last_frame - e.vsync_interval) * 1e6)
AS INT) AS frame_jank_ts,
CAST((e.delay_since_last_frame - e.vsync_interval) * 1e6 AS INT)
AS frame_jank_dur
FROM chrome_gesture_scroll_events s
JOIN chrome_janky_frames e
ON s.id = e. event_latency_id;
-- Frame presentation interval is the delta between when the frame was supposed
-- to be presented and when it was actually presented.
CREATE PERFETTO VIEW chrome_janky_frame_presentation_intervals(
-- Unique id.
id INT,
-- The start timestamp of the slice.
ts INT,
-- The duration of the slice.
dur INT,
-- How many vsyncs this frame missed its deadline by.
delayed_frame_count INT,
-- The stage of EventLatency that the caused the jank.
cause_of_jank STRING,
-- The stage of cause_of_jank that caused the jank.
sub_cause_of_jank STRING,
-- The id of the associated event latency in the slice table.
event_latency_id INT
) AS
SELECT
ROW_NUMBER() OVER(ORDER BY frame_jank_ts) AS id,
frame_jank_ts AS ts,
frame_jank_dur AS dur,
delayed_frame_count,
cause_of_jank,
sub_cause_of_jank,
id AS event_latency_id
FROM chrome_janky_event_latencies_v3;
-- Scroll jank frame presentation stats for individual scrolls.
CREATE PERFETTO TABLE chrome_scroll_stats(
-- Id of the individual scroll.
scroll_id INT,
-- The number of frames in the scroll.
frame_count INT,
-- The number of missed vsyncs in the scroll.
missed_vsyncs INT,
-- The number presented frames in the scroll.
presented_frame_count INT,
-- The number of janky frames in the scroll.
janky_frame_count INT,
-- The % of frames that janked in the scroll.
janky_frame_percent FLOAT
) AS
WITH vsyncs AS (
SELECT
COUNT() AS presented_vsync_count,
scroll.id AS scroll_id
FROM chrome_unique_frame_presentation_ts frame
JOIN chrome_scrolls scroll
ON frame.presentation_timestamp >= scroll.ts
AND frame.presentation_timestamp <= scroll.ts + scroll.dur
GROUP BY scroll_id),
missed_vsyncs AS (
SELECT
CAST(SUM((delay_since_last_frame / vsync_interval) - 1) AS INT)
AS total_missed_vsyncs,
scroll_id
FROM chrome_janky_frames
GROUP BY scroll_id),
frame_stats AS (
SELECT
scroll_id,
num_frames AS presented_frame_count,
IFNULL(num_janky_frames, 0) AS janky_frame_count,
ROUND(IFNULL(scroll_jank_percentage, 0), 2) AS janky_frame_percent
FROM chrome_frames_per_scroll
)
SELECT
vsyncs.scroll_id,
presented_vsync_count + IFNULL(total_missed_vsyncs, 0) AS frame_count,
total_missed_vsyncs AS missed_vsyncs,
presented_frame_count,
janky_frame_count,
janky_frame_percent
FROM vsyncs
LEFT JOIN missed_vsyncs
USING (scroll_id)
LEFT JOIN frame_stats
USING (scroll_id);
-- Defines slices for all of janky scrolling intervals in a trace.
CREATE PERFETTO TABLE chrome_scroll_jank_intervals_v3(
-- The unique identifier of the janky interval.
id INT,
-- The start timestamp of the janky interval.
ts INT,
-- The duration of the janky interval.
dur INT
) AS
-- Sub-table to retrieve all janky slice timestamps. Ordering calculations are
-- based on timestamps rather than durations.
WITH janky_latencies AS (
SELECT
s.frame_jank_ts AS start_ts,
s.frame_jank_ts + s.frame_jank_dur AS end_ts
FROM chrome_janky_event_latencies_v3 s),
-- Determine the local maximum timestamp for janks thus far; this will allow
-- us to coalesce all earlier events up to the maximum.
ordered_jank_end_ts AS (
SELECT
*,
MAX(end_ts) OVER (
ORDER BY start_ts ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW)
AS max_end_ts_so_far
FROM janky_latencies),
-- Determine the local minimum timestamp for janks thus far; this will allow
-- us to coalesce all later events up to the nearest local maximum.
range_starts AS (
SELECT
*,
CASE
-- This is a two-pass calculation to calculate the first event in the
-- group. An event is considered the first event in a group if all events
-- which started before it also finished the current one started.
WHEN start_ts <= 1 + LAG(max_end_ts_so_far) OVER (ORDER BY start_ts)
THEN 0
ELSE 1
END AS range_start
FROM ordered_jank_end_ts),
-- Assign an id to allow coalescing of individual slices.
range_groups AS (
SELECT
*,
SUM(range_start) OVER (ORDER BY start_ts) AS range_group
FROM range_starts)
-- Coalesce all slices within an interval.
SELECT
range_group AS id,
MIN(start_ts) AS ts,
MAX(end_ts) - MIN(start_ts) AS dur
FROM range_groups
GROUP BY range_group;
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