blob: 25079f310eeb18b4d44a10a01b8382912b13fbd7 [file] [log] [blame]
# Copyright 2013 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
import Queue
import threading
# Log marker containing SurfaceTexture timestamps.
_SURFACE_TEXTURE_TIMESTAMPS_MESSAGE = 'SurfaceTexture update timestamps'
class SurfaceStatsCollector(object):
"""Collects surface stats for a SurfaceView from the output of SurfaceFlinger.
device: A DeviceUtils instance.
def __init__(self, device):
self._device = device
self._collector_thread = None
self._surface_before = None
self._get_data_event = None
self._data_queue = None
self._stop_event = None
self._warn_about_empty_data = True
def DisableWarningAboutEmptyData(self):
self._warn_about_empty_data = False
def Start(self):
assert not self._collector_thread
if self._ClearSurfaceFlingerLatencyData():
self._get_data_event = threading.Event()
self._stop_event = threading.Event()
self._data_queue = Queue.Queue()
self._collector_thread = threading.Thread(target=self._CollectorThread)
raise Exception('SurfaceFlinger not supported on this device.')
def Stop(self):
assert self._collector_thread
(refresh_period, timestamps) = self._GetDataFromThread()
if self._collector_thread:
self._collector_thread = None
return (refresh_period, timestamps)
def _CollectorThread(self):
last_timestamp = 0
timestamps = []
retries = 0
while not self._stop_event.is_set():
refresh_period, new_timestamps = self._GetSurfaceFlingerFrameData()
if refresh_period is None or timestamps is None:
retries += 1
if retries < 3:
if last_timestamp:
# Some data has already been collected, but either the app
# was closed or there's no new data. Signal the main thread and
# wait.
self._data_queue.put((None, None))
raise Exception('Unable to get surface flinger latency data')
timestamps += [timestamp for timestamp in new_timestamps
if timestamp > last_timestamp]
if len(timestamps):
last_timestamp = timestamps[-1]
if self._get_data_event.is_set():
self._data_queue.put((refresh_period, timestamps))
timestamps = []
except Exception as e:
# On any error, before aborting, put the exception into _data_queue to
# prevent the main thread from waiting at _data_queue.get() infinitely.
def _GetDataFromThread(self):
ret = self._data_queue.get()
if isinstance(ret, Exception):
raise ret
return ret
def _ClearSurfaceFlingerLatencyData(self):
"""Clears the SurfaceFlinger latency data.
True if SurfaceFlinger latency is supported by the device, otherwise
# The command returns nothing if it is supported, otherwise returns many
# lines of result just like 'dumpsys SurfaceFlinger'.
results = self._device.RunShellCommand(
['dumpsys', 'SurfaceFlinger', '--latency-clear', 'SurfaceView'],
return not len(results)
def GetSurfaceFlingerPid(self):
pids_dict = self._device.GetPids('surfaceflinger')
if not pids_dict:
raise Exception('Unable to get surface flinger process id')
# TODO(cataput:#3378): Do more strict checks in GetPids when possible.
# For now it just returns the first pid found of some matching process.
return pids_dict.popitem()[1][0]
def _GetSurfaceFlingerFrameData(self):
"""Returns collected SurfaceFlinger frame timing data.
A tuple containing:
- The display's nominal refresh period in milliseconds.
- A list of timestamps signifying frame presentation times in
The return value may be (None, None) if there was no data collected (for
example, if the app was closed before the collector thread has finished).
# adb shell dumpsys SurfaceFlinger --latency <window name>
# prints some information about the last 128 frames displayed in
# that window.
# The data returned looks like this:
# 16954612
# 7657467895508 7657482691352 7657493499756
# 7657484466553 7657499645964 7657511077881
# 7657500793457 7657516600576 7657527404785
# (...)
# The first line is the refresh period (here 16.95 ms), it is followed
# by 128 lines w/ 3 timestamps in nanosecond each:
# A) when the app started to draw
# B) the vsync immediately preceding SF submitting the frame to the h/w
# C) timestamp immediately after SF submitted that frame to the h/w
# The difference between the 1st and 3rd timestamp is the frame-latency.
# An interesting data is when the frame latency crosses a refresh period
# boundary, this can be calculated this way:
# ceil((C - A) / refresh-period)
# (each time the number above changes, we have a "jank").
# If this happens a lot during an animation, the animation appears
# janky, even if it runs at 60 fps in average.
# We use the special "SurfaceView" window name because the statistics for
# the activity's main window are not updated when the main web content is
# composited into a SurfaceView.
results = self._device.RunShellCommand(
['dumpsys', 'SurfaceFlinger', '--latency', 'SurfaceView'],
if not len(results):
return (None, None)
timestamps = []
nanoseconds_per_millisecond = 1e6
refresh_period = long(results[0]) / nanoseconds_per_millisecond
# If a fence associated with a frame is still pending when we query the
# latency data, SurfaceFlinger gives the frame a timestamp of INT64_MAX.
# Since we only care about completed frames, we will ignore any timestamps
# with this value.
pending_fence_timestamp = (1 << 63) - 1
for line in results[1:]:
fields = line.split()
if len(fields) != 3:
timestamp = long(fields[1])
if timestamp == pending_fence_timestamp:
timestamp /= nanoseconds_per_millisecond
return (refresh_period, timestamps)