| # 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 logging |
| import Queue |
| import re |
| import threading |
| |
| |
| # Log marker containing SurfaceTexture timestamps. |
| _SURFACE_TEXTURE_TIMESTAMPS_MESSAGE = 'SurfaceTexture update timestamps' |
| _SURFACE_TEXTURE_TIMESTAMP_RE = r'\d+' |
| |
| |
| class SurfaceStatsCollector(object): |
| """Collects surface stats for a SurfaceView from the output of SurfaceFlinger. |
| |
| Args: |
| 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) |
| self._collector_thread.start() |
| else: |
| 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._stop_event.set() |
| self._collector_thread.join() |
| self._collector_thread = None |
| return (refresh_period, timestamps) |
| |
| def _CollectorThread(self): |
| last_timestamp = 0 |
| timestamps = [] |
| retries = 0 |
| |
| while not self._stop_event.is_set(): |
| self._get_data_event.wait(1) |
| try: |
| refresh_period, new_timestamps = self._GetSurfaceFlingerFrameData() |
| if refresh_period is None or timestamps is None: |
| retries += 1 |
| if retries < 3: |
| continue |
| 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)) |
| self._stop_event.wait() |
| break |
| 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._get_data_event.clear() |
| 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. |
| self._data_queue.put(e) |
| raise |
| |
| def _GetDataFromThread(self): |
| self._get_data_event.set() |
| ret = self._data_queue.get() |
| if isinstance(ret, Exception): |
| raise ret |
| return ret |
| |
| def _ClearSurfaceFlingerLatencyData(self): |
| """Clears the SurfaceFlinger latency data. |
| |
| Returns: |
| True if SurfaceFlinger latency is supported by the device, otherwise |
| False. |
| """ |
| # 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'], |
| check_return=True) |
| return not len(results) |
| |
| def GetSurfaceFlingerPid(self): |
| try: |
| # Returns the first matching PID found. |
| return next(p.pid for p in self._device.ListProcesses('surfaceflinger')) |
| except StopIteration: |
| raise Exception('Unable to get surface flinger process id') |
| |
| def _GetSurfaceViewWindowName(self): |
| results = self._device.RunShellCommand( |
| ['dumpsys', 'SurfaceFlinger', '--list'], check_return=True) |
| for window_name in results: |
| if window_name.startswith('SurfaceView'): |
| return window_name |
| return None |
| |
| def _GetSurfaceFlingerFrameData(self): |
| """Returns collected SurfaceFlinger frame timing data. |
| |
| Returns: |
| A tuple containing: |
| - The display's nominal refresh period in milliseconds. |
| - A list of timestamps signifying frame presentation times in |
| milliseconds. |
| 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). |
| """ |
| window_name = self._GetSurfaceViewWindowName() |
| command = ['dumpsys', 'SurfaceFlinger', '--latency'] |
| # Even if we don't find the window name, run the command to get the refresh |
| # period. |
| if window_name: |
| command.append(window_name) |
| output = self._device.RunShellCommand(command, check_return=True) |
| return ParseFrameData(output, parse_timestamps=bool(window_name)) |
| |
| |
| def ParseFrameData(lines, parse_timestamps): |
| # 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. |
| results = [] |
| for line in lines: |
| # Skip over lines with anything other than digits and whitespace. |
| if re.search(r'[^\d\s]', line): |
| logging.warning('unexpected output: %s', line) |
| else: |
| results.append(line) |
| if not results: |
| return None, None |
| |
| timestamps = [] |
| nanoseconds_per_millisecond = 1e6 |
| refresh_period = long(results[0]) / nanoseconds_per_millisecond |
| if not parse_timestamps: |
| return refresh_period, timestamps |
| |
| # 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: |
| logging.warning('Unexpected line: %s', line) |
| continue |
| timestamp = long(fields[1]) |
| if timestamp == pending_fence_timestamp: |
| continue |
| timestamp /= nanoseconds_per_millisecond |
| timestamps.append(timestamp) |
| |
| return refresh_period, timestamps |