Add --trace-memory option for tracing heap memory

build/android/adb_profile_chrome.py

 #!/usr/bin/env python
 #
 # 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 gzip
 import json
 import logging
 import optparse
@@ skipping 13 matching lines @@
 from pylib import constants
 from pylib import pexpect
 from pylib.device import device_utils
 
 _TRACE_VIEWER_ROOT = os.path.join(constants.DIR_SOURCE_ROOT,
                                   'third_party', 'trace-viewer')
 sys.path.append(_TRACE_VIEWER_ROOT)
 from trace_viewer.build import trace2html # pylint: disable=F0401
 
 _DEFAULT_CHROME_CATEGORIES = '_DEFAULT_CHROME_CATEGORIES'
-
+_HEAP_PROFILE_MMAP = 'heapprof.mmap'

[Sami, 2014/05/19 16:00:10]

nit: could you call this _HEAP_PROFILE_MMAP_PROPERTY instead so it's a little
clearer what it is for?

[JungJik, 2014/05/19 16:35:36]

sure!

 
 def _GetTraceTimestamp():
   return time.strftime('%Y-%m-%d-%H%M%S', time.localtime())
 
 
 class ChromeTracingController(object):
   def __init__(self, device, package_info, categories, ring_buffer):
     self._device = device
     self._package_info = package_info
     self._categories = categories
@@ skipping 257 matching lines @@
 def _ComputeChromeCategories(options):
   categories = []
   if options.trace_frame_viewer:
     categories.append('disabled-by-default-cc.debug')
   if options.trace_ubercompositor:
     categories.append('disabled-by-default-cc.debug*')
   if options.trace_gpu:
     categories.append('disabled-by-default-gpu.debug*')
   if options.trace_flow:
     categories.append('disabled-by-default-toplevel.flow')
+  if options.trace_memory:
+    categories.append('disabled-by-default-memory')
   if options.chrome_categories:
     categories += options.chrome_categories.split(',')
   return categories
 
 
 def _ComputeSystraceCategories(options):
   if not options.systrace_categories:
     return []
   return options.systrace_categories.split(',')
 
@@ skipping 42 matching lines @@
   categories.add_option('--trace-frame-viewer',
                         help='Enable enough trace categories for '
                         'compositor frame viewing.', action='store_true')
   categories.add_option('--trace-ubercompositor',
                         help='Enable enough trace categories for '
                         'ubercompositor frame data.', action='store_true')
   categories.add_option('--trace-gpu', help='Enable extra trace categories for '
                         'GPU data.', action='store_true')
   categories.add_option('--trace-flow', help='Enable extra trace categories '
                         'for IPC message flows.', action='store_true')
+  categories.add_option('--trace-memory', help='Enable extra trace categories '
+                        'for memory profile. (tcmalloc required)',
+                        action='store_true')
   parser.add_option_group(categories)
 
   output_options = optparse.OptionGroup(parser, 'Output options')
   output_options.add_option('-o', '--output', help='Save trace output to file.')
   output_options.add_option('--json', help='Save trace as raw JSON instead of '
                             'HTML.', action='store_true')
   output_options.add_option('--view', help='Open resulting trace file in a '
                             'browser.', action='store_true')
   parser.add_option_group(output_options)
 
@@ skipping 44 matching lines @@
     return 0
 
   if options.systrace_categories in ['list', 'help']:
     _PrintMessage('\n'.join(SystraceController.GetCategories(device)))
     return 0
 
   if not options.time and not options.continuous:
     _PrintMessage('Time interval or continuous tracing should be specified.')
     return 1
 
+  system_properties = device.old_interface.system_properties
+  if options.trace_memory:
+    if not device.old_interface.IsRootEnabled():
+      device.old_interface.EnableAdbRoot()

[Sami, 2014/05/19 16:00:10]

You can just call EnableAdbRoot() unconditionally since it is a no-op if we're
already root.

[JungJik, 2014/05/19 16:35:36]

thanks for your comment.

+    system_properties[_HEAP_PROFILE_MMAP] = 1
+  else:
+    system_properties[_HEAP_PROFILE_MMAP] = 0

[Sami, 2014/05/19 11:39:49]

Should we reset this property after tracing? Are there any side effects if it is
left enabled?

If so, would it make sense to add a MemoryTracingController class (similar to
ChromeTracingController etc.) that ensure the property is enabled only for the
duration of tracing?

[JungJik, 2014/05/19 12:08:10]

Thanks for your comment. 
I've just checked the code. if the profiler is stopped, the hooking functions
are unset. so whether the flag is enabled or not, it does not effect on browser.
ref: heap-profiler.cc/void HeapProfilerStop() http://goo.gl/8OC4mx

[Sami, 2014/05/19 16:00:10]

Thanks for checking. I was thinking more about the case where you record a trace
with adb_profile_chrome with --trace-memory and then use some other profiler
like telemetry. If we don't reset the flag you might get distorted results in
the second run.

[JungJik, 2014/05/19 16:35:36]

how about reset after pulling the trace file, then we don't need to worry about
the second run. I will file new patch.

+
   chrome_categories = _ComputeChromeCategories(options)
   systrace_categories = _ComputeSystraceCategories(options)
 
   if chrome_categories and 'webview' in systrace_categories:
     logging.warning('Using the "webview" category in systrace together with '
                     'Chrome tracing results in duplicate trace events.')
 
   controllers = []
   if chrome_categories:
     controllers.append(ChromeTracingController(device,
@@ skipping 18 matching lines @@
                                 options.json)
   if options.view:
     if sys.platform == 'darwin':
       os.system('/usr/bin/open %s' % os.path.abspath(result))
     else:
       webbrowser.open(result)
 
 
 if __name__ == '__main__':
   sys.exit(main())