Add an activity monitor which profiles IO and CPU utilization.

build/android/pylib/device_stats_monitor.py

Index: build/android/pylib/device_stats_monitor.py
diff --git a/build/android/pylib/device_stats_monitor.py b/build/android/pylib/device_stats_monitor.py
new file mode 100755
index 0000000000000000000000000000000000000000..79225028baf7c19ac51276b956181e1ab8eb33da
--- /dev/null
+++ b/build/android/pylib/device_stats_monitor.py
@@ -0,0 +1,116 @@
+# Copyright (c) 2012 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.
+
+"""Utilities for iotop/top style profiling for android."""
+
+import collections
+import json
+import os
+import subprocess
+import sys
+import urllib
+
+import constants
+import io_stats_parser
+
+
+class DeviceStatsMonitor(object):
+  """Class for collecting device stats such as IO/CPU usage.
+
+  Args:
+      adb: Instance of AndroidComannds.
+      hz: Frequency at which to sample device stats.
+  """
+
+  DEVICE_PATH = '/data/local/tmp/device_stats_monitor'
+  HOST_PATH = os.path.abspath(os.path.join(
+      constants.CHROME_DIR, 'out', 'Release', 'device_stats_monitor'))
+  PROFILE_PATH = '/sdcard/Download/device_stats_monitor.profile'
+  RESULT_VIEWER_PATH = os.path.abspath(os.path.join(
+      os.path.dirname(os.path.realpath(__file__)), 'device_stats_monitor.html'))
+
+  def __init__(self, adb, hz):
+    self._adb = adb
+    self._adb.PushIfNeeded(DeviceStatsMonitor.HOST_PATH,
+                           DeviceStatsMonitor.DEVICE_PATH)
+    self._hz = hz
+
+  def Start(self):
+    """Starts device stats monitor on the device."""
+    self._adb.SetFileContents(DeviceStatsMonitor.PROFILE_PATH, '')
+    self._process = subprocess.Popen(
+        ['adb', 'shell', '%s --hz=%d %s' % (
+            DeviceStatsMonitor.DEVICE_PATH, self._hz,
+            DeviceStatsMonitor.PROFILE_PATH)])
+
+  def StopAndCollect(self, output_path):
+    """Stops monitoring and saves results.
+
+    Args:
+      output_path: Path to save results.
+
+    Returns:
+      String of URL to load results in browser.
+    """
+    assert self._process
+    self._adb.KillAll(DeviceStatsMonitor.DEVICE_PATH)
+    self._process.wait()
+    profile = self._adb.GetFileContents(DeviceStatsMonitor.PROFILE_PATH)
+
+    results = collections.defaultdict(list)
+    last_io_stats = None
+    last_cpu_stats = None
+    for line in profile:
+      if ' mmcblk0 ' in line:
+        stats = io_stats_parser.ParseIoStatsLine(line)
+        if last_io_stats:
+          results['sectors_read'].append(stats.num_sectors_read -
+                                         last_io_stats.num_sectors_read)
+          results['sectors_written'].append(stats.num_sectors_written -
+                                            last_io_stats.num_sectors_written)
+        last_io_stats = stats
+      elif line.startswith('cpu '):
+        stats = self._ParseCpuStatsLine(line)
+        if last_cpu_stats:
+          results['user'].append(stats.user - last_cpu_stats.user)
+          results['nice'].append(stats.nice - last_cpu_stats.nice)
+          results['system'].append(stats.system - last_cpu_stats.system)
+          results['idle'].append(stats.idle - last_cpu_stats.idle)
+          results['iowait'].append(stats.iowait - last_cpu_stats.iowait)
+          results['irq'].append(stats.irq - last_cpu_stats.irq)
+          results['softirq'].append(stats.softirq- last_cpu_stats.softirq)
+        last_cpu_stats = stats
+    units = {
+      'sectors_read': 'sectors',
+      'sectors_written': 'sectors',
+      'user': 'jiffies',
+      'nice': 'jiffies',
+      'system': 'jiffies',
+      'idle': 'jiffies',
+      'iowait': 'jiffies',
+      'irq': 'jiffies',
+      'softirq': 'jiffies',
+    }
+    with open(output_path, 'w') as f:
+      f.write('display(%d, %s, %s);' % (self._hz, json.dumps(results), units))
+    return 'file://%s?results=file://%s' % (
+        DeviceStatsMonitor.RESULT_VIEWER_PATH, urllib.quote(output_path))
+
+
+  @staticmethod
+  def _ParseCpuStatsLine(line):
+    """Parses a line of cpu stats into a CpuStats named tuple."""
+    # Field definitions: http://www.linuxhowtos.org/System/procstat.htm
+    cpu_stats = collections.namedtuple('CpuStats',
+                                       ['device',
+                                        'user',
+                                        'nice',
+                                        'system',
+                                        'idle',
+                                        'iowait',
+                                        'irq',
+                                        'softirq',
+                                       ])
+    fields = line.split()
+    return cpu_stats._make([fields[0]] + [int(f) for f in fields[1:8]])