[Android] Support idle wakeup measurement with /proc/timer_stats

tools/telemetry/telemetry/internal/platform/android_platform_backend_unittest.py

Index: tools/telemetry/telemetry/internal/platform/android_platform_backend_unittest.py
diff --git a/tools/telemetry/telemetry/internal/platform/android_platform_backend_unittest.py b/tools/telemetry/telemetry/internal/platform/android_platform_backend_unittest.py
index 22939f862b8e7524d7f7a08347c6a6fe8093e12a..6ce664f20ff4c52ee48e0b2309b479280a2753b0 100644
--- a/tools/telemetry/telemetry/internal/platform/android_platform_backend_unittest.py
+++ b/tools/telemetry/telemetry/internal/platform/android_platform_backend_unittest.py
@@ -2,6 +2,7 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import os
 import unittest
 
 from telemetry.core import util
@@ -17,6 +18,23 @@ util.AddDirToPythonPath(util.GetChromiumSrcDir(), 'build', 'android')
 from pylib.device import battery_utils
 from pylib.device import device_utils
 
+
+class TestBackend(android_platform_backend.AndroidPlatformBackend):
+
+  # pylint: disable=W0223
+
+  def __init__(self, device, finder_options):
+    super(TestBackend, self).__init__(device, finder_options)
+    self._mock_files = {}
+
+  def SetMockFile(self, real_file, mock_file):
+    with open(os.path.join(util.GetUnittestDataDir(), real_file)) as f:
+      self._mock_files[mock_file] = f.read()
+
+  def GetFileContents(self, filename):
+    return self._mock_files.get(filename)
+
+
 class AndroidPlatformBackendTest(unittest.TestCase):
   def setUp(self):
     self._options = options_for_unittests.GetCopy()
@@ -45,12 +63,18 @@ class AndroidPlatformBackendTest(unittest.TestCase):
         GetProp=mock.MagicMock(side_effect=get_prop))
     self.device_patcher.start()
 
+    self.idle_wakeup_patcher = mock.patch.object(
+        android_platform_backend.AndroidPlatformBackend,
+        '_GetIdleWakeupCount', return_value=None)
+    self.idle_wakeup_patcher.start()
+
   def tearDown(self):
     self._stubs.Restore()
     android_platform_backend.psutil = self._actual_ps_util
     self.battery_patcher.stop()
     self.setup_prebuilt_tool_patcher.stop()
     self.device_patcher.stop()
+    self.idle_wakeup_patcher.stop()
 
   @decorators.Disabled('chromeos')
   def testGetCpuStats(self):
@@ -100,6 +124,34 @@ class AndroidPlatformBackendTest(unittest.TestCase):
       for state in result[cpu]:
         self.assertAlmostEqual(result[cpu][state], expected_cstate[cpu][state])
 
+  def testGetIdleWakeupCount(self):
+    self.idle_wakeup_patcher.stop()
+    with open(os.path.join(
+        util.GetUnittestDataDir(), 'ps_for_timer_stats')) as ps_return:
+      with mock.patch.object(
+          device_utils.DeviceUtils, 'RunShellCommand',
+          return_value=ps_return.read().splitlines()):
+        backend = TestBackend(
+            android_device.AndroidDevice('1234'), self._options)
+        backend.SetMockFile('timer_stats_empty', '/proc/timer_stats')
+        cpu_stats = backend.GetCpuStats('31735')
+        self.assertTrue('IdleWakeupCount' in cpu_stats)
+        result = cpu_stats['IdleWakeupCount'].total_sum()
+        self.assertEquals(result, 0)
+
+        backend.SetMockFile('timer_stats', '/proc/timer_stats')
+        cpu_stats = backend.GetCpuStats('31735')
+        self.assertTrue('IdleWakeupCount' in cpu_stats)
+        result = cpu_stats['IdleWakeupCount'].total_sum()
+        self.assertEquals(result, 111)
+
+        backend.SetMockFile('timer_stats_dup_pid', '/proc/timer_stats')
+        cpu_stats = backend.GetCpuStats('31735')
+        self.assertTrue('IdleWakeupCount' in cpu_stats)
+        result = cpu_stats['IdleWakeupCount'].total_sum()
+        self.assertEquals(result, 1400)
+    self.idle_wakeup_patcher.start()
+
   def testInstallTestCaFailure(self):
     backend = android_platform_backend.AndroidPlatformBackend(
         android_device.AndroidDevice('failure'), self._options)