michael@0: # Copyright (c) 2012 The Chromium Authors. All rights reserved.
michael@0: # Use of this source code is governed by a BSD-style license that can be
michael@0: # found in the LICENSE file.
michael@0: 
michael@0: import re
michael@0: 
michael@0: import android_commands
michael@0: import math
michael@0: 
michael@0: # Valid values of result type.
michael@0: RESULT_TYPES = {'unimportant': 'RESULT ',
michael@0:                 'default': '*RESULT ',
michael@0:                 'informational': ''}
michael@0: 
michael@0: 
michael@0: def _EscapePerfResult(s):
michael@0:   """Escapes |s| for use in a perf result."""
michael@0:   # Colons (:) and equal signs (=) are not allowed, and we chose an arbitrary
michael@0:   # limit of 40 chars.
michael@0:   return re.sub(':|=', '_', s[:40])
michael@0: 
michael@0: 
michael@0: def PrintPerfResult(measurement, trace, values, units, result_type='default',
michael@0:                     print_to_stdout=True):
michael@0:   """Prints numerical data to stdout in the format required by perf tests.
michael@0: 
michael@0:   The string args may be empty but they must not contain any colons (:) or
michael@0:   equals signs (=).
michael@0: 
michael@0:   Args:
michael@0:     measurement: A description of the quantity being measured, e.g. "vm_peak".
michael@0:     trace: A description of the particular data point, e.g. "reference".
michael@0:     values: A list of numeric measured values.
michael@0:     units: A description of the units of measure, e.g. "bytes".
michael@0:     result_type: A  tri-state that accepts values of ['unimportant', 'default',
michael@0:         'informational']. 'unimportant' prints RESULT, 'default' prints *RESULT
michael@0:         and 'informational' prints nothing.
michael@0:     print_to_stdout: If True, prints the output in stdout instead of returning
michael@0:         the output to caller.
michael@0: 
michael@0:     Returns:
michael@0:       String of the formated perf result.
michael@0:   """
michael@0:   assert result_type in RESULT_TYPES, 'result type: %s is invalid' % result_type
michael@0: 
michael@0:   assert isinstance(values, list)
michael@0:   assert len(values)
michael@0:   assert '/' not in measurement
michael@0:   avg = None
michael@0:   sd = None
michael@0:   if len(values) > 1:
michael@0:     try:
michael@0:       value = '[%s]' % ','.join([str(v) for v in values])
michael@0:       avg = sum([float(v) for v in values]) / len(values)
michael@0:       sqdiffs = [(float(v) - avg) ** 2 for v in values]
michael@0:       variance = sum(sqdiffs) / (len(values) - 1)
michael@0:       sd = math.sqrt(variance)
michael@0:     except ValueError:
michael@0:       value = ", ".join(values)
michael@0:   else:
michael@0:     value = values[0]
michael@0: 
michael@0:   trace_name = _EscapePerfResult(trace)
michael@0:   output = '%s%s: %s%s%s %s' % (
michael@0:     RESULT_TYPES[result_type],
michael@0:     _EscapePerfResult(measurement),
michael@0:     trace_name,
michael@0:     # Do not show equal sign if the trace is empty. Usually it happens when
michael@0:     # measurement is enough clear to describe the result.
michael@0:     '= ' if trace_name else '',
michael@0:     value,
michael@0:     units)
michael@0:   if avg:
michael@0:     output += '\nAvg %s: %f%s' % (measurement, avg, units)
michael@0:   if sd:
michael@0:     output += '\nSd  %s: %f%s' % (measurement, sd, units)
michael@0:   if print_to_stdout:
michael@0:     print output
michael@0:   return output
michael@0: 
michael@0: 
michael@0: class PerfTestSetup(object):
michael@0:   """Provides methods for setting up a device for perf testing."""
michael@0:   _DROP_CACHES = '/proc/sys/vm/drop_caches'
michael@0:   _SCALING_GOVERNOR = '/sys/devices/system/cpu/cpu%d/cpufreq/scaling_governor'
michael@0: 
michael@0:   def __init__(self, adb):
michael@0:     self._adb = adb
michael@0:     num_cpus = self._adb.GetFileContents('/sys/devices/system/cpu/online',
michael@0:                                          log_result=False)
michael@0:     assert num_cpus, 'Unable to find /sys/devices/system/cpu/online'
michael@0:     self._num_cpus = int(num_cpus[0].split('-')[-1])
michael@0:     self._original_scaling_governor = None
michael@0: 
michael@0:   def DropRamCaches(self):
michael@0:     """Drops the filesystem ram caches for performance testing."""
michael@0:     if not self._adb.IsRootEnabled():
michael@0:       self._adb.EnableAdbRoot()
michael@0:     self._adb.RunShellCommand('sync')
michael@0:     self._adb.RunShellCommand('echo 3 > ' + PerfTestSetup._DROP_CACHES)
michael@0: 
michael@0:   def SetUp(self):
michael@0:     """Sets up performance tests."""
michael@0:     if not self._original_scaling_governor:
michael@0:       self._original_scaling_governor = self._adb.GetFileContents(
michael@0:           PerfTestSetup._SCALING_GOVERNOR % 0,
michael@0:           log_result=False)[0]
michael@0:       self._SetScalingGovernorInternal('performance')
michael@0:     self.DropRamCaches()
michael@0: 
michael@0:   def TearDown(self):
michael@0:     """Tears down performance tests."""
michael@0:     if self._original_scaling_governor:
michael@0:       self._SetScalingGovernorInternal(self._original_scaling_governor)
michael@0:     self._original_scaling_governor = None
michael@0: 
michael@0:   def _SetScalingGovernorInternal(self, value):
michael@0:     for cpu in range(self._num_cpus):
michael@0:       self._adb.RunShellCommand(
michael@0:           ('echo %s > ' + PerfTestSetup._SCALING_GOVERNOR) % (value, cpu))