#
# Copyright (C) 2016 The Android Open Source Project
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import os
import tempfile
import shutil
import subprocess
import logging
PATH_SYSTRACE_SCRIPT = os.path.join('tools/external/chromium-trace',
'systrace.py')
EXPECTED_START_STDOUT = 'Starting tracing'
class SystraceController(object):
'''A util to start/stop systrace through shell command.
Attributes:
_android_vts_path: string, path to android-vts
_path_output: string, systrace temporally output path
_path_systrace_script: string, path to systrace controller python script
_device_serial: string, device serial string
_subprocess: subprocess.Popen, a subprocess objects of systrace shell command
is_valid: boolean, whether the current environment setting for
systrace is valid
process_name: string, process name to trace. The value can be empty.
'''
def __init__(self, android_vts_path, device_serial, process_name=''):
self._android_vts_path = android_vts_path
self._path_output = None
self._subprocess = None
self._device_serial = device_serial
if not device_serial:
logging.warning(
'Device serial is not provided for systrace. '
'Tool will not start if multiple devices are connected.')
self.process_name = process_name
self._path_systrace_script = os.path.join(android_vts_path,
PATH_SYSTRACE_SCRIPT)
self.is_valid = os.path.exists(self._path_systrace_script)
if not self.is_valid:
logging.error('invalid systrace script path: %s',
self._path_systrace_script)
@property
def is_valid(self):
''''returns whether the current environment setting is valid'''
return self._is_valid
@is_valid.setter
def is_valid(self, is_valid):
''''Set valid status'''
self._is_valid = is_valid
@property
def process_name(self):
''''returns process name'''
return self._process_name
@process_name.setter
def process_name(self, process_name):
''''Set process name'''
self._process_name = process_name
@property
def has_output(self):
''''returns whether output file exists and not empty.
Returns:
False if output path is not specified, or output file doesn't exist, or output
file size is zero; True otherwise.
'''
if not self._path_output:
logging.warning('systrace output path is empty.')
return False
try:
if os.path.getsize(self._path_output) == 0:
logging.warning('systrace output file is empty.')
return False
except OSError:
logging.info('systrace output file does not exist.')
return False
return True
def Start(self):
'''Start systrace process.
Use shell command to start a python systrace script
Returns:
True if successfully started systrace; False otherwise.
'''
self._subprocess = None
self._path_output = None
if not self.is_valid:
logging.error(
'Cannot start systrace: configuration is not correct for %s.',
self.process_name)
return False
# TODO: check target device for compatibility (e.g. has systrace hooks)
process_name_arg = ''
if self.process_name:
process_name_arg = '-a %s' % self.process_name
device_serial_arg = ''
if self._device_serial:
device_serial_arg = '--serial=%s' % self._device_serial
tmp_dir = tempfile.mkdtemp()
tmp_filename = self.process_name if self.process_name else 'systrace'
self._path_output = str(os.path.join(tmp_dir, tmp_filename + '.html'))
cmd = ('python -u {script} hal sched '
'{process_name_arg} {serial} -o {output}').format(
script=self._path_systrace_script,
process_name_arg=process_name_arg,
serial=device_serial_arg,
output=self._path_output)
process = subprocess.Popen(
str(cmd),
shell=True,
stdin=subprocess.PIPE,
stdout=subprocess.PIPE,
stderr=subprocess.PIPE)
line = ''
success = False
while process.poll() is None:
line += process.stdout.read(1)
if not line:
break
elif EXPECTED_START_STDOUT in line:
success = True
break
if not success:
logging.error('Failed to start systrace on process %s',
self.process_name)
stdout, stderr = process.communicate()
logging.error('stdout: %s', line + stdout)
logging.error('stderr: %s', stderr)
logging.error('ret_code: %s', process.returncode)
return False
self._subprocess = process
logging.info('Systrace started for %s', self.process_name)
return True
def Stop(self):
'''Stop systrace process.
Returns:
True if successfully stopped systrace or systrace already stopped;
False otherwise.
'''
if not self.is_valid:
logging.warn(
'Cannot stop systrace: systrace was not started for %s.',
self.process_name)
return False
if not self._subprocess:
logging.info('Systrace already stopped.')
return True
# Press enter to stop systrace script
self._subprocess.stdin.write('\n')
self._subprocess.stdin.flush()
# Wait for output to be written down
# TODO: use subprocess.TimeoutExpired after upgrading to python >3.3
out, err = self._subprocess.communicate()
logging.info('Systrace stopped for %s', self.process_name)
logging.info('Systrace stdout: %s', out)
logging.info('Systrace stderr: %s', err)
self._subprocess = None
return True
def ReadLastOutput(self):
'''Read systrace output html.
Returns:
string, data of systrace html output. None if failed to read.
'''
if not self.is_valid or not self._subprocess:
logging.warn(
'Cannot read output: systrace was not started for %s.',
self.process_name)
return None
if not self.has_output:
logging.error(
'systrace did not started/ended correctly. Output is empty.')
return False
try:
with open(self._path_output, 'r') as f:
data = f.read()
logging.info('Systrace output length for %s: %s', process_name,
len(data))
return data
except Exception as e:
logging.error('Cannot read output: file open failed, %s', e)
return None
def SaveLastOutput(self, report_path=None):
if not report_path:
logging.error('report path supplied is None')
return False
report_path = str(report_path)
if not self.has_output:
logging.error(
'systrace did not started/ended correctly. Output is empty.')
return False
parent_dir = os.path.dirname(report_path)
if not os.path.exists(parent_dir):
try:
os.makedirs(parent_dir)
except Exception as e:
logging.error('error happened while creating directory: %s', e)
return False
try:
shutil.copy(self._path_output, report_path)
except Exception as e: # TODO(yuexima): more specific error catch
logging.error('failed to copy output to report path: %s', e)
return False
return True
def ClearLastOutput(self):
'''Clear systrace output html.
Since output are created in temp directories, this step is optional.
Returns:
True if successfully deleted temp output file; False otherwise.
'''
if self._path_output:
try:
shutil.rmtree(os.path.basename(self._path_output))
except Exception as e:
logging.error('failed to remove systrace output file. %s', e)
return False
finally:
self._path_output = None
return True