text: #!/usr/bin/env python
  # Copyright 2015 gRPC authors.
  #
  # 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.
  """Run tests in parallel."""
  
  from __future__ import print_function
  
  import argparse
  import ast
  import collections
  import glob
  import itertools
  import json
  import logging
  import multiprocessing
  import os
  import os.path
  import pipes
  import platform
  import random
  import re
  import socket
  import subprocess
  import sys
  import tempfile
  import traceback
  import time
  from six.moves import urllib
  import uuid
  import six
  
  import python_utils.jobset as jobset
  import python_utils.report_utils as report_utils
  import python_utils.watch_dirs as watch_dirs
  import python_utils.start_port_server as start_port_server
  try:
      from python_utils.upload_test_results import upload_results_to_bq
  except (ImportError):
      pass  # It's ok to not import because this is only necessary to upload results to BQ.
  
  gcp_utils_dir = os.path.abspath(
      os.path.join(os.path.dirname(__file__), '../gcp/utils'))
  sys.path.append(gcp_utils_dir)
  
  _ROOT = os.path.abspath(os.path.join(os.path.dirname(sys.argv[0]), '../..'))
  os.chdir(_ROOT)
  
  _FORCE_ENVIRON_FOR_WRAPPERS = {
      'GRPC_VERBOSITY': 'DEBUG',
  }
  
  _POLLING_STRATEGIES = {
      'linux': ['epollex', 'epoll1', 'poll'],
      'mac': ['poll'],
  }
  
  BigQueryTestData = collections.namedtuple('BigQueryTestData', 'name flaky cpu')
  
  
  def get_bqtest_data(limit=None):
      import big_query_utils
  
      bq = big_query_utils.create_big_query()
      query = """
  SELECT
    filtered_test_name,
    SUM(result != 'PASSED' AND result != 'SKIPPED') > 0 as flaky,
    MAX(cpu_measured) + 0.01 as cpu
    FROM (
    SELECT
      REGEXP_REPLACE(test_name, r'/\d+', '') AS filtered_test_name,
      result, cpu_measured
    FROM
      [grpc-testing:jenkins_test_results.aggregate_results]
    WHERE
      timestamp >= DATE_ADD(CURRENT_DATE(), -1, "WEEK")
      AND platform = '""" + platform_string() + """'
      AND NOT REGEXP_MATCH(job_name, '.*portability.*') )
  GROUP BY
    filtered_test_name"""
      if limit:
          query += " limit {}".format(limit)
      query_job = big_query_utils.sync_query_job(bq, 'grpc-testing', query)
      page = bq.jobs().getQueryResults(
          pageToken=None, **query_job['jobReference']).execute(num_retries=3)
      test_data = [
          BigQueryTestData(row['f'][0]['v'], row['f'][1]['v'] == 'true',
                           float(row['f'][2]['v'])) for row in page['rows']
      ]
      return test_data
  
  
  def platform_string():
      return jobset.platform_string()
  
  
  _DEFAULT_TIMEOUT_SECONDS = 5 * 60
  _PRE_BUILD_STEP_TIMEOUT_SECONDS = 10 * 60
  
  
  def run_shell_command(cmd, env=None, cwd=None):
      try:
          subprocess.check_output(cmd, shell=True, env=env, cwd=cwd)
      except subprocess.CalledProcessError as e:
          logging.exception(
              "Error while running command '%s'. Exit status %d. Output:\n%s",
              e.cmd, e.returncode, e.output)
          raise
  
  
  def max_parallel_tests_for_current_platform():
      # Too much test parallelization has only been seen to be a problem
      # so far on windows.
      if jobset.platform_string() == 'windows':
          return 64
      return 1024
  
  
  # SimpleConfig: just compile with CONFIG=config, and run the binary to test
  class Config(object):
  
      def __init__(self,
                   config,
                   environ=None,
                   timeout_multiplier=1,
                   tool_prefix=[],
                   iomgr_platform='native'):
          if environ is None:
              environ = {}
          self.build_config = config
          self.environ = environ
          self.environ['CONFIG'] = config
          self.tool_prefix = tool_prefix
          self.timeout_multiplier = timeout_multiplier
          self.iomgr_platform = iomgr_platform
  
      def job_spec(self,
                   cmdline,
                   timeout_seconds=_DEFAULT_TIMEOUT_SECONDS,
                   shortname=None,
                   environ={},
                   cpu_cost=1.0,
                   flaky=False):
          """Construct a jobset.JobSpec for a test under this config
  
         Args:
           cmdline:      a list of strings specifying the command line the test
                         would like to run
      """
          actual_environ = self.environ.copy()
          for k, v in environ.items():
              actual_environ[k] = v
          if not flaky and shortname and shortname in flaky_tests:
              flaky = True
          if shortname in shortname_to_cpu:
              cpu_cost = shortname_to_cpu[shortname]
          return jobset.JobSpec(
              cmdline=self.tool_prefix + cmdline,
              shortname=shortname,
              environ=actual_environ,
              cpu_cost=cpu_cost,
              timeout_seconds=(self.timeout_multiplier *
                               timeout_seconds if timeout_seconds else None),
              flake_retries=4 if flaky or args.allow_flakes else 0,
              timeout_retries=1 if flaky or args.allow_flakes else 0)
  
  
  def get_c_tests(travis, test_lang):
      out = []
      platforms_str = 'ci_platforms' if travis else 'platforms'
      with open('tools/run_tests/generated/tests.json') as f:
          js = json.load(f)
          return [
              tgt for tgt in js
              if tgt['language'] == test_lang and platform_string() in
              tgt[platforms_str] and not (travis and tgt['flaky'])
          ]
  
  
  def _check_compiler(compiler, supported_compilers):
      if compiler not in supported_compilers:
          raise Exception('Compiler %s not supported (on this platform).' %
                          compiler)
  
  
  def _check_arch(arch, supported_archs):
      if arch not in supported_archs:
          raise Exception('Architecture %s not supported.' % arch)
  
  
  def _is_use_docker_child():
      """Returns True if running running as a --use_docker child."""
      return True if os.getenv('RUN_TESTS_COMMAND') else False
  
  
  _PythonConfigVars = collections.namedtuple('_ConfigVars', [
      'shell',
      'builder',
      'builder_prefix_arguments',
      'venv_relative_python',
      'toolchain',
      'runner',
      'test_name',
      'iomgr_platform',
  ])
  
  
  def _python_config_generator(name, major, minor, bits, config_vars):
      name += '_' + config_vars.iomgr_platform
      return PythonConfig(
          name, config_vars.shell + config_vars.builder +
          config_vars.builder_prefix_arguments +
          [_python_pattern_function(major=major, minor=minor, bits=bits)] +
          [name] + config_vars.venv_relative_python + config_vars.toolchain,
          config_vars.shell + config_vars.runner + [
              os.path.join(name, config_vars.venv_relative_python[0]),
              config_vars.test_name
          ])
  
  
  def _pypy_config_generator(name, major, config_vars):
      return PythonConfig(
          name, config_vars.shell + config_vars.builder +
          config_vars.builder_prefix_arguments +
          [_pypy_pattern_function(major=major)] + [name] +
          config_vars.venv_relative_python + config_vars.toolchain,
          config_vars.shell + config_vars.runner +
          [os.path.join(name, config_vars.venv_relative_python[0])])
  
  
  def _python_pattern_function(major, minor, bits):
      # Bit-ness is handled by the test machine's environment
      if os.name == "nt":
          if bits == "64":
              return '/c/Python{major}{minor}/python.exe'.format(major=major,
                                                                 minor=minor,
                                                                 bits=bits)
          else:
              return '/c/Python{major}{minor}_{bits}bits/python.exe'.format(
                  major=major, minor=minor, bits=bits)
      else:
          return 'python{major}.{minor}'.format(major=major, minor=minor)
  
  
  def _pypy_pattern_function(major):
      if major == '2':
          return 'pypy'
      elif major == '3':
          return 'pypy3'
      else:
          raise ValueError("Unknown PyPy major version")
  
  
  class CLanguage(object):
  
      def __init__(self, make_target, test_lang):
          self.make_target = make_target
          self.platform = platform_string()
          self.test_lang = test_lang
  
      def configure(self, config, args):
          self.config = config
          self.args = args
          if self.platform == 'windows':
              _check_compiler(
                  self.args.compiler,
                  ['default', 'cmake', 'cmake_vs2015', 'cmake_vs2017'])
              _check_arch(self.args.arch, ['default', 'x64', 'x86'])
              self._cmake_generator_option = 'Visual Studio 15 2017' if self.args.compiler == 'cmake_vs2017' else 'Visual Studio 14 2015'
              self._cmake_arch_option = 'x64' if self.args.arch == 'x64' else 'Win32'
              self._use_cmake = True
              self._make_options = []
          elif self.args.compiler == 'cmake':
              _check_arch(self.args.arch, ['default'])
              self._use_cmake = True
              self._docker_distro = 'jessie'
              self._make_options = []
          else:
              self._use_cmake = False
              self._docker_distro, self._make_options = self._compiler_options(
                  self.args.use_docker, self.args.compiler)
          if args.iomgr_platform == "uv":
              cflags = '-DGRPC_UV -DGRPC_CUSTOM_IOMGR_THREAD_CHECK -DGRPC_CUSTOM_SOCKET '
              try:
                  cflags += subprocess.check_output(
                      ['pkg-config', '--cflags', 'libuv']).strip() + ' '
              except (subprocess.CalledProcessError, OSError):
                  pass
              try:
                  ldflags = subprocess.check_output(
                      ['pkg-config', '--libs', 'libuv']).strip() + ' '
              except (subprocess.CalledProcessError, OSError):
                  ldflags = '-luv '
              self._make_options += [
                  'EXTRA_CPPFLAGS={}'.format(cflags),
                  'EXTRA_LDLIBS={}'.format(ldflags)
              ]
  
      def test_specs(self):
          out = []
          binaries = get_c_tests(self.args.travis, self.test_lang)
          for target in binaries:
              if self._use_cmake and target.get('boringssl', False):
                  # cmake doesn't build boringssl tests
                  continue
              auto_timeout_scaling = target.get('auto_timeout_scaling', True)
              polling_strategies = (_POLLING_STRATEGIES.get(
                  self.platform, ['all']) if target.get('uses_polling', True) else
                                    ['none'])
              if self.args.iomgr_platform == 'uv':
                  polling_strategies = ['all']
              for polling_strategy in polling_strategies:
                  env = {
                      'GRPC_DEFAULT_SSL_ROOTS_FILE_PATH':
                          _ROOT + '/src/core/tsi/test_creds/ca.pem',
                      'GRPC_POLL_STRATEGY':
                          polling_strategy,
                      'GRPC_VERBOSITY':
                          'DEBUG'
                  }
                  resolver = os.environ.get('GRPC_DNS_RESOLVER', None)
                  if resolver:
                      env['GRPC_DNS_RESOLVER'] = resolver
                  shortname_ext = '' if polling_strategy == 'all' else ' GRPC_POLL_STRATEGY=%s' % polling_strategy
                  if polling_strategy in target.get('excluded_poll_engines', []):
                      continue
  
                  timeout_scaling = 1
                  if auto_timeout_scaling:
                      config = self.args.config
                      if ('asan' in config or config == 'msan' or
                              config == 'tsan' or config == 'ubsan' or
                              config == 'helgrind' or config == 'memcheck'):
                          # Scale overall test timeout if running under various sanitizers.
                          # scaling value is based on historical data analysis
                          timeout_scaling *= 3
  
                  if self.config.build_config in target['exclude_configs']:
                      continue
                  if self.args.iomgr_platform in target.get('exclude_iomgrs', []):
                      continue
                  if self.platform == 'windows':
                      binary = 'cmake/build/%s/%s.exe' % (_MSBUILD_CONFIG[
                          self.config.build_config], target['name'])
                  else:
                      if self._use_cmake:
                          binary = 'cmake/build/%s' % target['name']
                      else:
                          binary = 'bins/%s/%s' % (self.config.build_config,
                                                   target['name'])
                  cpu_cost = target['cpu_cost']
                  if cpu_cost == 'capacity':
                      cpu_cost = multiprocessing.cpu_count()
                  if os.path.isfile(binary):
                      list_test_command = None
                      filter_test_command = None
  
                      # these are the flag defined by gtest and benchmark framework to list
                      # and filter test runs. We use them to split each individual test
                      # into its own JobSpec, and thus into its own process.
                      if 'benchmark' in target and target['benchmark']:
                          with open(os.devnull, 'w') as fnull:
                              tests = subprocess.check_output(
                                  [binary, '--benchmark_list_tests'],
                                  stderr=fnull)
                          for line in tests.split('\n'):
                              test = line.strip()
                              if not test: continue
                              cmdline = [binary,
                                         '--benchmark_filter=%s$' % test
                                        ] + target['args']
                              out.append(
                                  self.config.job_spec(
                                      cmdline,
                                      shortname='%s %s' %
                                      (' '.join(cmdline), shortname_ext),
                                      cpu_cost=cpu_cost,
                                      timeout_seconds=target.get(
                                          'timeout_seconds',
                                          _DEFAULT_TIMEOUT_SECONDS) *
                                      timeout_scaling,
                                      environ=env))
                      elif 'gtest' in target and target['gtest']:
                          # here we parse the output of --gtest_list_tests to build up a complete
                          # list of the tests contained in a binary for each test, we then
                          # add a job to run, filtering for just that test.
                          with open(os.devnull, 'w') as fnull:
                              tests = subprocess.check_output(
                                  [binary, '--gtest_list_tests'], stderr=fnull)
                          base = None
                          for line in tests.split('\n'):
                              i = line.find('#')
                              if i >= 0: line = line[:i]
                              if not line: continue
                              if line[0] != ' ':
                                  base = line.strip()
                              else:
                                  assert base is not None
                                  assert line[1] == ' '
                                  test = base + line.strip()
                                  cmdline = [binary,
                                             '--gtest_filter=%s' % test
                                            ] + target['args']
                                  out.append(
                                      self.config.job_spec(
                                          cmdline,
                                          shortname='%s %s' %
                                          (' '.join(cmdline), shortname_ext),
                                          cpu_cost=cpu_cost,
                                          timeout_seconds=target.get(
                                              'timeout_seconds',
                                              _DEFAULT_TIMEOUT_SECONDS) *
                                          timeout_scaling,
                                          environ=env))
                      else:
                          cmdline = [binary] + target['args']
                          shortname = target.get(
                              'shortname',
                              ' '.join(pipes.quote(arg) for arg in cmdline))
                          shortname += shortname_ext
                          out.append(
                              self.config.job_spec(
                                  cmdline,
                                  shortname=shortname,
                                  cpu_cost=cpu_cost,
                                  flaky=target.get('flaky', False),
                                  timeout_seconds=target.get(
                                      'timeout_seconds',
                                      _DEFAULT_TIMEOUT_SECONDS) * timeout_scaling,
                                  environ=env))
                  elif self.args.regex == '.*' or self.platform == 'windows':
                      print('\nWARNING: binary not found, skipping', binary)
          return sorted(out)
  
      def make_targets(self):
          if self.platform == 'windows':
              # don't build tools on windows just yet
              return ['buildtests_%s' % self.make_target]
          return [
              'buildtests_%s' % self.make_target,
              'tools_%s' % self.make_target, 'check_epollexclusive'
          ]
  
      def make_options(self):
          return self._make_options
  
      def pre_build_steps(self):
          if self.platform == 'windows':
              return [[
                  'tools\\run_tests\\helper_scripts\\pre_build_cmake.bat',
                  self._cmake_generator_option, self._cmake_arch_option
              ]]
          elif self._use_cmake:
              return [['tools/run_tests/helper_scripts/pre_build_cmake.sh']]
          else:
              return []
  
      def build_steps(self):
          return []
  
      def post_tests_steps(self):
          if self.platform == 'windows':
              return []
          else:
              return [['tools/run_tests/helper_scripts/post_tests_c.sh']]
  
      def makefile_name(self):
          if self._use_cmake:
              return 'cmake/build/Makefile'
          else:
              return 'Makefile'
  
      def _clang_make_options(self, version_suffix=''):
          if self.args.config == 'ubsan':
              return [
                  'CC=clang%s' % version_suffix,
                  'CXX=clang++%s' % version_suffix,
                  'LD=clang++%s' % version_suffix,
                  'LDXX=clang++%s' % version_suffix
              ]
  
          return [
              'CC=clang%s' % version_suffix,
              'CXX=clang++%s' % version_suffix,
              'LD=clang%s' % version_suffix,
              'LDXX=clang++%s' % version_suffix
          ]
  
      def _gcc_make_options(self, version_suffix):
          return [
              'CC=gcc%s' % version_suffix,
              'CXX=g++%s' % version_suffix,
              'LD=gcc%s' % version_suffix,
              'LDXX=g++%s' % version_suffix
          ]
  
      def _compiler_options(self, use_docker, compiler):
          """Returns docker distro and make options to use for given compiler."""
          if not use_docker and not _is_use_docker_child():
              _check_compiler(compiler, ['default'])
  
          if compiler == 'gcc4.9' or compiler == 'default':
              return ('jessie', [])
          elif compiler == 'gcc4.8':
              return ('jessie', self._gcc_make_options(version_suffix='-4.8'))
          elif compiler == 'gcc5.3':
              return ('ubuntu1604', [])
          elif compiler == 'gcc7.4':
              return ('ubuntu1804', [])
          elif compiler == 'gcc8.3':
              return ('buster', [])
          elif compiler == 'gcc_musl':
              return ('alpine', [])
          elif compiler == 'clang3.4':
              # on ubuntu1404, clang-3.4 alias doesn't exist, just use 'clang'
              return ('ubuntu1404', self._clang_make_options())
          elif compiler == 'clang3.5':
              return ('jessie', self._clang_make_options(version_suffix='-3.5'))
          elif compiler == 'clang3.6':
              return ('ubuntu1604',
                      self._clang_make_options(version_suffix='-3.6'))
          elif compiler == 'clang3.7':
              return ('ubuntu1604',
                      self._clang_make_options(version_suffix='-3.7'))
          elif compiler == 'clang7.0':
              # clang++-7.0 alias doesn't exist and there are no other clang versions
              # installed.
              return ('sanitizers_jessie', self._clang_make_options())
          else:
              raise Exception('Compiler %s not supported.' % compiler)
  
      def dockerfile_dir(self):
          return 'tools/dockerfile/test/cxx_%s_%s' % (
              self._docker_distro, _docker_arch_suffix(self.args.arch))
  
      def __str__(self):
          return self.make_target
  
  
  # This tests Node on grpc/grpc-node and will become the standard for Node testing
  class RemoteNodeLanguage(object):
  
      def __init__(self):
          self.platform = platform_string()
  
      def configure(self, config, args):
          self.config = config
          self.args = args
          # Note: electron ABI only depends on major and minor version, so that's all
          # we should specify in the compiler argument
          _check_compiler(self.args.compiler, [
              'default', 'node0.12', 'node4', 'node5', 'node6', 'node7', 'node8',
              'electron1.3', 'electron1.6'
          ])
          if self.args.compiler == 'default':
              self.runtime = 'node'
              self.node_version = '8'
          else:
              if self.args.compiler.startswith('electron'):
                  self.runtime = 'electron'
                  self.node_version = self.args.compiler[8:]
              else:
                  self.runtime = 'node'
                  # Take off the word "node"
                  self.node_version = self.args.compiler[4:]
  
      # TODO: update with Windows/electron scripts when available for grpc/grpc-node
      def test_specs(self):
          if self.platform == 'windows':
              return [
                  self.config.job_spec(
                      ['tools\\run_tests\\helper_scripts\\run_node.bat'])
              ]
          else:
              return [
                  self.config.job_spec(
                      ['tools/run_tests/helper_scripts/run_grpc-node.sh'],
                      None,
                      environ=_FORCE_ENVIRON_FOR_WRAPPERS)
              ]
  
      def pre_build_steps(self):
          return []
  
      def make_targets(self):
          return []
  
      def make_options(self):
          return []
  
      def build_steps(self):
          return []
  
      def post_tests_steps(self):
          return []
  
      def makefile_name(self):
          return 'Makefile'
  
      def dockerfile_dir(self):
          return 'tools/dockerfile/test/node_jessie_%s' % _docker_arch_suffix(
              self.args.arch)
  
      def __str__(self):
          return 'grpc-node'
  
  
  class PhpLanguage(object):
  
      def configure(self, config, args):
          self.config = config
          self.args = args
          _check_compiler(self.args.compiler, ['default'])
          self._make_options = ['EMBED_OPENSSL=true', 'EMBED_ZLIB=true']
  
      def test_specs(self):
          return [
              self.config.job_spec(['src/php/bin/run_tests.sh'],
                                   environ=_FORCE_ENVIRON_FOR_WRAPPERS)
          ]
  
      def pre_build_steps(self):
          return []
  
      def make_targets(self):
          return ['static_c', 'shared_c']
  
      def make_options(self):
          return self._make_options
  
      def build_steps(self):
          return [['tools/run_tests/helper_scripts/build_php.sh']]
  
      def post_tests_steps(self):
          return [['tools/run_tests/helper_scripts/post_tests_php.sh']]
  
      def makefile_name(self):
          return 'Makefile'
  
      def dockerfile_dir(self):
          return 'tools/dockerfile/test/php_jessie_%s' % _docker_arch_suffix(
              self.args.arch)
  
      def __str__(self):
          return 'php'
  
  
  class Php7Language(object):
  
      def configure(self, config, args):
          self.config = config
          self.args = args
          _check_compiler(self.args.compiler, ['default'])
          self._make_options = ['EMBED_OPENSSL=true', 'EMBED_ZLIB=true']
  
      def test_specs(self):
          return [
              self.config.job_spec(['src/php/bin/run_tests.sh'],
                                   environ=_FORCE_ENVIRON_FOR_WRAPPERS)
          ]
  
      def pre_build_steps(self):
          return []
  
      def make_targets(self):
          return ['static_c', 'shared_c']
  
      def make_options(self):
          return self._make_options
  
      def build_steps(self):
          return [['tools/run_tests/helper_scripts/build_php.sh']]
  
      def post_tests_steps(self):
          return [['tools/run_tests/helper_scripts/post_tests_php.sh']]
  
      def makefile_name(self):
          return 'Makefile'
  
      def dockerfile_dir(self):
          return 'tools/dockerfile/test/php7_jessie_%s' % _docker_arch_suffix(
              self.args.arch)
  
      def __str__(self):
          return 'php7'
  
  
  class PythonConfig(
          collections.namedtuple('PythonConfig', ['name', 'build', 'run'])):
      """Tuple of commands (named s.t. 'what it says on the tin' applies)"""
  
  
  class PythonLanguage(object):
  
      _TEST_SPECS_FILE = {
          'native': 'src/python/grpcio_tests/tests/tests.json',
          'gevent': 'src/python/grpcio_tests/tests/tests.json',
          'asyncio': 'src/python/grpcio_tests/tests_aio/tests.json',
      }
      _TEST_FOLDER = {
          'native': 'test',
          'gevent': 'test',
          'asyncio': 'test_aio',
      }
  
      def configure(self, config, args):
          self.config = config
          self.args = args
          self.pythons = self._get_pythons(self.args)
  
      def test_specs(self):
          # load list of known test suites
          with open(self._TEST_SPECS_FILE[
                  self.args.iomgr_platform]) as tests_json_file:
              tests_json = json.load(tests_json_file)
          environment = dict(_FORCE_ENVIRON_FOR_WRAPPERS)
          # TODO(https://github.com/grpc/grpc/issues/21401) Fork handlers is not
          # designed for non-native IO manager. It has a side-effect that
          # overrides threading settings in C-Core.
          if args.iomgr_platform != 'native':
              environment['GRPC_ENABLE_FORK_SUPPORT'] = '0'
          return [
              self.config.job_spec(
                  config.run,
                  timeout_seconds=5 * 60,
                  environ=dict(GRPC_PYTHON_TESTRUNNER_FILTER=str(suite_name),
                               **environment),
                  shortname='%s.%s.%s' %
                  (config.name, self._TEST_FOLDER[self.args.iomgr_platform],
                   suite_name),
              ) for suite_name in tests_json for config in self.pythons
          ]
  
      def pre_build_steps(self):
          return []
  
      def make_targets(self):
          return []
  
      def make_options(self):
          return []
  
      def build_steps(self):
          return [config.build for config in self.pythons]
  
      def post_tests_steps(self):
          if self.config.build_config != 'gcov':
              return []
          else:
              return [['tools/run_tests/helper_scripts/post_tests_python.sh']]
  
      def makefile_name(self):
          return 'Makefile'
  
      def dockerfile_dir(self):
          return 'tools/dockerfile/test/python_%s_%s' % (
              self._python_manager_name(), _docker_arch_suffix(self.args.arch))
  
      def _python_manager_name(self):
          """Choose the docker image to use based on python version."""
          if self.args.compiler in [
                  'python2.7', 'python3.5', 'python3.6', 'python3.7', 'python3.8'
          ]:
              return 'stretch_' + self.args.compiler[len('python'):]
          elif self.args.compiler == 'python_alpine':
              return 'alpine'
          else:
              return 'stretch_default'
  
      def _get_pythons(self, args):
          """Get python runtimes to test with, based on current platform, architecture, compiler etc."""
          if args.arch == 'x86':
              bits = '32'
          else:
              bits = '64'
  
          if os.name == 'nt':
              shell = ['bash']
              builder = [
                  os.path.abspath(
                      'tools/run_tests/helper_scripts/build_python_msys2.sh')
              ]
              builder_prefix_arguments = ['MINGW{}'.format(bits)]
              venv_relative_python = ['Scripts/python.exe']
              toolchain = ['mingw32']
          else:
              shell = []
              builder = [
                  os.path.abspath(
                      'tools/run_tests/helper_scripts/build_python.sh')
              ]
              builder_prefix_arguments = []
              venv_relative_python = ['bin/python']
              toolchain = ['unix']
  
          # Selects the corresponding testing mode.
          # See src/python/grpcio_tests/commands.py for implementation details.
          if args.iomgr_platform == 'native':
              test_command = 'test_lite'
          elif args.iomgr_platform == 'gevent':
              test_command = 'test_gevent'
          elif args.iomgr_platform == 'asyncio':
              test_command = 'test_aio'
          else:
              raise ValueError('Unsupported IO Manager platform: %s' %
                               args.iomgr_platform)
          runner = [
              os.path.abspath('tools/run_tests/helper_scripts/run_python.sh')
          ]
  
          config_vars = _PythonConfigVars(shell, builder,
                                          builder_prefix_arguments,
                                          venv_relative_python, toolchain, runner,
                                          test_command, args.iomgr_platform)
          python27_config = _python_config_generator(name='py27',
                                                     major='2',
                                                     minor='7',
                                                     bits=bits,
                                                     config_vars=config_vars)
          python35_config = _python_config_generator(name='py35',
                                                     major='3',
                                                     minor='5',
                                                     bits=bits,
                                                     config_vars=config_vars)
          python36_config = _python_config_generator(name='py36',
                                                     major='3',
                                                     minor='6',
                                                     bits=bits,
                                                     config_vars=config_vars)
          python37_config = _python_config_generator(name='py37',
                                                     major='3',
                                                     minor='7',
                                                     bits=bits,
                                                     config_vars=config_vars)
          python38_config = _python_config_generator(name='py38',
                                                     major='3',
                                                     minor='8',
                                                     bits=bits,
                                                     config_vars=config_vars)
          pypy27_config = _pypy_config_generator(name='pypy',
                                                 major='2',
                                                 config_vars=config_vars)
          pypy32_config = _pypy_config_generator(name='pypy3',
                                                 major='3',
                                                 config_vars=config_vars)
  
          if args.iomgr_platform == 'asyncio':
              if args.compiler not in ('default', 'python3.6', 'python3.7',
                                       'python3.8'):
                  raise Exception(
                      'Compiler %s not supported with IO Manager platform: %s' %
                      (args.compiler, args.iomgr_platform))
  
          if args.compiler == 'default':
              if os.name == 'nt':
                  return (python36_config,)
              else:
                  if args.iomgr_platform == 'asyncio':
                      return (python36_config,)
                  else:
                      return (
                          python27_config,
                          python36_config,
                          python37_config,
                      )
          elif args.compiler == 'python2.7':
              return (python27_config,)
          elif args.compiler == 'python3.5':
              return (python35_config,)
          elif args.compiler == 'python3.6':
              return (python36_config,)
          elif args.compiler == 'python3.7':
              return (python37_config,)
          elif args.compiler == 'python3.8':
              return (python38_config,)
          elif args.compiler == 'pypy':
              return (pypy27_config,)
          elif args.compiler == 'pypy3':
              return (pypy32_config,)
          elif args.compiler == 'python_alpine':
              return (python27_config,)
          elif args.compiler == 'all_the_cpythons':
              return (
                  python27_config,
                  python35_config,
                  python36_config,
                  python37_config,
                  python38_config,
              )
          else:
              raise Exception('Compiler %s not supported.' % args.compiler)
  
      def __str__(self):
          return 'python'
  
  
  class RubyLanguage(object):
  
      def configure(self, config, args):
          self.config = config
          self.args = args
          _check_compiler(self.args.compiler, ['default'])
  
      def test_specs(self):
          tests = [
              self.config.job_spec(['tools/run_tests/helper_scripts/run_ruby.sh'],
                                   timeout_seconds=10 * 60,
                                   environ=_FORCE_ENVIRON_FOR_WRAPPERS)
          ]
          tests.append(
              self.config.job_spec(
                  ['tools/run_tests/helper_scripts/run_ruby_end2end_tests.sh'],
                  timeout_seconds=20 * 60,
                  environ=_FORCE_ENVIRON_FOR_WRAPPERS))
          return tests
  
      def pre_build_steps(self):
          return [['tools/run_tests/helper_scripts/pre_build_ruby.sh']]
  
      def make_targets(self):
          return []
  
      def make_options(self):
          return []
  
      def build_steps(self):
          return [['tools/run_tests/helper_scripts/build_ruby.sh']]
  
      def post_tests_steps(self):
          return [['tools/run_tests/helper_scripts/post_tests_ruby.sh']]
  
      def makefile_name(self):
          return 'Makefile'
  
      def dockerfile_dir(self):
          return 'tools/dockerfile/test/ruby_jessie_%s' % _docker_arch_suffix(
              self.args.arch)
  
      def __str__(self):
          return 'ruby'
  
  
  class CSharpLanguage(object):
  
      def __init__(self):
          self.platform = platform_string()
  
      def configure(self, config, args):
          self.config = config
          self.args = args
          if self.platform == 'windows':
              _check_compiler(self.args.compiler, ['default', 'coreclr'])
              _check_arch(self.args.arch, ['default'])
              self._cmake_arch_option = 'x64'
          else:
              _check_compiler(self.args.compiler, ['default', 'coreclr'])
              self._docker_distro = 'stretch'
  
      def test_specs(self):
          with open('src/csharp/tests.json') as f:
              tests_by_assembly = json.load(f)
  
          msbuild_config = _MSBUILD_CONFIG[self.config.build_config]
          nunit_args = ['--labels=All', '--noresult', '--workers=1']
          assembly_subdir = 'bin/%s' % msbuild_config
          assembly_extension = '.exe'
  
          if self.args.compiler == 'coreclr':
              assembly_subdir += '/netcoreapp2.1'
              runtime_cmd = ['dotnet', 'exec']
              assembly_extension = '.dll'
          else:
              assembly_subdir += '/net45'
              if self.platform == 'windows':
                  runtime_cmd = []
              elif self.platform == 'mac':
                  # mono before version 5.2 on MacOS defaults to 32bit runtime
                  runtime_cmd = ['mono', '--arch=64']
              else:
                  runtime_cmd = ['mono']
  
          specs = []
          for assembly in six.iterkeys(tests_by_assembly):
              assembly_file = 'src/csharp/%s/%s/%s%s' % (
                  assembly, assembly_subdir, assembly, assembly_extension)
              if self.config.build_config != 'gcov' or self.platform != 'windows':
                  # normally, run each test as a separate process
                  for test in tests_by_assembly[assembly]:
                      cmdline = runtime_cmd + [assembly_file,
                                               '--test=%s' % test] + nunit_args
                      specs.append(
                          self.config.job_spec(
                              cmdline,
                              shortname='csharp.%s' % test,
                              environ=_FORCE_ENVIRON_FOR_WRAPPERS))
              else:
                  # For C# test coverage, run all tests from the same assembly at once
                  # using OpenCover.Console (only works on Windows).
                  cmdline = [
                      'src\\csharp\\packages\\OpenCover.4.6.519\\tools\\OpenCover.Console.exe',
                      '-target:%s' % assembly_file, '-targetdir:src\\csharp',
                      '-targetargs:%s' % ' '.join(nunit_args),
                      '-filter:+[Grpc.Core]*', '-register:user',
                      '-output:src\\csharp\\coverage_csharp_%s.xml' % assembly
                  ]
  
                  # set really high cpu_cost to make sure instances of OpenCover.Console run exclusively
                  # to prevent problems with registering the profiler.
                  run_exclusive = 1000000
                  specs.append(
                      self.config.job_spec(cmdline,
                                           shortname='csharp.coverage.%s' %
                                           assembly,
                                           cpu_cost=run_exclusive,
                                           environ=_FORCE_ENVIRON_FOR_WRAPPERS))
          return specs
  
      def pre_build_steps(self):
          if self.platform == 'windows':
              return [[
                  'tools\\run_tests\\helper_scripts\\pre_build_csharp.bat',
                  self._cmake_arch_option
              ]]
          else:
              return [['tools/run_tests/helper_scripts/pre_build_csharp.sh']]
  
      def make_targets(self):
          return ['grpc_csharp_ext']
  
      def make_options(self):
          return []
  
      def build_steps(self):
          if self.platform == 'windows':
              return [['tools\\run_tests\\helper_scripts\\build_csharp.bat']]
          else:
              return [['tools/run_tests/helper_scripts/build_csharp.sh']]
  
      def post_tests_steps(self):
          if self.platform == 'windows':
              return [['tools\\run_tests\\helper_scripts\\post_tests_csharp.bat']]
          else:
              return [['tools/run_tests/helper_scripts/post_tests_csharp.sh']]
  
      def makefile_name(self):
          if self.platform == 'windows':
              return 'cmake/build/%s/Makefile' % self._cmake_arch_option
          else:
              # no need to set x86 specific flags as run_tests.py
              # currently forbids x86 C# builds on both Linux and MacOS.
              return 'cmake/build/Makefile'
  
      def dockerfile_dir(self):
          return 'tools/dockerfile/test/csharp_%s_%s' % (
              self._docker_distro, _docker_arch_suffix(self.args.arch))
  
      def __str__(self):
          return 'csharp'
  
  
  class ObjCLanguage(object):
  
      def configure(self, config, args):
          self.config = config
          self.args = args
          _check_compiler(self.args.compiler, ['default'])
  
      def test_specs(self):
          out = []
          out.append(
              self.config.job_spec(
                  ['src/objective-c/tests/build_one_example_bazel.sh'],
                  timeout_seconds=10 * 60,
                  shortname='ios-buildtest-example-sample',
                  cpu_cost=1e6,
                  environ={
                      'SCHEME': 'Sample',
                      'EXAMPLE_PATH': 'src/objective-c/examples/Sample',
                      'FRAMEWORKS': 'NO'
                  }))
          # Currently not supporting compiling as frameworks in Bazel
          out.append(
              self.config.job_spec(
                  ['src/objective-c/tests/build_one_example.sh'],
                  timeout_seconds=20 * 60,
                  shortname='ios-buildtest-example-sample-frameworks',
                  cpu_cost=1e6,
                  environ={
                      'SCHEME': 'Sample',
                      'EXAMPLE_PATH': 'src/objective-c/examples/Sample',
                      'FRAMEWORKS': 'YES'
                  }))
          out.append(
              self.config.job_spec(
                  ['src/objective-c/tests/build_one_example.sh'],
                  timeout_seconds=20 * 60,
                  shortname='ios-buildtest-example-switftsample',
                  cpu_cost=1e6,
                  environ={
                      'SCHEME': 'SwiftSample',
                      'EXAMPLE_PATH': 'src/objective-c/examples/SwiftSample'
                  }))
          out.append(
              self.config.job_spec(
                  ['src/objective-c/tests/build_one_example_bazel.sh'],
                  timeout_seconds=10 * 60,
                  shortname='ios-buildtest-example-tvOS-sample',
                  cpu_cost=1e6,
                  environ={
                      'SCHEME': 'tvOS-sample',
                      'EXAMPLE_PATH': 'src/objective-c/examples/tvOS-sample',
                      'FRAMEWORKS': 'NO'
                  }))
          # Disabled due to #20258
          # TODO (mxyan): Reenable this test when #20258 is resolved.
          # out.append(
          #     self.config.job_spec(
          #         ['src/objective-c/tests/build_one_example_bazel.sh'],
          #         timeout_seconds=20 * 60,
          #         shortname='ios-buildtest-example-watchOS-sample',
          #         cpu_cost=1e6,
          #         environ={
          #             'SCHEME': 'watchOS-sample-WatchKit-App',
          #             'EXAMPLE_PATH': 'src/objective-c/examples/watchOS-sample',
          #             'FRAMEWORKS': 'NO'
          #         }))
          out.append(
              self.config.job_spec(['src/objective-c/tests/run_plugin_tests.sh'],
                                   timeout_seconds=60 * 60,
                                   shortname='ios-test-plugintest',
                                   cpu_cost=1e6,
                                   environ=_FORCE_ENVIRON_FOR_WRAPPERS))
          out.append(
              self.config.job_spec(
                  ['test/core/iomgr/ios/CFStreamTests/build_and_run_tests.sh'],
                  timeout_seconds=20 * 60,
                  shortname='ios-test-cfstream-tests',
                  cpu_cost=1e6,
                  environ=_FORCE_ENVIRON_FOR_WRAPPERS))
          # TODO: replace with run_one_test_bazel.sh when Bazel-Xcode is stable
          out.append(
              self.config.job_spec(['src/objective-c/tests/run_one_test.sh'],
                                   timeout_seconds=60 * 60,
                                   shortname='ios-test-unittests',
                                   cpu_cost=1e6,
                                   environ={'SCHEME': 'UnitTests'}))
          out.append(
              self.config.job_spec(['src/objective-c/tests/run_one_test.sh'],
                                   timeout_seconds=60 * 60,
                                   shortname='ios-test-interoptests',
                                   cpu_cost=1e6,
                                   environ={'SCHEME': 'InteropTests'}))
          out.append(
              self.config.job_spec(['src/objective-c/tests/run_one_test.sh'],
                                   timeout_seconds=60 * 60,
                                   shortname='ios-test-cronettests',
                                   cpu_cost=1e6,
                                   environ={'SCHEME': 'CronetTests'}))
          out.append(
              self.config.job_spec(['src/objective-c/tests/run_one_test.sh'],
                                   timeout_seconds=30 * 60,
                                   shortname='ios-perf-test',
                                   cpu_cost=1e6,
                                   environ={'SCHEME': 'PerfTests'}))
          out.append(
              self.config.job_spec(['src/objective-c/tests/run_one_test.sh'],
                                   timeout_seconds=30 * 60,
                                   shortname='ios-perf-test-posix',
                                   cpu_cost=1e6,
                                   environ={'SCHEME': 'PerfTestsPosix'}))
          out.append(
              self.config.job_spec(['test/cpp/ios/build_and_run_tests.sh'],
                                   timeout_seconds=30 * 60,
                                   shortname='ios-cpp-test-cronet',
                                   cpu_cost=1e6,
                                   environ=_FORCE_ENVIRON_FOR_WRAPPERS))
          out.append(
              self.config.job_spec(['src/objective-c/tests/run_one_test.sh'],
                                   timeout_seconds=60 * 60,
                                   shortname='mac-test-basictests',
                                   cpu_cost=1e6,
                                   environ={
                                       'SCHEME': 'MacTests',
                                       'PLATFORM': 'macos'
                                   }))
          out.append(
              self.config.job_spec(['src/objective-c/tests/run_one_test.sh'],
                                   timeout_seconds=30 * 60,
                                   shortname='tvos-test-basictests',
                                   cpu_cost=1e6,
                                   environ={
                                       'SCHEME': 'TvTests',
                                       'PLATFORM': 'tvos'
                                   }))
  
          return sorted(out)
  
      def pre_build_steps(self):
          return []
  
      def make_targets(self):
          return []
  
      def make_options(self):
          return []
  
      def build_steps(self):
          return []
  
      def post_tests_steps(self):
          return []
  
      def makefile_name(self):
          return 'Makefile'
  
      def dockerfile_dir(self):
          return None
  
      def __str__(self):
          return 'objc'
  
  
  class Sanity(object):
  
      def configure(self, config, args):
          self.config = config
          self.args = args
          _check_compiler(self.args.compiler, ['default'])
  
      def test_specs(self):
          import yaml
          with open('tools/run_tests/sanity/sanity_tests.yaml', 'r') as f:
              environ = {'TEST': 'true'}
              if _is_use_docker_child():
                  environ['CLANG_FORMAT_SKIP_DOCKER'] = 'true'
                  environ['CLANG_TIDY_SKIP_DOCKER'] = 'true'
              return [
                  self.config.job_spec(cmd['script'].split(),
                                       timeout_seconds=30 * 60,
                                       environ=environ,
                                       cpu_cost=cmd.get('cpu_cost', 1))
                  for cmd in yaml.load(f)
              ]
  
      def pre_build_steps(self):
          return []
  
      def make_targets(self):
          return ['run_dep_checks']
  
      def make_options(self):
          return []
  
      def build_steps(self):
          return []
  
      def post_tests_steps(self):
          return []
  
      def makefile_name(self):
          return 'Makefile'
  
      def dockerfile_dir(self):
          return 'tools/dockerfile/test/sanity'
  
      def __str__(self):
          return 'sanity'
  
  
  # different configurations we can run under
  with open('tools/run_tests/generated/configs.json') as f:
      _CONFIGS = dict(
          (cfg['config'], Config(**cfg)) for cfg in ast.literal_eval(f.read()))
  
  _LANGUAGES = {
      'c++': CLanguage('cxx', 'c++'),
      'c': CLanguage('c', 'c'),
      'grpc-node': RemoteNodeLanguage(),
      'php': PhpLanguage(),
      'php7': Php7Language(),
      'python': PythonLanguage(),
      'ruby': RubyLanguage(),
      'csharp': CSharpLanguage(),
      'objc': ObjCLanguage(),
      'sanity': Sanity()
  }
  
  _MSBUILD_CONFIG = {
      'dbg': 'Debug',
      'opt': 'Release',
      'gcov': 'Debug',
  }
  
  
  def _windows_arch_option(arch):
      """Returns msbuild cmdline option for selected architecture."""
      if arch == 'default' or arch == 'x86':
          return '/p:Platform=Win32'
      elif arch == 'x64':
          return '/p:Platform=x64'
      else:
          print('Architecture %s not supported.' % arch)
          sys.exit(1)
  
  
  def _check_arch_option(arch):
      """Checks that architecture option is valid."""
      if platform_string() == 'windows':
          _windows_arch_option(arch)
      elif platform_string() == 'linux':
          # On linux, we need to be running under docker with the right architecture.
          runtime_arch = platform.architecture()[0]
          if arch == 'default':
              return
          elif runtime_arch == '64bit' and arch == 'x64':
              return
          elif runtime_arch == '32bit' and arch == 'x86':
              return
          else:
              print(
                  'Architecture %s does not match current runtime architecture.' %
                  arch)
              sys.exit(1)
      else:
          if args.arch != 'default':
              print('Architecture %s not supported on current platform.' %
                    args.arch)
              sys.exit(1)
  
  
  def _docker_arch_suffix(arch):
      """Returns suffix to dockerfile dir to use."""
      if arch == 'default' or arch == 'x64':
          return 'x64'
      elif arch == 'x86':
          return 'x86'
      else:
          print('Architecture %s not supported with current settings.' % arch)
          sys.exit(1)
  
  
  def runs_per_test_type(arg_str):
      """Auxiliary function to parse the "runs_per_test" flag.
  
         Returns:
             A positive integer or 0, the latter indicating an infinite number of
             runs.
  
         Raises:
             argparse.ArgumentTypeError: Upon invalid input.
      """
      if arg_str == 'inf':
          return 0
      try:
          n = int(arg_str)
          if n <= 0: raise ValueError
          return n
      except:
          msg = '\'{}\' is not a positive integer or \'inf\''.format(arg_str)
          raise argparse.ArgumentTypeError(msg)
  
  
  def percent_type(arg_str):
      pct = float(arg_str)
      if pct > 100 or pct < 0:
          raise argparse.ArgumentTypeError(
              "'%f' is not a valid percentage in the [0, 100] range" % pct)
      return pct
  
  
  # This is math.isclose in python >= 3.5
  def isclose(a, b, rel_tol=1e-09, abs_tol=0.0):
      return abs(a - b) <= max(rel_tol * max(abs(a), abs(b)), abs_tol)
  
  
  # parse command line
  argp = argparse.ArgumentParser(description='Run grpc tests.')
  argp.add_argument('-c',
                    '--config',
                    choices=sorted(_CONFIGS.keys()),
                    default='opt')
  argp.add_argument(
      '-n',
      '--runs_per_test',
      default=1,
      type=runs_per_test_type,
      help='A positive integer or "inf". If "inf", all tests will run in an '
      'infinite loop. Especially useful in combination with "-f"')
  argp.add_argument('-r', '--regex', default='.*', type=str)
  argp.add_argument('--regex_exclude', default='', type=str)
  argp.add_argument('-j', '--jobs', default=multiprocessing.cpu_count(), type=int)
  argp.add_argument('-s', '--slowdown', default=1.0, type=float)
  argp.add_argument('-p',
                    '--sample_percent',
                    default=100.0,
                    type=percent_type,
                    help='Run a random sample with that percentage of tests')
  argp.add_argument('-f',
                    '--forever',
                    default=False,
                    action='store_const',
                    const=True)
  argp.add_argument('-t',
                    '--travis',
                    default=False,
                    action='store_const',
                    const=True)
  argp.add_argument('--newline_on_success',
                    default=False,
                    action='store_const',
                    const=True)
  argp.add_argument('-l',
                    '--language',
                    choices=sorted(_LANGUAGES.keys()),
                    nargs='+',
                    required=True)
  argp.add_argument('-S',
                    '--stop_on_failure',
                    default=False,
                    action='store_const',
                    const=True)
  argp.add_argument('--use_docker',
                    default=False,
                    action='store_const',
                    const=True,
                    help='Run all the tests under docker. That provides ' +
                    'additional isolation and prevents the need to install ' +
                    'language specific prerequisites. Only available on Linux.')
  argp.add_argument(
      '--allow_flakes',
      default=False,
      action='store_const',
      const=True,
      help=
      'Allow flaky tests to show as passing (re-runs failed tests up to five times)'
  )
  argp.add_argument(
      '--arch',
      choices=['default', 'x86', 'x64'],
      default='default',
      help=
      'Selects architecture to target. For some platforms "default" is the only supported choice.'
  )
  argp.add_argument(
      '--compiler',
      choices=[
          'default', 'gcc4.4', 'gcc4.6', 'gcc4.8', 'gcc4.9', 'gcc5.3', 'gcc7.4',
          'gcc8.3', 'gcc_musl', 'clang3.4', 'clang3.5', 'clang3.6', 'clang3.7',
          'clang7.0', 'python2.7', 'python3.5', 'python3.6', 'python3.7',
          'python3.8', 'pypy', 'pypy3', 'python_alpine', 'all_the_cpythons',
          'electron1.3', 'electron1.6', 'coreclr', 'cmake', 'cmake_vs2015',
          'cmake_vs2017'
      ],
      default='default',
      help=
      'Selects compiler to use. Allowed values depend on the platform and language.'
  )
  argp.add_argument('--iomgr_platform',
                    choices=['native', 'uv', 'gevent', 'asyncio'],
                    default='native',
                    help='Selects iomgr platform to build on')
  argp.add_argument('--build_only',
                    default=False,
                    action='store_const',
                    const=True,
                    help='Perform all the build steps but don\'t run any tests.')
  argp.add_argument('--measure_cpu_costs',
                    default=False,
                    action='store_const',
                    const=True,
                    help='Measure the cpu costs of tests')
  argp.add_argument(
      '--update_submodules',
      default=[],
      nargs='*',
      help=
      'Update some submodules before building. If any are updated, also run generate_projects. '
      +
      'Submodules are specified as SUBMODULE_NAME:BRANCH; if BRANCH is omitted, master is assumed.'
  )
  argp.add_argument('-a', '--antagonists', default=0, type=int)
  argp.add_argument('-x',
                    '--xml_report',
                    default=None,
                    type=str,
                    help='Generates a JUnit-compatible XML report')
  argp.add_argument('--report_suite_name',
                    default='tests',
                    type=str,
                    help='Test suite name to use in generated JUnit XML report')
  argp.add_argument(
      '--report_multi_target',
      default=False,
      const=True,
      action='store_const',
      help='Generate separate XML report for each test job (Looks better in UIs).'
  )
  argp.add_argument(
      '--quiet_success',
      default=False,
      action='store_const',
      const=True,
      help=
      'Don\'t print anything when a test passes. Passing tests also will not be reported in XML report. '
      + 'Useful when running many iterations of each test (argument -n).')
  argp.add_argument(
      '--force_default_poller',
      default=False,
      action='store_const',
      const=True,
      help='Don\'t try to iterate over many polling strategies when they exist')
  argp.add_argument(
      '--force_use_pollers',
      default=None,
      type=str,
      help='Only use the specified comma-delimited list of polling engines. '
      'Example: --force_use_pollers epoll1,poll '
      ' (This flag has no effect if --force_default_poller flag is also used)')
  argp.add_argument('--max_time',
                    default=-1,
                    type=int,
                    help='Maximum test runtime in seconds')
  argp.add_argument('--bq_result_table',
                    default='',
                    type=str,
                    nargs='?',
                    help='Upload test results to a specified BQ table.')
  argp.add_argument(
      '--auto_set_flakes',
      default=False,
      const=True,
      action='store_const',
      help=
      'Allow repeated runs for tests that have been failing recently (based on BQ historical data).'
  )
  args = argp.parse_args()
  
  flaky_tests = set()
  shortname_to_cpu = {}
  if args.auto_set_flakes:
      try:
          for test in get_bqtest_data():
              if test.flaky: flaky_tests.add(test.name)
              if test.cpu > 0: shortname_to_cpu[test.name] = test.cpu
      except:
          print("Unexpected error getting flaky tests: %s" %
                traceback.format_exc())
  
  if args.force_default_poller:
      _POLLING_STRATEGIES = {}
  elif args.force_use_pollers:
      _POLLING_STRATEGIES[platform_string()] = args.force_use_pollers.split(',')
  
  jobset.measure_cpu_costs = args.measure_cpu_costs
  
  # update submodules if necessary
  need_to_regenerate_projects = False
  for spec in args.update_submodules:
      spec = spec.split(':', 1)
      if len(spec) == 1:
          submodule = spec[0]
          branch = 'master'
      elif len(spec) == 2:
          submodule = spec[0]
          branch = spec[1]
      cwd = 'third_party/%s' % submodule
  
      def git(cmd, cwd=cwd):
          print('in %s: git %s' % (cwd, cmd))
          run_shell_command('git %s' % cmd, cwd=cwd)
  
      git('fetch')
      git('checkout %s' % branch)
      git('pull origin %s' % branch)
      if os.path.exists('src/%s/gen_build_yaml.py' % submodule):
          need_to_regenerate_projects = True
  if need_to_regenerate_projects:
      if jobset.platform_string() == 'linux':
          run_shell_command('tools/buildgen/generate_projects.sh')
      else:
          print(
              'WARNING: may need to regenerate projects, but since we are not on')
          print(
              '         Linux this step is being skipped. Compilation MAY fail.')
  
  # grab config
  run_config = _CONFIGS[args.config]
  build_config = run_config.build_config
  
  if args.travis:
      _FORCE_ENVIRON_FOR_WRAPPERS = {'GRPC_TRACE': 'api'}
  
  languages = set(_LANGUAGES[l] for l in args.language)
  for l in languages:
      l.configure(run_config, args)
  
  language_make_options = []
  if any(language.make_options() for language in languages):
      if not 'gcov' in args.config and len(languages) != 1:
          print(
              'languages with custom make options cannot be built simultaneously with other languages'
          )
          sys.exit(1)
      else:
          # Combining make options is not clean and just happens to work. It allows C & C++ to build
          # together, and is only used under gcov. All other configs should build languages individually.
          language_make_options = list(
              set([
                  make_option for lang in languages
                  for make_option in lang.make_options()
              ]))
  
  if args.use_docker:
      if not args.travis:
          print('Seen --use_docker flag, will run tests under docker.')
          print('')
          print(
              'IMPORTANT: The changes you are testing need to be locally committed'
          )
          print(
              'because only the committed changes in the current branch will be')
          print('copied to the docker environment.')
          time.sleep(5)
  
      dockerfile_dirs = set([l.dockerfile_dir() for l in languages])
      if len(dockerfile_dirs) > 1:
          print('Languages to be tested require running under different docker '
                'images.')
          sys.exit(1)
      else:
          dockerfile_dir = next(iter(dockerfile_dirs))
  
      child_argv = [arg for arg in sys.argv if not arg == '--use_docker']
      run_tests_cmd = 'python tools/run_tests/run_tests.py %s' % ' '.join(
          child_argv[1:])
  
      env = os.environ.copy()
      env['RUN_TESTS_COMMAND'] = run_tests_cmd
      env['DOCKERFILE_DIR'] = dockerfile_dir
      env['DOCKER_RUN_SCRIPT'] = 'tools/run_tests/dockerize/docker_run_tests.sh'
      if args.xml_report:
          env['XML_REPORT'] = args.xml_report
      if not args.travis:
          env['TTY_FLAG'] = '-t'  # enables Ctrl-C when not on Jenkins.
  
      subprocess.check_call(
          'tools/run_tests/dockerize/build_docker_and_run_tests.sh',
          shell=True,
          env=env)
      sys.exit(0)
  
  _check_arch_option(args.arch)
  
  
  def make_jobspec(cfg, targets, makefile='Makefile'):
      if platform_string() == 'windows':
          return [
              jobset.JobSpec([
                  'cmake', '--build', '.', '--target',
                  '%s' % target, '--config', _MSBUILD_CONFIG[cfg]
              ],
                             cwd=os.path.dirname(makefile),
                             timeout_seconds=None) for target in targets
          ]
      else:
          if targets and makefile.startswith('cmake/build/'):
              # With cmake, we've passed all the build configuration in the pre-build step already
              return [
                  jobset.JobSpec(
                      [os.getenv('MAKE', 'make'), '-j',
                       '%d' % args.jobs] + targets,
                      cwd='cmake/build',
                      timeout_seconds=None)
              ]
          if targets:
              return [
                  jobset.JobSpec(
                      [
                          os.getenv('MAKE', 'make'), '-f', makefile, '-j',
                          '%d' % args.jobs,
                          'EXTRA_DEFINES=GRPC_TEST_SLOWDOWN_MACHINE_FACTOR=%f' %
                          args.slowdown,
                          'CONFIG=%s' % cfg, 'Q='
                      ] + language_make_options +
                      ([] if not args.travis else ['JENKINS_BUILD=1']) + targets,
                      timeout_seconds=None)
              ]
          else:
              return []
  
  
  make_targets = {}
  for l in languages:
      makefile = l.makefile_name()
      make_targets[makefile] = make_targets.get(makefile, set()).union(
          set(l.make_targets()))
  
  
  def build_step_environ(cfg):
      environ = {'CONFIG': cfg}
      msbuild_cfg = _MSBUILD_CONFIG.get(cfg)
      if msbuild_cfg:
          environ['MSBUILD_CONFIG'] = msbuild_cfg
      return environ
  
  
  build_steps = list(
      set(
          jobset.JobSpec(cmdline,
                         environ=build_step_environ(build_config),
                         timeout_seconds=_PRE_BUILD_STEP_TIMEOUT_SECONDS,
                         flake_retries=2)
          for l in languages
          for cmdline in l.pre_build_steps()))
  if make_targets:
      make_commands = itertools.chain.from_iterable(
          make_jobspec(build_config, list(targets), makefile)
          for (makefile, targets) in make_targets.items())
      build_steps.extend(set(make_commands))
  build_steps.extend(
      set(
          jobset.JobSpec(cmdline,
                         environ=build_step_environ(build_config),
                         timeout_seconds=None)
          for l in languages
          for cmdline in l.build_steps()))
  
  post_tests_steps = list(
      set(
          jobset.JobSpec(cmdline, environ=build_step_environ(build_config))
          for l in languages
          for cmdline in l.post_tests_steps()))
  runs_per_test = args.runs_per_test
  forever = args.forever
  
  
  def _shut_down_legacy_server(legacy_server_port):
      try:
          version = int(
              urllib.request.urlopen('http://localhost:%d/version_number' %
                                     legacy_server_port,
                                     timeout=10).read())
      except:
          pass
      else:
          urllib.request.urlopen('http://localhost:%d/quitquitquit' %
                                 legacy_server_port).read()
  
  
  def _calculate_num_runs_failures(list_of_results):
      """Calculate number of runs and failures for a particular test.
  
    Args:
      list_of_results: (List) of JobResult object.
    Returns:
      A tuple of total number of runs and failures.
    """
      num_runs = len(list_of_results)  # By default, there is 1 run per JobResult.
      num_failures = 0
      for jobresult in list_of_results:
          if jobresult.retries > 0:
              num_runs += jobresult.retries
          if jobresult.num_failures > 0:
              num_failures += jobresult.num_failures
      return num_runs, num_failures
  
  
  # _build_and_run results
  class BuildAndRunError(object):
  
      BUILD = object()
      TEST = object()
      POST_TEST = object()
  
  
  def _has_epollexclusive():
      binary = 'bins/%s/check_epollexclusive' % args.config
      if not os.path.exists(binary):
          return False
      try:
          subprocess.check_call(binary)
          return True
      except subprocess.CalledProcessError as e:
          return False
      except OSError as e:
          # For languages other than C and Windows the binary won't exist
          return False
  
  
  # returns a list of things that failed (or an empty list on success)
  def _build_and_run(check_cancelled,
                     newline_on_success,
                     xml_report=None,
                     build_only=False):
      """Do one pass of building & running tests."""
      # build latest sequentially
      num_failures, resultset = jobset.run(build_steps,
                                           maxjobs=1,
                                           stop_on_failure=True,
                                           newline_on_success=newline_on_success,
                                           travis=args.travis)
      if num_failures:
          return [BuildAndRunError.BUILD]
  
      if build_only:
          if xml_report:
              report_utils.render_junit_xml_report(
                  resultset, xml_report, suite_name=args.report_suite_name)
          return []
  
      if not args.travis and not _has_epollexclusive() and platform_string(
      ) in _POLLING_STRATEGIES and 'epollex' in _POLLING_STRATEGIES[
              platform_string()]:
          print('\n\nOmitting EPOLLEXCLUSIVE tests\n\n')
          _POLLING_STRATEGIES[platform_string()].remove('epollex')
  
      # start antagonists
      antagonists = [
          subprocess.Popen(['tools/run_tests/python_utils/antagonist.py'])
          for _ in range(0, args.antagonists)
      ]
      start_port_server.start_port_server()
      resultset = None
      num_test_failures = 0
      try:
          infinite_runs = runs_per_test == 0
          one_run = set(spec for language in languages
                        for spec in language.test_specs()
                        if (re.search(args.regex, spec.shortname) and
                            (args.regex_exclude == '' or
                             not re.search(args.regex_exclude, spec.shortname))))
          # When running on travis, we want out test runs to be as similar as possible
          # for reproducibility purposes.
          if args.travis and args.max_time <= 0:
              massaged_one_run = sorted(one_run, key=lambda x: x.cpu_cost)
          else:
              # whereas otherwise, we want to shuffle things up to give all tests a
              # chance to run.
              massaged_one_run = list(
                  one_run)  # random.sample needs an indexable seq.
              num_jobs = len(massaged_one_run)
              # for a random sample, get as many as indicated by the 'sample_percent'
              # argument. By default this arg is 100, resulting in a shuffle of all
              # jobs.
              sample_size = int(num_jobs * args.sample_percent / 100.0)
              massaged_one_run = random.sample(massaged_one_run, sample_size)
              if not isclose(args.sample_percent, 100.0):
                  assert args.runs_per_test == 1, "Can't do sampling (-p) over multiple runs (-n)."
                  print("Running %d tests out of %d (~%d%%)" %
                        (sample_size, num_jobs, args.sample_percent))
          if infinite_runs:
              assert len(massaged_one_run
                        ) > 0, 'Must have at least one test for a -n inf run'
          runs_sequence = (itertools.repeat(massaged_one_run) if infinite_runs
                           else itertools.repeat(massaged_one_run, runs_per_test))
          all_runs = itertools.chain.from_iterable(runs_sequence)
  
          if args.quiet_success:
              jobset.message(
                  'START',
                  'Running tests quietly, only failing tests will be reported',
                  do_newline=True)
          num_test_failures, resultset = jobset.run(
              all_runs,
              check_cancelled,
              newline_on_success=newline_on_success,
              travis=args.travis,
              maxjobs=args.jobs,
              maxjobs_cpu_agnostic=max_parallel_tests_for_current_platform(),
              stop_on_failure=args.stop_on_failure,
              quiet_success=args.quiet_success,
              max_time=args.max_time)
          if resultset:
              for k, v in sorted(resultset.items()):
                  num_runs, num_failures = _calculate_num_runs_failures(v)
                  if num_failures > 0:
                      if num_failures == num_runs:  # what about infinite_runs???
                          jobset.message('FAILED', k, do_newline=True)
                      else:
                          jobset.message('FLAKE',
                                         '%s [%d/%d runs flaked]' %
                                         (k, num_failures, num_runs),
                                         do_newline=True)
      finally:
          for antagonist in antagonists:
              antagonist.kill()
          if args.bq_result_table and resultset:
              upload_extra_fields = {
                  'compiler': args.compiler,
                  'config': args.config,
                  'iomgr_platform': args.iomgr_platform,
                  'language': args.language[
                      0
                  ],  # args.language is a list but will always have one element when uploading to BQ is enabled.
                  'platform': platform_string()
              }
              try:
                  upload_results_to_bq(resultset, args.bq_result_table,
                                       upload_extra_fields)
              except NameError as e:
                  logging.warning(
                      e)  # It's fine to ignore since this is not critical
          if xml_report and resultset:
              report_utils.render_junit_xml_report(
                  resultset,
                  xml_report,
                  suite_name=args.report_suite_name,
                  multi_target=args.report_multi_target)
  
      number_failures, _ = jobset.run(post_tests_steps,
                                      maxjobs=1,
                                      stop_on_failure=False,
                                      newline_on_success=newline_on_success,
                                      travis=args.travis)
  
      out = []
      if number_failures:
          out.append(BuildAndRunError.POST_TEST)
      if num_test_failures:
          out.append(BuildAndRunError.TEST)
  
      return out
  
  
  if forever:
      success = True
      while True:
          dw = watch_dirs.DirWatcher(['src', 'include', 'test', 'examples'])
          initial_time = dw.most_recent_change()
          have_files_changed = lambda: dw.most_recent_change() != initial_time
          previous_success = success
          errors = _build_and_run(check_cancelled=have_files_changed,
                                  newline_on_success=False,
                                  build_only=args.build_only) == 0
          if not previous_success and not errors:
              jobset.message('SUCCESS',
                             'All tests are now passing properly',
                             do_newline=True)
          jobset.message('IDLE', 'No change detected')
          while not have_files_changed():
              time.sleep(1)
  else:
      errors = _build_and_run(check_cancelled=lambda: False,
                              newline_on_success=args.newline_on_success,
                              xml_report=args.xml_report,
                              build_only=args.build_only)
      if not errors:
          jobset.message('SUCCESS', 'All tests passed', do_newline=True)
      else:
          jobset.message('FAILED', 'Some tests failed', do_newline=True)
      exit_code = 0
      if BuildAndRunError.BUILD in errors:
          exit_code |= 1
      if BuildAndRunError.TEST in errors:
          exit_code |= 2
      if BuildAndRunError.POST_TEST in errors:
          exit_code |= 4
      sys.exit(exit_code)
  