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run_tests.py

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    Jan Tattermusch authored
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    run_tests.py 55.78 KiB
    #!/usr/bin/env python2.7
    # Copyright 2015, Google Inc.
    # All rights reserved.
    #
    # Redistribution and use in source and binary forms, with or without
    # modification, are permitted provided that the following conditions are
    # met:
    #
    #     * Redistributions of source code must retain the above copyright
    # notice, this list of conditions and the following disclaimer.
    #     * Redistributions in binary form must reproduce the above
    # copyright notice, this list of conditions and the following disclaimer
    # in the documentation and/or other materials provided with the
    # distribution.
    #     * Neither the name of Google Inc. nor the names of its
    # contributors may be used to endorse or promote products derived from
    # this software without specific prior written permission.
    #
    # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    
    """Run tests in parallel."""
    
    from __future__ import print_function
    
    import argparse
    import ast
    import collections
    import glob
    import itertools
    import json
    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 python_utils.jobset as jobset
    import python_utils.report_utils as report_utils
    import python_utils.watch_dirs as watch_dirs
    
    
    _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': ['epoll', 'poll', 'poll-cv']
    }
    
    
    def platform_string():
      return jobset.platform_string()
    
    
    _DEFAULT_TIMEOUT_SECONDS = 5 * 60
    
    
    # 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
        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=5 if flaky or args.allow_flakes else 0,
                              timeout_retries=3 if 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'])
    
    
    def _python_config_generator(name, major, minor, bits, config_vars):
      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])])
    
    
    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.args.compiler == 'cmake':
          _check_arch(self.args.arch, ['default'])
          self._use_cmake = True
          self._docker_distro = 'jessie'
          self._make_options = []
        elif self.platform == 'windows':
          self._use_cmake = False
          self._make_options = [_windows_toolset_option(self.args.compiler),
                                _windows_arch_option(self.args.arch)]
        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 '
          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
          polling_strategies = (_POLLING_STRATEGIES.get(self.platform, ['all'])
                                if target.get('uses_polling', True)
                                else ['all'])
          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/lib/tsi/test_creds/ca.pem',
                 'GRPC_POLL_STRATEGY': polling_strategy,
                 'GRPC_VERBOSITY': 'DEBUG'}
            shortname_ext = '' if polling_strategy=='all' else ' GRPC_POLL_STRATEGY=%s' % polling_strategy
            timeout_scaling = 1
            if polling_strategy == 'poll-cv':
              timeout_scaling *= 5
    
            if polling_strategy in target.get('excluded_poll_engines', []):
              continue
    
            # Scale overall test timeout if running under various sanitizers.
            config = self.args.config
            if ('asan' in config
                or config == 'msan'
                or config == 'tsan'
                or config == 'ubsan'
                or config == 'helgrind'
                or config == 'memcheck'):
              timeout_scaling *= 20
    
            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':
              if self._use_cmake:
                binary = 'cmake/build/%s/%s.exe' % (_MSBUILD_CONFIG[self.config.build_config], target['name'])
              else:
                binary = 'vsprojects/%s%s/%s.exe' % (
                    'x64/' if self.args.arch == 'x64' else '',
                    _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):
              if '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]
                    out.append(self.config.job_spec(cmdline,
                                                    shortname='%s --gtest_filter=%s %s' % (binary, test, shortname_ext),
                                                    cpu_cost=cpu_cost,
                                                    timeout_seconds=_DEFAULT_TIMEOUT_SECONDS * timeout_scaling,
                                                    environ=env))
              else:
                cmdline = [binary] + target['args']
                out.append(self.config.job_spec(cmdline,
                                                shortname=' '.join(
                                                              pipes.quote(arg)
                                                              for arg in cmdline) +
                                                          shortname_ext,
                                                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]
    
      def make_options(self):
        return self._make_options;
    
      def pre_build_steps(self):
        if self._use_cmake:
          if self.platform == 'windows':
            return [['tools\\run_tests\\helper_scripts\\pre_build_cmake.bat']]
          else:
            return [['tools/run_tests/helper_scripts/pre_build_cmake.sh']]
        else:
          if self.platform == 'windows':
            return [['tools\\run_tests\\helper_scripts\\pre_build_c.bat']]
          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=''):
        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 == 'gcc4.4':
          return ('wheezy', self._gcc_make_options(version_suffix='-4.4'))
        elif compiler == 'gcc4.6':
          return ('wheezy', self._gcc_make_options(version_suffix='-4.6'))
        elif compiler == 'gcc4.8':
          return ('jessie', self._gcc_make_options(version_suffix='-4.8'))
        elif compiler == 'gcc5.3':
          return ('ubuntu1604', [])
        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'))
        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
    
    
    class NodeLanguage(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', 'electron1.3'])
        if self.args.compiler == 'default':
          self.runtime = 'node'
          self.node_version = '4'
        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:]
    
      def test_specs(self):
        if self.platform == 'windows':
          return [self.config.job_spec(['tools\\run_tests\\helper_scripts\\run_node.bat'])]
        else:
          run_script = 'run_node'
          if self.runtime == 'electron':
            run_script += '_electron'
          return [self.config.job_spec(['tools/run_tests/helper_scripts/{}.sh'.format(run_script),
                                        self.node_version],
                                       None,
                                       environ=_FORCE_ENVIRON_FOR_WRAPPERS)]
    
      def pre_build_steps(self):
        if self.platform == 'windows':
          return [['tools\\run_tests\\helper_scripts\\pre_build_node.bat']]
        else:
          build_script = 'pre_build_node'
          if self.runtime == 'electron':
            build_script += '_electron'
          return [['tools/run_tests/helper_scripts/{}.sh'.format(build_script), self.node_version]]
    
      def make_targets(self):
        return []
    
      def make_options(self):
        return []
    
      def build_steps(self):
        if self.platform == 'windows':
          return [['tools\\run_tests\\helper_scripts\\build_node.bat']]
        else:
          build_script = 'build_node'
          if self.runtime == 'electron':
            build_script += '_electron'
            # building for electron requires a patch version
            self.node_version += '.0'
          return [['tools/run_tests/helper_scripts/{}.sh'.format(build_script), self.node_version]]
    
      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 'node'
    
    
    class PhpLanguage(object):
    
      def configure(self, config, args):
        self.config = config
        self.args = args
        _check_compiler(self.args.compiler, ['default'])
    
      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 []
    
      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'])
    
      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 []
    
      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):
    
      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('src/python/grpcio_tests/tests/tests.json') as tests_json_file:
          tests_json = json.load(tests_json_file)
        environment = dict(_FORCE_ENVIRON_FOR_WRAPPERS)
        return [self.config.job_spec(
            config.run,
            timeout_seconds=5*60,
            environ=dict(list(environment.items()) +
                         [('GRPC_PYTHON_TESTRUNNER_FILTER', str(suite_name))]),
            shortname='%s.test.%s' % (config.name, 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):
        return []
    
      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):
        return 'pyenv' if self.args.compiler in ['python3.5', 'python3.6'] else 'jessie'
    
      def _get_pythons(self, args):
        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']
    
        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)
        python27_config = _python_config_generator(name='py27', major='2',
                                                   minor='7', bits=bits,
                                                   config_vars=config_vars)
        python34_config = _python_config_generator(name='py34', major='3',
                                                   minor='4', 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)
        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.compiler == 'default':
          if os.name == 'nt':
            return (python27_config,)
          else:
            return (python27_config, python34_config,)
        elif args.compiler == 'python2.7':
          return (python27_config,)
        elif args.compiler == 'python3.4':
          return (python34_config,)
        elif args.compiler == 'python3.5':
          return (python35_config,)
        elif args.compiler == 'python3.6':
          return (python36_config,)
        elif args.compiler == 'pypy':
          return (pypy27_config,)
        elif args.compiler == 'pypy3':
          return (pypy32_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):
        return [self.config.job_spec(['tools/run_tests/helper_scripts/run_ruby.sh'],
                                     timeout_seconds=10*60,
                                     environ=_FORCE_ENVIRON_FOR_WRAPPERS)]
    
      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':
          # Explicitly choosing between x86 and x64 arch doesn't work yet
          _check_arch(self.args.arch, ['default'])
          # CoreCLR use 64bit runtime by default.
          arch_option = 'x64' if self.args.compiler == 'coreclr' else self.args.arch
          self._make_options = [_windows_toolset_option(self.args.compiler),
                                _windows_arch_option(arch_option)]
        else:
          _check_compiler(self.args.compiler, ['default', 'coreclr'])
          if self.platform == 'linux' and self.args.compiler == 'coreclr':
            self._docker_distro = 'coreclr'
          else:
            self._docker_distro = 'jessie'
    
          if self.platform == 'mac':
            # TODO(jtattermusch): EMBED_ZLIB=true currently breaks the mac build
            self._make_options = ['EMBED_OPENSSL=true']
            if self.args.compiler != 'coreclr':
              # On Mac, official distribution of mono is 32bit.
              self._make_options += ['CFLAGS=-m32', 'LDFLAGS=-m32']
          else:
            self._make_options = ['EMBED_OPENSSL=true', 'EMBED_ZLIB=true']
    
      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']
        assembly_subdir = 'bin/%s' % msbuild_config
        assembly_extension = '.exe'
    
        if self.args.compiler == 'coreclr':
          assembly_subdir += '/netcoreapp1.0'
          runtime_cmd = ['dotnet', 'exec']
          assembly_extension = '.dll'
        else:
          nunit_args += ['--noresult', '--workers=1']
          if self.platform == 'windows':
            runtime_cmd = []
          else:
            runtime_cmd = ['mono']
    
        specs = []
        for assembly in tests_by_assembly.iterkeys():
          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']]
        else:
          return [['tools/run_tests/helper_scripts/pre_build_csharp.sh']]
    
      def make_targets(self):
        return ['grpc_csharp_ext']
    
      def make_options(self):
        return self._make_options;
    
      def build_steps(self):
        if self.args.compiler == 'coreclr':
          if self.platform == 'windows':
            return [['tools\\run_tests\\helper_scripts\\build_csharp_coreclr.bat']]
          else:
            return [['tools/run_tests/helper_scripts/build_csharp_coreclr.sh']]
        else:
          if self.platform == 'windows':
            return [[_windows_build_bat(self.args.compiler),
                     'src/csharp/Grpc.sln',
                     '/p:Configuration=%s' % _MSBUILD_CONFIG[self.config.build_config]]]
          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):
        return '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):
        return [
            self.config.job_spec(['src/objective-c/tests/run_tests.sh'],
                                  timeout_seconds=60*60,
                                  shortname='objc-tests',
                                  environ=_FORCE_ENVIRON_FOR_WRAPPERS),
            self.config.job_spec(['src/objective-c/tests/build_example_test.sh'],
                                  timeout_seconds=30*60,
                                  shortname='objc-examples-build',
                                  environ=_FORCE_ENVIRON_FOR_WRAPPERS),
        ]
    
      def pre_build_steps(self):
        return []
    
      def make_targets(self):
        return ['interop_server']
    
      def make_options(self):
        return []
    
      def build_steps(self):
        return [['src/objective-c/tests/build_tests.sh']]
    
      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'
          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'
    
    class NodeExpressLanguage(object):
      """Dummy Node express test target to enable running express performance
      benchmarks"""
    
      def __init__(self):
        self.platform = platform_string()
    
      def configure(self, config, args):
        self.config = config
        self.args = args
        _check_compiler(self.args.compiler, ['default', 'node0.12',
                                             'node4', 'node5', 'node6'])
        if self.args.compiler == 'default':
          self.node_version = '4'
        else:
          # Take off the word "node"
          self.node_version = self.args.compiler[4:]
    
      def test_specs(self):
        return []
    
      def pre_build_steps(self):
        if self.platform == 'windows':
          return [['tools\\run_tests\\helper_scripts\\pre_build_node.bat']]
        else:
          return [['tools/run_tests/helper_scripts/pre_build_node.sh', self.node_version]]
    
      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 'node_express'
    
    # 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'),
        'node': NodeLanguage(),
        'node_express': NodeExpressLanguage(),
        '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 _windows_build_bat(compiler):
      """Returns name of build.bat for selected compiler."""
      # For CoreCLR, fall back to the default compiler for C core
      if compiler == 'default' or compiler == 'vs2013' or compiler == 'coreclr':
        return 'vsprojects\\build_vs2013.bat'
      elif compiler == 'vs2015':
        return 'vsprojects\\build_vs2015.bat'
      elif compiler == 'vs2010':
        return 'vsprojects\\build_vs2010.bat'
      else:
        print('Compiler %s not supported.' % compiler)
        sys.exit(1)
    
    
    def _windows_toolset_option(compiler):
      """Returns msbuild PlatformToolset for selected compiler."""
      # For CoreCLR, fall back to the default compiler for C core
      if compiler == 'default' or compiler == 'vs2013' or compiler == 'coreclr':
        return '/p:PlatformToolset=v120'
      elif compiler == 'vs2015':
        return '/p:PlatformToolset=v140'
      elif compiler == 'vs2010':
        return '/p:PlatformToolset=v100'
      else:
        print('Compiler %s not supported.' % compiler)
        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):
        """Auxilary 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)
    
    
    # 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('-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=['all'] + sorted(_LANGUAGES.keys()),
                      nargs='+',
                      default=['all'])
    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',
                               'clang3.4', 'clang3.5', 'clang3.6', 'clang3.7',
                               'vs2010', 'vs2013', 'vs2015',
                               'python2.7', 'python3.4', 'python3.5', 'python3.6', 'pypy', 'pypy3',
                               'node0.12', 'node4', 'node5', 'node6', 'node7',
                               'electron1.3',
                               'coreclr',
                               'cmake'],
                      default='default',
                      help='Selects compiler to use. Allowed values depend on the platform and language.')
    argp.add_argument('--iomgr_platform',
                      choices=['native', 'uv'],
                      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 dont 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('--quiet_success',
                      default=False,
                      action='store_const',
                      const=True,
                      help='Dont 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='Dont try to iterate over many polling strategies when they exist')
    args = argp.parse_args()
    
    if args.force_default_poller:
      _POLLING_STRATEGIES = {}
    
    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))
        subprocess.check_call('git %s' % cmd, cwd=cwd, shell=True)
      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':
        subprocess.check_call('tools/buildgen/generate_projects.sh', shell=True)
      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'}
    
    if 'all' in args.language:
      lang_list = _LANGUAGES.keys()
    else:
      lang_list = args.language
    # We don't support code coverage on some languages
    if 'gcov' in args.config:
      for bad in ['objc', 'sanity']:
        if bad in lang_list:
          lang_list.remove(bad)
    
    languages = set(_LANGUAGES[l] for l in lang_list)
    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:
        language_make_options = next(iter(languages)).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:
        if 'gcov' in args.config:
          dockerfile_dir = 'tools/dockerfile/test/multilang_jessie_x64'
          print ('Using multilang_jessie_x64 docker image for code coverage for '
                 'all languages.')
        else:
          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':
        if makefile.startswith('cmake/build/'):
          return [jobset.JobSpec(['cmake', '--build', '.',
                                  '--target', '%s' % target,
                                  '--config', _MSBUILD_CONFIG[cfg]],
                                 cwd='cmake/build',
                                 timeout_seconds=None) for target in targets]
        extra_args = []
        # better do parallel compilation
        # empirically /m:2 gives the best performance/price and should prevent
        # overloading the windows workers.
        extra_args.extend(['/m:2'])
        # disable PDB generation: it's broken, and we don't need it during CI
        extra_args.extend(['/p:Jenkins=true'])
        return [
          jobset.JobSpec([_windows_build_bat(args.compiler),
                          'vsprojects\\%s.sln' % target,
                          '/p:Configuration=%s' % _MSBUILD_CONFIG[cfg]] +
                          extra_args +
                          language_make_options,
                          shell=True, 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] +
                                  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), flake_retries=5)
                       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 _start_port_server(port_server_port):
      # check if a compatible port server is running
      # if incompatible (version mismatch) ==> start a new one
      # if not running ==> start a new one
      # otherwise, leave it up
      try:
        version = int(urllib.request.urlopen(
            'http://localhost:%d/version_number' % port_server_port,
            timeout=10).read())
        print('detected port server running version %d' % version)
        running = True
      except Exception as e:
        print('failed to detect port server: %s' % sys.exc_info()[0])
        print(e.strerror)
        running = False
      if running:
        current_version = int(subprocess.check_output(
            [sys.executable, os.path.abspath('tools/run_tests/python_utils/port_server.py'),
             'dump_version']))
        print('my port server is version %d' % current_version)
        running = (version >= current_version)
        if not running:
          print('port_server version mismatch: killing the old one')
          urllib.request.urlopen('http://localhost:%d/quitquitquit' % port_server_port).read()
          time.sleep(1)
      if not running:
        fd, logfile = tempfile.mkstemp()
        os.close(fd)
        print('starting port_server, with log file %s' % logfile)
        args = [sys.executable, os.path.abspath('tools/run_tests/python_utils/port_server.py'),
                '-p', '%d' % port_server_port, '-l', logfile]
        env = dict(os.environ)
        env['BUILD_ID'] = 'pleaseDontKillMeJenkins'
        if platform_string() == 'windows':
          # Working directory of port server needs to be outside of Jenkins
          # workspace to prevent file lock issues.
          tempdir = tempfile.mkdtemp()
          port_server = subprocess.Popen(
              args,
              env=env,
              cwd=tempdir,
              creationflags = 0x00000008, # detached process
              close_fds=True)
        else:
          port_server = subprocess.Popen(
              args,
              env=env,
              preexec_fn=os.setsid,
              close_fds=True)
        time.sleep(1)
        # ensure port server is up
        waits = 0
        while True:
          if waits > 10:
            print('killing port server due to excessive start up waits')
            port_server.kill()
          if port_server.poll() is not None:
            print('port_server failed to start')
            # try one final time: maybe another build managed to start one
            time.sleep(1)
            try:
              urllib.request.urlopen('http://localhost:%d/get' % port_server_port,
                              timeout=1).read()
              print('last ditch attempt to contact port server succeeded')
              break
            except:
              traceback.print_exc()
              port_log = open(logfile, 'r').read()
              print(port_log)
              sys.exit(1)
          try:
            urllib.request.urlopen('http://localhost:%d/get' % port_server_port,
                            timeout=1).read()
            print('port server is up and ready')
            break
          except socket.timeout:
            print('waiting for port_server: timeout')
            traceback.print_exc();
            time.sleep(1)
            waits += 1
          except urllib.error.URLError:
            print('waiting for port_server: urlerror')
            traceback.print_exc();
            time.sleep(1)
            waits += 1
          except:
            traceback.print_exc()
            port_server.kill()
            raise
    
    
    def _calculate_num_runs_failures(list_of_results):
      """Caculate 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()
    
    
    # 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 []
    
      # start antagonists
      antagonists = [subprocess.Popen(['tools/run_tests/python_utils/antagonist.py'])
                     for _ in range(0, args.antagonists)]
      port_server_port = 32766
      _start_port_server(port_server_port)
      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:
          massaged_one_run = sorted(one_run, key=lambda x: x.shortname)
        else:
          # whereas otherwise, we want to shuffle things up to give all tests a
          # chance to run.
          massaged_one_run = list(one_run)  # random.shuffle needs an indexable seq.
          random.shuffle(massaged_one_run)  # which it modifies in-place.
        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, infinite_runs=infinite_runs, maxjobs=args.jobs,
            stop_on_failure=args.stop_on_failure,
            add_env={'GRPC_TEST_PORT_SERVER': 'localhost:%d' % port_server_port},
            quiet_success=args.quiet_success)
        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 xml_report and resultset:
          report_utils.render_junit_xml_report(resultset, xml_report,
                                               suite_name=args.report_suite_name)
    
      number_failures, _ = jobset.run(
          post_tests_steps, maxjobs=1, stop_on_failure=True,
          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)