class_docstr: TFX Tuner executor impl as a worker in a Google Cloud AI Platform job.
class_docstr_tok: ["TFX","Tuner","executor","impl","as","a","worker","in","a","Google","Cloud","AI","Platform","job","."]
docstr: Starts a chief oracle in a subprocess.
docstr_tok: ["Starts","a","chief","oracle","in","a","subprocess","."]
code: def _start_chief_oracle_in_subprocess(
      self,
      input_dict: Dict[str, List[types.Artifact]],
      output_dict: Dict[str, List[types.Artifact]],
      exec_properties: Dict[str, List[types.Artifact]],
  ):
      """Starts a chief oracle in a subprocess."""
      # Because of KerasTuner's interface whereby behavior is controlled
      # by environment variables, starting the chief oracle in a sub-process,
      # as opposed to another thread in the main process, in order not to leak
      # the environment variables.
      result = multiprocessing.Process(  # pytype: disable=attribute-error  # re-none
          target=self._run_chief_oracle,
          args=(
              input_dict,
              output_dict,
              exec_properties,
          ),
      )
      result.start()
  
      logging.info("Chief oracle started at PID: %s", result.pid)
      return result
  
imports: import datetime
  import json
  import os
  from typing import Any, Dict, List
  from absl import logging
  from tfx import types
  from tfx.components.tuner import executor
  from tfx.dsl.components.base import base_executor
  from tfx.extensions.google_cloud_ai_platform import constants
  from tfx.extensions.google_cloud_ai_platform import runner
  from tfx.extensions.google_cloud_ai_platform.trainer import executor
  from tfx.types import standard_component_specs
  from tfx.utils import doc_controls
  from tfx.utils import json_utils
  from tfx.utils import name_utils
  import multiprocessing
label_desc: Use image node_id 2 for calling the _WorkerExecutor obj's underlying member method code with example usage: obj._start_chief_oracle_in_subprocess(input_dict, output_dict, exec_properties) and returns: result