text: # Copyright (c) 2019 PaddlePaddle Authors. All Rights Reserved.
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #     http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  
  import os
  import sys
  import signal
  import unittest
  import multiprocessing
  import time
  
  import paddle.compat as cpt
  from paddle.fluid import core
  
  
  def set_child_signal_handler(self, child_pid):
      core._set_process_pid(id(self), child_pid)
      current_handler = signal.getsignal(signal.SIGCHLD)
      if not callable(current_handler):
          current_handler = None
  
      def __handler__(signum, frame):
          core._throw_error_if_process_failed()
          if current_handler is not None:
              current_handler(signum, frame)
  
      signal.signal(signal.SIGCHLD, __handler__)
  
  
  class TestDygraphDataLoaderSingalHandler(unittest.TestCase):
      def test_child_process_exit_with_error(self):
          def __test_process__():
              core._set_process_signal_handler()
              sys.exit(1)
  
          exception = None
          try:
              test_process = multiprocessing.Process(target=__test_process__)
              test_process.start()
  
              set_child_signal_handler(id(self), test_process.pid)
              time.sleep(3)
          except core.EnforceNotMet as ex:
              self.assertIn("FatalError", cpt.get_exception_message(ex))
              exception = ex
  
          self.assertIsNotNone(exception)
  
      def test_child_process_killed_by_sigsegv(self):
          def __test_process__():
              core._set_process_signal_handler()
              os.kill(os.getpid(), signal.SIGSEGV)
  
          exception = None
          try:
              test_process = multiprocessing.Process(target=__test_process__)
              test_process.start()
  
              set_child_signal_handler(id(self), test_process.pid)
              time.sleep(3)
          except core.EnforceNotMet as ex:
              self.assertIn("Segmentation fault", cpt.get_exception_message(ex))
              exception = ex
  
          self.assertIsNotNone(exception)
  
      def test_child_process_killed_by_sigbus(self):
          def __test_process__():
              core._set_process_signal_handler()
              os.kill(os.getpid(), signal.SIGBUS)
  
          exception = None
          try:
              test_process = multiprocessing.Process(target=__test_process__)
              test_process.start()
  
              set_child_signal_handler(id(self), test_process.pid)
              time.sleep(3)
          except core.EnforceNotMet as ex:
              self.assertIn("Bus error", cpt.get_exception_message(ex))
              exception = ex
  
          self.assertIsNotNone(exception)
  
      def test_child_process_killed_by_sigterm(self):
          def __test_process__():
              core._set_process_signal_handler()
              time.sleep(10)
  
          test_process = multiprocessing.Process(target=__test_process__)
          test_process.daemon = True
          test_process.start()
  
          set_child_signal_handler(id(self), test_process.pid)
          time.sleep(1)
  
  
  if __name__ == '__main__':
      unittest.main()
  