content: import sys
  from multiprocessing import Lock
  
  import pytest
  from flaky import flaky
  
  from tests.background_callback.utils import setup_background_callback_app
  
  
  @pytest.mark.skipif(
      sys.version_info < (3, 7), reason="Python 3.6 long callbacks tests hangs up"
  )
  @flaky(max_runs=3)
  def test_lcbc006_long_callback_caching_multi(dash_duo, manager):
      lock = Lock()
  
      with setup_background_callback_app(manager, "app6") as app:
          dash_duo.start_server(app)
          dash_duo.wait_for_text_to_equal("#status1", "Progress 2/4", 15)
          dash_duo.wait_for_text_to_equal("#status1", "Finished", 15)
          dash_duo.wait_for_text_to_equal("#result1", "Result for 'AAA'", 8)
  
          # Check initial status/output of second long_callback
          # prevent_initial_callback=True means no calculation should have run yet
          dash_duo.wait_for_text_to_equal("#status2", "Finished", 8)
          dash_duo.wait_for_text_to_equal("#result2", "No results", 8)
  
          # Click second run button
          dash_duo.find_element("#run-button2").click()
          dash_duo.wait_for_text_to_equal("#status2", "Progress 2/4", 15)
          dash_duo.wait_for_text_to_equal("#result2", "Result for 'aaa'", 8)
  
          # Update input text box to BBB
          input_ = dash_duo.find_element("#input1")
          dash_duo.clear_input(input_)
          for key in "BBB":
              with lock:
                  input_.send_keys(key)
  
          # Click run button and check that status eventually cycles to 2/4
          dash_duo.find_element("#run-button1").click()
          dash_duo.wait_for_text_to_equal("#status1", "Progress 2/4", 20)
          dash_duo.wait_for_text_to_equal("#status1", "Finished", 12)
          dash_duo.wait_for_text_to_equal("#result1", "Result for 'BBB'", 8)
  
          # Check there were no changes in second long_callback output
          dash_duo.wait_for_text_to_equal("#status2", "Finished", 15)
          dash_duo.wait_for_text_to_equal("#result2", "Result for 'aaa'", 8)
  
          # Update input text box back to AAA
          input_ = dash_duo.find_element("#input1")
          dash_duo.clear_input(input_)
          for key in "AAA":
              with lock:
                  input_.send_keys(key)
  
          # Click run button and this time the cached result is used,
          # So we can get the result right away
          dash_duo.find_element("#run-button1").click()
          dash_duo.wait_for_text_to_equal("#status1", "Finished", 8)
          dash_duo.wait_for_text_to_equal("#result1", "Result for 'AAA'", 8)
  
          # Update input text box back to BBB
          input_ = dash_duo.find_element("#input1")
          dash_duo.clear_input(input_)
          for key in "BBB":
              with lock:
                  input_.send_keys(key)
  
          # Click run button and this time the cached result is used,
          # So we can get the result right away
          dash_duo.find_element("#run-button1").click()
          dash_duo.wait_for_text_to_equal("#status1", "Finished", 8)
          dash_duo.wait_for_text_to_equal("#result1", "Result for 'BBB'", 8)
  
          # Update second input text box to BBB, make sure there is not a cache hit
          input_ = dash_duo.find_element("#input2")
          dash_duo.clear_input(input_)
          for key in "BBB":
              with lock:
                  input_.send_keys(key)
          dash_duo.find_element("#run-button2").click()
          dash_duo.wait_for_text_to_equal("#status2", "Progress 2/4", 20)
          dash_duo.wait_for_text_to_equal("#status2", "Finished", 12)
          dash_duo.wait_for_text_to_equal("#result2", "Result for 'BBB'", 8)
  
          # Update second input text box back to aaa, check for cache hit
          input_ = dash_duo.find_element("#input2")
          dash_duo.clear_input(input_)
          for key in "aaa":
              with lock:
                  input_.send_keys(key)
          dash_duo.find_element("#run-button2").click()
          dash_duo.wait_for_text_to_equal("#status2", "Finished", 12)
          dash_duo.wait_for_text_to_equal("#result2", "Result for 'aaa'", 8)
  
          # Update input text box back to AAA
          input_ = dash_duo.find_element("#input1")
          dash_duo.clear_input(input_)
          for key in "AAA":
              with lock:
                  input_.send_keys(key)
  
          # Change cache key to cause cache miss
          app._cache_key.value = 1
  
          # Check for cache miss for first long_callback
          dash_duo.find_element("#run-button1").click()
          dash_duo.wait_for_text_to_equal("#status1", "Progress 2/4", 20)
          dash_duo.wait_for_text_to_equal("#status1", "Finished", 12)
          dash_duo.wait_for_text_to_equal("#result1", "Result for 'AAA'", 8)
  
          # Check for cache miss for second long_callback
          dash_duo.find_element("#run-button2").click()
          dash_duo.wait_for_text_to_equal("#status2", "Progress 2/4", 20)
          dash_duo.wait_for_text_to_equal("#status2", "Finished", 12)
          dash_duo.wait_for_text_to_equal("#result2", "Result for 'aaa'", 8)
  
          assert not dash_duo.redux_state_is_loading
          assert dash_duo.get_logs() == []
  