Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/dummy_threading.py: 2%

1"""Faux ``threading`` version using ``dummy_thread`` instead of ``thread``. 

2 

3The module ``_dummy_threading`` is added to ``sys.modules`` in order 

4to not have ``threading`` considered imported. Had ``threading`` been 

5directly imported it would have made all subsequent imports succeed 

6regardless of whether ``_thread`` was available which is not desired. 

7 

8""" 

9from sys import modules as sys_modules 

10 

11import _dummy_thread 

12 

13# Declaring now so as to not have to nest ``try``s to get proper clean-up. 

14holding_thread = False 

15holding_threading = False 

16holding__threading_local = False 

17 

18try: 

19 # Could have checked if ``_thread`` was not in sys.modules and gone 

20 # a different route, but decided to mirror technique used with 

21 # ``threading`` below. 

22 if '_thread' in sys_modules: 

23 held_thread = sys_modules['_thread'] 

24 holding_thread = True 

25 # Must have some module named ``_thread`` that implements its API 

26 # in order to initially import ``threading``. 

27 sys_modules['_thread'] = sys_modules['_dummy_thread'] 

28 

29 if 'threading' in sys_modules: 

30 # If ``threading`` is already imported, might as well prevent 

31 # trying to import it more than needed by saving it if it is 

32 # already imported before deleting it. 

33 held_threading = sys_modules['threading'] 

34 holding_threading = True 

35 del sys_modules['threading'] 

36 

37 if '_threading_local' in sys_modules: 

38 # If ``_threading_local`` is already imported, might as well prevent 

39 # trying to import it more than needed by saving it if it is 

40 # already imported before deleting it. 

41 held__threading_local = sys_modules['_threading_local'] 

42 holding__threading_local = True 

43 del sys_modules['_threading_local'] 

44 

45 import threading 

46 # Need a copy of the code kept somewhere... 

47 sys_modules['_dummy_threading'] = sys_modules['threading'] 

48 del sys_modules['threading'] 

49 sys_modules['_dummy__threading_local'] = sys_modules['_threading_local'] 

50 del sys_modules['_threading_local'] 

51 from _dummy_threading import * 

52 from _dummy_threading import __all__ 

53 

54finally: 

55 # Put back ``threading`` if we overwrote earlier 

56 

57 if holding_threading: 

58 sys_modules['threading'] = held_threading 

59 del held_threading 

60 del holding_threading 

61 

62 # Put back ``_threading_local`` if we overwrote earlier 

63 

64 if holding__threading_local: 

65 sys_modules['_threading_local'] = held__threading_local 

66 del held__threading_local 

67 del holding__threading_local 

68 

69 # Put back ``thread`` if we overwrote, else del the entry we made 

70 if holding_thread: 

71 sys_modules['_thread'] = held_thread 

72 del held_thread 

73 else: 

74 del sys_modules['_thread'] 

75 del holding_thread 

76 

77 del _dummy_thread 

78 del sys_modules