|
| 1 | +```python |
| 2 | + |
| 3 | +import threading |
| 4 | +from time import sleep |
| 5 | +import logging |
| 6 | + |
| 7 | +logging.basicConfig(level=logging.DEBUG, format='%(threadName)s: %(message)s') |
| 8 | + |
| 9 | +def print_range(start_num, end_num) -> None: |
| 10 | + for i in range(start_num, end_num): |
| 11 | + if threading.current_thread().daemon: |
| 12 | + # This daemon thread should monitor if all the threads running this are finished |
| 13 | + logging.info(f"Current active threads: {threading.active_count()}") |
| 14 | + if threading.active_count() == 1: |
| 15 | + logging.info('All threads finished.') |
| 16 | + break |
| 17 | + sleep(1) |
| 18 | + else: |
| 19 | + logging.info(i) |
| 20 | + sleep(0.2) |
| 21 | + |
| 22 | +t1 = threading.Thread(target=print_range, args=(1, 10)) |
| 23 | +t2 = threading.Thread(target=print_range, args=(-10, 0)) |
| 24 | +t3 = threading.Thread(target=print_range, args=(0, 1000), daemon=True) |
| 25 | + |
| 26 | + |
| 27 | +t1.start() |
| 28 | +t2.start() |
| 29 | +t3.start() |
| 30 | + |
| 31 | +t1.join() |
| 32 | +t2.join() |
| 33 | +t3.join() |
| 34 | + |
| 35 | +if not t1.is_alive() and not t2.is_alive(): |
| 36 | + print('Finished') |
| 37 | +``` |
| 38 | + |
| 39 | +# Which one of the answers below is a possible output of the Python code above? |
| 40 | + |
| 41 | + |
| 42 | +# a) |
| 43 | +``` |
| 44 | +Thread-1 (print_range): 1 |
| 45 | +Thread-2 (print_range): -10 |
| 46 | +Thread-3 (print_range): Current active threads: 4 |
| 47 | +Thread-2 (print_range): -9 |
| 48 | +Thread-1 (print_range): 2 |
| 49 | +Thread-2 (print_range): -8 |
| 50 | +Thread-1 (print_range): 3 |
| 51 | +Thread-2 (print_range): -7 |
| 52 | +Thread-1 (print_range): 4 |
| 53 | +Thread-2 (print_range): -6 |
| 54 | +Thread-1 (print_range): 5 |
| 55 | +Thread-3 (print_range): Current active threads: 4 |
| 56 | +Thread-1 (print_range): 6 |
| 57 | +Thread-2 (print_range): -5 |
| 58 | +Thread-1 (print_range): 7 |
| 59 | +Thread-2 (print_range): -4 |
| 60 | +Thread-1 (print_range): 8 |
| 61 | +Thread-2 (print_range): -3 |
| 62 | +Thread-2 (print_range): -2 |
| 63 | +Thread-1 (print_range): 9 |
| 64 | +Thread-2 (print_range): -1 |
| 65 | +Thread-3 (print_range): Current active threads: 3 |
| 66 | +Thread-3 (print_range): Current active threads: 2 |
| 67 | +... |
| 68 | +...995 more lines of (Thread-3 (print_range): Current active threads: 2) |
| 69 | +... |
| 70 | +Thread-3 (print_range): Current active threads: 2 |
| 71 | +Finished |
| 72 | +``` |
| 73 | + |
| 74 | +# b) |
| 75 | +``` |
| 76 | +Thread-1 (print_range): 1 |
| 77 | +Thread-2 (print_range): -10 |
| 78 | +Thread-3 (print_range): Current active threads: 3 |
| 79 | +Thread-1 (print_range): 2 |
| 80 | +Thread-2 (print_range): -9 |
| 81 | +Thread-1 (print_range): 3 |
| 82 | +Thread-2 (print_range): -8 |
| 83 | +Thread-1 (print_range): 4 |
| 84 | +Thread-2 (print_range): -7 |
| 85 | +Thread-1 (print_range): 5 |
| 86 | +Thread-2 (print_range): -6 |
| 87 | +Thread-3 (print_range): Current active threads: 3 |
| 88 | +Thread-1 (print_range): 6 |
| 89 | +Thread-2 (print_range): -5 |
| 90 | +Thread-1 (print_range): 7 |
| 91 | +Thread-2 (print_range): -4 |
| 92 | +Thread-1 (print_range): 8 |
| 93 | +Thread-2 (print_range): -3 |
| 94 | +Thread-1 (print_range): 9 |
| 95 | +Thread-2 (print_range): -2 |
| 96 | +Thread-2 (print_range): -1 |
| 97 | +Thread-3 (print_range): All threads finished. |
| 98 | +Finished |
| 99 | +``` |
| 100 | + |
| 101 | +# c) |
| 102 | +``` |
| 103 | +Thread-2 (print_range): -10 |
| 104 | +Thread-1 (print_range): 1 |
| 105 | +Thread-3 (print_range): Current active threads: 3 |
| 106 | +Thread-2 (print_range): -9 |
| 107 | +Thread-2 (print_range): -8 |
| 108 | +Thread-1 (print_range): 2 |
| 109 | +Thread-1 (print_range): 3 |
| 110 | +Thread-1 (print_range): 4 |
| 111 | +Thread-1 (print_range): 5 |
| 112 | +Thread-2 (print_range): -7 |
| 113 | +Thread-2 (print_range): -6 |
| 114 | +Thread-1 (print_range): 6 |
| 115 | +Thread-2 (print_range): -5 |
| 116 | +Thread-2 (print_range): -4 |
| 117 | +Thread-2 (print_range): -3 |
| 118 | +Thread-2 (print_range): -2 |
| 119 | +Thread-2 (print_range): -1 |
| 120 | +Thread-3 (print_range): Current active threads: 2 |
| 121 | +Thread-1 (print_range): 7 |
| 122 | +Thread-1 (print_range): 8 |
| 123 | +Thread-1 (print_range): 9 |
| 124 | +Thread-3 (print_range): Current active threads: 1 |
| 125 | +Thread-3 (print_range): All threads finished. |
| 126 | +Finished |
| 127 | +``` |
| 128 | + |
| 129 | +# d) |
| 130 | +``` |
| 131 | +Thread-2 (print_range): -10 |
| 132 | +Thread-1 (print_range): 1 |
| 133 | +Thread-3 (print_range): Current active threads: 4 |
| 134 | +Thread-2 (print_range): -9 |
| 135 | +Thread-2 (print_range): -8 |
| 136 | +Thread-1 (print_range): 2 |
| 137 | +Thread-1 (print_range): 3 |
| 138 | +Thread-1 (print_range): 4 |
| 139 | +Thread-1 (print_range): 5 |
| 140 | +Thread-2 (print_range): -7 |
| 141 | +Thread-2 (print_range): -6 |
| 142 | +Thread-1 (print_range): 6 |
| 143 | +Thread-3 (print_range): Current active threads: 4 |
| 144 | +Thread-2 (print_range): -5 |
| 145 | +Thread-2 (print_range): -4 |
| 146 | +Thread-2 (print_range): -3 |
| 147 | +Thread-2 (print_range): -2 |
| 148 | +Thread-2 (print_range): -1 |
| 149 | +Thread-1 (print_range): 7 |
| 150 | +Thread-1 (print_range): 8 |
| 151 | +Thread-1 (print_range): 9 |
| 152 | +Finished |
| 153 | +``` |
| 154 | + |
| 155 | +# e) |
| 156 | +```None of the above``` |
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