線程忽略KeyboardInterrupt異常

我跑我這簡單的代碼：線程忽略KeyboardInterrupt異常

import threading, time 

class reqthread (threading.Thread): 
    def __init__ (self): 
    threading.Thread.__init__(self) 

    def run (self): 
    for i in range(0,10): 
     time.sleep(1) 
     print '.' 

try: 
    thread=reqthread() 
    thread.start() 
except (KeyboardInterrupt, SystemExit): 
    print '\n! Received keyboard interrupt, quitting threads.\n'

但是當我運行它，它打印

$ python prova.py 
` 
. 
. 
^C. 
. 
. 
. 
. 
. 
. 
. 
Exception KeyboardInterrupt in <module 'threading' from '/usr/lib/python2.6/threading.pyc'> ignored 
`

其實蟒蛇線程無視我按Ctrl +Ç鍵盤中斷並不打印Received Keyboard Interrupt。爲什麼？這段代碼有什麼問題？

來源

2010-09-24 Emilio

嘗試

try: 
    thread=reqthread() 
    thread.daemon=True 
    thread.start() 
    while True: time.sleep(100) 
except (KeyboardInterrupt, SystemExit): 
    print '\n! Received keyboard interrupt, quitting threads.\n'

沒有調用time.sleep，主要工藝是太早跳出try...except塊，所以KeyboardInterrupt沒有被捕獲。我的第一個想法是使用thread.join，但似乎阻止主進程（忽略KeyboardInterrupt），直到thread完成。

thread.daemon=True會導致主進程結束時線程終止。

來源

2010-09-24 14:51:04 unutbu

我相信'join'上的超時，即'while thread.isAlive：thread.join（5）'也可以使主線程響應異常。 – 2012-09-11 19:51:03

+11

'thread.daemon = True'實際上並不推薦，因爲它不允許線程清理掉任何留下的資源...... – 2013-09-29 14:47:59

總結推薦的變化the comments，下面的工作很適合我：

try: 
    thread = reqthread() 
    thread.start() 
    while thread.isAlive(): 
    thread.join(1) # not sure if there is an appreciable cost to this. 
except (KeyboardInterrupt, SystemExit): 
    print '\n! Received keyboard interrupt, quitting threads.\n' 
    sys.exit()

來源

2014-05-01 17:30:18 rattray

在「while thread.isAlive」中反覆調用「thread.join（）」（）：「好東西/有關係嗎？ – DevPlayer 2016-09-15 13:39:00

我個人不知道;可能值得嘗試制定一個基準，如果性能對你有用嗎？ – rattray 2016-09-16 00:43:14

請注意exit（）和sys.exit（）不一樣。建議使用sys.exit（）。 – DevPlayer 2016-11-18 01:23:26

我（哈克）解決方案是猴子修補Thread.join()這樣的：

def initThreadJoinHack(): 
    import threading, thread 
    mainThread = threading.currentThread() 
    assert isinstance(mainThread, threading._MainThread) 
    mainThreadId = thread.get_ident() 
    join_orig = threading.Thread.join 
    def join_hacked(threadObj, timeout=None): 
    """ 
    :type threadObj: threading.Thread 
    :type timeout: float|None 
    """ 
    if timeout is None and thread.get_ident() == mainThreadId: 
     # This is a HACK for Thread.join() if we are in the main thread. 
     # In that case, a Thread.join(timeout=None) would hang and even not respond to signals 
     # because signals will get delivered to other threads and Python would forward 
     # them for delayed handling to the main thread which hangs. 
     # See CPython signalmodule.c. 
     # Currently the best solution I can think of: 
     while threadObj.isAlive(): 
     join_orig(threadObj, timeout=0.1) 
    else: 
     # In all other cases, we can use the original. 
     join_orig(threadObj, timeout=timeout) 
    threading.Thread.join = join_hacked

來源

2015-03-06 13:27:34 Albert

稍作修改的Ubuntu解決方案。

卸下tread.daemon =真所建議由Eric和更換通過signal.pause休眠循環（）：

import signal 
try: 
    thread=reqthread() 
    thread.start() 
    signal.pause() # instead of: while True: time.sleep(100) 
except (KeyboardInterrupt, SystemExit): 
    print '\n! Received keyboard interrupt, quitting threads.\n'

來源

2016-02-26 08:36:28 yaccob

不錯 - 但不幸的是，在Windows上不支持 – 2016-08-25 09:36:35

把在每個線程try ... except，並且也是在signal.pause()真main()作品我。但是，請注意import lock。我猜這就是爲什麼Python默認情況下不能解決ctrl-C的問題。

來源

2017-09-21 23:39:20

線程忽略KeyboardInterrupt異常

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