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线程忽略键盘中断异常

keyboardinterrupt exception events multithreading python

Emilio · 技术社区 · 14 年前

我运行这个简单的代码:

import threading, time

class reqthread(threading.Thread):    
    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')

但当我运行它时,它会打印出来

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

实际上python线程忽略了我的 + 键盘中断,无法打印 Received Keyboard Interrupt

5 回复 | 直到 6 年前

unutbu 14 年前

尝试

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

time.sleep ,主要过程是跳出 try...except 封锁太早,所以 KeyboardInterrupt 没有被抓住。我的第一个想法是 thread.join ,但这似乎阻止了主进程(忽略键盘中断),直到 thread 完成了。

thread.daemon=True 使线程在主进程结束时终止。

Community CDub 8 年前

总结中建议的更改 the comments ,以下内容对我很有用:

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()

yaccob 9 年前

对ubuntu的解决方案稍加修改。

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'

Albert 10 年前

我的解决办法是猴子补丁 Thread.join() 这样地:

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

personal_cloud 7 年前

把 try ... except signal.pause() 在里面是的 main()

当心 import lock 不过。我猜这就是Python在默认情况下不解决ctrl-C的原因。