关于多线程：Python – 无法使用KeyboardInterrupt杀死主线程

Python - Can't kill main thread with KeyboardInterrupt

我正在制作一个简单的多线程端口扫描器。它扫描主机上的所有端口并返回打开的端口。麻烦在于中断扫描。扫描完成需要花费大量时间，有时我希望在扫描过程中用C-c杀死程序。麻烦的是扫描不会停止。主线程被锁定在queue.join()上，并且忘记了KeyboardInterrupt，直到处理了队列中的所有数据，因此解除了主线程并正常退出程序。我的所有线程都被守护进来，所以当主线程死掉时，他们应该和他一起死掉。

我尝试使用信号库，没有成功。重写threading.Thread类和正常终止的添加方法不起作用...主线程在执行queue.join()时不会收到KeyboardInterrupt

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import threading, sys, Queue, socket

queue = Queue.Queue()

def scan(host):
while True:
port = queue.get()

if port > 999 and port % 1000 == 0:
print port
try:
#sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
#sock.settimeout(2) #you need timeout or else it will try to connect forever!
#sock.connect((host, port))
#----OR----
sock = socket.create_connection((host, port), timeout = 2)

sock.send('aaa')
data = sock.recv(100)
print"Port {} open, message: {}".format(port, data)
sock.shutdown()
sock.close()
queue.task_done()
except:
queue.task_done()

def main(host):
#populate queue
for i in range(1, 65536):
queue.put(i)
#spawn worker threads
for port in range(100):
t = threading.Thread(target = scan, args = (host,))
t.daemon = True
t.start()

if __name__ == '__main__':
host =""

#does input exist?
try:
host = sys.argv[1]
except:
print"No argument was recivied!"
exit(1)

#is input sane?
try:
host = socket.gethostbyname(host)
except:
print"Adress does not exist"
exit(2)

#execute main program and wait for scan to complete
main(host)
print"Post main() call!"
try:
queue.join()
except KeyboardInterrupt:
print"C-C"
exit(3)

编辑：

我通过使用时间模块找到了解决方案。

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#execute main program and wait for scan to complete
main(host)

#a little trick. queue.join() makes main thread immune to keyboardinterrupt. So use queue.empty() with time.sleep()
#queue.empty() is"unreliable" so it may return True a bit earlier then intented.
#when queue is true, queue.join() is executed, to confirm that all data was processed.
#not a true solution, you can't interrupt main thread near the end of scan (when queue.empty() returns True)
try:
while True:
if queue.empty() == False:
time.sleep(1)
else:
break
except KeyboardInterrupt:
print"Alas poor port scanner..."
exit(1)
queue.join()