Python - 無法用KeyboardInterrupt殺死主線程

Question

我正在製作一個簡單的多線程端口掃描器。它掃描主機上的所有端口並返回開放端口。麻煩是中斷掃描。掃描完成需要很長時間，有時我希望在掃描過程中用C-c殺死程序。麻煩是掃描不會停止。主線程被鎖定在queue.join（）上，並且忘記KeyboardInterrupt，直到隊列中的所有數據都被處理，從而對主線程進行解鎖並優雅地退出程序。我的所有線程都被守護進程，所以當主線程死亡時，它們應該與他一起死亡。

我嘗試使用信號庫，沒有成功。重寫threading.Thread類，並增加了對正常終止沒有工作方法...主線程就不會在執行queue.join收到一個KeyboardInterrupt（）

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) 

編輯：

我已經找到了解決方案使用時間模塊。

#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() 

Answer 1

當您創建的線程將它們添加到正在運行的線程的列表，並使用Ctrl-C打交道時發送kill信號給名單上的每個線程。這樣，你正在積極清理，而不是依靠它爲你做。

Answer 2

你已經做出你的線程守護程序，但你必須保持你的主線程活着，而守護線程都在那裏，還有如何做到這一點：Cannot kill Python script with Ctrl-C