扭曲的線程與子進程.Popen？

Question

我試圖實現與扭曲的一種服務，是相當接近的「手指」教程這裏找到：http://twistedmatrix.com/documents/current/core/howto/tutorial/intro.html

我有一個basic.LineListener等待命令，然後執行它，那麼我有一個客戶端連接和發佈命令。麻煩的是，該命令有時需要執行其他的東西，我正在使用python的子進程模塊。這不僅僅是溝通（）的呼叫掛起，這是一個正常的子進程問題，我知道如何克服它。就是那個子進程.Popen調用是掛起的。

這裏是扭曲的服務器代碼：

from twisted.application import internet, service 
from twisted.internet import protocol, reactor, defer, threads 
from twisted.protocols import basic 
import sys 
import time 
import subprocess 

class MyProtocol(basic.LineReceiver): 
    def lineReceived(self, line): 
     self.go() 
    def go(self): 
     def writeResponse(message): 
      self.transport.write(message + '\r\n') 
      self.transport.loseConnection() 
     threads.deferToThread(self.factory.action).addCallback(writeResponse) 
    def connectionMade(self): 
     self.lines = [] 

class ActionService(service.Service): 
    def __init__(self, **kwargs): 
     pass 
     #self.users = kwargs 

def action(self): 
    print "launching subprocess" 
    sys.stdout.flush() 
    p = subprocess.Popen(["ls"], stderr=subprocess.PIPE, stdout=subprocess.PIPE, stdin=subprocess.PIPE) 
    print "launched subprocess, trying to communicate..." 
    sys.stdout.flush() 
    p.communicate() 
    print "returning" 
    sys.stdout.flush() 
    return "%032d" % (0) 

    def getActionFactory(self): 
     f = protocol.ServerFactory() 
     f.protocol = MyProtocol 
     f.action = self.action 
     return f 

reactor.suggestThreadPoolSize(300) 
application = service.Application('Action', uid=0, gid=0) 
f = ActionService() 
serviceCollection = service.IServiceCollection(application) 
internet.TCPServer(31337,f.getActionFactory() 
        ).setServiceParent(serviceCollection) 

...這是一些客戶端代碼：

#!/usr/bin/python 
import time 
import threading 
import socket 

def connectAction(host): 
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) 
    s.connect((host, 31337)) 
    s.send("asdf\r\n") 
    resp = s.recv(32) 
    s.close() 
    return resp 

class sscceThread(threading.Thread): 
    def __init__(self, host): 
     self.host = host 
     threading.Thread.__init__(self) 
    def run(self): 
     connectAction(self.host) 

def main(): 
    threads = [] 
    for i in range(0, 1000): 
     for j in range(0,5): 
      t = sscceThread("localhost") 
      t.start() 
      threads.append(t) 
     for t in threads: 
      t.join() 
     print i 
     time.sleep(1) 
    # print i 

if __name__ == "__main__": 
    main() 

運行啓動服務：

twistd -y sscce_twisted_service.py -l twistdLog; tail -f twistdLog 

並運行客戶機通過運行：

​​

你應該看到客戶端進行了幾次迭代（我已經看到它多達10個）然後掛起。客戶端代碼中包含有1秒的睡眠，讓你可以告訴每個迭代上掛起你會看到在扭曲日誌是這樣一個扭曲的日誌條目之間的區別：

2009-12-22 11:18:47-0800 [MyProtocol,55,127.0.0.1] launching subprocess 
2009-12-22 11:18:47-0800 [MyProtocol,56,127.0.0.1] launching subprocess 
2009-12-22 11:18:47-0800 [MyProtocol,55,127.0.0.1] launched subprocess, trying to communicate... 
2009-12-22 11:18:47-0800 [MyProtocol,57,127.0.0.1] launching subprocess 
2009-12-22 11:18:47-0800 [MyProtocol,58,127.0.0.1] launching subprocess 
2009-12-22 11:18:47-0800 [MyProtocol,56,127.0.0.1] launched subprocess, trying to communicate... 
2009-12-22 11:18:47-0800 [MyProtocol,55,127.0.0.1] returning 
2009-12-22 11:18:47-0800 [MyProtocol,57,127.0.0.1] launching subprocess 
2009-12-22 11:18:47-0800 [MyProtocol,56,127.0.0.1] launching subprocess returning 
2009-12-22 11:18:47-0800 [MyProtocol,59,127.0.0.1] launching subprocess 
2009-12-22 11:18:47-0800 [MyProtocol,58,127.0.0.1] launched subprocess, trying to communicate... 
2009-12-22 11:18:47-0800 [MyProtocol,58,127.0.0.1] returning 
2009-12-22 11:18:47-0800 [MyProtocol,59,127.0.0.1] launched subprocess, trying to communicate... 
2009-12-22 11:18:47-0800 [MyProtocol,59,127.0.0.1] returning 

特別請注意MyProtocol，57。它說它即將嘗試啓動子進程，但它從不打印「啓動的子進程，嘗試進行通信」行。我認爲它一定是掛在那裏的。

Answer 1

由於毫克在他的評論中說，不要使用子進程模塊。在POSIX平臺上，有必要（或多或少）處理SIGCHLD信號以處理退出的子進程。由於只能有一個SIGCHLD處理程序，因此多個庫通常不會合作。 Twisted的子進程支持和子進程模塊的支持衝突。要麼使用Twisted的支持（見http://twistedmatrix.com/documents/current/core/howto/process.html）或通過傳遞installSignalHandlers=False到reactor.run（我推薦前者，因爲subprocess禮物阻塞接口不順利集成到基於雙絞線的應用程序）關閉Twisted的支持。