我正在尝试编写一个小程序来通过HTTP接口发送和接收UDP流量以及接收命令。 HTTP服务器位于一个multiprocessing.Process中； UDP服务器位于另一个服务器中。这两个进程通过python multiprocessing.Pipe进行通信。我已经附上了完整的代码。
我有2个相关问题：
如何在python中使用kqueue处理多个文件描述符/ kevent（套接字文件描述符有效，管道文件描述符似乎无法确定-我不确定所使用的管道是否等效于文件）？
如何区分这些kevent，以便在读取管道与套接字时可以应用不同的功能？
我想要UDP服务器执行的伪代码：
kq = new kqueue
udpEvent = kevent when socket read
pipeEvent = kevent when pipe read
while:
for event in kq.conrol([udpEvent, pipeEvent]):
if event == udpEvent:
# do something
elif event == pipeEvent:
print "HTTP command via pipe:", pipe.recv()
现在，UDP服务器可以识别套接字事件并正确读取套接字。但是，当我将管道事件添加到kqueue时，程序会不停地吐出管道事件。我将过滤器设置为已写入管道，但我假设1）这是错误的2）更具体地说，python
multiprocessing.Pipe就像常规的unix管道，需要以不同的方式处理。.....
<select.kevent ident=4297866384 filter=-29216 flags=0x4000 fflags=0x1 data=0x16 udata=0x4000000000000>
<select.kevent ident=4297866384 filter=-29216 flags=0x4000 fflags=0x1 data=0x16 udata=0x4000000000000>
<select.kevent ident=4297866384 filter=-29216 flags=0x4000 fflags=0x1 data=0x16 udata=0x4000000000000>
<select.kevent ident=4297866384 filter=-29216 flags=0x4000 fflags=0x1 data=0x16 udata=0x4000000000000>
<select.kevent ident=4297866384 filter=-29216 flags=0x4000 fflags=0x1 data=0x16 udata=0x4000000000000>
<select.kevent ident=4297866384 filter=-29216 flags=0x4000 fflags=0x1 data=0x16 ^C<select.kevent ident=4297866384 filter=-29216 flags=0x4000 fflags=0x1 data=0x16 udata=0x4000000000000>
main.py
import sys
from multiprocessing import Process, Pipe
# from userinterface import OSXstatusbaritem # use like so: OSXstatusbaritem.start(pipe)
from server import Server
import handler # UI thingy
# For UI, use simple HTTP server with various endpoints
# open a connection: localhost:[PORT]/open/[TARGET_IP]
def startServer(pipe):
UDP_IP = "127.0.0.1"
UDP_PORT = 9000
print "starting server"
s = Server(pipe)
s.listen(UDP_IP, UDP_PORT)
print "finishing server"
import BaseHTTPServer
def startUI(pipe):
HTTP_PORT = 4567
server_class = BaseHTTPServer.HTTPServer
myHandler = handler.handleRequestsUsing(pipe)
httpd = server_class(('localhost', 4567), myHandler)
try:
httpd.serve_forever()
except KeyboardInterrupt:
pass
httpd.server_close()
def main():
# Named full duplex pipe for communicating between server process and UI
pipeUI, pipeServer = Pipe()
# Start subprocesses
pServer = Process(target=startServer, args=(pipeServer,))
pServer.start()
startUI(pipeUI)
pServer.join()
if __name__ == "__main__": sys.exit(main())
server.py（UDP）
import sys
import select # for kqueue
from socket import socket, AF_INET, SOCK_DGRAM
from multiprocessing import Process, Pipe
class Server:
def __init__(self, pipe):
self.pipe = pipe
def listen (self, ipaddress, port):
print "starting!"
# Initialize listening UDP socket
sock = socket(AF_INET, SOCK_DGRAM)
sock.bind((ipaddress, port))
# Configure kqueue
kq = select.kqueue()
# Event for UDP socket data available
kevent0 = select.kevent( sock.fileno(),
filter=select.KQ_FILTER_READ,
flags=select.KQ_EV_ADD | select.KQ_EV_ENABLE | select.KQ_EV_CLEAR)
# Event for message queue from other processes (ui)
kevent1 = select.kevent( self.pipe.fileno(),
filter=select.KQ_FILTER_WRITE,
flags=select.KQ_EV_ADD | select.KQ_EV_ENABLE)
# TODO: Figure out how to handle multiple kevents on kqueue
# TODO: Need an event for TUN data
# Start kqueue
while True:
revents = kq.control([kevent0, kevent1], 1, None)
for event in revents:
print event
kq.close()
# close file descriptors (os.close(fd))
handler.py（HTTP接口）
import BaseHTTPServer
# Simple HTTP endpoints for controlling prototype Phantom implementation.
# The following commands are supported:
# 1. Open a connection via /open/[IP]:[PORT]
# 2. ????
class RequestHandler(BaseHTTPServer.BaseHTTPRequestHandler):
pipe = None
def __init__(self, pipe, *args):
RequestHandler.pipe = pipe
BaseHTTPServer.BaseHTTPRequestHandler.__init__(self, *args)
def do_HEAD(s):
s.send_response(200)
s.send_header("Content-type", "application/json")
s.end_headers()
def do_GET(s):
s.send_response(200)
s.send_header("Content-type", "application/json")
s.end_headers()
# Open connection command
if s.path.startswith('/open/'):
addrStr = s.path[6:len(s.path)]
(address, port) = tuple(filter(None, addrStr.split(':')))
port = int(port)
print "opening address: ", address, "port:", port
RequestHandler.pipe.send(['open', address, port])
def handleRequestsUsing(logic):
return lambda *args: RequestHandler(logic, *args)
更新：
我用select重写了服务器侦听方法。对于不会使用超过3或4 fds的慢速python原型，无论如何速度都没有关系。 Kqueue将成为另一天的主题。
def监听（自我，ip地址，端口）：
打印“开始！”
# Initialize listening non-blocking UDP socket
sock = socket(AF_INET, SOCK_DGRAM)
sock.setblocking(0)
sock.bind((ipaddress, port))
inputs = [sock, self.pipe] # stuff we read
outputs = [] # stuff we expect to write
while inputs:
readable, writable, exceptional = select.select(inputs, outputs, inputs)
for event in readable:
if event is sock:
self.handleUDPData( sock.recvfrom(1024) )
if event is self.pipe:
print "pipe event", self.pipe.recv()
最佳答案
我知道这是一个古老的问题，但是我可以举一个我正在用于多线程HTTP服务器的kqueue套接字轮询的例子，在阅读C源代码和kqueue的手册页后我才知道。
#bsd socket polling
#I make all the relevant flags more C like to match the kqueue man pages
from select import kevent, kqueue
from select import KQ_EV_ADD as EV_ADD, KQ_EV_ONESHOT as EV_ONESHOT
from select import KQ_EV_EOF as EV_EOF
from .common import Client_Thread #a parent class who's implementation is irrelevant to the question, lol
class BSD_Client(Client_Thread):
def __init__(self, *args):
Client_Thread.__init__(self, *args)
#Make a kqueue object for the thread
kq = kqueue()
#Make a one-shot kev for this kqueue for when the kill socket is
#connected to. The connection is only made once, so why not tell
#that to our kqueue? The default filter is EVFILT_READ, so we don't
#need to specify that. The default flag is just EV_ADD.
kill_kev = kevent(self.kill_fd, flags=EV_ADD|EV_ONESHOT)
#using defaults for the client socket.
client_kev = kevent(self.client_sock)
#we only need to keep track of the kqueue's control func.
#This also makes things prettier in the run func.
self.control = kq.control
#now, we add thel list of events we just made to our kqueue.
#The first 0 means we want a list of at most 0 length in return.
#the second 0 means we want no timeout (i.e. do this in a
#non-blocking way.)
self.control([client_kev, kill_kev], 0, 0)
def run(self):
while True:
#Here we poll the kqueue object.
#The empty list means we are adding no new events to the kqueue.
#The one means we want a list of at most 1 element. Then None
#Means we want block until an event is triggered.
events = self.control([], 1, None)
#If we have an event, and the event is for the kill socket
#(meaning somebody made a connection to it), then we break the
#loop and die.
if events and events[0].ident == self.kill_fd:
self.die()
break
#If all that is left is an EOF in our socket, then we break
#the loop and die. Kqueues will keep returning a kevent
#that has been read once, even when they are empty.
if events and events[0].flags & EV_EOF:
self.die()
break
#Finally, if we have an event that isn't for the kill socket and
#does not have the EOF flag set, then there is work to do. If
#the handle client function (defined in the parent class) returns
#1, then we are done serving a page and we can die.
if events and self.handle_client():
self.die()
break
client.close()
self.die所做的只是将客户端ip：port字符串
put放入用于消息传递的队列中。来自队列的另一个线程get将该字符串作为字符串，打印一条消息并join关联线程对象。当然，我不是为此使用管道，而只是使用插座。我确实在kqueue的在线手册页上找到了这个Fifos，管道
当有要读取的数据时返回；否则返回false。数据包含的数量
可用字节。
当最后一个编写器断开连接时，过滤器会将EV_EOF设置为
标志。这可以通过传递EV_CLEAR来清除，此时
过滤器将继续等待数据变为可用之前重新
转弯
因此，也许在您的udp服务器中，您遍历revents列表时，应该按照手册页上的说明进行操作？实际上，您甚至不需要遍历最长为1的列表。也许您的监听功能应该看起来像这样...
def listen(self, ip, port):
print "Starting!"
sock = socket.socket(AF_INET, SOCK_DGRAM)
sock.bind((ip, port))
kq = select.kqueue()
kev0 = select.kevent(sock)
kev1 = select.kevent(self.pipe)
kq.control([kev0, kev1], 0, 0)
while True: #this loop never breaks! so this whole function blocks forever like this
revents = kq.control([], 1, None)
if revents:
event = revents[0]
if event.flags & select.KQ_EV_EOF:
new_event = select.kevent(event.ident, flags=select.KQ_EV_CLEAR)
kq.control([new_event], 0, 0)
else:
print event
我确实建议以我的方式导入标志和函数，这使其与您将要比较的基于C的手册页更加相似，而且我认为它看起来更漂亮。
我还想指出，我的类与您的类有所不同，因为每个新客户端都将获取此实例，并且每个实例都将在其自己的线程中运行。