Stackless python network performance degrading over time?
So i'm toying around with stackless python, writing a very simple webserver to teach myself programming with microthreads/tasklets. But now to my problem, when I run something like
ab -n 100000 -c 50 http://192.168.0.192/ (100k requests, 50 concurrency) in apache bench I get something like 6k req/s, the second time I run it I get 5.5k, third time 5k, fourth time, 4.5k, etc. all the way down to 100req/s or something.
The problem goes away when I restart the python script, though.
Now my question is why? Am i forgetting to delete tasklets? I've checked the stackless.getruncount() (and it always seems to return 1, for some reason) so it doesn't seem like there would be any dead tasklets hanging around? I've tried calling .kill() on all tasklets that are done, didn't help. I just can't figure this one out.
import socket import select import stackless import time class socket_wrapper(object): def __init__(self, sock, sockets): super(socket_wrapper, self).__init__() self.sock = sock self.fileno = sock.fileno self.sockets_list = sockets self.channel = stackless.channel() self.writable = False self.error = False def remove(self): self.sock.close() self.sockets_list.remove(self) def send(self, data): self.sock.send(data) def push(self, bytes): self.channel.send(self.sock.recv(bytes)) def stackless_accept(accept, handler, recv_size=1024, timeout=0): sockets = [accept] while True: read, write, error = select.select(sockets, sockets, sockets, timeout) for sock in read: if sock is accept: # Accept socket and create wrapper sock = socket_wrapper(sock.accept(), sockets) # Create tasklett for this connection tasklet = stackless.tasklet(handler) tasklet.setup(sock) # Store socket sockets.append(sock) else: # Send data to handler sock.push(recv_size) # Tag all writable sockets for sock in write: if sock is not accept: sock.writable = True # Tag all faulty sockets for sock in error: if sock is not accept: sock.error = True else: pass # should do something here if the main socket is faulty timeout = 0 if socket else 1 stackless.schedule() def simple_handler(tsock): data = "" while data[-4:] != "\r\n\r\n": data += tsock.channel.receive() while not tsock.writable and not tsock.error: stackless.schedule() if not tsock.error: tsock.send("HTTP/1.1 200 OK\r\nContent-length: 8\r\n\r\nHi there") tsock.remove() sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) sock.bind(("192.168.0.192", 8000)) sock.listen(5) stackless.tasklet(stackless_accept)(sock, simple_handler) stackless.run()
First, please make Class Name start with an Upper Case Letter. It's more conventional and easier to read.
More importantly, in the
stackless_accept function you accumulate a
Sock objects, named
sockets. This list appears to grow endlessly. Yes, you have a
remove, but it isn't always invoked. If the socket gets an error, then it appears that it will be left in the collection forever.