Re: Java NIO server and Python asyncore client
On Tuesday, February 5, 2013 10:09:28 AM UTC+2, foobar...@gmail.com wrote:
Can someone help answer this?
http://stackoverflow.com/questions/14698020/java-nio-server-and-python-asyncore-client
Blocking python client works, asyncore doesn't work.
There was return missing in writeable().
Modified code::
import socket
import select
import asyncore
class Connector(asyncore.dispatcher):
def __init__(self, host, port):
asyncore.dispatcher.__init__(self)
self.debug = True
self.buffer = bytes(hi,ascii)
self.create_socket(socket.AF_INET,socket.SOCK_STREAM)
print(Connector.connect(({},{})).format(host,port))
self.connect((host, port))
def handle_connect(self):
print(handle_connect()) # not called --
def handle_read(self):
print(handle_read())
self.recv(4096)
self.close()
def writable(self):
print(writable())
return len(self.buffer) 0 # remember RETURN
def handle_write(self):
print(handle_write())
sent = self.send(self.buffer)
print(send({}).format(self.buffer[0:sent]))
self.buffer = self.buffer[sent:]
def handle_close(self):
print(handle_close())
self.close()
connector = Connector(localhost, 12000) # Handler()
print(asyncore.loop() enter)
asyncore.loop()
print(asyncore.loop() leave)
BSD socket communication framework does not itself support connection
indications
on connection-oriented protocols, so asyncore fakes the indication by
detecting
if socket is writable. As the writable was false = no write event = no
connection indication.
asyncore usage and documentation is bad, so when using the module, read the
source
code to understand it's usage and functioning, or use other implementation eg.
Tornado.
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Java NIO server and Python asyncore client
Can someone help answer this?
http://stackoverflow.com/questions/14698020/java-nio-server-and-python-asyncore-client
Blocking python client works, asyncore doesn't work.
Server.java:
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.nio.channels.SelectionKey;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.nio.channels.SelectableChannel;
import java.nio.channels.Selector;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.Set;
class Server
{
public Selector sel;
public ServerSocketChannel ssc;
public SocketChannel channel;
public static void main(String[] args) throws Exception
{
Server s = new Server();
s.openSocket(12000);
s.run();
}
private void openSocket(int port) throws Exception
{
InetSocketAddress address = new InetSocketAddress(0.0.0.0, port);
ssc = ServerSocketChannel.open();
ssc.configureBlocking(false);
ssc.socket().bind(address);
sel = Selector.open();
ssc.register(sel, SelectionKey.OP_ACCEPT);
}
public void run() throws Exception
{
while (true)
{
sel.select();
SetSelectionKey keys = sel.selectedKeys();
IteratorSelectionKey i = keys.iterator();
while (i.hasNext())
{
SelectionKey key = (SelectionKey) i.next();
i.remove();
if (!key.isValid())
{
continue;
}
if (key.isAcceptable())
{
channel = ssc.accept();
channel.configureBlocking(false);
System.out.println(Accepted...\n);
channel.register(sel, SelectionKey.OP_READ);
}
if (key.isReadable())
{
if (channel == key.channel())
{
System.out.println(Readable\n);
ByteBuffer buffer = ByteBuffer.wrap(new byte[1024]);
int pos = channel.read(buffer);
buffer.flip();
System.out.println(new String(buffer.array(), 0, pos));
}
}
}
}
}
}
Asyncore Python Code:
import socket
import select
import asyncore
class Connector(asyncore.dispatcher):
def __init__(self, host, port):
asyncore.dispatcher.__init__(self)
self.buffer = hi
self.create_socket()
self.connect((host, port))
def handle_connect(self):
print([]--[]) # not called --
def handle_read(self):
pass
def writable(self):
len(self.buffer) 0
def handle_write(self):
sent = self.send(self.buffer)
print([]--- + self.buffer[0:sent])
self.buffer = self.buffer[sent:]
def handle_close(self):
print([]...x...[])
self.close()
connector = Connector(localhost, 12000, Handler())
asyncore.loop()
Python Blocking client:
# Echo client program
import socket
import sys
HOST = 'localhost'# The remote host
PORT = 12000 # The same port as used by the server
s = None
for res in socket.getaddrinfo(HOST, PORT, socket.AF_UNSPEC, socket.SOCK_STREAM):
af, socktype, proto, canonname, sa = res
try:
s = socket.socket(af, socktype, proto)
print(socket)
except OSError as msg:
s = None
continue
try:
s.connect(sa)
print(connected)
except OSError as msg:
s.close()
s = None
continue
break
if s is None:
print('could not open socket')
sys.exit(1)
print(Sending)
s.sendall(bytes(Hey server, UTF-8))
data = s.recv(1024)
#s.close()
print('Received', repr(data))
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Re: Java NIO server and Python asyncore client
foobarome...@gmail.com writes: Can someone help answer this? http://stackoverflow.com/questions/14698020/java-nio-server-and-python-asyncore-client Blocking python client works, asyncore doesn't work. I fear you must tell us which Python version you are using. Your call to dispatcher.create_socket is incompatible with the code in Python 2.7 (it lacks parameters family and type). Otherwise, I could not detect a problem in your code. I assume that does not work does not mean I get an exception but means I do not get anything. You might need some debugging to detect the problem. Check dispatcher.socket_map after you have set up your connector. It should contain your connector object and this should be both readable() and writable(). If this is the case, I would debug asyncore.loop: asyncore.dispatcher treats the socket as connected as soon as it becomes either readable or writable. Both should happen after connect is successful. Thus, I would look what goes wrong: * the socket does not become readable/writable this would proabably mean that the socket never gets connected, maybe because of bad parameters to create_socket. * the channel is not properly registered * bad internal state -- http://mail.python.org/mailman/listinfo/python-list
