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Coroutines and asynchronous I/O using enhanced generators from python 2.5, including a enhanced WSGI server.

Project Description


This is a library for network oriented, coroutine based programming.

cogen’s goal is to enable writing code in a synchronous and easy manner in the form of generators that yield calls and recieve the result from that yield. These calls translate to asynchronous and fast os calls in cogen’s internals.

Notable features

  • a WSGI server, HTTP1.1 compilat, with asynchronous extensions
  • use epoll, kqueue where supported, select based otherwise
  • a Queue with the same interface as the standard library Queue, but for coroutines

Quick introduction

Programming with cogen library should be straightforward, similar with programming threads but without all the problems. A coroutine is just a generator wrapped in a operation handling class:

def mycoro(bla):
    result = yield <operation>
    result = yield <operation>
  • the operation instructs the scheduler what to do with the coroutine: suspend it till something happens, add another coro in the scheduler, raise a event and so on.
  • the operations are split up in 2 modules: events and sockets * the operations from sockets are related to network, like reading and writing, and these are done asynchronously but your code in the coroutine will see them as a regular synchronous or blocking call.
  • the operations from events are related to signals and coroutine/scheduler management.
  • if a operation has a result associated then the yield will return that result (eg. a string or a (connection, address) tuple) otherwise it will return the operation instance.

Echo server example

def server():
    srv = sockets.Socket()
    while 1:
        print "Listening..."
        conn, addr = yield sockets.Accept(srv)
        print "Connection from %s:%s" % addr
        m.add(handler, conn, addr)

def handler(sock, addr):
    yield sockets.Write(sock, "WELCOME TO ECHO SERVER !\r\n")

    while 1:
        line = yield sockets.ReadLine(sock, 8192)
        if line.strip() == 'exit':
            yield sockets.Write(sock, "GOOD BYE")
        yield sockets.Write(sock, line)

m = Scheduler()

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Filename, Size & Hash SHA256 Hash Help File Type Python Version Upload Date
(86.6 kB) Copy SHA256 Hash SHA256
Egg 2.5 Jan 21, 2008
(201.5 kB) Copy SHA256 Hash SHA256
Source None Jan 21, 2008

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