cablehead

Ben Bangert raised an excellent point about leaking abandoned coroutines in a recent talk:

https://docs.google.com/presentation/d/1LO_WI3N-3p2Wp9PDWyv5B6EGFZ8XTOTNJ7Hd40WOUHo/edit#slide=id.g70b0035b2_1_168

This gist demonstrates a design decision in Vanilla to attempt to help with this.

The sender, recver ends of pipes are only connected by weakref's which have callback's registered for when the corresponding end is garbage collected. When one end is blocked on a send or a recv, and the other end is abandoned without being closed explicitly the blocked coroutine will receive a vanilla.Abandoned exception. This will also result in a StopIteration exception if you are iterating over a recver.

cablehead

$ levee run -e '
local levee = require("levee")

local h = levee.Hub()

local serve = h.http:listen(8000)

for conn in serve do
        h:spawn(function()
                local req = conn:recv()

cablehead

local sys = require("levee.sys")

local r, w = sys.os.pipe()
sys.os.write(w, s, #s)

local r, w = sys.fd.pipe()
sys.fd.write(w, s, #s)

cablehead

struct LeveeMiddle {
            struct LeveeEnd* ends[2];
}

struct LeveeEnd {
            struct LeveeMiddle middle;
}

cablehead

local ev = require("ev")                                                                                              

ev.run(function(h)
  function echo(conn)
    for message in conn do
      print("Echo:", message)                                                                                         
    end
  end                                                                                                                 
  
  local serve = h.tcp:listen(8000)                                                                                    

cablehead

import json

import vanilla


h = vanilla.Hub()

users = ['antirez', 'justinrosenthal', 'jverkoey']

done = (

cablehead

import vanilla

h = vanilla.Hub()

serve = h.http.listen()

client = h.http.connect('http://localhost:%s' % serve.port)
response = client.get('/')

conn = serve.recv()  # recvs http connection

cablehead

import vanilla


h = vanilla.Hub()


def handle_request(request):
    print request
    request.reply(vanilla.http.Status(200), {}, "Hello")

cablehead

lines = h.pipe()
@h.spawn
def _():
  while True:
    line = child.stdout.recv_partion('\n')
    lines.send(line)
  lines.pipe(out)

cablehead

import vanilla

h = vanilla.Hub()

b = h.bean(8080)

@b.websocket('/')
def _(ws):
    child = h.process.execv(['/usr/bin/env', 'grep', '--line-buffered', 'foo'])
    child.stdout.pipe(ws)