simple_async.nim

import asyncdispatch, asyncnet, strutils

var port: Port
proc createServer() {.async.} =
  var server = newAsyncSocket()
  server.setSockOpt(OptReuseAddr, true)
  bindAddr(server)
  port = getLocalAddr(server)[1]
  server.listen()
  while true:
    let client = await server.accept()
    discard await client.recvLine()
    client.close()

asyncCheck createServer()

var done = false
proc f(): Future[void] {.async.} =
  let s = createAsyncNativeSocket()
  await s.connect("localhost", port)
  await s.send("123\C\L")
  done = true
  s.closeSocket()

for i in 0..100_000:
  waitFor f()
doAssert done
GC_fullCollect()
echo formatSize getOccupiedMem()