from wsgiref.simple_server import make_server
from signal import *
from os import kill, getpid
import threading, socket
from sys import stdout
from time import *

try:  # Python 3
    stdout = stdout.buffer.raw
except AttributeError:  # Python < 3
    pass

def app(environ, start_response):
    start_response("200 OK", [])
    return [b"3" * int(20e6)]

server = make_server("0", 0, app)
received = 0

def run_client():
    global received
    sock = socket.create_connection(server.server_address)
    reader = sock.makefile("rb")
    try:
        sock.sendall(b"GET / HTTP/1.0\r\n\r\n")
        for _ in range(30):
            line = reader.readline(100)
            if not line.rstrip(b"\r\n"):
                break
            stdout.write("header line {!r}\n".format(line).encode())
        chunk = len(reader.read(100))
        stdout.write("1st read -> {}\n".format(chunk).encode())
        received += chunk
        sleep(1)
        kill(getpid(), SIGALRM)
        sleep(1)
        chunk = len(reader.read())
        stdout.write("2nd read -> {}\n".format(chunk).encode())
        received += chunk
    finally:
        reader.close()
        sock.close()

def sighandler(signum, frame):
    stdout.write(b"# signal\n")

signal(SIGALRM, sighandler)

background = threading.Thread(target=run_client)
background.start()
try:
    server.handle_request()
finally:
    background.join()
    server.server_close()
assert received == 20e6