Files
forgefirm/scripts/bench/ctlport_test.py
T
ScottW514 b29bb9e023 bench: the controller port and manual home harnesses
Two host harnesses for the grblHAL driver's null-sink build, in the bench
registry and the README with the others. The driver's CI runs them.

ctlport_test.py drives the controller port beside a scripted Grbl sender
that counts every ok and error it is sent, which is the only way to see a
status routed to the wrong source. 13 cases: the socket's mode; a port
jog's status going to the port with the sender's count exact and the jog
run whole under the sender's '?' polls; a port error the sender's next line
does not inherit; the sender's line canceling a fast port jog and drawing
its own ok (fast on purpose: a slow jog stops at once and would pass with no
hold at all); a sender line queued right behind the port's; the refusals;
one client, and five reconnects right after a close; the status hook across
a soft reset; the dead-man; a CR LF sender; a sender that polls the way
LightBurn does, '?' with an end of line behind it, LF and CR LF (every port
jog accepted, a 60 mm port jog run whole with the polls landing inside it,
one ok per poll, a real line still canceling a port jog); and every
operation of both sets under an open armed window with M3 modal and S500,
where the dump must hold no FIRE tick.

manual_home_test.py reads the stream dump (GFSINK_DUMP) and the attribute
log (GFSINK_ATTR_LOG), so it can say that nothing was shipped and which
current was written, and how many times. 9 cases: a manual $H ships no step
and no FIRE tick and declares the offsets with the soft limits on and Z
kept; $H refused in a cycle; $MD refused under an open armed window with
nothing written; every motion source and $X refused while released; each
energize written exactly once; the port's panel operations; both pairs of
home offsets, alone and at once; and a controller killed under a release,
whose replacement writes only 0 and 0.

Both pass against the driver's extensions tree. The poll cases fail against
the driver without its empty-line rule ("8 of 8 port jogs were refused under
a status poll"), which is the defect they were written from: it was found
on the bench reference with LightBurn connected, and the sender these
harnesses had until then polled a bare '?'.
2026-09-20 07:13:31 -04:00

661 lines
25 KiB
Python

#!/usr/bin/env python3
# Copyright 2026 514 LLC d/b/a OpenGlow
# Written by Scott Wiederhold
# https://community.openglow.org
# SPDX-License-Identifier: MIT
"""Host-side verification of the controller port and the stream's line
multiplexer.
Runs the native grblHAL_glowforge binary in null-sink mode and drives two
clients at once: a scripted sender on the Grbl TCP socket that counts every
response it gets, and the port's one client on the Unix socket grbl.ctl in
the state directory. The sender's count is the point: a sender synchronizes
on ok and error, so one response too many or too few desynchronizes every
job after it.
1. a port jog's status goes to the port and never to the sender, which
sees a [MSG:] and nothing else
2. a port jog that errors does not leave its error with the sender: with
COMPATIBILITY_LEVEL 0 the core holds a parser error against the next
g-code line, and the next line here is the sender's
3. the sender always wins: a sender line that arrives during a port jog
cancels the jog, waits, and gets its own ok, never error:9
4. a port jog is refused while the sender is active, while a program
runs, and when its words carry anything a jog does not need; a motion
word the core's jog grammar rejects comes back as the core's error
5. the port has one client: a second connection is refused and the first
keeps working (it never displaces, unlike the Grbl socket); a client
that closes and reconnects at once is served
6. a CR LF sender keeps its count across a port jog, an empty line
included
7. the status hook survives a soft reset (the core puts its own report
handlers back at every reset)
8. the port's client is the dead-man: closing it cancels its jog
9. every port operation ships dark. Under an open armed window, with M3
modal and S above zero, a port jog, a canceled port jog, the refused
jogs, and the panel operations add steps to the shipped stream and not
one FIRE tick. A jog block carries the modal spindle state, so the
stream's mask on jogging is the only thing that keeps a jog dark, and
this is what holds the port to it
Usage: ctlport_test.py [path/to/grblHAL_glowforge]
"""
import json
import os
import re
import shutil
import signal
import socket
import subprocess
import sys
import tempfile
import threading
import time
BIN = os.path.abspath(sys.argv[1] if len(sys.argv) > 1 else "build-native/grblHAL_glowforge")
PORT = 2397
def fail(msg):
print("FAIL: %s" % msg)
sys.exit(1)
class Sender:
"""The scripted sender: every line it receives is classified, and the
responses (ok, error:N) are counted apart from everything else."""
def __init__(self, port, eol="\n"):
self.eol = eol
self.responses = [] # "ok" / "error:N", in order
self.other = [] # messages, reports, the banner
self.lock = threading.Lock()
for _ in range(50):
try:
self.sock = socket.create_connection(("127.0.0.1", port), timeout=1)
break
except OSError:
time.sleep(0.1)
else:
fail("cannot connect to the controller")
self.sock.settimeout(0.2)
self.alive = True
self.thread = threading.Thread(target=self._read, daemon=True)
self.thread.start()
time.sleep(0.5) # the banner
def _read(self):
buf = b""
while self.alive:
try:
data = self.sock.recv(4096)
except socket.timeout:
continue
except OSError:
return
if not data:
return
buf += data
while b"\n" in buf:
raw, buf = buf.split(b"\n", 1)
line = raw.decode(errors="replace").strip()
if not line:
continue
with self.lock:
if line == "ok" or line.startswith("error:"):
self.responses.append(line)
else:
self.other.append(line)
def count(self):
with self.lock:
return len(self.responses)
def send(self, line, timeout=5.0):
"""Send one line and return its response: the one response that
arrives for it."""
n = self.count()
self.sock.sendall((line + self.eol).encode())
end = time.time() + timeout
while time.time() < end:
if self.count() > n:
with self.lock:
return self.responses[n]
time.sleep(0.01)
fail("no response to the sender's %r" % line)
def realtime(self, byte):
self.sock.sendall(byte)
def state(self):
with self.lock:
n = len(self.other)
self.sock.sendall(b"?")
end = time.time() + 2.0
while time.time() < end:
with self.lock:
for line in self.other[n:]:
m = re.match(r"<([A-Za-z]+)", line)
if m:
return m.group(1)
time.sleep(0.01)
fail("no status report")
def wait_state(self, want, timeout=20.0):
end = time.time() + timeout
while time.time() < end:
if self.state() == want:
return
time.sleep(0.1)
fail("the controller never reached %s (now %s)" % (want, self.state()))
def saw(self, needle):
with self.lock:
return sum(needle in line for line in self.other)
def close(self):
self.alive = False
try:
self.sock.close()
except OSError:
pass
class PortClient:
def __init__(self, path):
self.sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
self.sock.settimeout(5.0)
self.sock.connect(path)
self.buf = b""
def request(self, line):
self.sock.sendall((line + "\n").encode())
return self.reply()
def reply(self):
while b"\n" not in self.buf:
data = self.sock.recv(4096)
if not data:
return None
self.buf += data
raw, self.buf = self.buf.split(b"\n", 1)
return raw.decode()
def state(self):
return json.loads(self.request("state"))
def close(self):
try:
self.sock.close()
except OSError:
pass
def publish_verdicts(path, stop):
"""Stand in for the cooling engine: a clean verdict that acknowledges the
armed window, refreshed twice a second. A laser line arms against it."""
while not stop.is_set():
tmp = path + ".tmp"
with open(tmp, "w") as f:
f.write('{"ts_mono":%.3f,"fire_ok":true,"verdict":"OK","hold":false,'
'"resume_ok":true,"armed":true,"reason":""}'
% time.clock_gettime(time.CLOCK_MONOTONIC))
os.replace(tmp, path)
stop.wait(0.5)
class Session:
def __init__(self, eol="\n", laser=False):
self.workdir = tempfile.mkdtemp(prefix="ctlport-")
conf = os.path.join(self.workdir, "forgefirm.conf")
with open(conf, "w") as f:
f.write("cool_fan_grace_s = 0\nlaser_disarm_s = 30\nhoming_mode = manual\n")
env = dict(os.environ, GFHOME_CONF=conf, GF_STATE_DIR=self.workdir, FFLOG_STDERR="1")
env.pop("GFSINK", None)
env.pop("GF_SWITCH_FILE", None)
self.dump = os.path.join(self.workdir, "stream.bin")
self.stop = threading.Event()
self.pub = None
if laser:
verdict = os.path.join(self.workdir, "cooling.state")
env.update(GFSINK_DUMP=self.dump, GF_VERDICT_FILE=verdict)
self.pub = threading.Thread(target=publish_verdicts, args=(verdict, self.stop),
daemon=True)
self.pub.start()
self.proc = subprocess.Popen([BIN, "-p", str(PORT)], cwd=self.workdir, env=env,
stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
self.sender = Sender(PORT, eol)
self.path = os.path.join(self.workdir, "grbl.ctl")
for _ in range(50):
if os.path.exists(self.path):
break
time.sleep(0.1)
else:
fail("the controller did not create %s" % self.path)
self.port = PortClient(self.path)
def quiet(self):
"""Past the port's sender-quiet interval."""
time.sleep(0.45)
def ticks(self):
"""(step ticks, FIRE ticks) shipped so far. A byte with bit 7 set is a
power byte; in a tick byte 0x25 are the X, Y and Z steps and 0x10 is FIRE."""
with open(self.dump, "rb") as f:
data = f.read()
return (sum(1 for b in data if not b & 0x80 and b & 0x25),
sum(1 for b in data if not b & 0x80 and b & 0x10))
def close(self):
self.port.close()
self.sender.close()
self.proc.send_signal(signal.SIGINT)
try:
self.proc.wait(5)
except subprocess.TimeoutExpired:
self.proc.kill()
self.stop.set()
if self.pub is not None:
self.pub.join(2)
shutil.rmtree(self.workdir, ignore_errors=True)
def test_socket_mode(s):
mode = os.stat(s.path).st_mode & 0o777
if mode != 0o600:
fail("[mode] grbl.ctl is %o, not 600" % mode)
print("PASS [mode]: grbl.ctl is a socket with mode 600")
def test_status_routing(s):
if s.sender.send("G91") != "ok" or s.sender.send("G0 X1") != "ok":
fail("[routing] the sender's own lines did not get ok")
s.sender.wait_state("Idle")
s.quiet()
before = s.sender.count()
x0 = s.port.state()["mpos"][0]
r = s.port.request("jog G91 X2 F600")
if r != "ok":
fail("[routing] the port jog got %r, not ok" % r)
s.sender.wait_state("Idle")
# The sender polled its status all the way through the jog. A realtime
# character is not a line: it cancels nothing, and the jog ran whole.
moved = s.port.state()["mpos"][0] - x0
if abs(moved - 2.0) > 0.01:
fail("[routing] the sender's status polls cut the port jog short: moved %.3f of 2" % moved)
if s.sender.count() != before:
fail("[routing] the sender got a response for the port's line: %r"
% s.sender.responses[before:])
if not s.sender.saw("[MSG:Panel jog]"):
fail("[routing] the sender got no [MSG:] for the port jog")
if s.sender.send("G0 X1") != "ok":
fail("[routing] the sender's next line did not get ok")
print("PASS [routing]: the port jog's ok went to the port and the jog ran whole under the "
"sender's status polls; the sender saw a [MSG:] and its count is intact")
def test_error_not_inherited(s):
s.sender.wait_state("Idle")
s.quiet()
before = s.sender.count()
r = s.port.request("jog G91 X1") # no feed rate: the core refuses it
if not (r or "").startswith("error:"):
fail("[error] a jog with no feed rate got %r, not an error" % r)
if s.sender.count() != before:
fail("[error] the sender got the port's error: %r" % s.sender.responses[before:])
r2 = s.sender.send("G0 X1")
if r2 != "ok":
fail("[error] the sender's next g-code line got %r: it inherited the port's %s" % (r2, r))
print("PASS [error]: the port got %s; the sender's next line ran and got ok" % r)
def test_sender_wins(s):
s.sender.wait_state("Idle")
s.quiet()
x0 = s.port.state()["mpos"][0]
# Fast, so the cancel is a real deceleration: the core stays in the jog
# state for the length of it, and a sender line read in that window is
# the error:9 the hold exists to prevent. A slow jog stops at once and
# would pass with no hold at all.
if s.port.request("jog G91 X300 F6000") != "ok": # 3 s if nothing stops it
fail("[sender-wins] the long port jog was refused")
time.sleep(0.7)
st = s.port.state()
if st["state"] != "Jog" or not st["port_jog"]:
fail("[sender-wins] not jogging for the port: %r" % st)
t0 = time.time()
r = s.sender.send("G0 X1", timeout=10.0)
dt = time.time() - t0
if r != "ok":
fail("[sender-wins] the sender's line during a port jog got %r, not ok" % r)
s.sender.wait_state("Idle")
st = s.port.state()
if st["port_jog"]:
fail("[sender-wins] the port still claims the jog: %r" % st)
moved = st["mpos"][0] - x0
if moved > 200:
fail("[sender-wins] the port jog was not canceled (X moved %.1f mm)" % moved)
print("PASS [sender-wins]: the sender's line canceled the port jog, waited %.2f s, "
"and got ok" % dt)
def test_sender_wins_queued(s):
"""The window the read gate exists for. The core reads a line's bytes
in one pass and polls the stream only at the end of line, so a sender
line that sits in the ring right behind the port's jog line is read
while the jog it follows is still running, with no poll in between to
cancel it. A dwell opens the window on purpose: the port's line is
queued during it, and the sender streams its next line behind that."""
s.sender.wait_state("Idle")
s.sender.send("G91")
n = s.sender.count()
s.sender.sock.sendall(("G4 P1.5" + s.sender.eol).encode()) # no ok until the dwell ends
s.quiet()
s.port.sock.sendall(b"jog G91 X300 F6000\n") # queued behind the dwell
time.sleep(0.2)
s.sender.sock.sendall(("G0 X1" + s.sender.eol).encode()) # streamed behind the port's line
end = time.time() + 10.0
while time.time() < end and s.sender.count() < n + 2:
time.sleep(0.02)
got = s.sender.responses[n:n + 2]
port_reply = s.port.reply()
if port_reply != "ok":
fail("[sender-wins-queued] the queued port jog got %r, not ok" % port_reply)
if got != ["ok", "ok"]:
fail("[sender-wins-queued] the sender's dwell and the line behind the port jog got %r, "
"not two ok" % got)
s.sender.wait_state("Idle")
print("PASS [sender-wins-queued]: a sender line queued right behind the port's jog line "
"waited for the cancel and got ok")
class NewlinePoller(threading.Thread):
"""A sender that polls the way LightBurn does: '?' with an end of line
behind it, on a timer. The '?' is a realtime character; the end of line
is an empty line, which the core answers ok."""
def __init__(self, sender, period=0.25):
super().__init__(daemon=True)
self.sender, self.period = sender, period
self.polls = 0
self.halt = threading.Event()
def run(self):
while not self.halt.is_set():
self.sender.sock.sendall(b"?" + self.sender.eol.encode())
self.polls += 1
self.halt.wait(self.period)
def stop(self):
self.halt.set()
self.join()
def poll_case(tag, eol):
"""An empty line is not the sender speaking. With a sender polling
'?'<eol> four times a second (LightBurn polls about twice a second): a
port jog is never refused for it, a long port jog runs whole under it,
and every poll still draws its one ok, during the jog too. A real line
still goes first."""
s = Session(eol=eol)
try:
s.sender.wait_state("Idle")
s.quiet()
before = s.sender.count()
poller = NewlinePoller(s.sender)
poller.start()
time.sleep(0.6)
refused = []
for i in range(8): # spread across the poll period
r = s.port.request("jog G91 X0.5 F3000")
if r != "ok":
refused.append(r)
time.sleep(0.11)
if refused:
fail("[%s] %d of 8 port jogs were refused under a status poll: %s" % (tag, len(refused), refused))
while s.port.state()["state"] != "Idle":
time.sleep(0.05)
x0 = s.port.state()["mpos"][0]
if s.port.request("jog G91 X60 F3000") != "ok": # 1.2 s and more: several polls long
fail("[%s] the long port jog was refused under a status poll" % tag)
t0 = time.time()
while time.time() - t0 < 10:
st = s.port.state()
if st["state"] == "Idle" and not st["port_jog"]:
break
time.sleep(0.05)
moved = s.port.state()["mpos"][0] - x0
if abs(moved - 60.0) > 0.02:
fail("[%s] a status poll cut the port jog short: moved %.3f of 60" % (tag, moved))
polls_mid = poller.polls
# A real line still goes first: it cancels a port jog and draws its ok.
x1 = s.port.state()["mpos"][0]
if s.port.request("jog G91 X-300 F6000") != "ok":
fail("[%s] the fast port jog was refused" % tag)
time.sleep(0.7)
poller.stop() # the real line's response is then the only one outstanding
time.sleep(0.3)
n = s.sender.count()
s.sender.sock.sendall(("G4 P0" + eol).encode())
end = time.time() + 10
while time.time() < end and s.sender.count() <= n:
time.sleep(0.01)
if s.sender.count() != n + 1 or s.sender.responses[n] != "ok":
fail("[%s] the sender's real line under a port jog got %r" % (tag, s.sender.responses[n:]))
s.sender.wait_state("Idle")
back = x1 - s.port.state()["mpos"][0]
if back > 250:
fail("[%s] the sender's real line did not cancel the port jog: it ran %.1f of 300" % (tag, back))
time.sleep(0.5)
got = s.sender.count() - before
want = poller.polls + 1 # one ok per poll's empty line, and the G4
if got != want:
fail("[%s] %d polls and one line drew %d responses, not %d" % (tag, poller.polls, got, want))
print("PASS [%s]: under a '?'+EOL poll 8 of 8 port jogs were accepted, a 60 mm port jog ran whole "
"(%d polls into it), every poll drew its ok (%d), and a real line still canceled a port jog at "
"%.1f of 300" % (tag, polls_mid, poller.polls, back))
finally:
s.close()
def test_poll_lf():
poll_case("poll-lf", "\n")
def test_poll_crlf():
poll_case("poll-crlf", "\r\n")
def test_refusals(s):
s.sender.wait_state("Idle")
s.sender.send("G90")
r = s.port.request("jog G91 X1 F600") # inside the quiet interval
if r != "busy:sender":
fail("[refusals] a jog right after a sender line got %r, not busy:sender" % r)
s.quiet()
for words in ("G91 X1 F600 $H", "g91 x1 f600", "G91 X1 F600;M3", ""):
r = s.port.request("jog " + words)
if r != "error:invalid":
fail("[refusals] jog %r got %r, not error:invalid" % (words, r))
x0 = s.port.state()["mpos"][0]
r = s.port.request("jog G1 X5 F600") # a motion mode is not a jog word
if not (r or "").startswith("error:"):
fail("[refusals] jog G1 got %r, not the core's error" % r)
r = s.port.request("jog G91 X1 F600 S500 M3")
if not (r or "").startswith("error:"):
fail("[refusals] a jog with S and M3 got %r, not the core's error" % r)
time.sleep(0.3)
if abs(s.port.state()["mpos"][0] - x0) > 0.001:
fail("[refusals] a refused jog moved the machine")
s.sender.send("G91")
s.sender.send("G1 X40 F300") # a program: 8 s of Run
s.quiet()
st = s.port.state()
r = s.port.request("jog G91 Y1 F600")
if r != "busy:state":
fail("[refusals] a jog during a program (%s) got %r, not busy:state" % (st["state"], r))
s.sender.realtime(b"\x18") # end the program
time.sleep(1.0)
s.sender.send("$X")
print("PASS [refusals]: busy:sender inside the quiet interval, error:invalid for stray "
"characters, the core's error for G1 and for S/M3, busy:state during a program")
def test_single_client(s):
second = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
second.settimeout(3.0)
second.connect(s.path)
try:
second.sendall(b"state\n")
data = second.recv(100)
except OSError:
data = b""
second.close()
if data:
fail("[single-client] a second port client was served: %r" % data)
if s.port.state().get("state") is None:
fail("[single-client] the first client stopped working")
# A client that closes and reconnects at once is not a second client: the
# port has to notice the hang-up before it judges the new connection.
for i in range(5):
s.port.close()
s.port = PortClient(s.path)
try:
ok = s.port.state().get("state") is not None
except (OSError, TypeError, ValueError):
ok = False
if not ok:
fail("[single-client] reconnect %d right after a close was refused" % (i + 1))
print("PASS [single-client]: the second connection was refused, the first kept working, and "
"five reconnects right after a close were each served")
def test_crlf():
s = Session(eol="\r\n")
try:
for line in ("G91", "G0 X1", ""):
if s.sender.send(line) != "ok":
fail("[crlf] %r did not get ok" % line)
s.sender.wait_state("Idle")
s.quiet()
before = s.sender.count()
if s.port.request("jog G91 X1 F600") != "ok":
fail("[crlf] the port jog was refused")
s.sender.wait_state("Idle")
for line in ("", "G0 X1", "", ""):
if s.sender.send(line) != "ok":
fail("[crlf] %r after the port jog did not get ok" % line)
time.sleep(0.5)
got = s.sender.count() - before
if got != 4:
fail("[crlf] 4 sender lines after the port jog got %d responses" % got)
print("PASS [crlf]: a CR LF sender's count is exact across a port jog, empty lines included")
finally:
s.close()
def test_port_dark():
s = Session(laser=True)
try:
s.sender.send("G91")
s.sender.send("M3 S500")
s.sender.send("G1 X10 F1500")
s.sender.wait_state("Idle")
time.sleep(0.5)
if not s.sender.saw("laser armed"):
fail("[dark] the laser line did not arm: the case would prove nothing")
steps0, fire0 = s.ticks()
if fire0 == 0:
fail("[dark] the armed G1 shipped no FIRE tick: the dump cannot see emission")
s.quiet()
replies = {}
replies["state"] = s.port.request("state")
replies["jog"] = s.port.request("jog G91 X8 F1200")
s.sender.wait_state("Idle")
replies["jog-long"] = s.port.request("jog G91 X200 F6000")
time.sleep(0.4)
replies["cancel"] = s.port.request("cancel")
s.sender.wait_state("Idle")
for words in ("G1 X5 F600", "G91 X5 F600 S900 M3", "G91 X5 F600 M4", "G91 G2 X5 I2 F600"):
replies["jog " + words] = s.port.request("jog " + words)
replies["release"] = s.port.request("release") # refused: a laser job is armed
replies["energize"] = s.port.request("energize")
replies["home"] = s.port.request("home") # manual: declares X0 Y0, moves nothing
replies["jog-after-home"] = s.port.request("jog G91 X6 F1200")
s.sender.wait_state("Idle")
time.sleep(0.5)
steps1, fire1 = s.ticks()
if replies["jog"] != "ok" or replies["jog-long"] != "ok" or replies["jog-after-home"] != "ok":
fail("[dark] a port jog under the open window was refused: %r" % replies)
if steps1 <= steps0:
fail("[dark] the port jogs shipped no step: the case would prove nothing")
if s.sender.saw("laser disarmed"):
fail("[dark] the armed window closed during the case: %r" % replies)
if fire1 != fire0:
fail("[dark] port operations under an open window with M3 S500 shipped %d FIRE ticks: %r"
% (fire1 - fire0, replies))
print("PASS [dark]: under an open armed window with M3 S500, %d port operations shipped "
"%d steps and no FIRE tick" % (len(replies), steps1 - steps0))
finally:
s.close()
def test_reset_keeps_hook(s):
s.sender.realtime(b"\x18")
time.sleep(1.0)
s.sender.send("$X")
s.sender.wait_state("Idle")
s.quiet()
before = s.sender.count()
if s.port.request("jog G91 X1 F600") != "ok":
fail("[reset] the port jog after a soft reset was refused")
s.sender.wait_state("Idle")
if s.sender.count() != before:
fail("[reset] after a soft reset the port's ok went to the sender")
print("PASS [reset]: the status hook survives a soft reset")
def test_dead_man(s):
s.sender.wait_state("Idle")
s.quiet()
if s.port.request("jog G91 X60 F200") != "ok":
fail("[dead-man] the long port jog was refused")
time.sleep(0.5)
s.port.close()
t0 = time.time()
s.sender.wait_state("Idle", timeout=6.0)
print("PASS [dead-man]: closing the port's client canceled its jog (idle after %.2f s)"
% (time.time() - t0))
s.port = PortClient(s.path)
if s.port.state()["port_jog"]:
fail("[dead-man] a new client inherited the old jog")
def main():
if not os.path.exists(BIN):
fail("no controller binary at %s" % BIN)
s = Session()
try:
test_socket_mode(s)
test_status_routing(s)
test_error_not_inherited(s)
test_sender_wins(s)
test_sender_wins_queued(s)
test_refusals(s)
test_single_client(s)
test_reset_keeps_hook(s)
test_dead_man(s)
finally:
s.close()
test_crlf()
test_poll_lf()
test_poll_crlf()
test_port_dark()
print("ALL PASS")
if __name__ == "__main__":
main()