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# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
#
# SPDX-License-Identifier: MPL-2.0
#
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, you can obtain one at https://mozilla.org/MPL/2.0/.
#
# See the COPYRIGHT file distributed with this work for additional
# information regarding copyright ownership.
import concurrent.futures
import os
import subprocess
import time
def run_rndc(server, rndc_command):
"""
Send the specified 'rndc_command' to 'server' with a timeout of 10 seconds
"""
rndc = os.getenv("RNDC")
port = os.getenv("CONTROLPORT")
cmdline = [rndc, "-c", "../common/rndc.conf", "-p", port, "-s", server]
cmdline.extend(rndc_command)
subprocess.check_output(cmdline, stderr=subprocess.STDOUT, timeout=10)
def rndc_loop(test_state, domain):
"""
Run "rndc addzone", "rndc modzone", and "rndc delzone" in a tight loop
until the test is considered finished, ignoring errors
"""
rndc_commands = [
["addzone", domain, '{ type master; file "example.db"; };'],
[
"modzone",
domain,
'{ type master; file "example.db"; allow-transfer { any; }; };',
],
["delzone", domain],
]
while not test_state["finished"]:
for command in rndc_commands:
try:
run_rndc("10.53.0.3", command)
except subprocess.SubprocessError:
pass
def check_if_server_is_responsive():
"""
Check if server status can be successfully retrieved using "rndc status"
"""
try:
run_rndc("10.53.0.3", ["status"])
return True
except subprocess.SubprocessError:
return False
def test_rndc_deadlock():
"""
Test whether running "rndc addzone", "rndc modzone", and "rndc delzone"
commands concurrently does not trigger a deadlock
"""
test_state = {"finished": False}
# Create 4 worker threads running "rndc" commands in a loop.
with concurrent.futures.ThreadPoolExecutor() as executor:
for i in range(1, 5):
domain = "example%d" % i
executor.submit(rndc_loop, test_state, domain)
# Run "rndc status" 10 times, with 1-second pauses between attempts.
# Each "rndc status" invocation has a timeout of 10 seconds. If any of
# them fails, the loop will be interrupted.
server_is_responsive = True
attempts = 10
while server_is_responsive and attempts > 0:
server_is_responsive = check_if_server_is_responsive()
attempts -= 1
time.sleep(1)
# Signal worker threads that the test is finished.
test_state["finished"] = True
# Check whether all "rndc status" commands succeeded.
assert server_is_responsive
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