1 files changed, 92 insertions, 0 deletions
diff --git a/bin/tests/system/addzone/tests_rndc_deadlock.py b/bin/tests/system/addzone/tests_rndc_deadlock.py
new file mode 100755
index 0000000..bd21d62
--- /dev/null
+++ b/bin/tests/system/addzone/tests_rndc_deadlock.py
@@ -0,0 +1,92 @@
+# 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 primary; file "example.db"; };'],
+        [
+            "modzone",
+            domain,
+            '{ type primary; 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