SIGUSR2 logs stack traces for active threads.
* doc/source/zuul.rst: Document SIGUSR2 behavior.
* zuul/cmd/server.py: When SIGUSR2 is received log stack traces for all
active running threads. This is useful for debugging deadlock
situations. Note that this makes use of sys._current_frames which may
not play nice with all implementations of Python.
*tests/test_stack_dump.py: Test the stack dump signal handler with a new
test file, class, and test method.
* requirements.txt: Add argparse to requirements list so that py26 tests
can pass when zuul.cmd.server is imported.
Change-Id: I8ad8155b16f324e832c191f0a619ff89ef804a87
diff --git a/tests/test_stack_dump.py b/tests/test_stack_dump.py
new file mode 100644
index 0000000..cc8cf8f
--- /dev/null
+++ b/tests/test_stack_dump.py
@@ -0,0 +1,34 @@
+# Copyright 2013 Hewlett-Packard Development Company, L.P.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+import fixtures
+import logging
+import signal
+import testtools
+
+import zuul.cmd.server
+
+
+class TestStackDump(testtools.TestCase):
+ def setUp(self):
+ super(TestStackDump, self).setUp()
+ self.log_fixture = self.useFixture(
+ fixtures.FakeLogger(level=logging.DEBUG))
+
+ def test_stack_dump_logs(self):
+ "Test that stack dumps end up in logs."
+
+ zuul.cmd.server.stack_dump_handler(signal.SIGUSR2, None)
+ self.assertIn("Thread", self.log_fixture.output)
+ self.assertIn("test_stack_dump_logs", self.log_fixture.output)