From 519a1b48431ddedb3602d77c971fefc5397c9c5b Mon Sep 17 00:00:00 2001 From: Lucas Meneghel Rodrigues Date: Tue, 10 Jun 2014 16:19:37 -0300 Subject: [PATCH] docs: Add resources about test subprocesses and using test timeouts Signed-off-by: Lucas Meneghel Rodrigues --- docs/source/WritingTests.rst | 158 +++++++++++++++++++++++++++++++++++ 1 file changed, 158 insertions(+) diff --git a/docs/source/WritingTests.rst b/docs/source/WritingTests.rst index 9ae7b249..b85495b6 100644 --- a/docs/source/WritingTests.rst +++ b/docs/source/WritingTests.rst @@ -250,6 +250,164 @@ The ``action`` method just gets into the base directory of the compiled suite and executes the ``./synctest`` command, with appropriate parameters, using :func:`avocado.utils.process.system`. +Avocado Tests run on a separate process +======================================= + +In order to avoid tests to mess around the environment used by the main +avocado runner process, tests are run on a forked subprocess. This allows +for more robustness (tests are not easily able to mess/break avocado) and +some nifty features, such as setting test timeouts. + +Setting a Test Timeout +====================== + +Sometimes your test suite/test might get stuck forever, and this might +impact your test grid. You can account for that possibility and set up a +``timeout`` parameter for your test. The test timeout can be set through +2 means, in the following order of precedence: + +* Multiplex variable parameters. You may just set the timeout parameter, like + in the following simplistic example: + +:: + + variants: + - sleeptest: + sleep_length = 5 + sleep_length_type = float + timeout = 3 + timeout_type = float + +:: + + avocado run sleeptest --multiplex /tmp/sleeptest-example.mplx + DEBUG LOG: /home/lmr/avocado/logs/run-2014-06-10-16.13.33/debug.log + TOTAL TESTS: 1 + (1/1) sleeptest.1: ERROR (3.00 s) + TOTAL PASSED: 0 + TOTAL ERROR: 1 + TOTAL FAILED: 0 + TOTAL SKIPPED: 0 + TOTAL WARNED: 0 + ELAPSED TIME: 3.00 s + +:: + + $ cat /home/lmr/avocado/logs/run-2014-06-10-16.13.33/debug.log + 16:13:33 test L0136 INFO | START sleeptest.1 + 16:13:33 test L0137 DEBUG| + 16:13:33 test L0138 DEBUG| Test instance parameters: + 16:13:33 test L0145 DEBUG| _name_map_file = {'sleeptest-example.mplx': 'sleeptest'} + 16:13:33 test L0145 DEBUG| _short_name_map_file = {'sleeptest-example.mplx': 'sleeptest'} + 16:13:33 test L0145 DEBUG| dep = + 16:13:33 test L0145 DEBUG| name = sleeptest + 16:13:33 test L0145 DEBUG| shortname = sleeptest + 16:13:33 test L0145 DEBUG| sleep_length = 5.0 + 16:13:33 test L0145 DEBUG| sleep_length_type = float + 16:13:33 test L0145 DEBUG| timeout = 3.0 + 16:13:33 test L0145 DEBUG| timeout_type = float + 16:13:33 test L0147 DEBUG| + 16:13:33 test L0150 DEBUG| Default parameters: + 16:13:33 test L0152 DEBUG| sleep_length = 1.0 + 16:13:33 test L0154 DEBUG| + 16:13:33 test L0155 DEBUG| Test instance params override defaults whenever available + 16:13:33 test L0156 DEBUG| + 16:13:33 test L0162 INFO | Test timeout set. Will wait 3.00 s for PID 23953 to end + 16:13:33 test L0163 INFO | + 16:13:33 sysinfo L0154 DEBUG| Not logging /proc/slabinfo (lack of permissions) + 16:13:33 sleeptest L0035 DEBUG| Sleeping for 5.00 seconds + 16:13:36 test L0054 ERROR| + 16:13:36 test L0057 ERROR| Traceback (most recent call last): + 16:13:36 test L0057 ERROR| File "/home/lmr/Code/avocado/tests/sleeptest/sleeptest.py", line 36, in action + 16:13:36 test L0057 ERROR| time.sleep(self.params.sleep_length) + 16:13:36 test L0057 ERROR| File "/home/lmr/Code/avocado/avocado/job.py", line 101, in timeout_handler + 16:13:36 test L0057 ERROR| raise exceptions.TestTimeoutError(e_msg) + 16:13:36 test L0057 ERROR| TestTimeoutError: Timeout reached waiting for sleeptest to end + 16:13:36 test L0058 ERROR| + 16:13:36 test L0376 ERROR| ERROR sleeptest.1 -> TestTimeoutError: Timeout reached waiting for sleeptest to end + 16:13:36 test L0363 INFO | + + +If you pass that multiplex file to the runner multiplexer, this will register +a timeout of 3 seconds before avocado ends the test forcefully by sending a +:class:`signal.SIGTERM` to the test, making it raise a +:class:`avocado.core.exceptions.TestTimeoutError`. + +* Default params attribute. Consider the following example: + +:: + + import time + + from avocado import test + from avocado import job + + + class timeouttest(test.Test): + + """ + Functional test for avocado. Throw a TestTimeoutError. + """ + default_params = {'timeout': 3.0, + 'sleep_time': 5.0} + + def action(self): + """ + This should throw a TestTimeoutError. + """ + self.log.info('Sleeping for %.2f seconds (2 more than the timeout)', + self.params.sleep_time) + time.sleep(self.params.sleep_time) + + + if __name__ == "__main__": + job.main() + +This accomplishes a similar effect to the multiplex setup defined in there. + +:: + + $ scripts/avocado run timeouttest + DEBUG LOG: /home/lmr/avocado/logs/run-2014-06-10-16.14.19/debug.log + TOTAL TESTS: 1 + (1/1) timeouttest.1: ERROR (3.00 s) + TOTAL PASSED: 0 + TOTAL ERROR: 1 + TOTAL FAILED: 0 + TOTAL SKIPPED: 0 + TOTAL WARNED: 0 + ELAPSED TIME: 3.00 s + +:: + + $ cat /home/lmr/avocado/logs/run-2014-06-10-16.14.19/debug.log + 16:14:19 test L0136 INFO | START timeouttest.1 + 16:14:19 test L0137 DEBUG| + 16:14:19 test L0138 DEBUG| Test instance parameters: + 16:14:19 test L0145 DEBUG| shortname = timeouttest + 16:14:19 test L0147 DEBUG| + 16:14:19 test L0150 DEBUG| Default parameters: + 16:14:19 test L0152 DEBUG| sleep_time = 5.0 + 16:14:19 test L0152 DEBUG| timeout = 3.0 + 16:14:19 test L0154 DEBUG| + 16:14:19 test L0155 DEBUG| Test instance params override defaults whenever available + 16:14:19 test L0156 DEBUG| + 16:14:19 test L0162 INFO | Test timeout set. Will wait 3.00 s for PID 24008 to end + 16:14:19 test L0163 INFO | + 16:14:19 sysinfo L0154 DEBUG| Not logging /proc/slabinfo (lack of permissions) + 16:14:20 timeouttes L0036 INFO | Sleeping for 5.00 seconds (2 more than the timeout) + 16:14:22 test L0054 ERROR| + 16:14:22 test L0057 ERROR| Traceback (most recent call last): + 16:14:22 test L0057 ERROR| File "/home/lmr/Code/avocado/tests/timeouttest/timeouttest.py", line 37, in action + 16:14:22 test L0057 ERROR| time.sleep(self.params.sleep_time) + 16:14:22 test L0057 ERROR| File "/home/lmr/Code/avocado/avocado/job.py", line 101, in timeout_handler + 16:14:22 test L0057 ERROR| raise exceptions.TestTimeoutError(e_msg) + 16:14:22 test L0057 ERROR| TestTimeoutError: Timeout reached waiting for timeouttest to end + 16:14:22 test L0058 ERROR| + 16:14:22 test L0376 ERROR| ERROR timeouttest.1 -> TestTimeoutError: Timeout reached waiting for timeouttest to end + 16:14:22 test L0363 INFO | + + Wrap Up ======= -- GitLab