From 0ac0f70ece24bdec1734952ee420adc82e55a818 Mon Sep 17 00:00:00 2001 From: =?utf8?q?J=C3=A9r=C3=A9mie=20Galarneau?= Date: Wed, 3 May 2023 14:14:51 -0400 Subject: [PATCH] Tests: environment: use a context manager to restore original signal handler MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The original signal handler for SIGUSR1 was not restored when launching the session daemon. This didn't cause any issue, but is unexpected and would have been a real head scratcher if we wanted to use it later. To prevent us from forgetting to restore signals when using a _SignalWaitQueue, a context manager is provided to handle that automatically. Signed-off-by: Jérémie Galarneau Change-Id: I86599846ad2000af5d1e3c5cb2a0a73fb1c91455 --- tests/utils/lttngtest/environment.py | 65 ++++++++++++++++------------ 1 file changed, 38 insertions(+), 27 deletions(-) diff --git a/tests/utils/lttngtest/environment.py b/tests/utils/lttngtest/environment.py index 42b0a61b9..2710a7efb 100644 --- a/tests/utils/lttngtest/environment.py +++ b/tests/utils/lttngtest/environment.py @@ -6,7 +6,7 @@ # from types import FrameType -from typing import Callable, Iterator, Optional, Tuple, List +from typing import Callable, Iterator, Optional, Tuple, List, Generator import sys import pathlib import signal @@ -63,6 +63,19 @@ class _SignalWaitQueue: def wait_for_signal(self): self._queue.get(block=True) + @contextlib.contextmanager + def intercept_signal(self, signal_number): + # type: (int) -> Generator[None, None, None] + original_handler = signal.getsignal(signal_number) + signal.signal(signal_number, self.signal) + try: + yield + except: + # Restore the original signal handler and forward the exception. + raise + finally: + signal.signal(signal_number, original_handler) + class WaitTraceTestApplication: """ @@ -358,35 +371,33 @@ class _Environment(logger._Logger): sessiond_env["LTTNG_HOME"] = str(self._lttng_home.path) wait_queue = _SignalWaitQueue() - signal.signal(signal.SIGUSR1, wait_queue.signal) - - self._log( - "Launching session daemon with LTTNG_HOME=`{home_dir}`".format( - home_dir=str(self._lttng_home.path) + with wait_queue.intercept_signal(signal.SIGUSR1): + self._log( + "Launching session daemon with LTTNG_HOME=`{home_dir}`".format( + home_dir=str(self._lttng_home.path) + ) + ) + process = subprocess.Popen( + [ + str(sessiond_path), + consumerd_path_option_name, + str(consumerd_path), + "--sig-parent", + ], + stdout=subprocess.PIPE, + stderr=subprocess.STDOUT, + env=sessiond_env, ) - ) - process = subprocess.Popen( - [ - str(sessiond_path), - consumerd_path_option_name, - str(consumerd_path), - "--sig-parent", - ], - stdout=subprocess.PIPE, - stderr=subprocess.STDOUT, - env=sessiond_env, - ) - if self._logging_function: - self._sessiond_output_consumer = ProcessOutputConsumer( - process, "lttng-sessiond", self._logging_function - ) # type: Optional[ProcessOutputConsumer] - self._sessiond_output_consumer.daemon = True - self._sessiond_output_consumer.start() + if self._logging_function: + self._sessiond_output_consumer = ProcessOutputConsumer( + process, "lttng-sessiond", self._logging_function + ) # type: Optional[ProcessOutputConsumer] + self._sessiond_output_consumer.daemon = True + self._sessiond_output_consumer.start() - # Wait for SIGUSR1, indicating the sessiond is ready to proceed - wait_queue.wait_for_signal() - signal.signal(signal.SIGUSR1, wait_queue.signal) + # Wait for SIGUSR1, indicating the sessiond is ready to proceed + wait_queue.wait_for_signal() return process -- 2.34.1