ros2_tracing/tracetools_launch/tracetools_launch/action.py
2019-07-05 14:46:02 +02:00

83 lines
2.8 KiB
Python

# Copyright 2019 Robert Bosch GmbH
#
# 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.
"""Module for the Trace action."""
import os
from typing import List
from typing import Optional
from launch.action import Action
from launch.event import Event
from launch.event_handlers import OnShutdown
from launch.launch_context import LaunchContext
from tracetools_trace.tools import lttng
from tracetools_trace.tools import names
from tracetools_trace.tools import path
class Trace(Action):
"""
Tracing action for launch.
Sets up and enables tracing through a launch file description.
"""
def __init__(
self,
*,
session_name: str,
base_path: str = path.DEFAULT_BASE_PATH,
events_ust: List[str] = names.DEFAULT_EVENTS_ROS,
events_kernel: List[str] = names.DEFAULT_EVENTS_KERNEL,
**kwargs,
) -> None:
"""
Constructor.
:param session_name: the name of the tracing session
:param base_path: the path to the base directory in which to create the tracing session directory
:param events_ust: the list of ROS UST events to enable
:param events_kernel: the list of kernel events to enable
"""
super().__init__(**kwargs)
self.__session_name = session_name
self.__base_path = base_path
self.__events_ust = events_ust
self.__events_kernel = events_kernel
def execute(self, context: LaunchContext) -> Optional[List[Action]]:
# TODO make sure this is done as late as possible
context.register_event_handler(OnShutdown(on_shutdown=self._destroy))
# TODO make sure this is done as early as possible
self._setup()
def _setup(self) -> None:
lttng.lttng_init(
self.__session_name,
self.__base_path,
ros_events=self.__events_ust,
kernel_events=self.__events_kernel)
def _destroy(self, event: Event, context: LaunchContext) -> None:
lttng.lttng_fini(self.__session_name)
def __repr__(self):
return (
"Trace("
f"session_name='{self.__session_name}', "
f"base_path='{self.__base_path}', "
f"num_events_ust={len(self.__events_ust)}, "
f"num_events_kernel={len(self.__events_kernel)})"
)