Merge branch '43-add-ld_preload-feature-for-tracing' into 'master'

Resolve "Add LD_PRELOAD feature for tracing"

Closes #43

See merge request micro-ROS/ros_tracing/ros2_tracing!84

tracetools_launch/test/test_copyright.py

@@ -0,0 +1,23 @@
+# Copyright 2017 Open Source Robotics Foundation, Inc.
+#
+# 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.
+
+from ament_copyright.main import main
+import pytest
+
+
+@pytest.mark.copyright
+@pytest.mark.linter
+def test_copyright():
+    rc = main(argv=['.', 'test'])
+    assert rc == 0, 'Found errors'

tracetools_launch/test/test_flake8.py

@@ -0,0 +1,23 @@
+# Copyright 2017 Open Source Robotics Foundation, Inc.
+#
+# 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.
+
+from ament_flake8.main import main
+import pytest
+
+
+@pytest.mark.flake8
+@pytest.mark.linter
+def test_flake8():
+    rc = main(argv=[])
+    assert rc == 0, 'Found errors'

tracetools_launch/test/test_pep257.py

@@ -0,0 +1,23 @@
+# Copyright 2017 Open Source Robotics Foundation, Inc.
+#
+# 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.
+
+from ament_pep257.main import main
+import pytest
+
+
+@pytest.mark.linter
+@pytest.mark.pep257
+def test_pep257():
+    rc = main(argv=[])
+    assert rc == 0, 'Found code style errors / warnings'

tracetools_launch/test/test_xmllint.py

@@ -0,0 +1,23 @@
+# Copyright 2019 Open Source Robotics Foundation, Inc.
+#
+# 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.
+
+from ament_xmllint.main import main
+import pytest
+
+
+@pytest.mark.linter
+@pytest.mark.xmllint
+def test_xmllint():
+    rc = main(argv=[])
+    assert rc == 0, 'Found errors'

tracetools_launch/test/tracetools_launch/test_trace_action.py

@@ -0,0 +1,57 @@
+# 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.
+
+import unittest
+
+from tracetools_launch.action import Trace
+
+
+class TestTraceAction(unittest.TestCase):
+
+    def __init__(self, *args) -> None:
+        super().__init__(
+            *args,
+        )
+
+    def test_has_profiling_events(self) -> None:
+        events_lists_match = [
+            [
+                'lttng_ust_cyg_profile_fast:func_entry',
+                'hashtag:yopo',
+            ],
+            [
+                'lttng_ust_cyg_profile:func_entry',
+                'some_other_event',
+                'lttng_ust_cyg_profile:func_exit',
+            ],
+        ]
+        events_lists_no_match = [
+            [
+                'lttng_ust_statedump:bin_info',
+                'ros2:event',
+            ],
+            []
+        ]
+        for events in events_lists_match:
+            self.assertTrue(Trace.has_profiling_events(events))
+        for events in events_lists_no_match:
+            self.assertFalse(Trace.has_profiling_events(events))
+
+    def test_get_shared_lib_path(self) -> None:
+        # Only test not finding a lib for now
+        self.assertIsNone(Trace.get_shared_lib_path('random_lib_that_does_not_exist_I_hope.so'))
+
+
+if __name__ == '__main__':
+    unittest.main()

tracetools_launch/tracetools_launch/action.py

@@ -14,11 +14,14 @@
 
 """Module for the Trace action."""
 
-import os
+import re
+import subprocess
 from typing import List
 from typing import Optional
+from typing import Union
 
 from launch.action import Action
+from launch.actions import SetEnvironmentVariable
 from launch.event import Event
 from launch.event_handlers import OnShutdown
 from launch.launch_context import LaunchContext
@@ -34,6 +37,10 @@ class Trace(Action):
     Sets up and enables tracing through a launch file description.
     """
 
+    PROFILE_LIB_NORMAL = 'liblttng-ust-cyg-profile.so'
+    PROFILE_LIB_FAST = 'liblttng-ust-cyg-profile-fast.so'
+    PROFILE_EVENT_PATTERN = '^lttng_ust_cyg_profile.*:func_.*'
+
     def __init__(
         self,
         *,
@@ -42,6 +49,7 @@ class Trace(Action):
         base_path: str = path.DEFAULT_BASE_PATH,
         events_ust: List[str] = names.DEFAULT_EVENTS_ROS,
         events_kernel: List[str] = names.DEFAULT_EVENTS_KERNEL,
+        profile_fast: bool = True,
         **kwargs,
     ) -> None:
         """
@@ -49,9 +57,10 @@ class Trace(Action):
 
         :param session_name: the name of the tracing session
         :param append_timestamp: whether to append timestamp to the session name
-        :param base_path: the path to the base directory in which to create the tracing session directory
+        :param base_path: the path to the base directory in which to create the session directory
         :param events_ust: the list of ROS UST events to enable
         :param events_kernel: the list of kernel events to enable
+        :param profile_fast: `True` to use fast profiling, `False` for normal (only if necessary)
         """
         super().__init__(**kwargs)
         if append_timestamp:
@@ -60,12 +69,47 @@ class Trace(Action):
         self.__base_path = base_path
         self.__events_ust = events_ust
         self.__events_kernel = events_kernel
+        self.__profile_fast = profile_fast
+        self.__ld_preload_action = None
+        if self.has_profiling_events(events_ust):
+            profile_lib_name = self.PROFILE_LIB_FAST if profile_fast else self.PROFILE_LIB_NORMAL
+            self.__ld_preload_action = SetEnvironmentVariable(
+                'LD_PRELOAD',
+                self.get_shared_lib_path(profile_lib_name),
+            )
+
+    @classmethod
+    def has_profiling_events(cls, events_ust: List[str]) -> bool:
+        """Check if the UST events list contains at least one profiling event."""
+        return any(re.match(cls.PROFILE_EVENT_PATTERN, event_name) for event_name in events_ust)
+
+    @staticmethod
+    def get_shared_lib_path(lib_name: str) -> Union[str, None]:
+        """
+        Get the full path to a given shared lib, if possible.
+
+        :param lib_name: the name of the shared library
+        :return: the full path if found, `None` otherwise
+        """
+        (exit_code, output) = subprocess.getstatusoutput(f'whereis -b {lib_name}')
+        if exit_code != 0:
+            return None
+        # Output of whereis is
+        # <input_lib_name>: <full path, if found>
+        # Filter out empty strings, in case lib is not found
+        output_split = [split_part for split_part in output.split(':') if len(split_part) > 0]
+        if len(output_split) != 2:
+            return None
+        return output_split[1].strip()
 
     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()
+        if self.__ld_preload_action is not None:
+            return [self.__ld_preload_action]
+        return None
 
     def _setup(self) -> None:
         lttng.lttng_init(
@@ -79,9 +123,11 @@ class Trace(Action):
 
     def __repr__(self):
         return (
-            "Trace("
+            'Trace('
-            f"session_name='{self.__session_name}', "
+            f'session_name={self.__session_name}, '
-            f"base_path='{self.__base_path}', "
+            f'base_path={self.__base_path}, '
-            f"num_events_ust={len(self.__events_ust)}, "
+            f'num_events_ust={len(self.__events_ust)}, '
-            f"num_events_kernel={len(self.__events_kernel)})"
+            f'num_events_kernel={len(self.__events_kernel)}), '
+            f'profiling={self.__ld_preload_action is not None}, '
+            f'profile_fast={self.__profile_fast}'
         )