QUALITY_DECLARATION

This document is a declaration of software quality for the rcl package, based on the guidelines in REP-2004.

rcl Quality Declaration

The package rcl claims to be in the Quality Level 1 category when it is used with a Quality Level 1 middleware.

Below are the rationales, notes, and caveats for this claim, organized by each requirement listed in the Package Quality Categories in REP-2004.

Version Policy [1]

Version Scheme [1.i]

rcl uses semver according to the recommendation for ROS Core packages in the ROS 2 Developer Guide.

Version Stability [1.ii]

rcl is at a stable version, i.e. >= 1.0.0. The current version can be found in its package.xml, and its change history can be found in its CHANGELOG.

Public API Declaration [1.iii]

All symbols in the installed headers are considered part of the public API.

All installed headers are in the include directory of the package, headers in any other folders are not installed and considered private.

API Stability Policy [1.iv]

rcl will not break public API within a released ROS distribution, i.e. no major releases once the ROS distribution is released.

ABI Stability Policy [1.v]

rcl contains C code and therefore must be concerned with ABI stability, and will maintain ABI stability within a ROS distribution.

ABI and ABI Stability Within a Released ROS Distribution [1.vi]

rcl will not break API nor ABI within a released ROS distribution, i.e. no major releases once the ROS distribution is released.

Change Control Process [2]

Change Requests [2.i]

All changes will occur through a pull request, check the ROS 2 Developer Guide for additional information.

Contributor Origin [2.ii]

This package uses DCO as its confirmation of contributor origin policy. More information can be found in CONTRIBUTING.

Peer Review Policy [2.iii]

All pull requests will be peer-reviewed, check ROS 2 Developer Guide for additional information.

Continuous Integration [2.iv]

All pull requests must pass CI on all tier 1 platforms.

Currently nightly results can be seen here:

Documentation Policy [2.v]

All pull requests must resolve related documentation changes before merging.

Documentation [3]

Feature Documentation [3.i]

rcl provides the main elements of its API listed using doxygen. Refer to the ROS 2 concepts and ROS 2 Client Libraries pages for reference of elements covered by this package.

Public API Documentation [3.ii]

rcl has embedded API documentation and it is generated using doxygen. Currently, its latest version is hosted here.

New additions to the public API require documentation before being added.

License [3.iii]

The license for rcl is Apache 2.0, and a summary is in each source file, the type is declared in the package.xml manifest file, and a full copy of the license is in the LICENSE file.

There is an automated test which runs a linter that ensures each file has a license statement. Here can be found a list with the latest results of the various linters being run on the package.

Testing [4]

Feature Testing [4.i]

Most features in rcl have corresponding tests which simulate typical usage, and they are located in the test directory. New features are required to have tests before being added. Currently nightly test results can be seen here:

Public API Testing [4.ii]

Each part of the public API has tests, and new additions or changes to the public API require tests before being added. The tests aim to cover both typical usage and corner cases, but are quantified by contributing to code coverage.

The following functions are partially supported: rcl_take_loaned_message, rcl_return_loaned_message_from_subscription, rcl_borrow_loaned_message, rcl_return_loaned_message_from_publisher and rcl_publish_loaned_message because they are not currently supported on Tier 1 RMW providers.

Coverage [4.iii]

rcl follows the recommendations for ROS Core packages in the ROS 2 Developer Guide, and opts to use line coverage instead of branch coverage.

This includes:

  • tracking and reporting line coverage statistics

  • no lines are manually skipped in coverage calculations

Changes are required to make a best effort to keep or increase coverage before being accepted, but decreases are allowed if properly justified and accepted by reviewers.

Current coverage statistics can be viewed here. A description of how coverage statistics are calculated is summarized in this page “ROS 2 Onboarding Guide”.

Performance [4.iv]

rcl follows the recommendations for performance testing of C code in the ROS 2 Developer Guide, and opts to do performance analysis on each release rather than each change.

System level performance benchmarks that cover features of rcl can be found at:

Changes that introduce regressions in performance must be adequately justified in order to be accepted and merged.

Linters and Static Analysis [4.v]

rcl uses and passes all the ROS 2 standard linters and static analysis tools for a C++ package as described in the ROS 2 Developer Guide. Passing implies there are no linter/static errors when testing against CI of supported platforms.

Currently nightly test results can be seen here:

Dependencies [5]

Below are evaluations of each of rcl’s run-time and build-time dependencies that have been determined to influence the quality.

It has several “buildtool” dependencies, which do not affect the resulting quality of the package, because they do not contribute to the public library API. It also has several test dependencies, which do not affect the resulting quality of the package, because they are only used to build and run the test code.

Direct Runtime ROS Dependencies [5.i]

rmw

The rmw package provides the API used by rcl to interact with the underlying middleware in an abstract way.

It is Quality Level 1, see its Quality Declaration document.

rcl_interfaces

The rcl_interfaces package provides some common ROS Message and ROS Service types which are used to implement certain client library features.

It is Quality Level 1, see its Quality Declaration document.

rcl_logging_spdlog

The rcl_logging_spdlog package provides the default logging implementation by wrapping the spdlog library.

It is Quality Level 1, see its Quality Declaration document.

rcl_yaml_param_parser

The rcl_yaml_param_parser package provides an API that is used to parse YAML configuration files which may be used to configure ROS and specific nodes.

It is Quality Level 1, see its Quality Declaration document.

rcutils

The rcutils package provides an API which contains common utilities and data structures needed when programming in C.

It is Quality Level 1, see its Quality Declaration document.

rmw_implementation

The rmw_implementation package provides access to the default rmw implementation, and provides the ability to dynamically switch rmw implementations if more than one is available.

It is Quality Level 1, see its Quality Declaration document.

rosidl_runtime_c

The rosidl_runtime_c package provides runtime interfaces in C based on user defined ROS Messages and ROS Services, as well as associated support functions for those types.

It is Quality Level 1, see its Quality Declaration document.

tracetools

The tracetools package provides utilities for instrumenting the code in rcl so that it may be traced for debugging and performance analysis.

It is Quality Level 1, see its Quality Declaration document.

Optional Direct Runtime ROS Dependencies [5.ii]

rcl has no optional Direct Runtime ROS dependencies that need to be considered for this declaration.

Direct Runtime non-ROS Dependency [5.iii]

rcl has no Direct Runtime non-ROS dependencies that need to be considered for this declaration.

Platform Support [6]

rcl supports all of the tier 1 platforms as described in REP-2000, and tests each change against all of them.

Security [7]

Vulnerability Disclosure Policy [7.i]

This package conforms to the Vulnerability Disclosure Policy in REP-2006.

Current status Summary

The chart below compares the requirements in the REP-2004 with the current state of the rcl package.

Number

Requirement

Current state

1

Version policy

—

1.i

Version Policy available

✓

1.ii

Stable version

✓

1.iii

Declared public API

✓

1.iv

API stability policy

✓

1.v

ABI stability policy

✓

1.vi_

API/ABI stable within ros distribution

✓

2

Change control process

—

2.i

All changes occur on change request

✓

2.ii

Contributor origin (DCO, CLA, etc)

✓

2.iii

Peer review policy

✓

2.iv

CI policy for change requests

✓

2.v

Documentation policy for change requests

✓

3

Documentation

—

3.i

Per feature documentation

✓

3.ii

Per public API item documentation

✓

3.iii

Declared License(s)

✓

3.iv

Copyright in source files

✓

3.v.a

Quality declaration linked to README

✓

3.v.b

Centralized declaration available for peer review

✓

4

Testing

—

4.i

Feature items tests

✓

4.ii

Public API tests

✓

4.iii.a

Using coverage

✓

4.iii.a

Coverage policy

✓

4.iv.a

Performance tests (if applicable)

✓

4.iv.b

Performance tests policy

✓

4.v.a

Code style enforcement (linters)

✓

4.v.b

Use of static analysis tools

✓

5

Dependencies

—

5.i

Must not have ROS lower level dependencies

✓

5.ii

Optional ROS lower level dependencies

✓

5.iii

Justifies quality use of non-ROS dependencies

✓

6

Platform support

—

6.i

Support targets Tier1 ROS platforms

✓

7

Security

—

7.i

Vulnerability Disclosure Policy

✓