[#1202] Add concurrency primitives crate to building blocks

[orecham]

Notes for Reviewer

1. Adds iceoryx2-bb-concurrency crate
2. Re-exports atomic types from iceoryx2-pal
3. Renames atomic types to drop the Iox prefix
   1. This change is more of a proposal - can be reverted if not agreed upon
4. Change upper-layer crates to depend on iceoryx2-bb-concurrency instead of iceoryx2-pal-concurrency-sync
5. Adds SpinLock to iceoryx2-bb-concurrency and uses it instead of the spin crate

A number of crates in upper layers of the architecture were depending directly on iceoryx2-pal for concurrency primitives, which is not congruent with the defined architecture.

A new crate is added to iceoryx2-bb to re-export required concurrency primitives which are implemented in iceoryx2-pal. Only the primitives required by upper layers are currently re-exported, more can be added as needed.
Some additional concurrency primitives useful to upper layers of iceoryx2 but not required in iceoryx2-pal are also included in this crate.

Pre-Review Checklist for the PR Author

• Add sensible notes for the reviewer
• PR title is short, expressive and meaningful
• Relevant issues are linked in the References section
• Every source code file has a copyright header with SPDX-License-Identifier: Apache-2.0 OR MIT
• Branch follows the naming format (iox2-123-introduce-posix-ipc-example)
• Commits messages are according to this guideline
  • Commit messages have the issue ID ([#123] Add posix ipc example)
  • Commit author matches Eclipse Contributor Agreement(and ECA is signed)
• Tests follow the best practice for testing
• Changelog updated in the unreleased section including API breaking changes
• Assign PR to reviewer
• All checks have passed (except task-list-completed)

Checklist for the PR Reviewer

• Commits are properly organized and messages are according to the guideline
• Unit tests have been written for new behavior
• Public API is documented
• PR title describes the changes

Post-review Checklist for the PR Author

• All open points are addressed and tracked via issues

References

Closes #1202

[orecham]

This approach adds a new (compile-time) dependency paste to simplify the code for wrapping atomics in iceoryx2-pal-concurrency-sync in a new type so that iceoryx2-bb traits may be defined on it. If this new dependency is an issue, could potentially manually import all types as aliases for use in the macro instead...

[codecov]

Codecov Report

❌ Patch coverage is 90.62500% with 18 lines in your changes missing coverage. Please review.
✅ Project coverage is 78.46%. Comparing base (e0a0541) to head (7cbc40e).
⚠️ Report is 4 commits behind head on main.

Files with missing lines	Patch %	Lines
iceoryx2-bb/lock-free/src/spsc/index_queue.rs	50.00%	5 Missing ⚠️
iceoryx2-bb/concurrency/src/atomic.rs	75.00%	3 Missing ⚠️
...x2-cal/src/zero_copy_connection/used_chunk_list.rs	70.00%	3 Missing ⚠️
iceoryx2-bb/concurrency/src/spin.rs	94.28%	2 Missing ⚠️
iceoryx2-bb/elementary/src/lazy_singleton.rs	0.00%	2 Missing ⚠️
iceoryx2-bb/log/src/logger/console.rs	0.00%	1 Missing ⚠️
iceoryx2-bb/posix/src/shared_memory.rs	66.66%	1 Missing ⚠️
iceoryx2-pal/concurrency-sync/src/atomic.rs	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1204      +/-   ##
==========================================
+ Coverage   78.39%   78.46%   +0.07%     
==========================================
  Files         411      413       +2     
  Lines       41008    41049      +41     
  Branches     1095     1095              
==========================================
+ Hits        32149    32210      +61     
+ Misses       8026     8006      -20     
  Partials      833      833              

Flag	Coverage Δ
CPP	72.80% <ø> (ø)
Rust	78.28% <90.62%> (+0.07%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
iceoryx2-bb/container/src/flatmap.rs	78.86% <100.00%> (ø)
iceoryx2-bb/container/src/queue.rs	91.44% <100.00%> (ø)
iceoryx2-bb/container/src/slotmap.rs	90.00% <100.00%> (ø)
...ryx2-bb/elementary-traits/src/placement_default.rs	20.37% <ø> (+5.55%)	⬆️
...ceoryx2-bb/elementary-traits/src/zero_copy_send.rs	75.00% <ø> (ø)
iceoryx2-bb/elementary/src/bump_allocator.rs	100.00% <100.00%> (ø)
iceoryx2-bb/elementary/src/cyclic_tagger.rs	100.00% <100.00%> (ø)
iceoryx2-bb/elementary/src/relocatable_ptr.rs	100.00% <100.00%> (ø)
iceoryx2-bb/elementary/src/unique_id.rs	100.00% <ø> (ø)
iceoryx2-bb/linux/src/epoll.rs	71.21% <100.00%> (ø)
... and 53 more

... and 5 files with indirect coverage changes

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[elfenpiff]

I think this approach is a bit cumbersome and introduces a dependency which we actually do not need. What do you think about the following approach:

1. iceoryx2-bb-elementary depends directly on iceoryx2-pal-concurrency-sync as the only crate. In there we implement PlacementDefault and ZeroCopySend as it was before.
2. iceoryx2-bb-concurrency re-exports the iceoryx2-pal-concurrency-sync Atomic**'s with the new namespace iceoryx2-bb-concurrency

With this we get rid of the paste dependency and do it like the Rust lib does it with core and the std re-exports. Also I do not see the benefit of removing the iceoryx2-pal-concurrency-sync dependency in iceoryx2-bb-elementary .

[orecham]

@elfenpiff

Do you mean iceoryx2-bb-elementary-traits instead of iceoryx2-bb-elementary throughout this comment?

I think this approach is a bit cumbersome

If you mean the use of the "new type" wrapper, I can see how this could be undesirable if we need the atomics in iceoryx2-pal and iceoryx2-bb to be recognized as the same type in some instances, but do we have this use-case if we change the upper-layer crates use the iceoryx2-bb version everywhere?

Do we have the same requirement as std and core, where some use crates would like to seamlessly switch between depending on iceoryx2-bb and iceoryx2-pal?

get rid of the paste dependency

If paste is a problem (even though it is compile-time only), it can be removed by just writing some more boilerplate code by hand.

I do not see the benefit of removing the iceoryx2-pal-concurrency-sync dependency in iceoryx2-bb-elementary .

The motivation was to have a less tangled dependency tree. I was aiming to only have one crate in iceoryx2-bb depend on iceoryx2-pal-concurrency-sync.

[elfenpiff]

When possible, please use rather this approach: https://github.com/eclipse-iceoryx/iceoryx2/pull/1204/files#r2573007733

[elfenpiff]

This is a cyclic dependency and cannot be published to crates.io - even when it is a dev-dependency!

Since iceoryx2-bb-posix requires atomics, you must remove this dependency or iceoryx2-bb-posix dependends again on the iceoryx2-pal-concurrency-sync crate.

[elfenpiff]

As far as I can see only the spin_tests.rs depends on posix, see use iceoryx2_bb_posix::system_configuration::SystemInfo; It is used to acquire the number of cpu cores to parallelize the tests as much as the hardware allows.

But I think for something simple like a spinlock tests it is maybe a bit overkill and we can hardcode this to always 2 so that the tests use exactly two threads.

With this the dev-dependency to iceoryx2-bb-posix would be removed.

[orecham]

Fixed