Fast-forward merge dashing to main

[jacobperron]

@esteve If this looks good to you, I can fast-forward merge dashing into master from the command line so that the head of each branch is the same.

I'll follow-up with any necessary updates to CI and documentation, as well as PRs for compatibility with Eloquent.

[esteve]

I know this was not introduced in this branch, but given that it touches it, could you replace the wget call with curl to make it consistent with https://github.com/ros2-java/ros2_java/pull/117/files#diff-04c6e90faac2675aa89e2176d2eec7d8R102 ? Thanks.

[jacobperron]

I've been meaning to update the README anyways. #119 updates the README for dashing. I'll add it to this fast-forward to master after it is merged.

[esteve]

This could be master now that we intend to merge dashing into it.

[jacobperron]

That's correct. Though, I'm planning to make this change after the fast-forward. This way the commits on dashing and master will be even up to the point where we start making changes for Eloquent and beyond.

[esteve]

Locking at the method level would only prevent multiple calls to rclJavaInit, but globalExecutor needs to be protected as well, hence the use of synchronized at the class level and not at the method level.

[jacobperron]

I don't think this is true. My understanding is that synchronizing the static method acquires the same class-level lock as the one used in getGlobalExecutor. I.e. I believe the following two are equivalent:

public static synchronized void rclJavaInit() {
  ...
}

and

public static void rclJavaInit() {
  synchronized (RCLJava.class)  {
    ...
  }
}

Reference

[jacobperron]

I've rebased this PR and targeted main.
I've also updated the CI configuration to try and make it green (05c98dd).

@ivanpauno Let me know if this batch of changes will make porting things from our fork easier and we can merge it first.

[jacobperron]

@esteve it would be great if you could take another look at the changes proposed in this PR. It will effectively make main compatible with Dashing. Then we can add updates for other distros from there.

[ivanpauno]

@jacobperron is this a fast-forward from https://github.com/osrf/ros2_java/commits/dashing?

I see some changes in https://github.com/ros2_java/ros2_java/commits/dashing that aren't here.
I also see that there are conflicts between osrf:dashing and osrf:galactic_devel, I will check what happened there.

---

More info

$ git merge-base osrf/dashing origin/dashing

cf2ef07

$ git rev-list cf2ef0707f7420f9b83e6c053775c9d52752a9e2^..osrf/dashing

cf2ef07

# i.e. ros2_java:dashing has all commits that osrf:dashing has

$ git rev-list cf2ef0707f7420f9b83e6c053775c9d52752a9e2^..origin/dashing

d4163f8
4681ca3
a9244b8
e5dcec2
0a3df77
c3a2d7a
0e8e8cc
efe2df5
66d622c
0b48353
720cbed
7fb3dfe
95fefa6
cf2ef07

# i.e. There are 13 commits in ros2_java:dashing not in osrf:dashing

---

There are also 8 commits on osrf:dashing that aren't in osrf:galactic_devel, and there were some conflicts when rebasing 😕.

[jacobperron]

I see some changes in https://github.com/ros2_java/ros2_java/commits/dashing that aren't here.

Oops, you're right. I forgot to include changes since this PR was opened. I've reapplied changes from dashing.

[ivanpauno]

Oops, you're right. I forgot to include changes since this PR was opened. I've reapplied changes from dashing.

I have checked locally, I can rebase osrf:galactic_devel on ros2_java:dashing more or less easily https://github.com/osrf/ros2_java/tree/ivanpauno/galactic-devel-rebase-origin-dashing.
So I think this fast-forward is a good idea 👍.

---

This isn't actually a fast-forward though, and rebasing again on this branch adds more conflicts.
Can we just make the dashing branch the exact new main?

There isn't anything interesting in main that isn't in dashing really:

$ git log $(git merge-base origin/main origin/dashing)^..origin/main
commit b4e64f71538a057b3a1dbb49315aabeeedab3c88 (origin/master, origin/main, origin/HEAD)
Author: Esteve Fernandez <esteve@apache.org>
Date:   Fri Dec 18 07:45:04 2020 +0100

    Pin version of rcl_interfaces

commit f861280c504d311991c4152635778edea711592f
Author: Esteve Fernandez <esteve@apache.org>
Date:   Fri Dec 18 07:44:25 2020 +0100

    Pin version of rcl_interfaces

commit 62918477f4fb8810d4df0ac9c9e67b885b635d01 (osrf/master)
Author: Martin Huber <mhubii@users.noreply.github.com>
Date:   Fri Jan 17 14:46:25 2020 +0100

    Update README.md (#72)

The changes on the readme were already done in the dashing branch and the pinning is irrelevant.

[jacobperron]

Good point. I'm fine just making this the new main, pending approval.

[ivanpauno]

Good point. I'm fine just making this the new main, pending approval.

To be more clear, the new main would be the dashing branch and not this branch (the diff between the two branches is empty, it only makes the process of cherry-picking changes from osrf:ros2_java a bit easier to me.)

[jacobperron]

To be more clear, the new main would be the dashing branch and not this branch

Right, that's what I meant 👍

[jacobperron]

Alright, with all the comments addressed, I've created a new branch main based on the dashing branch and made that the default branch for the repository. We should start targeting new development there. I'll open up a PR documenting our procedure.