Using a linked list for fast efficient tracking of [publisher confirm] delivery tags

[stebet]

Proposed Changes

This PR adds deliveryTag tracking using a linked list. Since the list and the delivery tags are only ever manipulated inside locks we can guarantee that the list contains unique values and is always sorted, making it a very fast way of keeping track of pending items. This is better than the original change I made where i stopped tracking individual tags and used separate counters, since now all delivery tags can be tracked which should make debugging easier in case of errors, now that the list is always available.

Also using a CountdownEvent do replace the Monitor.Pulse logic to signal when all delivery tags have been confirmed, simplifying code and reducing lock contention.

Types of Changes

• Bug fix (non-breaking change which fixes issue #NNNN)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause an observable behavior change in existing systems)
• Documentation improvements (corrections, new content, etc)
• Cosmetic change (whitespace, formatting, etc)

Checklist

• I have read the CONTRIBUTING.md document
• I have signed the CA (see https://cla.pivotal.io/sign/rabbitmq)
• All tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)
• Any dependent changes have been merged and published in related repositories

Further Comments

If this is a relatively large or complex change, kick off the discussion by
explaining why you chose the solution you did and what alternatives you
considered, etc.

[michaelklishin]

I like this idea. Please rebase this against master.

[stebet]

I like this idea. Please rebase this against master.

Done :)

[bording]

@stebet Technically, you didn't rebase the branch as asked, you merged master into your branch. Not the same thing! 😀

[stebet]

@stebet Technically, you didn't rebase the branch as asked, you merged master into your branch. Not the same thing! 😀

Gahhh you are right, my git-foo gets messed up sometimes. I'll see if I can fix it.

[michaelklishin]

merging is fine with me :)

…

On 15 May 2020, at 03:13, Stefán Jökull Sigurðarson ***@***.***> wrote:  @stebet Technically, you didn't rebase the branch as asked, you merged master into your branch. Not the same thing! 😀 Gahhh you are right, my git-foo gets messed up sometimes. I'll see if I can fix it. — You are receiving this because you commented. Reply to this email directly, view it on GitHub, or unsubscribe.