readerwriterqueue VS libdill

I have looked at the commonly recommended - https://github.com/cameron314/readerwriterqueue - https://github.com/rigtorp/MPMCQueue

The PREEMPT error looks like its a C module but I cannot tell from he little snippet of the log - you may do better to move the *arr and Synchthing into Docker containers to keep the OS cleaner.

For audio DSP in a Qt app I have good success with using a lock-free queue (e.g. https://github.com/cameron314/readerwriterqueue) to communicate from / to the UI threads. Code more-or-less looks like

    connect(model, &ModelObject::somethingChanged, [=] {

We recently removed readerwriterqueue from our project due to issues and replaced with simple locking queue (and got better performance in the result). Your code looks interesting, but we can't use it due to C++17 usage.

libmill (https://github.com/sustrik/libmill) and libdill (https://github.com/sustrik/libdill) should be similar and probably mentioned.

As far as I understand the differences between CspChan and libmill might be that libmill also implements lightweight tasks (coroutines) and everything that goes with it (IO multiplexing, async timers, etc), while CspChan uses OS threads?

I saw this in 2017. Unfortunately, not much activity now. https://github.com/sustrik/libdill/commits/master

Might be fun to play with, but I wouldn't rely on it. Generally, better off with libuv for existing projects or Rust for greener fields where lifetimes are checked and safe concurrency is much easier.