Sentinel based Deque

As I continue playing with Rust I was looking for a sentinel deque/list and could not find one. So I decided to try and implement it myself. Coming from Java I thought it's going to be an easy task :slight_smile: ha ha not so much but eventually I think I succeeded.

Again it's based on raw pointers, but I believe that the simplicity of the code justifies the unsafety of the raw pointers.
If some one finds it useful -> I am happy :slight_smile: Here is the repo: GitHub - atsiporu/sentinel_list

The idea is once you push element on to the list you get a handle back. With this handle you can query the element or you can unlink it from the list.
That's really it.

Because it's sentinel based I don't need to do null checks, which is not that expensive but still.

List lacks iterator implementations which I am going to do next, for now its a deque.

Any comments or critique are welcome. If you think there is a better way please let me know.

Thanks.

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Cool work :+1: Did you ever look at crossbeam's MsQueue? It exposes a thread-safe queue, I think as a linked list with a sentinel, so could be an interesting implementation to trawl through, though it doesn't give you a linked list API. There is a LinkedList struct in the standard library though. I'm a bit of a casual when it comes to data structures though so my input could be off the mark :slight_smile:

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Thanks. No I didn't see the crossbeam's MsQueue, but after your post I took a quick look and it looks really cool. I would need to spend more time reading through the code though. Concurrent data structures are interesting beasts. After looking at crossbeam I started to read the blob of Aaron Turon on lock free ds: Lock-freedom without garbage collection ยท Aaron Turon
And it's enjoyable reading. I come from a single threaded world and I rarely have to deal with threads, however I am aware of the "counter/epoch" technique, it comes up in a single threaded world two, that's how java, for example, detects concurrent modification to the collection to invalidate an iterator.

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