Comments on: Concurrent Skip List woes

By: Concurrent Skip List issues « Handwaving

Concurrent Skip List issues « Handwaving — Wed, 26 Aug 2009 19:52:05 +0000

[...] Skip List issues By Pinku A commenter on my code sample for a concurrent skiplist correctly pointed out two errors in the program. I [...]

By: Pinku

Pinku — Tue, 25 Aug 2009 20:53:42 +0000

You are right about both bugs. On the first, I changed it so it doesn’t ask for a MaxHeight anymore. On the second, I failed to copy the code from the paper correctly. Your fix is correct.

By: D Meatte

D Meatte — Wed, 10 Jun 2009 19:04:32 +0000

Thanks for posting this source. This was the only thread safe C# skip list I could find and it was a lot easier to adapt this than to make my own from one of Pugh’s papers.

I found what I think are two bugs in the posted source.

The first is on line 37. You’re follow up post says it isn’t needed, but I found if the randomLevel wasn’t capped, I would get a level for my new node greater than the max height used to declare a new node’s next lists.

The second is on line 59. I’m fairly sure the ‘lFound.HasValue’ in ‘if (lFound.HasValue && v.CompareTo(curr.key) == 0)’ should be ‘!lFound.HasValue’ otherwise there’s no opportunity for that function to ever initialize the variable and succeed in the find.

By: Complexity Matters « Handwaving

Complexity Matters « Handwaving — Mon, 19 Jan 2009 03:05:45 +0000

[...] Handwaving “glossing over detail for the sake of time or clarity” « Concurrent Skip List woes [...]