Threading Issue

[josephnarai]

Hi and thanks for your great open source project!

I've been using a SynchronizedObservableCollection and came across a strange threading / race condition... it only happens on certain machines, so I'm guessing it's a speed issue or something - or I'm just misunderstanding how it's supposed to operate.

I have calls to Add and Remove happening on different threads, and I'm seeing the following:

Main thread (UI) calls Add(item) but seems to take some time to return... and during this time, if the background thread tries to call Remove(item) ... I get the InvalidOperationException("SynchronizedObservableCollection reentrancy not allowed"); which makes sense, it's inside Add when Remove is being called...

I got around this issue by adding a queue for adding and removing items, but am not sure if there would be better way to handle this? I tried locking around the Add / Remove calls, but then I just found that the call to Add that takes a long time just never returns... so am confused by what's happening...

Is there a different way of handling the calls from multiple threads?

I've not tried to make a simple test project to reproduce it, but thought I'd let you know in case it was something obvious...

Thanks again,

Joseph