Do you use LazyInitMode.AllowMultipleExecution?

re: Do you use LazyInitMode.AllowMultipleExecution?

Sat, 04 Apr 2009 14:23:17 GMT

i think it is not unlikely to have thousands of lazyinit instances. imagine a tree data structure whose children are lazily initialized by a cheap operation which is idempotent.

re: Do you use LazyInitMode.AllowMultipleExecution?

Ben — Sat, 04 Apr 2009 04:46:05 GMT

While we don't use LazyInit itself, we use a similar coding pattern for the following reasons:

- The operation is slow enough we want to cache the result

- The operation cannot block

- Usually, there is only 1 thread doing this

- We don't care if it returns different values on different threads

This is used purely as a speed boost to operations that run a 2nd time.

re: Do you use LazyInitMode.AllowMultipleExecution?

Jon Skeet — Fri, 03 Apr 2009 19:26:20 GMT

I have no opinion at the moment about whether or not AllowMultipleExecution should be included (although the weird exception situation suggests not) but I just wanted to applaud the attitude being taken here:

1) Designing an API carefully and trying to streamline it as much as possible (instead of "kitchen sink" syndrome).

2) *Explaining* to the audience what the pros and cons of a particular decision might be.

3) Asking the community for input.

Bravo!

Jon

re: Do you use LazyInitMode.AllowMultipleExecution?

dimkaz — Fri, 03 Apr 2009 17:18:39 GMT

I use the same technique as AllowMultipleExecution in a few places where I think the collision is unlikely but the code still needs to be thread safe.

In general there is also a concern for the nested locks (deadlock).