I'm doing metrics collection for a piece of code and want to store a collection of time differences (type primitive `long`) for later analysis

The insert operation for this collection should be as efficient as possible to add least overhead to the results.

I first tested out a `ConcurrentLinkedQueue<Long>` collection. This gave the worst performance (probably due to boxing/unboxing)

I've currently settled on using a *synchronized* `gnu.trove.TLongArrayList` which is almost 7 times faster for a data set of 5 million longs.

Any recommendations for other collection libraries that may be good candidates to benchmark for this use case would be gratefully acknowledged. I took a look at the guava API, but couldn't seem to find anything