- Change a `queue:len/1` call during a checkout in the ready state to use `queue:is_empty/1`. All operations in poolboy that aren't informational or disaster recovery should now theoretically be O(1). - There is now "transaction" support using `transaction/2`. This will run a user defined function passed the worker checked out in a try block, ensuring that the worker is checked back into the pool should the operation fail. - A `child_spec/2` helper for embedding poolboy pools within your supervisors. - Documentation updates.
…'pool_size'). 2. Fixed bad behavior in case of checkout_blocks=true and long running workers.