What happen when a pool is cloned?

[sylvain101010]

Hi,
I noticed that Pool implements the Clone trait (https://docs.rs/sqlx/0.4.2/sqlx/struct.Pool.html). What is the behavior of a pool when it is cloned?

Is a new pool created (and thus doubling the number of max open connections)?

[mehcode]

Refer to:

sqlx/sqlx-core/src/pool/mod.rs

Line 217 in 3aeb46f

pub struct Pool<DB: Database>(pub(crate) Arc<SharedPool<DB>>);

The actual connection pool is a private SharedPool type. The public Pool type wraps that type in an Arc.

In effect, all that pool.clone() does is clone the reference, thus giving you more places you can reference the pool from.

It's fully intended to be cloned all over the place and given to different threads, etc.

[abonander]

For the record, this is documented on the Clone impl: https://github.com/launchbadge/sqlx/blob/master/sqlx-core/src/pool/mod.rs#L308

It's not immediately obvious from the docs though since documentation on trait impls is collapsed by default.

[sylvain101010]

Awesome thank you!

May I submit a little PR this afternoon to add a line in the docs to describe this behavior?