Independent SQL connections...race condition?

I would like to be able to manage different db connections per request.
I’ve
gotten this working by using establish_connection in a before_filter on
all
controllers. My concern is whether or not there could be a race
condition
where two or more overlapping requests might reset the SQL connection.
Is
there any serialization logic which will prevent this? Must I introduce
this
logic manually?

Thanks for any help.

James