Ensuring every request is assigned to a drained socket or nothing.
Because is has no benifit for a request to be attached to a non
drained socket and it prevents the request from being assigned to
a drained one, which might occur soon or already in the free pool
We achieve this by claiming a socket as free only when the socket
is drained.
PR-URL: https://github.com/nodejs/node/pull/43902
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Paolo Insogna <paolo@cowtech.it>
Reviewed-By: Robert Nagy <ronagy@icloud.com>