1. A computer-implemented process, comprising: receiving a request from a process executing on a sender to send an RPC request to a receiver for execution; transmitting a request for receiver control data from the sender to the receiver via an RDMA read message, the receiver control data comprising a list of free slots of the receiver; in response to receipt of the requested control data by the sender, transmitting a reservation request for one of the free slots from the sender to the receiver via an RDMA atomic compare and swap message; writing the RPC request from the sender to the reserved slot of the receiver via an RDMA write message; and executing the RPC request on the receiver.