Receive queue device with efficient queue flow control, segment placement and virtualization mechanisms

A mechanism for offloading the management of receive queues in a split (e.g. split socket, split iSCSI, split DAFS) stack environment, including efficient queue flow control and TCP/IP retransmission support. An Upper Layer Protocol (ULP) creates receive work queues and completion queues that are utilized by an Internet Protocol Suite Offload Engine (IPSOE) and the ULP to transfer information and carry out send operations. As consumers initiate receive operations, receive work queue entries (RWQEs) are created by the ULP and written to the receive work queue (RWQ). The ISPOE is notified of a new entry to the RWQ and it subsequently reads this entry that contains pointers to the data that is to be received. After the data is received, the IPSOE creates a completion queue entry (CQE) that is written into the completion queue (CQ). After the CQE is written, the ULP subsequently processes the entry and removes it from the CQE, freeing up a space in both the RWQ and CQ. The number of entries available in the RWQ are monitored by the ULP so that it does not overwrite any valid entries. Likewise, the IPSOE monitors the number of entries available in the CQ, so as not overwrite the CQ.