A hybrid computing environment in which the host computer allocates, in the shadow memory area of the host computer, a memory region for a packet to be written to the shared memory of an accelerator; writes packet data to the accelerator's shared memory in a memory region corresponding to the allocated memory region; inserts, in a next available element of the accelerator's descriptor array, a descriptor identifying the written packet data; increments the copy of the head pointer of the accelerator's descriptor array maintained on the host computer; and updates a copy of the head pointer of the accelerator's descriptor array maintained on the accelerator with the incremented copy.