Dynamic network interface with zero-copy frames
A dynamic network interface is described, intended to enable the efficient processing of received data within a computer network by a target computer system by reducing excessive copying of the received data prior to being accessed by a network software application.
1. A method comprising:
receiving a frame of data transmitted across a network into a receiving buffer of a target computer system;
recognizing and initiating a copy of said frame of data, said initiating comprising identifying at least one available Application Memory (AM) buffer in which to store a payload of said frame of data;
storing a header of said frame of data to a Receiving Frame Descriptor (RFD), said header comprising at least one sequence number;
zero-copying said payload of said received frame of data to said at least one AM buffer, wherein said zero-copying is aborted if an available Receiving Buffer Descriptor (RBD) queue entry is not identified.
2. The method of claim 1 further comprising allocating a new AM buffer if at least one available AM buffer is not identified, said allocating comprising creating a Receiving Buffer Descriptor (RBD) within an available RBD queue entry, said RBD comprising a value corresponding to a start address and a value corresponding to a size of said new AM buffer.
3. The method of claim 2 further comprising creating a flow descriptor if said new AM buffer is allocated, said flow descriptor identifying a zero-copy flow.
4. The method of claim 2 wherein said identifying comprises searching a pre-defined number of RBD's within said RBD queue for an RBD corresponding to said at least one available AM buffer.
5. The method of claim 4 wherein said search is based on a difference between a an AM buffer size and a size of said payload of said frame of data.
6. The method of claim 5 wherein said search is aborted if said search is unsuccessful after searching said predefined number of RBD's within said RBD queue.
7. The method of claim 6 wherein said RBD queue is indexed by a head pointer, a tail pointer and a Last Completed RBD Number (LCRN) pointer, said head pointer comprising a value corresponding to an address of a next available RBD entry within said RBD queue and said tail pointer comprising a value corresponding to an address of an oldest incomplete RBD within said RBD queue and said LCRN pointer comprising a value corresponding to a full AM buffer.
8. The method of claim 7 wherein an RBD entry within said RBD queue corresponding to a full AM buffer is invalidated.
9. The method of claim 8 wherein said invalidated RBD entry is used to store future or pending RBD's.