Abstract: Performing parallel comparisons of variables to determine program code execution flow or to compare multiple variables is disclosed. Memory locations are packed with multiple sub-variables for comparison to sub-variables generated, for example, at runtime. Each binary sub-variable includes a “carryout” bit used to determine whether a comparison of one sub-variable with another sub-variable results in a “true” or a “false.” A modified version of twos complement arithmetic is performed on a set of sub-variables and may be completed at runtime or earlier. The modified version involves inverting each bit of the sub-variables, performing a masking operation to change the carryout bits to 0, adding a binary 1 to each sub-variable, and performing the masking operation a second time to change the carryout bits to 0. The result of this calculation may be stored in a separate memory location for future comparisons.

Abstract: A method and system for offloading I/O processing from a first computer to a second computer, using RDMA-capable network interconnects, are disclosed. The method and system include a client on the first computer communicating over an RDMA connection to a server on the second computer by way of a lightweight input/output (LWIO) protocol. The protocol generally comprises a network discovery phase followed by an I/O processing phase. During the discovery phase, the client and server determine a minimal list of shared RDMA-capable providers. During the I/O processing phase, the client posts I/O requests for offloading to the second machine over a mutually-authenticated RDMA channel. The I/O model is asymmetric, with read operations being implemented using RDMA and write operations being implemented using normal sends. Read and write requests may be completed in polling mode and in interrupt mode. Buffers are managed by way of a credit mechanism.

Abstract: A method and system for providing state-full access to files and resuming access should a connection be broken. A resume key is returned to the client that allows the client to request a duplicate handle to an open file. The duplicate handle can be used to access the file in the same manner as the handle used to open the file. When a connection is broken, the file remains open on the server for a period of time and the state information associated with the file is maintained. Even if a connection is not broken, a client may request one or more duplicate handles and establish other channels (also known as connections) with which to access the file.