Abstract: Embodiments of the present invention provide a system that executes program code in a processor. The system starts by executing the program code in a normal mode using a primary strand while concurrently executing the program code ahead of the primary strand using a subordinate strand in a scout mode. Upon resolving a branch using the subordinate strand, the system records a resolution for the branch in a speculative branch resolution table. Upon subsequently encountering the branch using the primary strand, the system uses the recorded resolution from the speculative branch resolution table to predict a resolution for the branch for the primary strand. Upon determining that the resolution of the branch was mispredicted for the primary strand, the system determines that the subordinate strand mispredicted the branch. The system then recovers the subordinate strand to the branch and restarts the subordinate strand executing the program code.

Abstract: A token generator such as a keyfob is used to access the computer of an authentication entity different from the authentication entity that issued the token generator. The token generator stores authentication entity identification information identifying the authentication entity that issued the token generator. The token generator causes a user computer to transmit an authentication request including such authentication entity identification information together with a token generated in synchronization with the authentication entity issuing the token generator, so that the authentication request can be routed to the appropriate authentication entity that issued the keyfob for validation. The authentication request can be sent directly to the authentication entity that issued the token generator. The authentication request can also be sent to the authentication entity that issued the token generator via another authentication entity to which the user computer attempts to access.

Abstract: One embodiment of the present invention provides a system that manages an LRU list such that the rank, or position, of data records in the sequence can be determined efficiently. The system initializes an index field in each record to the record's initial rank. When a record is accessed, the system moves it to the beginning of the LRU list and appends the value of the record's index field to a “change list.” The system then sets the record's index field to zero. The change list effectively tracks the records accessed since initialization, and combined with the records' index fields can be used to efficiently compute the rank of any record in the list. This ability to efficiently compute the rank of the data record in the LRU list reduces the frequency with which the computationally-expensive initialization operation must be executed on the LRU list.

Abstract: One embodiment of the present invention provides a system that facilitates construction of a forward error correction (FEC) coded Ethernet frame. The system generates a number of FEC parity bits for the conventional Ethernet frame and inserts a start sequence before the conventional Ethernet frame. Next, the system appends an even- or odd-delimiter to the conventional Ethernet frame. The even-delimiter and the odd-delimiter are selected such that there is a sufficiently large Hamming distance between them, thereby reducing the probability of mistaking the even-delimiter for the odd-delimiter, or mistaking the odd-delimiter for the even-delimiter, if bit error occurs.

Abstract: One embodiment of the present invention provides a system that facilitates efficient flow control for data transmissions between a sender and a plurality of receivers. The system operates by sending a stream of packets from the sender to the plurality of receivers, wherein the packets include information specifying a sampling window for the stream of packets. The sender subsequently receives feedback information from the plurality of receivers, wherein a receiver sends feedback information to the sender if a congestion condition occurs at the receiver while receiving packets within the sampling window. In response to the feedback information, the sender adjusts a rate of transmission for the stream of packets. In one embodiment of the present invention, the feedback information from the receivers is aggregated at intermediate nodes prior to reaching the sender in order to eliminate redundant feedback information.

Abstract: One embodiment of the invention provides a system that creates a phase-shifting mask for a photolithographic process used in fabricating an integrated circuit. The system starts by receiving a layout for the integrated circuit. The system then associates nodes with features in the layout, and generates arcs between the nodes. Next, the system generates a coloring for the nodes using two colors. The system then generates phase shifters for the phase-shifting mask and assigns different phases to the phase shifters based upon the coloring of the nodes.