Abstract: A method for controlling sharing of resources in a multi-threaded environment includes entering a finite state machine state sequence; controlling resource-sharing threads using the finite state machine state sequence; and exiting the finite state machine state sequence when shared resource control is complete. A multi-threaded shared resource control system includes a finite state machine configured to control multi-threaded access to shared resources; a plurality of producer threads regulated by the finite state machine; and a plurality of consumer threads regulated by the finite state machine.

Abstract: A system and method for routing between nodes in a network or subnet. An end node is associated with multiple identifiers for routing purposes, and therefore multiple paths may exist between two end nodes. Network nodes and components (e.g., switches) are grouped into fault zones. Each physical enclosure of network entities may comprise a separate fault zone. For each zone through which a path between two nodes passes, a weight is calculated equal to the number of paths between the nodes that traverse that zone. Path weights are calculated for each path between the nodes, equal to the sum of the weights of each zone in the path. To improve network fault tolerance, new paths may be designed to avoid fault zones and existing paths with high weights. Instead of fault zones, other criteria may be used to assign weights, such as mean time between failures (MTBF), cost, speed, etc.

Abstract: A system and method for efficiently managing membership in a multicast communication group. The system may comprise any number of end nodes (e.g., channel adapters, network interface adapters) and routing nodes (e.g., switches), and the method may be implemented by a processor coupled to any node. Each node in a network may be a member of the multicast group and/or the multicast tree (MCT) that routes the group's multicast communications. A node need not be a member of the group to be a member of the tree. Network links included in the MCT are a subset of a network minimum spanning tree (MST). When a node is added to the group, the MST is searched from that node until a node within the MCT is found. Each time a member is removed from the group, the MCT is pruned to reduce unneeded communications.