Abstract: An information processing system is provided which includes a plurality of system resources, and an event queue having a maximum number of entries. An event recording mechanism of the information processing system is operable to make entries regarding events in the event queue, wherein the entries are limited to a predetermined number of active entries in the event queue per each type of event per each of the system resources. In a particular embodiment, the number of entries per each type of event for each of the system resources is limited to one.

Abstract: An information processing system is provided which includes an interrupt table including a plurality of entries relating to interrupts requested by entries in a plurality of event queues. The entries of the interrupt table reference identifiers, and the identifiers are assigned to events from a pool of identifiers in accordance with an order in which the events occur.

Abstract: A retry filter and circulating echo apparatus and method are provided for a digital processing system of the type having multiple nodes that communicate via one or more unidirectional rings. The nodes of a digital processing system communicate packets to each other over a unidirectional ring bus. An origination node allocates a sequence identification and transmits a packet to a destination node, which generates a first echo packet and also sets a packet filter indication to drop any further copies of that packet. The first echo packet is sent to the origination node as a confirmation. The origination node generates a second echo packet and sends the generated second echo packet onward to the destination node again as an indication that the packet will not be retransmitted. The destination node transmits a third echo packet as an indication that the sequence can be deallocated.