Abstract: In one embodiment, a physical device (e.g., packet switching device, computer, server) is booted using custom-created frozen partially-booted virtual machines, avoiding the time required for an end-to-end boot process. In one embodiment while the system is operating under a current version, a partially-booted virtual image of a new operating version for each of multiple processing elements of the device is produced according to static configuration information specific to the device, with each of these partially-booted virtual machines frozen. The device is rebooted to a fully operational device by unfreezing these partially-booted virtual machines, thus removing this portion of a boot process from the real-time booting of the device. The generation of the frozen partially-booted virtual machines is advantageously performed by the device itself based on current static configuration information and the availability of the specific hardware configuration of the device.

Abstract: In one embodiment, a packet switching device creates multiple virtual packet switching devices within the same physical packet switching device using virtual machines and sharing particular physical resources of the packet switching device. One embodiment uses this functionality to change the operating version (e.g., upgrade or downgrade) of the packet switching device by originally operating according to a first operating version, operating according to both a first and second operating version, and then ceasing operating according to the first operating version. Using such a technique, a packet switching device can be upgraded or downgraded while fully operating (e.g., without having to reboot line cards and route processing engines).

Abstract: In one embodiment, a packet switching device creates multiple virtual packet switching devices within the same physical packet switching device using virtual machines and sharing particular physical resources of the packet switching device. One embodiment uses this functionality to change the operating version (e.g., upgrade or downgrade) of the packet switching device by originally operating according to a first operating version, operating according to both a first and second operating version, and then ceasing operating according to the first operating version. Using such a technique, a packet switching device can be upgraded or downgraded while fully operating (e.g., without having to reboot line cards and route processing engines).

Abstract: In one embodiment, a packet switching device creates multiple virtual packet switching devices within the same physical packet switching device using virtual machines and sharing particular physical resources of the packet switching device. One embodiment uses this functionality to change the operating version (e.g., upgrade or downgrade) of the packet switching device by originally operating according to a first operating version, operating according to both a first and second operating version, and then ceasing operating according to the first operating version. Using such a technique, a packet switching device can be upgraded or downgraded while fully operating (e.g., without having to reboot line cards and route processing engines).

Abstract: In one embodiment, a physical device (e.g., packet switching device, computer, server) is booted using custom-created frozen partially-booted virtual machines, avoiding the time required for an end-to-end boot process. In one embodiment while the system is operating under a current version, a partially-booted virtual image of a new operating version for each of multiple processing elements of the device is produced according to static configuration information specific to the device, with each of these partially-booted virtual machines frozen. The device is rebooted to a fully operational device by unfreezing these partially-booted virtual machines, thus removing this portion of a boot process from the real-time booting of the device. The generation of the frozen partially-booted virtual machines is advantageously performed by the device itself based on current static configuration information and the availability of the specific hardware configuration of the device.

Abstract: In one embodiment, an operating system kernel and/or one or more processes of a high-availability system are modified while the system is operating and providing high-availability service. In accomplishing this, one embodiment uses a second virtual machine to operate a second operating system kernel including a second set of processes in the standby mode, which receive state information from corresponding process(es) in the active mode. Individually, the operating system kernel and processes within the second set of processes may be a same or different version of their counterpart in a first virtual machine and its processes which are being replaced. When the second set of processes have acquired sufficient state information to perform the standby role, the operation of the first virtual machine is typically ceased as the version modified second virtual machine is performing the version modified functionality of the first virtual machine.

Abstract: In one embodiment, an operating system kernel and/or one or more processes of a high-availability system are modified while the system is operating and providing high-availability service. In accomplishing this, one embodiment uses a second virtual machine to operate a second operating system kernel including a second set of processes in the standby mode, which receive state information from corresponding process(es) in the active mode. Individually, the operating system kernel and processes within the second set of processes may be a same or different version of their counterpart in a first virtual machine and its processes which are being replaced. When the second set of processes have acquired sufficient state information to perform the standby role, the operation of the first virtual machine is typically ceased as the version modified second virtual machine is performing the version modified functionality of the first virtual machine.

Abstract: In one embodiment, a packet switching device creates multiple virtual packet switching devices within the same physical packet switching device using virtual machines and sharing particular physical resources of the packet switching device. One embodiment uses this functionality to change the operating version (e.g., upgrade or downgrade) of the packet switching device by originally operating according to a first operating version, operating according to both a first and second operating version, and then ceasing operating according to the first operating version. Using such a technique, a packet switching device can be upgraded or downgraded while fully operating (e.g., without having to reboot line cards and route processing engines).

Abstract: Method, computer program, system and apparatus for operating system dynamic event management and task scheduling using function calls. Method, computer program product, and system for non-preemptively scheduling tasks in a computer system. Scheduler and scheduling method that schedules tasks that are broken into a number of short actions, without preempting the actions as they are executed and without assigning a priority to tasks. Invention decreases the overhead as compared to existing methods and systems.

Abstract: Method, system, apparatus and computer program product for interrupt scheduling in processing communication. In one embodiment the method includes: a sending computer program and a receiving computer program, coupling at least one registered signal identifier and a corresponding registered signal function with said receiving computer program; sending a communication including a request signal identifier by said sending computer program to said receiving computer program; receiving said communication sent at (B) by said receiving computer program; and performing said corresponding registered signal function without context switching of said receiving computer program if said request signal identifier received is coupled with said registered signal identifier. A system, router, computer program and computer program product are also disclosed.

Abstract: In summary, one aspect of the present invention is directed to a method for a shared memory queue to support communicating between computer processes, such as an enqueuing process and a dequeuing process. A buffer may be allocated including at least one element having a data field and a reserve field, a head pointer and a tail pointer. The enqueuing process may enqueue a communication into the buffer using mutual exclusive access to the element identified by the head pointer. The dequeuing process may dequeue a communication from the buffer using mutual exclusive access to the element identified by the tail pointer. Mutual exclusive access to said head pointer and tail pointer is not required. A system and computer program for a shared memory queue are also disclosed.

Abstract: Method, system, apparatus and computer program for processing a state machine. The method includes: coupling at least two attributes with a state machine selected from said at least one state machine; identifying at least one value corresponding with a first attribute selected from said at least two attributes; determining a processing order based on said at least one value to process at least one second attribute selected from said at least two attributes; and processing said second attribute according to said order.

Abstract: Method, system, apparatus and computer program product for memory management. In one embodiment the method includes: configuring a first memory including allocating at least one node; and defining a status including: defining a class list, wherein each node is capable of storing a class instance corresponding to a class selected from said class list; and defining a node list to identify an allocation status of each node including an available status, and an allocated status; receiving an allocation request including a class identifier, responding to the allocation request with a node identifier representing said available node and updating the available node allocation status; otherwise responding with a failure indication; and receiving a deallocation request and responding to said deallocation request by updating the allocation status to the available status. A system, router, computer program and computer program product are also disclosed.