Arista Networks, Inc.

Christopher Elisha Neilson

Sebastian Sapa

Duncan Stuart Ritchie

Eric Secules

Peter Edwards

Roman Olegovich Chertov

Ronan Mac Fhlannchadha

Stuart Ritchie

Jonathan Antusiak

Francois Guy Maurice Ripault

Vijay Varma Galbaransingh

The present disclosure is directed to a shared first-in-first-out (FIFO) queue architecture in a computing device, such as a network device, that allows lock-free, concurrent access to a writer process (writer) and one or more reader processes (readers). The writer enqueues information provided to the computing device. One or more readers dequeue the information and process the information. A queue manager provides an interface to the shared queue to allow the writer to push data onto the queue and readers to access the queue; e.g., peek and pop the queue. The readers inform the writer when they perform dequeue operations so that the writer knows when to age out queue entries for deletion from the queue.

Sharing state information using shared memory

Embodiments as disclosed allow the definition and use of custom models in association with a network agent on a network device. In particular, custom models can be placed on a network device and utilized by the network device. The use of these custom models including, notifications and responses associated with those custom models, may appear indistinguishable to use of vendor supplied models.

Method and system for use of custom data models in network device management

A method and apparatus of a network device that allocates a shared memory buffer for an object is described. In an exemplary embodiment, the network device receives an allocation request for the shared memory buffer for the object. In addition, the network device allocates the shared memory buffer from shared memory of a network device, where the shared memory buffer is accessible by a writer and a plurality of readers. The network device further returns a writer pointer to the writer, where the writer pointer references a base address of the shared memory buffer. Furthermore, the network device stores the object in the shared memory buffer, wherein the writer accesses the shared memory using the writer pointer. The network device further shares the writer pointer with at least a first reader of the plurality of readers. The network device additionally translates the base address of the shared memory buffer to a reader pointer, where the reader pointer is expressed in a memory space of the first reader.

Shared memory allocator with child process

Methods and apparatus for enabling detection of configuration changes in a network device. One method uses a configuration counter in a system database of the network device. In response to an atomic submission of CLI commands to a configuration agent and the storing of the corresponding configuration in a system database, the configuration counter is incremented. An OpenConfig module maintains an expected value of the configuration counter and, upon completion of its own command submissions, compares the expected value to the value in the configuration counter. If the two values do not match, it indicates that the configuration counter in the system database has been incremented as a result of a configuration change from a source other than the OpenConfig module. A configuration client can then be notified of the configuration change so that it can revert the configuration to a desired configuration.

Detecting configuration collisions between multiple configuration clients

Dynamic type resolution for shared memory

Systems and methods for implementing polymorphic allocators in an operating system are disclosed. An illustrative method includes a method of allocating memory space in a memory by creating a first allocator. In response to receiving a first request to allocate memory space in the memory for a data buffer instance using the first allocator, the method allocates one or more pages of a first region in the memory by populating one or more entries of an allocator table. The one or more entries of the allocator table correspond to the one or more pages of the first region. The entries of the allocator table are indexed by page indexes corresponding to page addresses identifying the pages of the first region in the memory. Each of the populated entries of the allocator table includes a specific allocator identifier identifying a corresponding allocator to that entry.

Polymorphic allocators in an operating system

Systems and methods for creating a new entry in a hierarchical state data structure with object entries is disclosed. The method includes allocating a shared memory buffer for a new entry in a shared memory. A request to create the new entry for a child object in a hierarchical state data structure in the shared memory is received. The new entry is to span at least one shared memory buffer uniquely identifiable in a location of the shared memory. The child object is a logical representation of a state of a system. In response to a request for an allocation of a shared memory buffer within a region of the shared memory for the new entry, a location identifier corresponding to a location of a parent entry holding a parent object to the child object in the hierarchical state data structure of an allocated region is received. The child object is created in the shared memory buffer for the new entry, and the new entry is available for concurrent access by one or more readers of the shared memory.

Lock-free method of transmitting hierarchical collections through shared memory

Systems and methods for processing memory address spaces corresponding to a shared memory are disclosed. After a writer restart process, pre-restart writer pointers of a pre-restart writer addressable space in the shared memory are replaced with corresponding location independent pointers. A writer pointer translation table is rebuilt in the shared memory to replace an association of modified pre-restart writer pointers and pre-restart translation base pointers based on the pre-restart writer pointers, respectively, with an association of modified post-restart writer pointers and post-restart translation base pointers based on post-restart writer pointers, respectively. After the writer pointer translation table is rebuilt, the location independent pointers are replaced with post-restart writer pointers in the shared memory, respectively, and the post-restart writer pointers are stored in the shared memory for access by one or more readers of the shared memory.

Restartable, lock-free concurrent shared memory state with pointers

Techniques are described herein for managing data structure groups. Such techniques may include providing to a data structure group, by a reader, a plurality of data structure identifiers including a first data structure identifier and a second data structure identifier; mounting, by the data structure group, a first data structure identified by the first data structure identifier and including a first instance identifier; mounting, by the data structure group, a second data structure identified by the second data structure identifier and including a second instance identifier; making a first determination that the first data structure and the second data structure are mounted; making a second determination that the first instance identifier and the second instance identifier match; and marking, based on the first determination and the second determination, the data structure group as ready-to-read.

System and method for cohesive shared multi-data structure lifecycle

System and method of a shared memory allocator

A method and apparatus of a device that reads and writes a plurality of counters is described. In an exemplary embodiment, a device receives plurality labels that correspond to the plurality of counters. The plurality of counters is stored in a shared memory table in the shared memory of the device. In addition, a writer writes counter data for each of the plurality of counters to the shared memory table. For each of the plurality of labels, the device performs a lookup of that label for a memory reference to a corresponding counter that is one of the plurality of counters and retrieves the memory reference for the corresponding counter. The device further reads the counter data for plurality of counters using the plurality of memory references. The device additionally sends the counter data to the client.

Growing community of inventors

Vancouver, Canada

Christopher Elisha Neilson