Methods and apparatus are disclosed for controlling distributed software applications implementing asynchronous replication of shared data objects. Each shared data object has a distinct token. A token has respective states (active or inactive) at each computing system sharing the data object. At most one computing system can have the token active at any time; possessing an active token allows a computing system to update the shared data object. Counters maintain state across the computing systems, and semantic checks specific to a class of data objects (or, a single object) ensure consistency of updates across computing systems. Token activation requests and update replication requests are supported. Participating computing systems can have asymmetric or symmetric roles. Token management can be provided by a framework offering superior performance compared to conventional locking systems, co-existence with local conventional locking systems, and a single uniform interface for streamlined integration with existing software applications.

Providing self-resetting multi-producer multi-consumer semaphores in distributed processor-based systems is disclosed. In one aspect, a synchronization management circuit provides a semaphore including a counting semaphore value indicator, a current wait count indicator, and a target wait count indicator. When a consumer completes a wait operation, the synchronization management circuit adjusts the value of the current wait count indicator towards the value of the target wait count indicator, and compares the value of the current wait count indicator to the value of the target wait count indicator. If the value of the current wait count indicator has reached the value of the target wait count indicator, the synchronization management circuit infers that all consumers have observed the semaphore, and accordingly resets both the counting semaphore value indicator and the current wait count indicator to an initial wait value to place the semaphore in its initial state for reuse.

Methods and apparatus for token-based admission control for replicated writes are disclosed. Data objects are divided into partitions, and corresponding to each partition, at least a master replica and a slave replica are stored. A determination as to whether to accept a write request directed to the partition is made based at least in part on one or more of (a) available throughput capacity at the master replica, and (b) an indication, obtained using a token-based protocol, of available throughput capacity at the slave replica. If the write request is accepted, one or more data modification operations are initiated.

The disclosure provides a method for managing multiple operating systems in a terminal. The terminal includes multiple operating systems and a management system. The management system is configured to manage the multiple operating systems. The management system includes a cross-system application database. The method includes: when a first operating system in the multiple operating systems runs in a foreground, and a second operating system in the multiple operating systems runs in a background, if the second operating system receives a first message of a first application in the second operating system, sending, by the second operating system, a notification message to the management system; storing, by the management system, the notification message into the cross-system application database; and listening, by the first operating system, on the cross-system application database, and outputting a prompt of the first message when listening and obtaining the notification message.

Described is a two-phase spinlock that controls access to a resource from a plurality of threads. The two-phase spinlock receives requests from threads to acquire the resource, places the threads in a first queue associated with a first phase of the two-phase spinlock, determines whether at least one of a predetermined number of slots in a second phase of the two-phase spinlock is available and when the slots are unavailable, processes an interrupt served by a select one of the threads based on a number of attempts by the selected thread to enter the second phase.

The disclosure provide a method for prompting a message in a terminal and a terminal. The terminal includes multiple operating systems and a management system. The management system is configured to manage the multiple operating systems. The management system includes a cross-system application database. The method includes: when a first operating system in the multiple operating systems runs in a foreground, and a second operating system in the multiple operating systems runs in a background, if the second operating system receives a first message of a first application in the second operating system, sending, by the second operating system, a notification message to the management system; storing, by the management system, the notification message into the cross-system application database; and listening, by the first operating system, on the cross-system application database, and outputting a prompt of the first message when listening and obtaining the notification message.

The present disclosure generally relates to controlling access to resources by selectively processing requests stored in a task queue to prioritize certain requests over others, thereby preventing automated scripts from accessing the resources. More specifically, the present disclosure relates to a normalization and prioritization system for controlling access to resources by queuing resource requests based on a client-defined normalization process that uses one or more data sources.

Described is a two-phase spinlock that controls access to a resource from a plurality of threads. The two-phase spinlock receives requests from threads to acquire the resource, places the threads in a first queue associated with a first phase of the two-phase spinlock, determines whether at least one of a predetermined number of slots in a second phase of the two-phase spinlock is available and when the slots are unavailable, processes an interrupt served by a select one of the threads based on a number of attempts by the selected thread to enter the second phase.

A building management system for generating a building model for a building and operating building equipment of the building based on the building model. The system includes a processing circuit configured to receive a context, wherein the context includes metadata defining the building model for the building and generate a building model editor interface for viewing and editing the received context, wherein the building model interface includes building elements for the building model, wherein the building elements are based on the received context and represent the building equipment. The processing circuit is configured to receive user edits of the context via the building model interface, wherein the user edits include edits to the building elements, generate an updated context based on the user edits of the context, and deploy the updated context to control environmental conditions of the building with the building equipment based on the updated context.

Providing self-resetting multi-producer multi-consumer semaphores in distributed processor-based systems is disclosed. In one aspect, a synchronization management circuit provides a semaphore including a counting semaphore value indicator, a current wait count indicator, and a target wait count indicator. When a consumer completes a wait operation, the synchronization management circuit adjusts the value of the current wait count indicator towards the value of the target wait count indicator, and compares the value of the current wait count indicator to the value of the target wait count indicator. If the value of the current wait count indicator has reached the value of the target wait count indicator, the synchronization management circuit infers that all consumers have observed the semaphore, and accordingly resets both the counting semaphore value indicator and the current wait count indicator to an initial wait value to place the semaphore in its initial state for reuse.