Semaphore system based on process events

Abstract

A method and apparatus are described for a semaphore system based on process events. The system may have multiple processes; one or more shared resources; and a semaphore system corresponding to each of the processes. When multiple processes simultaneously request access to a given shared resource, each semaphore system arbitrates on behalf of its corresponding process. In one embodiment, a semaphore system is self-contained and can arbitrate for its corresponding process based on the other process's events. In another embodiment, the semaphore system interacts with a global arbiter to resolve conflicts.

Description

technical field [0001] The present invention relates generally to parallel processes and, more particularly, to semaphores for managing access to shared system resources. Background technique [0002] Systems that perform parallel processing include multiple processes executing simultaneously. A common problem when using parallel processing is protecting the contents of common resources. [0003] One well-known way to achieve this protection is to use semaphores, which are generally hardware or software flags. In a multitasking system, a semaphore is a variable that indicates the state of a common resource. Semaphores are used to lock resources that are being used. Processes requiring the resource check the semaphore to determine the state of the resource and then decide how to proceed. A semaphore indicates to other potential users that a file or other resource is in use and prevents access by more than one process. [0004] However, problems such as starvation and / or ...

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Problems solved by technology

However, this workaround is not very efficient when the number of resources becomes large

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