Extended semaphore operations

✍ Scribed by Hodgson, S. ;Dunstan, N. ;Fris, I.

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 123 KB
• Volume: 12
• Category: Article
• ISSN: 1040-3108
• DOI: 10.1002/1096-9128(20001225)12:15<1495::aid-cpe541>3.0.co;2-f

✦ Synopsis

Extended semaphores systems such as in UNIX System V are a powerful extension of Dijkstra's semaphores. They allow efficient solutions to a number of classic synchronization problems. UNIX semaphore operations appear to be insufficiently well defined, in particular when a semaphore is repeated in an operator. This results in several solutions relying on assumed properties. A new semaphore operator, isem, based on extended semaphore operators is introduced. The operator isem is clearly defined, can be implemented efficiently, and yields simple solutions to many classic synchronization problems.