Hardware semaphore intended for a multi-processor system
First Claim
1. A hardware semaphore lock intended for a multi-processor system having an operating system, being configured to:
- protect a shared resource in connection with said multi-processor system;
reserve a semaphore lock at a memory location representing the semaphore lock; and
simultaneously return a number of holder positions, representing a number of keyholes, that are vacant at the time of reservation of said semaphore lock, wherein an allowed maximum number of vacant holder positions is arranged to be initialized in the semaphore lock by the operating system of the multi-processor system.
0 Assignments
0 Petitions
Accused Products
Abstract
The invention relates to a method in a hardware semaphore lock (L1–LN) intended for a multi-processor system, which semaphore lock (L1–LN) protects a shared resource (R1–RN) in connection with the system in such a way that only a process which has reserved the semaphore lock (L1–LN) and has thus become a holder of the lock, has access to use the resource protected by the lock. The semaphore lock (L1–LN) is reserved by a single read operation of a memory location representing the semaphore lock by the process software. The read operation returns to the process the number of vacant holder positions, i.e. keyholes vacant at the time of the reservation of the lock. The semaphore lock does not require the support of the system for atomic read/write operations.
43 Citations
16 Claims
-
1. A hardware semaphore lock intended for a multi-processor system having an operating system, being configured to:
-
protect a shared resource in connection with said multi-processor system; reserve a semaphore lock at a memory location representing the semaphore lock; and simultaneously return a number of holder positions, representing a number of keyholes, that are vacant at the time of reservation of said semaphore lock, wherein an allowed maximum number of vacant holder positions is arranged to be initialized in the semaphore lock by the operating system of the multi-processor system. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. An apparatus comprising:
-
a hardware semaphore lock intended for a multi-processor system having an operating system, said hardware semaphore lock configured to; protect a shared resource in connection with said multi-processor system; reserve a semaphore lock at a memory location representing the semaphore lock; and simultaneously return a number of holder positions, representing a number of keyholes, that are vacant at a time of reservation of said semaphore lock, wherein an allowed maximum number of vacant holder positions is arranged to be initialized in the semaphore lock by the operating system of the multi-processor system. - View Dependent Claims (9, 10, 11, 12, 13, 14)
-
-
15. An apparatus comprising:
-
means for protecting a shared resource in connection with a multi-processor system; means for reserving a semaphore lock at a memory location representing the semaphore lock; and means for simultaneously returning a number of holder positions, representing a number of keyholes, that are vacant at a time of reservation of said semaphore lock, wherein an allowed maximum number of vacant holder positions is arranged to be initialized in the semaphore lock by the operating system of the multi-processor system. - View Dependent Claims (16)
-
Specification