RE: semaphore and spin locks

["atul" <atul_info@yahoo.com>]

> A spin lock is a primitive mechanism to prevent two or more processes
> accessing a certain data structure at the same time. The lock is an
> integer that's initially set to 0. A process which wants to enter the
> critical area has to set the lock to 1 using an atomic "if 0 then set
> 1"-operation. If the lock is in use, the process has to busy-wait,
> spinning in a tight loop. ==> CPU-time-consuming if you have to wait
> long, but very efficient if you don't have to wait.

Since a process has to busy wait on spin-lock, what if 2 or more processes
get stuck on the same spin lock, which process will be allowed to enter the
critical region..??

atul


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