Re: Is there spinlocks/semaphores available for drivers?

[Andrew Reilly]

On Sun, Mar 26, 2000 at 11:24:50PM -0700, Warner Losh wrote:
> In message <[EMAIL PROTECTED]> Matthew Dillon writes:
> :     complex.  For example, using fixed-length FIFOs rather then linked lists.
> :     The writer manipulates the write index variable, the reader manipulates
> :     the read index variable.  No locking is required between reader and 
> :     writer.
> 
> What about wrap around?

You mean queue empty or queue full?  That's when you have to
punt to a rate-limit mechanism.  Dunno what that would be in
interrupt context.

-- 
Andrew


To Unsubscribe: send mail to [EMAIL PROTECTED]
with "unsubscribe freebsd-current" in the body of the message