P/V using SysV semop(2)

[Chris Torek]

In article <1001 at uwbull.uwbln.UUCP> ckl at uwbln.UUCP (Christoph Kuenkel) writes:
>... is it impossible to implement P/V without starvation?

Yes.  At least one SysV implementation (probably two; I doubt yours is
the same as the other I heard of) will, when asked to switch among
three processes A,B,C, run in the order A,B,A,B,A,B,A,B....

This problem does not occur when using 4.3BSD's file locking primitive
to implement semaphores.
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7163)
Domain:	chris at mimsy.umd.edu	Path:	uunet!mimsy!chris