RE: Priority revisited: a new primitive

["Gerald Hilderink" <g.h.hilderink@xxxxxxxxxxxxx>]

In my response about the PAR PRI in my previous message, I mentioned that
the PRI PAR could be used in a hardware compilation. I would like to make a
correction, because I think that a PRI PAR in a hardware compilation is a
PAR. In a hardware compilation there is no shared resource on which priority
can be used as a scheduling parameter -- there is no scheduling. So, PRI
before PAR has no meaning in hardware. For the PRI ALT this is different.
The PRI ALT has a shared resource on which priority is used as a scheduling
parameter, namely the choice mechanism. This applies for hardware and
software.

Thus the PRI PARs in EXAMPLE2 and EXAMPLE3 are PRI PAR in software and PAR
in hardware.

Gerald.



> -----Original Message-----
> From: Gerald H. Hilderink [mailto:g.h.hilderink@xxxxxxxxxxxxx]
> Sent: Monday, October 09, 2000 1:43 AM
> To: Occam-com mail group; A E Lawrence
> Subject: RE: Priority revisited: a new primitive
>
>
>
> EXAMPLE 2:
>
> PRI PAR
>   WHILE TRUE
>     PRI ALT
>       a'?x
>         a''!x
>       b'?x
>         b''!x
>       c'?x
>         c''!x
>   PAR
>     P(a')
>     Q(b')
>     R(c')
>     S(a'')
>     T(b'')
>     U(c'')
>
> Note: the direction of communication is not considered here.
>
> EXAMPLE 3:
>
> PRI PAR
>   WHILE TRUE
>     PRI MALT
>       a'? & a''!
>         SEQ
>           a'?x
>           a''!x
>       b'? & b''!
>         SEQ
>           b'?x
>           b''!x
>       c'? & c''!
>         SEQ
>           c'?x
>           c''!x
>   PAR
>     P(a')
>     Q(b')
>     R(c')
>     S(a'')
>     T(b'')
>     U(c'')
>