[Oberon] Volatile variables in Oberon

[Douglas G. Danforth]

If by volatile you mean
"In computer programming 
<https://en.wikipedia.org/wiki/Computer_programming>, particularly in 
the C <https://en.wikipedia.org/wiki/C_%28programming_language%29>, C++ 
<https://en.wikipedia.org/wiki/C%2B%2B>, C# 
<https://en.wikipedia.org/wiki/C_Sharp_%28programming_language%29>, and 
Java <https://en.wikipedia.org/wiki/Java_%28programming_language%29> 
programming languages 
<https://en.wikipedia.org/wiki/Programming_language>, the *volatile* 
keyword 
<https://en.wikipedia.org/wiki/Keyword_%28computer_programming%29> 
indicates that a value 
<https://en.wikipedia.org/wiki/Value_%28computer_science%29> may change 
between different accesses, even if it does not appear to be modified. 
This keyword prevents an optimizing compiler 
<https://en.wikipedia.org/wiki/Optimizing_compiler> from optimizing away 
subsequent reads or writes and thus incorrectly reusing a stale value or 
omitting writes. Volatile values primarily arise in hardware access 
(memory-mapped I/O <https://en.wikipedia.org/wiki/Memory-mapped_I/O>), 
where reading from or writing to memory is used to communicate with 
peripheral devices <https://en.wikipedia.org/wiki/Peripheral_device>, 
and in threading <https://en.wikipedia.org/wiki/Thread_%28computing%29>, 
where a different thread may have modified a value."

Then I would say any variable, x, exported from a module m as read only, 
m.x-, would be nonvolatile to modules external to m.  A call to any 
procedure m.p could, of course, change the value of m.x.  The Oberon 
language (at least to my knowledge) does not support the concept volatile.
What is the need driving your question?

-Doug Danforth

On 7/28/2016 9:27 AM, Srinivas Nayak wrote:
> Dear All,
>
> In Oberon, do we have a way to specify, if a variable is volatile?
> If not, how do we work around for such a need?
>

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