[Info-vax] LLVM, volatile and async VMS I/O and system calls

[Dave Froble]

On 10/3/2021 7:15 PM, Lawrence D’Oliveiro wrote:
> On Monday, October 4, 2021 at 7:20:00 AM UTC+13, Dave Froble wrote:
>> As an example, back in the day, the RSTS Basic+ interpreter had an
>> interesting quirk. For example:
>>
>> A = "abc"
>> B = A
>>
>> One would expect the value in A to be placed in the location where the
>> pointer to B points. However, Basic+ would change the pointer to B to
>> the value of the pointer to A, thus losing the old location of B. I
>> think this happened with strings, don't really remember, it has been a
>> very long time.
>>
>> Now consider that the pointer to B was in an I/O buffer. After the
>> operation, B would no longer be pointing into the I/O buffer. Perhaps
>> not such a good thing. (Actually a horrible thing!)
>
> Isn’t that what LSET and RSET were for?
>

Yes.  Not much used anymore.

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David Froble                       Tel: 724-529-0450
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