🚀 go-pugleaf

X-Original-Date: Tue, 02 Jan 1996 15:25:49 -0800

Srinivas Vobilisetti wrote:
> 
> X-Original-Date: 31 Dec 1995 01:42:27 GMT
> 
> Hello,
>

Concept of volatile can be easily using a simple example:

int a

a = 1;
a++
if (a==1) {
	...
}

typically compiler loads the value of variable a, into a register of a processor 
before executing 'a++'. and compares the value of register that holds the value 
instead of checking the value at the actual memory location. This optimization is default
in any C compiler. If suppose the location of variable a is a hardware location like
printer port, this optimization won't work, to supress such optimization we add the keyword
volatile, In that case compiler generate instruction to fetch from actual location instead
of fetching value from register.


 
> I referred to various books on C++ including The C++ Programming Language
> -Bjarne Stroustrup, C++ Primer -Stanley Lipmann, etc.  Nowhere i could find
> exact meaning of the specifier volatile. Thanks in advance for your help. I
> would appreciate the reply at my email address srv@cs.wayne.edu
> 
> Thanks
> Srinivas
> srv@cs.wayne.edu

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