R help - Apr 2008 - R_alloc vs. malloc

Dear list
I have two (trivial) memory-questions related to a call with .C:
 
If I allocate memory with R_alloc in a C-program (called with .C), will that
memory "be taken from" the "available memory pool" (of a
maximum of 4gb?) which R can allocate? (This is the impression I get from
"Writing R extensions".)
 
If instead I use malloc; will that memory then be taken from the available pool
for R? Or does that happen without having an impact on R's "available
memory pool"?
 
Regards
S?ren

On Fri, 11 Apr 2008, S?ren H?jsgaard wrote:
> Dear list
> I have two (trivial) memory-questions related to a call with .C:
On Windows, I presume from past questions from yourself.  The answers 
really are completely Windows-specific, so please do remember to tell us 
your OS!
> If I allocate memory with R_alloc in a C-program (called with .C), will 
> that memory "be taken from" the "available memory pool"
(of a maximum of
> 4gb?) which R can allocate? (This is the impression I get from
"Writing
> R extensions".)
Yes.  Same for Calloc.
> If instead I use malloc; will that memory then be taken from the 
> available pool for R? Or does that happen without having an impact on 
> R's "available memory pool"?
>From a different pool, but from the same address space.  There is no more 
virtual memory that R does not have access too, so you would just be 
setting up in competition.

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
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