From: "Michael Erdmann" <boavista@berlin.snafu.de>
Subject: Re: Q: How to do memory access with gnat
Date: 1997/07/20
Date: 1997-07-20T00:00:00+00:00 [thread overview]
Message-ID: <ckaobqsgzooryod.pminews@boavista.berlin.snafu.de> (raw)
In-Reply-To: qw67meleuoc.fsf@esmeralda.enst.fr
On 20 Jul 1997 15:10:11 +0200, Samuel Tardieu wrote:
:>>>>>> "Michael" == Michael Erdmann <boavista@berlin.snafu.de> writes:
:>
:>Michael> In Ada95 i am not able to copy data from an Ada object into a
:>Michael> some external memory. Any idea ?
:>
:>You should try using the predefined generic package
:>System.Address_To_Access_Conversions. Then given a variable of type
:>System.Address, you can obtain an access value on your shared data.
The data structure to be stored in the shared stat looks like this,
type Message_Record( Record_Size : Integer ) is record
Nbr_Of_Bytes : Integer := Record_Size;
data : Data_Buffer( 1,,Record_Size);
end record;
My Problem is to address the data array correctly. It seems because
it is not managed under Ada memory management it is not possible
to do the following:
To_Message(share),data(1,,Nbr_Of_Bytes) := data(1... )
I get allways a constraint error. In order to avoid this i thought about a
procedure which is intended to set the shared memory at a offset
relative to a certain base address. The result is this:
procedure Store_At( base : Address ; offset : Integer ; value:BYTE ) is
package BYTE_Access is new System.Address_To_Access_Conversions(
Object => BYTE );
use BYTE_Access;
begin
BYTE_Access.To_Pointer(base+offset).all := value;
end Store_At;
But is does not work, because i am not able to add the offset to the base.
Michael
next prev parent reply other threads:[~1997-07-20 0:00 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
1997-07-20 0:00 Q: How to do memory access with gnat Michael Erdmann
1997-07-20 0:00 ` Tucker Taft
1997-07-20 0:00 ` Q: How to do memory access with gnat - os.ADB (0/1) Michael Erdmann
1997-07-20 0:00 ` Q: How to do memory access with gnat - OS.ADS (0/1) Michael Erdmann
1997-07-20 0:00 ` Q: How to do memory access with gnat - OS.ADS (1/1) Michael Erdmann
1997-07-20 0:00 ` Q: How to do memory access with gnat Samuel Tardieu
1997-07-20 0:00 ` Michael Erdmann [this message]
1997-07-22 0:00 ` Michael Erdmann
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