Re: 64-bit support for display device

I'm not sure what will happen when Intel moves to 64bit addresses.
Maybe we'll get %lp and _far again.

Igor.

----- Original Message ----- 
From: "Russell Lang" <[email protected]>
To: <[email protected]>
Sent: Thursday, February 12, 2004 12:59 PM
Subject: Re: [gs-code-review] 64-bit support for display device


> Ray,
> 
> Kim suggested a variation on this patch.  Instead of parsing the 
> pointer value in a string ourselves,  let the caller do
>   sprintf(buf, "%p", handle);
> and ghostscript do
>   sscanf(buf, "%p", &handle);
> 
> Is %p portable enough for this?
> 
> Russell
> 
> On 11 Feb 2004 at 19:38, Russell Lang wrote:
> 
> > Ray,
> > 
> > Please review the following patch.  I have not tested it on a 64-
> > bit platform (I don't have one).  I would like this added to 
> > 8.14.  If all goes well it should be harmless.  Worst case is 
> > probably some compiler warnings when compiled on a 64-bit 
> > platform.    For HEAD, GS_8_1X and GS_8_0X.
> > 
> > Log message:
> > 
> > Change display device parameter DisplayHandle from an integer
> > to a string, to add support for 64-bit platforms.
> > 
> > DETAILS:
> > 
> > The display device passes a (void *) handle to callback 
> > functions.  The handle is set before the device is opened, and 
> > attempting to change it afterwards is an error.  The handle may 
> > be used by the caller to identify an instance of the display 
> > device, for example it may point to the display instance object 
> > in the caller. This handle was set using a PostScript integer 
> > which is 32-bits long, typically with -dDisplayHandle.  The 
> > existing code will not work correctly on 64-bit architectures.   
> > 
> > 
> > The display device is changed to return a string as the
> > DisplayHandle parameter.
> > Previously the handle would be set using -dDisplayHandle=1234.
> > The changed code allows it to be passed as
> >  -dDisplayHandle=1234
> >  -dDisplayHandle=(1234)
> >  -sDisplayHandle=1234
> >  -sDisplayHandle=10#1234
> >  -sDisplayHandle=16#04d2
> > This should be backward compatible, since users of the
> > display device will most likely only set the DisplayHandle,
> > not read its value.
> > 
> > The ghostscript example code in dw*.c, dx*.c and dp*.c
> > does not use DisplayHandle, so is unaffected by this change.
> > GSview does use DisplayHandle and will require this
> > change for operation on 64-bit platforms.
> > 
> > It is assumed that size_t is an integer with the same size
> > as a pointer.
> > 
> > 
> > Russell Lang                   [email protected]
> > Ghostgum Software Pty Ltd      http://www.ghostgum.com.au/
> > 
> > 
> > 
> > 
> 
> 
> Russell Lang                   [email protected]
> Ghostgum Software Pty Ltd      http://www.ghostgum.com.au/
> 
> 
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