Under 16-bit large model, what function can I use to determine whether a given pointer is actually a valid heap pointer, either _far or _huge.  The memory management runtimes should be able to tell me this information.  I looked in the documentation (web and PDF) but did not find anything.

Mark

Mark,

Which 16 bits platform are you working on?
I suppose Win16?
Win16 should have:
IsBadCodePtr
IsBadHugeReadPtr
IsBadHugeWritePtr
IsBadReadPtr
IsBadStringPtr
IsBadWritePtr

HTH

Jan



Mark Evans wrote:

> Under 16-bit large model, what function can I use to determine whether a given pointer is actually a valid heap pointer, either _far or _huge.  The memory management runtimes should be able
> to tell me this information.  I looked in the documentation (web and PDF) but did not find anything.
>
> Mark

Yes Win16.

When the functions are listed without parameters they look useful.  This appearance is deceiving.  One of the required parameters is the size of the allocation block.  Even a good pointer is then reported as "bad" if the size with which it was allocated does not match the parameter to the function.

So these functions strike me as defeating their own purpose.  If I knew the block size then I would already know it was a good pointer.

What I want is a function that will recognize *any* previously allocated __far or __huge pointer, of any size, without my having to track the size.  Does DM have such a function in its runtimes?

Mark


On Mon, 04 Jun 2001 11:47:47 -0400, Jan Knepper <jan@smartsoft.cc> wrote:
> Mark,
> 
> Which 16 bits platform are you working on?
> I suppose Win16?
> Win16 should have:
> IsBadCodePtr
> IsBadHugeReadPtr
> IsBadHugeWritePtr
> IsBadReadPtr
> IsBadStringPtr
> IsBadWritePtr
> 
> HTH
> 
> Jan
> 
> 
> 
> Mark Evans wrote:
> 
> > Under 16-bit large model, what function can I use to determine whether a given pointer is actually a valid heap pointer, either
_far or _huge.  The memory management runtimes should be able
> > to tell me this information.  I looked in the documentation (web and PDF) but did not find anything.
> >
> > Mark
> 

Mark Evans wrote:

> Yes Win16.

Copied the reply to c++.windows.16-bits

> When the functions are listed without parameters they look useful.  This appearance is deceiving.  One of the required
> parameters is the size of the allocation block.  Even a good pointer is then reported as "bad" if the size with which it was
> allocated does not match the parameter to the function.

Well... I figured that you had a helpfile or something where you could look them up and see how they can or can-not help you.

> So these functions strike me as defeating their own purpose.  If I knew the block size then I would already know it was a good
> pointer.
>
> What I want is a function that will recognize *any* previously allocated __far or __huge pointer, of any size, without my having to
> track the size.  Does DM have such a function in its runtimes?

Check into _msize. That might help you a little.

Jan