Re: [Discuss-gnuradio] aligned memory and posix_memalign

[Josh Blum]

here is my fix attempt:
http://gnuradio.org/cgit/jblum.git/commit/?h=wip/volk/remove_posix_memalign

-josh

On 03/06/2011 09:08 AM, Tom Rondeau wrote:
> On Sun, Mar 6, 2011 at 9:48 AM, Don Ward <address@hidden> wrote:
> 
>> A worrisome (to me) issue with the volk library is the use of
>> posix_memalign() in the qa tests.  The worry is:
>>
>> * posix_memalign() will never work on Windows with Microsoft's runtime
>> library *
>>
>> That means that code that uses posix_memalign won't work on Windows with
>> MinGW or Microsoft native compilers.  (The problem is not that memory
>> alignment is difficult; it is simply that there is no memory-aligned version
>> of malloc() in the Microsoft API that works with free().)
>>
>> At present, posix_memalign is used in GNU Radio in machine-dependent code
>> (gcell, altivec, and arm7) and in the volk qa tests.  If we can replace it
>> in volk and avoid its spread, we can continue to use GNU Radio on Windows.
>>
>> One option is to use something like malloc16Align/free16Align (in
>> malloc16.{h,c}) in gnuradio-core.  Can we structure the code to make this
>> available in volk, and anywhere else it is needed?  We can add a version to
>> do more general alignment if needed.  Would it help to wrap aligned buffers
>> in a C++ class to make it easier to catch errors (such as using free() on a
>> malloc16Align() buffer)?
>>
>> Note that simply enhancing our own missing/posix_memalign function using
>> _mingw_aligned_malloc() or Microsofts's _aligned_malloc() won't work because
>> memory allocated with those cannot be released with free().
>>
>> Trying not to cause too much trouble,
>>
>> -- Don W.
>>
> 
> 
> Thanks for bringing this up. I'll look into it and we'll try to figure out a
> general solution for all platforms involved.
> 
> Tom
> 
> 
> 
> 
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