[Insight-developers] Mac Semaphores (Was: Failing tests and compile errors after your check in)

[Bill Lorensen]

"It's always something--if it ain't one thing, it's another," ,
Roseanne Roseannadanna

On Fri, Feb 18, 2011 at 12:59 PM, Daniel Blezek <Blezek.Daniel at mayo.edu> wrote:
> POSIX semaphores are not fully supported on the Mac.  I don't know why this
> works in the 64-bit version...
>
> We are using sem_destroy to destroy our semaphores.  On the 32-bit Mac, I
> get this return value (perror()):
>
> 536: sem_destroy: Function not implemented
>
> Why this linked and run, I'll never know...  Looks like I need to add some
> APPLE specific code.  I suspect this will fix the problem on the Sun.
>
> We also have a race-condition in our Semaphore code.  On the Mac, the
> semaphores need unique names.  We generate this using the time() function,
> but it has a one second resolution.  Thus if two semaphores are created
> within 1 second, they will collide.  Not very nice.
>
> I'll try to track this down once again.
> -dan
>
>
> On 2/17/11 11:07 AM, "Bill Lorensen" <bill.lorensen at gmail.com> wrote:
>
>> Dan,
>>
>> I assume you noticed the failing tests and build errors after your
>> check in yesterday?
>>
>> Bill
>
> --
> Daniel Blezek, PhD
> Medical Imaging Informatics Innovation Center
>
> P 127 or (77) 8 8886
> T 507 538 8886
> E blezek.daniel at mayo.edu
>
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> "It is more complicated than you think." -- RFC 1925
>
>