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Re: To standardize Boost.Pool

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On 4/13/2011 9:41 AM, Phil Bouchard wrote:
> On 4/13/2011 8:28 AM, Öö Tiib wrote:
>>
>> Please elaborate what is process::stack? On most platforms a process
>> may have several threads, number of these threads often changes
>> dynamically during processes lifetime and each of these threads does
>> have its own stack.
>
> process::stack represents the memory pages reserved for the stack of the
> current thread quite simply. The details of the implementation would
> have to be hidden from the programmer so that all that he is exposed to
> are member functions such as malloc(size_t), free(void *), if_from(void
> *), etc. Note that the malloc(size_t) call would be available only for
> the heap memory pool and so on.

There was a discussion on the validity of a 'false' statement returned 
by is_from() because out-of-bounds pointer comparison would invoke 
undefined behavior according to 5.7.6.  This was bringing the idea of 
having adjacent pools stack & data to the heap pool.

But it looks like heap.is_from() could work without adjacent stack and 
data pools in all cases, even if the pointers are arbitrary.  This is 
because they can be casted to an integral type before they are compared 
together as stated by 5.2.10/4.  The following example is thus valid for 
arbitrary pointers:

bool is_from(const char* p)
{
     return reinterpret_cast<long>(buffer)<= reinterpret_cast<long>(p)&& 
  reinterpret_cast<long>(p)<  reinterpret_cast<long>(buffer + 
sizeof(buffer));
}


Thanks,
-Phil

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To standardize Boost.Pool  Phil Bouchard <phil@fornux.com> - 2011-04-12 07:44 -0600
  Re: To standardize Boost.Pool Jorgen Grahn <grahn+nntp@snipabacken.se> - 2011-04-12 21:56 +0000
    Re: To standardize Boost.Pool Phil Bouchard <phil@fornux.com> - 2011-04-12 17:31 -0700
      Re: To standardize Boost.Pool Phil Bouchard <phil@fornux.com> - 2011-04-13 00:08 -0700
        Re: To standardize Boost.Pool Öö Tiib <ootiib@hot.ee> - 2011-04-13 08:28 -0700
          Re: To standardize Boost.Pool Phil Bouchard <phil@fornux.com> - 2011-04-13 09:41 -0700
            Re: To standardize Boost.Pool Phil Bouchard <phil@fornux.com> - 2011-04-13 14:49 -0700
              Re: To standardize Boost.Pool Phil Bouchard <phil@fornux.com> - 2011-04-13 15:57 -0700
                Re: To standardize Boost.Pool Paavo Helde <myfirstname@osa.pri.ee> - 2011-04-13 23:39 -0500
                Re: To standardize Boost.Pool Phil Bouchard <phil@fornux.com> - 2011-04-13 22:43 -0700
                Re: To standardize Boost.Pool Phil Bouchard <phil@fornux.com> - 2011-04-13 22:53 -0700
                Re: To standardize Boost.Pool Miles Bader <miles@gnu.org> - 2011-04-14 15:55 +0900
                Re: To standardize Boost.Pool Phil Bouchard <phil@fornux.com> - 2011-04-14 00:15 -0700

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