Re: [boost] [interprocess] [container] Can iterator hold raw-pointer instead of offset_ptr?

Subject: Re: [boost] [interprocess] [container] Can iterator hold raw-pointer instead of offset_ptr?
From: Ion Gaztañaga (igaztanaga_at_[hidden])
Date: 2013-04-29 12:26:06

El 29/04/2013 9:54, Mathias Gaunard escribió:
> On 28/04/13 09:06, TONGARI wrote:
>> Hi there,
>>
>> When putting containers in shared memory, offset_ptr is used internally,
>> and IIUC, the iterator of the container will also use offset_ptr. But it
>> seems to me that in most cases we only use iterator locally rather than
>> putting those iterators in shared memory as well, so the
>> plain-old-raw-pointer is sufficient and hopefully more efficient for
>> iterator's usage.
>>
>> What do you think?
>
> I have seen some people force a shared memory segment to be mapped at
> the same address in all processes so that they could avoid using
> offset_ptr and get better performance.
>
> If you're looking for performance, that might be an option as well. I
> don't know how much boost.interprocess makes it easy to do this.

You can do it. Using fixed_managed_shared_memory all pointers are raw 
pointers. You can map it in a fixed address.

Ion