Re: [Boost-users] [interprocess] shared_memory_object constructor with create_only parameter

Subject: Re: [Boost-users] [interprocess] shared_memory_object constructor with create_only parameter
From: Philipp Hamann (philipp.hamann_at_[hidden])
Date: 2010-01-26 03:55:12

Hi all,

I am sorry. I made a mistake. My first problem is solved. It is not a bug.

>  I have some problems using the shared_memory_object constructor with the
>  create_only parameter.
>  The goal is to allow only one process to write to the shared memory. So
>  I create a shared_memory_object with the create_only parameter. For the
>  first process this is successful (as I assumed), but for the second
>  process (same parameters) this is successful, too (not as I assumed).
>  The documentation of boost says that it should throw an exception, if
>  the shared memory is allready created. Is this a bug or a misuse or
>  understanding of the library?

But the second problem concerning shared_memory_object::remove(const
char* name) is still present.

>  I realized another problem. If I call the static function
>  shared_memory_object::remove(const char* name), the memory should be
>  removed only when no further process has access to the memory. This
>  seems also not to work. I did the following:
>  1. create shared memory for writing.
>  2. open shared memory for reading
>  3. shared_memory_object::remove(const char* name) (from the reading
>  process)
>  4. reopen the shared memory for reading ->  exception: can not find the file

Thanks for your help and apoligizes for bothering you with my first problem.

   Philipp