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To: modules-dev@httpd.apache.org
Subject: Re: Binary Tree Shared Memory Problem
References: 
 <CA+JKf00k8ph-FT3sRp8fUyZ-_sx9dzMsHzhPALiaMZWncW6QqQ@mail.gmail.com>
Date: Mon, 28 Nov 2011 22:52:23 +0100
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From: "Ignaz Birnstingl" <ignazb@gmail.com>
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 <CA+JKf00k8ph-FT3sRp8fUyZ-_sx9dzMsHzhPALiaMZWncW6QqQ@mail.gmail.com>
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Hi,

apr_shm_baseaddr_get returns the base address for the shared memory  
segment. You will have to implement your own "allocator" within the shared  
memory. Also keep in mind that you can't reliably use pointers inside the  
shared memory segment, because - as the documentation states - the address  
returned by apr_shm_baseaddr_get "is only usable within the callers  
address space, since this API does not guarantee that other attaching  
processes will maintain the same address mapping."
Inter- and intra-process synchronization will be problems you will  
encounter later on.
Btw Apache 2.3 offers mod_slotmem which helps in using shared memory -  
maybe you should have a look at it?

-- Ignaz