Queries related to SHM

[Mihir Mohan <mi...@gmail.com>]

hi 

I am writing a module to enable dynamic configuraiton. The way i do it is :

1. At the time of module boot up :
    -I parse the configuration file and populate my configuration
object Configuration.cpp
    -I initialize the shared memory with the size of the struct given below
    -I have a struct as shown below : 
     typedef struct MyConfiguration{
     int counter;
     Configuration * myConfig; //A c++ object reference
     }MyConfiguration;
    -I put the above struct in the shm
    -
2. At the time of request : 
    - myConfiguration = (Configuration*)apr_shm_baseaddr_get(my_shm);
    - I retrieve the primitive value 'counter' 
      int counter = myConfiguration->counter
    - increment it 
    - i get the right value across the processes 
    - I get the referenced value myConfig 
      myConfiguration->myConfig
    - I update it 
      myConfiguraiton->myConfig->requestCount = 50;
    - This updated value does not get reflected in the next process

I have following questions :

1. Since all the processes store different memory locations for the
same reference in the shared memory, how do i align it within a
process to get the correct value ? I observed that with primitive
types, it automativally gets aligned by getting the base address.
However, with structs/class references, it does not. How do i do it ?

Thanks in advance for your help.

Regards
Mihir Mohan 
-- 
There is nothing more difficult to take in hand, more perilous to
conduct, or more uncertain in its success, than to take the lead in
the introduction of a new order of things.
Machiavelli in 'The Prince'