Hi, I am a little confused about how to make 'interprocess_mutex' part of the 'managed_shared_memory' object which actually represents the shared_memory? Is there a base class or something that can take the mutex? I placed an '*interprocess_mutex*' as a member variable *in the class that contains my 'managed_shared_memory'* object as a member variable and was locking it in the methods that accessed the shared memory. I guess this did not work out as I believe what I did effectively locked the object of my class that was holding the embers. And since this is not actually the shaed resource between the processes it didn't work out.. I'd really appreciate if you could provide an example of just show me bbased on my initial code.. how the 'managed_shared_memory' can be locked using the mutex. Sreenu On 1/9/08, Srinivas Gardas wrote:

Hi Ion, Probably that's the reason.. I haven't used any mutexes thought it's all implemented in the 'interprocess'. I am kind of new to this stuff.. Could please give me a code example where 'interprocess_mutex' is used by a 'Server' and 'Client' to lock the managed_shared_memory ?

I really appreciate your help.

Thanks & Regards Sreenu

On 1/8/08, Ion Gaztañaga wrote:

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Hi, I am facing an issue with the 'Shared Memory File'.. Sometimes I get

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'SharedMemory File Name' as the first element of the structure that I used, to create a 'interprocess::list' and when this happens, it means that

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SharedMemory got corrupted and my program crashes. Has anyone faced

Srinivas Gardas escribió: the the this

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issue, or does anyone know what might be wrong?

I don't see any problem with your approach, can you give me more information? Also, take in care that you need to use mutexes to protect concurrent accesses to the list (an interprocess_mutex constructed in the segment should work).

Regards,

Ion _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

Thanks so much Ion! It worked fine.. now I just have to wait and see that my problem doesn't arise again.. Sreenu On 1/10/08, Ion Gaztañaga wrote:

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Hi, I am a little confused about how to make 'interprocess_mutex' part of

...

'managed_shared_memory' object which actually represents the shared_memory? Is there a base class or something that can take the mutex?

I placed an '*interprocess_mutex*' as a member variable *in the class

...

contains my 'managed_shared_memory'* object as a member variable and was locking it in the methods that accessed the shared memory. I guess this did not work out as I believe what I did effectively locked the object of my class that was holding the embers. And since this is not actually the shaed resource between the processes it didn't work out..

I'd really appreciate if you could provide an example of just show me bbased on my initial code.. how the 'managed_shared_memory' can be locked using

Srinivas Gardas escribió: the that the

...

mutex.

Sreenu

Just create the mutex like you create the list and use scoped_lock to lock and unlock it more easily (pseudo_code, not compiled):

using namespace boost::interprocess;

interprocess_mutex *mut = m_shMemPtr->find_or_construct ("PROCESS-SHARED MUTEX")();

struct_a stOne; strcpy(stOne.sym, "ABCDE"); strcpy(stOne.desc, "FGHIJK"); stOne.price = 10.25;

{ //Begin of locked scope

//Now lock the mutex to protect concurrent access //to the list scoped_lock locker(*mut);

//Do the operation m_pList->push_back(stOne);

//Mutex will be unlocked by locker's destructor } //End of locked scope

The other process should also lock the same mutex when operating with the list so that one process is blocked while the other one is manipulating the list. There are several alternatives to build the mutex in the segment but I think this is the simplest one.

Regards,

Ion _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users