Sending Data over Shared Memories (MFC)

[volker_nitschke]

Hi,

I want to develop a program, that transmits several classes between two
processes. It should be built after the guidelines of the
iso/osi-reference model and work with a shared memory. At the moment I
copy all the data into a buffer, add the specific overhead and send
them to the memory. But if the data contains any strings, it adds only
the pointer and not the string itsself. How can I realize, that the
program copies the string and not the pointer into "pBuffer"? I have
already looked at serialization and streams, but it still didn't work.

Anyone knows, how to handle this problem?


The structure for the data transport looks like this:

struct SDataModule // layer 7 module
{
long commandCount; // number of elements in the buffer
char pBuffer[MAX_COUNT_BYTES]; // storage buffer
};

struct STransportModule // layer 4 module
{
long seqNumber; // a sequence number to mark each block
SDataModule data; // the data to transport
};

struct SNetworkModule // layer 3 module
{
char source[16]; // the ip from the user computer
STransportModule transport; // the data to transport
};

struct SMemoryModule // layer 1 module
{
BOOL full; // indication that the shared memory is full
SNetworkModule network; // the data to transport
};


TIA
Volker Nitschke

 

[Robbie Hatley]

(MFC question)

That's strictly Microsoft stuff. Has nothing to do with C++.

Ask HERE instead:

comp.os.ms-windows.programmer.win32 (I set followup here.)

--
Cheers,
Robbie Hatley
East Tustin, CA, USA
lone wolf intj at pac bell dot net
(put "[usenet]" in subject to bypass spam filter)
http://home.pacbell.net/earnur/

 

[Jim Langston]

Hi,

I want to develop a program, that transmits several classes between two
processes. It should be built after the guidelines of the
iso/osi-reference model and work with a shared memory. At the moment I
copy all the data into a buffer, add the specific overhead and send
them to the memory. But if the data contains any strings, it adds only
the pointer and not the string itsself. How can I realize, that the
program copies the string and not the pointer into "pBuffer"? I have
already looked at serialization and streams, but it still didn't work.

Anyone knows, how to handle this problem?


The structure for the data transport looks like this:

struct SDataModule // layer 7 module
{
long commandCount; // number of elements in the buffer
char pBuffer[MAX_COUNT_BYTES]; // storage buffer
};

struct STransportModule // layer 4 module
{
long seqNumber; // a sequence number to mark each block
SDataModule data; // the data to transport
};

struct SNetworkModule // layer 3 module
{
char source[16]; // the ip from the user computer
STransportModule transport; // the data to transport
};

struct SMemoryModule // layer 1 module
{
BOOL full; // indication that the shared memory is full
SNetworkModule network; // the data to transport
};

Those structures are interesting, but not much help without telling us what
you are trying to do with them. Nor are you showing us the structures.

Quote: "But if the data contains any strings, it adds only the pointer and
not the string itsself."

What is this "it" you are refering to? A function? A method? An
assignment?

Your answer may be as simple as how to use strncpy or memcpy or an iterator.
Or not. Show us what you are trying to do that is not working.