[castord]

Hello,

I need some help with c++ objects instantiated into a shared memory segment.

I wrote a class that acts as an interface to the common (shared mem.) operations.

Everything works fine until I needed to copy a dynamically created array of structs that also contains subarrays of the same type and two integer members.

I created a clone function that receives origin and destination and uses memcpy to "clone" the whole structure.

Bellow I put some working code that behaves exactly like the original.

struct test2
{
	int a;
};

struct test
{
	int a;
	int b;
	test2 *c;
};


void Clone(test* from, void *destination)
{
memcpy (destination, from, sizeof(NodeInformation));
				test *to	= (test *) destination;

				to->c						= (test2 *) calloc(10 , sizeof(test2));

				memcpy (to->c, from->c , 10 * sizeof(test));
}

The destination parameter is a pointer to a shared memory segment. The function should copy the origin content to the destination using struct test architecture.

The first line (of Clone()) works ok. I am able to see its content a the memory position.

Memory:

destination = 0xb7fde000
to = 0x08049460
to = 0xb7fde000
to.a = 123
to.b = 234

to.c = 0x08053170 // t.c = array of test2

As you can see to.c points to a local memory segment, not to a part of the shared memory as it should be.

What I want to achieve is to get to.c point to the righ direction but I don't know how. I used calloc() to initialize to.c. Without this I get a segfault.

Main code

SharedMemory *sm1 	= new SharedMemory(SHAMEM_ID, 1600, true);
		void *pool			= sm1->Get();
		test *tp			= (test *)pool;
		test *t				= new test;
		t->a =  123;
		t->b = 234;
		t->c = (test2 *) malloc(sizeof(test2) * 10);
		t->c[0].a =  777;
		t->c[7].a =  888;
		Clone(t, pool);

Both test.a and test.b field are copied correctly but the array always point to invalid places.

What am i doing wrong?

Thanks in advance.