DBUS Server Crashing

Question

I am implementing a DBUS object with Glib bindings and am having problems with returning GArrays:

gboolean TestObject_get_data(TestObject* obj, GArray* buffer, GError** error)
{
    int i;

    printf("%s Entering\n", __PRETTY_FUNCTION__);

    buffer = g_array_new(FALSE, FALSE, sizeof(char));

    if(buffer)
    {
        for(i = 0; i < 5 ; i++)
        {
            g_array_append_val(buffer, i);
        }
        return TRUE;
    }

    /* TODO: Error handling */

    return FALSE;
}

When I call the object's method with a test client, I get a segmentation fault:

waffleman@thegriddle$ ./testObject 
TestObject_get_data Entering

** ERROR **: out of memory
aborting...
Aborted (core dumped)

The program crashes after the function returns. This is the first time I've ever used Glib, so there may be something obvious that I am missing. I have been reading this tutorial, and most of the examples works. Unfortunately it does not have an example for returning an array to the client.

Looks like @Mike is correct. You create a new area of memory and get an address. You need to somehow pass that address back to the callee. The answer is a pointer to a pointer. — Earlz, Nov 07 '11 at 22:59

score 1 · Accepted Answer · answered Nov 07 '11 at 21:56

If you want to allocate the array inside your function you need to pass in a reference. Your current function leaks memory since you are assigning a local variable when you create the array.

gboolean TestObject_get_data(TestObject *obj, GArray **buffer, GError **error)
{
    if (buffer) {
        *buffer = g_array_new(FALSE, FALSE, sizeof(char));
        if (*buffer) {
            int i;
            for (i = 0; i < 5 ; ++i) {
                g_array_append_val(*buffer, i);
            }
            return TRUE;
        }
    }
    return FALSE;
}

Good catch. Some how I missed that. – waffleman Nov 08 '11 at 13:34 — waffleman, Nov 08 '11 at 13:34

DBUS Server Crashing

1 Answers1