How to correctly (and effectively) release memory in a gtk widget

Question

I'm trying to understand how to correctly release memory when I am finished with a GTK widget, for example if I need to create and destroy many widgets. However, valgrind seems to indicate a memory leak regardless of what I try. I've looked at other questions, including one that lists a valgrind supression file for GTK, but it didn't change the result. Here's the simplest code snippet to reproduce my issue: ``` #include "gtk/gtk.h" int main() { GtkWidget * widget = gtk_fixed_new(); g_object_ref(widget); g_object_ref_sink(widget); // remove floating reference, and own this object ourselves g_object_unref(widget); gtk_widget_destroy(widget); } ``` My expectation is that (after dealing with floating references), the unref() function should reduce the reference count to zero, and then all memory is released. I threw the gtk_widget_destroy() in there for good measure, but I'm not sure it should actually be necessary (and it doesn't change the magnitude of the leak). The output with the val…

Accepted Answer

```
 - g_object_ref

Increases ref count by one

- g_object_unref

Decreases ref count by one, if ref count == 0, the object is destroyed

- g_object_ref_sink

IF the object has a floating ref, it converts that reference to a normal ref (sinks it)
  ELSE it increases the ref count by one

- All objects start with a floating ref count of 1
```

For some further reading, I would suggest you take a look at the following article: Introduction to Memory Management in GTK+

Now, moving on to your example, lets look at the function calls and what they do:

```
GtkWidget * widget = gtk_fixed_new(); //widget created with ref count of 1 | floating = true
g_object_ref(widget); // floating = true, ref count increased to 2
g_object_ref_sink(widget); // floating = false, ref count remains at 2

g_object_unref(widget); // floating = false, ref count decreases to 1

//No further unrefs, hello leak!
```

I hope that explains your leak, be sure to read the article mentioned above.

How to correctly (and effectively) release memory in a gtk widget

Solution

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