glib:source-name (source)

source -- a g:source instance
name -- a string with the debug name for the source

The g:source-name function gets a name for the source, used in debugging and profiling. The (setf g:source-name) function sets a name for the source. The name may be nil. The source name should describe in a human readable way what the source does. For example, "X11 event queue" or "GTK repaint idle handler" or whatever it is.

It is permitted to call this function multiple times, but is not recommended due to the potential performance impact. For example, one could change the name in the g:source-func callback function to include details like the event type in the source name.