Queue limitations?

[mateom at gmail.com]

I am creating the images by reading from texture memory using
glGetTexImage(). As an experiment, I tried calling glGetTexImage() only
once and letting imagQueue use that same reference over and over, but
the images were all the same.

So, this leads me to believe that the references returned by
glGetTexImage() are to unique buffers, right? ( documentation for
glGetTexImage() doesn't seem to disagree )

Perhaps, as an OpenGL program, something strange is happening with the
references when my producer method goes out of scope. I guess for now I
can be content to just pass immutable types across the thread boundary.