I'm creating a bin to decode a Transport Stream. 
The bin/elements are:
o  created
o  inserted into the pipeline using an input-selector
o  played
o  disconnected
o  set to NULL state
o  destroyed

This works fine.  However, there are a number of memory leaks that I'm tracking down.  Each time we lose around 4KB in around 150 chunks.

One of the leaks is a string "<queue name>:src".  This turns out to be the name of a thread.

I think the problem is related to gst_task_join.  It does:

  if (pool) {
    if (id)
      gst_task_pool_join (pool, id);
    gst_object_unref (pool);
  }

The id is zero and the pool_join is skipped.
The reason that the id is zero is that gst_task_pool_push (default_push) returns zero normally.  The documentation says this is OK.

Removing the if (id) seems to fix the problem.  However, I'm not familiar enough with the code to be sure that this is the right thing to do.