This is a companion method to add_queue_runner(). It just starts
threads for all queue runners collected in the graph. It returns
the list of all threads.
Args
sess
Session used to run the queue ops. Defaults to the
default session.
coord
Optional Coordinator for coordinating the started threads.
daemon
Whether the threads should be marked as daemons, meaning
they don't block program exit.
start
Set to False to only create the threads, not start them.
collection
A GraphKey specifying the graph collection to
get the queue runners from. Defaults to GraphKeys.QUEUE_RUNNERS.
Raises
ValueError
if sess is None and there isn't any default session.