tensorflow : .eval() never ends

Question

i am loading the cifar-10 data set , the methods adds the data to tensor array , so to access the data i used .eval() with session , on a normal tf constant it return the va

Answer 1

You must call tf.train.start_queue_runners(sess) before you call train_data.eval() or train_labels.eval().

This is a(n unfortunate) consequence of how TensorFlow input pipelines are implemented: the tf.train.string_input_producer(), tf.train.shuffle_batch(), and tf.train.batch() functions internally create queues that buffer records between different stages in the input pipeline. The tf.train.start_queue_runners() call tells TensorFlow to start fetching records into these buffers; without calling it the buffers remain empty and eval() hangs indefinitely.