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tf.distribute.get_replica_context

TensorFlow 2.0 version View source on GitHub

Returns the current tf.distribute.ReplicaContext or None.

Aliases:

  • tf.compat.v1.distribute.get_replica_context
  • tf.compat.v2.distribute.get_replica_context
  • tf.contrib.distribute.get_replica_context
tf.distribute.get_replica_context()

Returns None if in a cross-replica context.

Note that execution:

  1. starts in the default (single-replica) replica context (this function will return the default ReplicaContext object);
  2. switches to cross-replica context (in which case this will return None) when entering a with tf.distribute.Strategy.scope(): block;
  3. switches to a (non-default) replica context inside extended.call_for_each_replica(fn, ...);
  4. if fn calls get_replica_context().merge_call(merge_fn, ...), then inside merge_fn you are back in the cross-replica context (and again this function will return None).

Note that you can also go directly from step 1 to 4 to switch to a cross-replica context for the default tf.distribute.Strategy. You may also switch from the cross-replica context of 4 to a replica context by calling extended.call_for_each_replica(), jumping back to step 3.

Most tf.distribute.Strategy methods may only be executed in a cross-replica context, in a replica context you should use the ReplicaContext API instead.

Returns:

The current ReplicaContext object when in a replica context scope, else None.

Within a particular block, exactly one of these two things will be true:

  • get_replica_context() returns non-None, or
  • tf.distribute.is_cross_replica_context() returns True.