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Returns the current tf.distribute.ReplicaContext
or None
.
tf.distribute.get_replica_context()
Returns None
if in a cross-replica context.
Note that execution:
- starts in the default (single-replica) replica context (this function
will return the default
ReplicaContext
object); - switches to cross-replica context (in which case this will return
None
) when entering awith tf.distribute.Strategy.scope():
block; - switches to a (non-default) replica context inside
strategy.run(fn, ...)
; - if
fn
callsget_replica_context().merge_call(merge_fn, ...)
, then insidemerge_fn
you are back in the cross-replica context (and again this function will returnNone
).
Most tf.distribute.Strategy
methods may only be executed in
a cross-replica context, in a replica context you should use the
API of the tf.distribute.ReplicaContext
object returned by this
method instead.
assert tf.distribute.get_replica_context() is not None # default
with strategy.scope():
assert tf.distribute.get_replica_context() is None
def f():
replica_context = tf.distribute.get_replica_context() # for strategy
assert replica_context is not None
tf.print("Replica id: ", replica_context.replica_id_in_sync_group,
" of ", replica_context.num_replicas_in_sync)
strategy.run(f)
Returns | |
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The current tf.distribute.ReplicaContext object when in a replica context
scope, else None .
Within a particular block, exactly one of these two things will be true:
|