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Holds a list of enqueue operations for a queue, each to be run in a thread.
tf.compat.v1.train.QueueRunner(
queue=None, enqueue_ops=None, close_op=None, cancel_op=None,
queue_closed_exception_types=None, queue_runner_def=None, import_scope=None
)
Queues are a convenient TensorFlow mechanism to compute tensors asynchronously using multiple threads. For example in the canonical 'Input Reader' setup one set of threads generates filenames in a queue; a second set of threads read records from the files, processes them, and enqueues tensors on a second queue; a third set of threads dequeues these input records to construct batches and runs them through training operations.
There are several delicate issues when running multiple threads that way: closing the queues in sequence as the input is exhausted, correctly catching and reporting exceptions, etc.
The QueueRunner, combined with the Coordinator, helps handle these issues.
Args | |
|---|---|
queue
|
A Queue.
|
enqueue_ops
|
List of enqueue ops to run in threads later. |
close_op
|
Op to close the queue. Pending enqueue ops are preserved. |
cancel_op
|
Op to close the queue and cancel pending enqueue ops. |
queue_closed_exception_types
|
Optional tuple of Exception types that
indicate that the queue has been closed when raised during an enqueue
operation. Defaults to (tf.errors.OutOfRangeError,). Another common
case includes (tf.errors.OutOfRangeError, tf.errors.CancelledError),
when some of the enqueue ops may dequeue from other Queues.
|
queue_runner_def
|
Optional QueueRunnerDef protocol buffer. If specified,
recreates the QueueRunner from its contents. queue_runner_def and the
other arguments are mutually exclusive.
|
import_scope
|
Optional string. Name scope to add. Only used when
initializing from protocol buffer.
|
Raises | |
|---|---|
ValueError
|
If both queue_runner_def and queue are both specified.
|
ValueError
|
If queue or enqueue_ops are not provided when not
restoring from queue_runner_def.
|
RuntimeError
|
If eager execution is enabled. |
Eager Compatibility
QueueRunners are not compatible with eager execution. Instead, please
use tf.data to get data into your model.
Attributes | |
|---|---|
cancel_op
|
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close_op
|
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enqueue_ops
|
|
exceptions_raised
|
Exceptions raised but not handled by the QueueRunner threads.
Exceptions raised in queue runner threads are handled in one of two ways
depending on whether or not a
|
name
|
The string name of the underlying Queue. |
queue
|
|
queue_closed_exception_types
|
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Methods
create_threads
create_threads(
sess, coord=None, daemon=False, start=False
)
Create threads to run the enqueue ops for the given session.
This method requires a session in which the graph was launched. It creates
a list of threads, optionally starting them. There is one thread for each
op passed in enqueue_ops.
The coord argument is an optional coordinator that the threads will use
to terminate together and report exceptions. If a coordinator is given,
this method starts an additional thread to close the queue when the
coordinator requests a stop.
If previously created threads for the given session are still running, no new threads will be created.
| Args | |
|---|---|
sess
|
A Session.
|
coord
|
Optional Coordinator object for reporting errors and checking
stop conditions.
|
daemon
|
Boolean. If True make the threads daemon threads.
|
start
|
Boolean. If True starts the threads. If False the
caller must call the start() method of the returned threads.
|
| Returns | |
|---|---|
| A list of threads. |
from_proto
@staticmethodfrom_proto( queue_runner_def, import_scope=None )
Returns a QueueRunner object created from queue_runner_def.
to_proto
to_proto(
export_scope=None
)
Converts this QueueRunner to a QueueRunnerDef protocol buffer.
| Args | |
|---|---|
export_scope
|
Optional string. Name scope to remove.
|
| Returns | |
|---|---|
A QueueRunnerDef protocol buffer, or None if the Variable is not in
the specified name scope.
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