Get Queue Status

Returns information about the current state of a queue, such as the number of elements currently in the queue.

Using this node in parallel code may result in race conditions. To avoid race conditions, use this node only for monitoring and not for controlling code.

1378

Inputs/Outputs

datatype_icon

queue

A reference to a queue.

datatype_icon

return elements

A Boolean value that determines whether to return the elements in the queue.

True This node returns the elements in the queue.
False This node does not return the elements in the queue.

Default value: False

datatype_icon

error in

Error conditions that occur before this node runs.

Unlike most nodes, this node runs normally even if an error occurs before this node runs.

Standard Error Behavior

Default value: no error

datatype_icon

max queue size

The maximum number of elements the queue can contain.

If max queue size is -1, the queue can contain an unlimited number of elements.

datatype_icon

queue name

The name of the queue, if the queue is named.

datatype_icon

queue out

Reference to the queue.

datatype_icon

number pending remove

The number of Dequeue Element or Preview Queue Element nodes currently waiting to remove an element from the queue.

datatype_icon

number pending insert

The number of Enqueue Element or Enqueue Element at Opposite End nodes currently waiting to insert an element in the queue.

If the maximum queue size is -1, this output returns 0.

datatype_icon

error out

Error information.

The node produces this output according to standard error behavior.

Standard Error Behavior

datatype_icon

number elements in queue

Current number of elements in the queue.

datatype_icon

elements

An array of all the elements currently in the queue.

If return elements? is set to False, this output returns an empty array.

The data type of the array elements changes to match the data type of the queue elements.

Programming Patterns

Transferring Data Between Loops Using Queue Nodes

Verifying Valid Queue References

You can use Get Queue Status to verify that a queue reference is valid. If a queue reference is not valid, this node returns error code 1.