Owning Palette: Queue Operations Functions
Requires: Base Development System
Returns the element at the front of the queue without removing the element from the queue.
|queue is a reference to a queue. Use the Obtain Queue function to obtain a queue reference.|
|timeout in ms specifies the time, in milliseconds, that the function waits for an element to become available in the queue if the queue is empty. The default is –1, indicating never to time out.
If the function waits timeout in ms and the queue remains empty, timed out? is TRUE.
|error in describes error conditions that occur before this node runs. With the following exception, this input provides standard error in functionality.
This node runs normally even if an error occurred before this node runs.
|queue out returns the reference to the queue unchanged.|
|element is the element at the front of the queue. This data type changes to match the subtype of queue.|
|timed out? is TRUE if an element did not become available in the queue before the function timed out or if an error occurred.|
|error out contains error information. This output provides standard error out functionality.|
Use the Dequeue Element function to return the element at the front of the queue and remove it from the queue. If the queue is empty, the function waits timeout in ms before timing out. If an element becomes available in the queue during the wait, the function returns the element and timed out? is FALSE. If queue becomes invalid (for example, the queue reference is released), the function stops waiting and returns error code 1122.