A queue name.
A node ID on which to open the queue.
The maximum number of messages if creating the queue.
The open mode for the queue.
This function opens a queue for reading or writing, as well as possibly creating it. The max_msgs is ignored unless the queue is being created. The possible values for mode are the same as the open modes for the open system call. Typically a queue should be opened for reading or writing, but not both.