The Queue block stores entities that wait for an idle resource.
Every time a new entity is received, the external transition function inserts it in the queue (following the policy configured in the Queue element) and forces an immediate internal transition. That internal transition will send the seize petition to the Seize block. The value of the message that represents the seize petition includes the reference to the queue where the entities are stored. In this way, when the Seize block receives the confirmation of the seize operation it can directly extract the entity from the queue. In the case of immediately available resources, the entity inserted in the queue will be extracted during the same simulation time.
If the capacity of the queue is reached, the newly arrived entities are sent through the BALK port. If that port is not connected to another block, the entities are disposed from the system.
The variable NQ contains the number of elements in the queue over the simulation.
| Name | Description |
|---|---|
| queue | |
| con | Confluent Transtition Function |
| int | Internal Transition Function |
| ext | External Transition Function |
| out | Output Function |
| ta | Time Advance Function |
| st | |
| initst |