This element represent a resource in the system that is composed by a number of seizable units.
This element has been implemented as a Parallel DEVS atomic model, due to its capacity to receive seize and release petitions and send confirmations.
Each message received through port S is considered as a seize petition. The type of the message indicates the number of resource units to seize, and the value is a reference to the origin of the petition.
Seize petitions are stored in a FIFO queue, and served while idle resource units are available.
When a petition is served, a confirmation message is sent through the port S.
The value of that confirmation is the reference to the origin of the petition, so the Seize block that receives it can identify it.
Each message received through port R is considered as a release petition. The type of the message indicates the number of resource units to release.
After releasing the resource units, the seize queue is examined to check if any of the waiting petitions can be satisfied with the newly released units.
| Name | Description |
|---|---|
| resource | |
| con | Confluent Transtition Function |
| int | Internal Transition Function |
| ext | External Transition Function |
| out | Output Function |
| ta | Time Advance Function |
| st | |
| initst |