Model Parts, Diagrams, Dictionary Items, and Properties > Dictionary items > Monitor (dictionary item)
Monitor (dictionary item)
For automation interface information about a Monitor, see Monitor (automation interface).
The Monitor provides a higher level of data management than the Semaphore. It controls all shared resources through a set of variables, data structures and procedures. Tasks are allowed to enter the Monitor one at a time. By administering each task separately, the Monitor allows processes to perform multiple, uninterrupted functions on the data.
You can create a Monitor through the context menu of a Package: right-click the Package, point to New, point to Proprietary, point to Concurrency, and then click Monitor. In addition, you can create a Monitor through a Concurrency Diagram.
When used on a diagram, a Monitor's notation is as follows:
In the Modeler panes, a short-cut symbol on the Monitor's icon indicates that the item is a stub.
The following sections provide information about how a Monitor is used in the model. For more information about a property, item, model part or diagram, click it.
In addition to the standard properties, a Monitor has these properties:
Number of Instances
The Class box on the Options tab of a Monitor's Property Pages shows the Class, Data Type or Interface that owns the Operations that implement the Monitor.
Owned by
Dependency —The Dependency is owned jointly by the Monitor and the other associated item. The access permissions you have to a Dependency are determined by the access permissions of the dependent item.
Defined in these parts of the model
Concurrency Model
Shown on these diagrams
Concurrency Diagram
Variant Diagram
Can be linked to these dictionary items
In addition to the owning Package or Model, a Monitor can be linked to the following items.
Class —The linked Class contains the Operations required to implement the Monitor (drag Class to Monitor symbol on diagram).
Data Type —The linked Data Type contains the Operations required to implement the Monitor (drag Data Type to Monitor symbol on diagram).
Interface —The linked Interface contains the Operations required to implement the Monitor (drag Interface to Monitor symbol on diagram).