Scenario: A Receipt Number Generator That Uses the Shared Property Manager

[This product will work only on Windows NT 4.0 versions and earlier. For Windows 2000 and later, see COM+ (Component Services).]

This chapter introduces the Receipt component, which dispenses unique receipt numbers for fund transfers. When a bank transaction takes place, the MoveMoney object creates a Receipt object. The Receipt component contains a single method, GetNextReceipt.

GetNextReceipt uses the Shared Property Manager to get a unique receipt number. The Shared Property Manager has an object hierarchy as shown in the following figure:

Within a server process, there is only one instance of the SharedPropertyGroupManager object. The value of the receipt number is maintained by a SharedProperty object, which provides locking mechanisms to ensure that no two calls to GetNextReceipt retrieve the same value.

See Also

Resource Dispensers, Creating the Receipt Component, Application Design Notes: Sharing State by Using the Shared Property Manager, SharedPropertyGroupManager object, SharedPropertyGroup object, SharedProperty object