340
Chapter 15: Using Persistent Data and Locking
<!--- Do initializations --->
<cfset APPLICATION.varible1 = someValue >
...
<!--- Set the Application scope initialization flag --->
<cfset APPLICATION.initialized = "yes">
</cfif>
</cflock>
</cfif>
Examples of cflock
The following examples show how to use
cflock
blocks in a variety of situations.
Example with application, server, and session variables
This example shows how you can use
cflock
to guarantee the consistency of data updates to
variables in the Application, Server, and Session scopes.
This example does not handle exceptions that arise if a lock times out. As a result, users see the
default exception error page on lock time-outs.
The following sample code might be part of the Application.cfm file:
<cfapplication name="ETurtle"
sessiontimeout=#createtimespan(0,1,30,0)#
sessionmanagement="yes">
<!--- Initialize the Session and Application
variables that will be used by E-Turtleneck. Use
the Session lock scope for the session variables. --->
<cflock scope="Session"
timeout="10" type ="Exclusive">
<cfif not IsDefined("session.size")>
<cfset session.size = "">
</cfif>
<cfif not IsDefined("session.color")>
<cfset session.color = "">
</cfif>
</cflock>
<!--- Use the Application scope lock for the Application.number variable.
This variable keeps track of the total number of turtlenecks sold.
The following code implements the scheme shown in the Locking Application
variables effectively section --->
<cfset app_is_initialized = "no">
<cflock scope="Application" type="readonly">
<cfset app_is_initialized = IsDefined("Application.initialized")>
</cflock>
<cfif not app_is_initialized >
<cflock scope="application" timeout="10" type="exclusive">
<cfif not IsDefined("Application.initialized") >
<cfset Application.number = 1>
<cfset Application.initialized = "yes">
</cfif>
</cflock>
</cfif>
Содержание ColdFusion MX
Страница 1: ...Developing ColdFusion MX Applications...
Страница 22: ...22 Contents...
Страница 38: ......
Страница 52: ...52 Chapter 2 Elements of CFML...
Страница 162: ......
Страница 218: ...218 Chapter 10 Writing and Calling User Defined Functions...
Страница 250: ...250 Chapter 11 Building and Using ColdFusion Components...
Страница 264: ...264 Chapter 12 Building Custom CFXAPI Tags...
Страница 266: ......
Страница 314: ...314 Chapter 14 Handling Errors...
Страница 344: ...344 Chapter 15 Using Persistent Data and Locking...
Страница 349: ...About user security 349...
Страница 357: ...Security scenarios 357...
Страница 370: ...370 Chapter 16 Securing Applications...
Страница 388: ...388 Chapter 17 Developing Globalized Applications...
Страница 408: ...408 Chapter 18 Debugging and Troubleshooting Applications...
Страница 410: ......
Страница 426: ...426 Chapter 19 Introduction to Databases and SQL...
Страница 476: ...476 Chapter 22 Using Query of Queries...
Страница 534: ...534 Chapter 24 Building a Search Interface...
Страница 556: ...556 Chapter 25 Using Verity Search Expressions...
Страница 558: ......
Страница 582: ...582 Chapter 26 Retrieving and Formatting Data...
Страница 668: ......
Страница 734: ...734 Chapter 32 Using Web Services...
Страница 760: ...760 Chapter 33 Integrating J2EE and Java Elements in CFML Applications...
Страница 786: ...786 Chapter 34 Integrating COM and CORBA Objects in CFML Applications...
Страница 788: ......
Страница 806: ...806 Chapter 35 Sending and Receiving E Mail...