User Guide

Examples of cflock 241

Example of synchronizing access to a file system

The following example shows how to use cflock to synchronize access to a file

system. The

cflock tag protects a cffile tag from attempting to append data to a

file already open for writing by the same tag executing on another request.

Note that if an append operation takes more that 30 seconds, a request waiting to

obtain an exclusive lock to this code might time out. Also, note the use of a dynamic

value for the

name attribute so that a different locks controls access to each file. As a

result, locking access to one file does not delay access to any other file.

<cffile action="Append"

file=#fileName#

output=#textToAppend#>

</cflock>

Example of protecting ColdFusion Extensions

The following example illustrates how you can build a custom tag wrapper around a

CFX tag that is not thread-safe. The wrapper forwards attributes to the

non-thread-safe CFX tag that is used inside a cflock tag.

<cflock timeout=5

type="Exclusive"

name="cfx_not_thread_safe">

<cfx_not_thread_safe attributeone=#attributes.attributeone#

attributetwo=#attributes.attributetwo#

attributethree=#attributes.attributethree#>

</cflock>