cflock
271
Attributes
Note:
Limit the scope of code that updates shared data structures, files, and CFXs. Exclusive locks
are required to ensure the integrity of updates, but read-only locks are faster. In a performance-
sensitive application, substitute read-only locks for exclusive locks where possible; for example, when
reading shared data.
Usage
ColdFusion MX is a multithreaded server; it can process multiple page requests at a time. Use the
cflock
tag for these purposes:
•
To ensure that modifications to shared data and objects made in concurrently executing
requests occur sequentially.
•
Around file manipulation constructs, to ensure that file updates do not fail because files are
open for writing by other applications or tags.
•
Around CFX invocations, to ensure that ColdFusion can safely invoke CFXs that are not
implemented in a thread-safe manner. (This applies only to CFXs developed in C++.)
Attribute
Req/Opt Default
Description
timeout
Required
Maximum length of time, in seconds, to wait to obtain a
lock. If lock is obtained, tag execution continues.
Otherwise, behavior depends on
throwOnTimeout
attribute
value. If you set
timout="0"
, the timeout is determined by
the "Timeout Requests after
x
" setting in the ColdFusion
MX Administrator Settings page, if that setting is enabled.
However, if the setting is not enabled, and you set
timeout="0"
, ColdFusion can wait indefinitely to obtain the
lock.
scope
Optional
Lock scope. Mutually exclusive with the
name
attribute.
Lock name. Only one request in the specified scope can
execute the code within this tag (or within any other
cflock
tag with the same lock scope) at a time.
•
Application
•
Server
•
Session
name
Optional
Lock name. Mutually exclusive with the
scope
attribute.
Only one request can execute the code within a
cflock
tag
with a given name at a time. Cannot be an empty string.
Permits synchronizing access to resources from different
parts of an application. Lock names are global to a
ColdFusion server. They are shared among applications
and user sessions, but not clustered servers.
throwOnTimeout Optional
yes
How timeout conditions are handled:
•
yes: exception is generated for the timeout.
•
no: execution continues past this tag.
type
Optional
Exclusive
•
readOnly: lets more than one request read shared data.
•
exclusive: lets one request read or write shared data.
Содержание COLFUSION MX 7 - INSTALLING AND USING COLDFUSION MX
Страница 1: ...COLDFUSION MX7 CFML Reference...
Страница 20: ...20 Chapter 1 Reserved Words and Variables...
Страница 50: ...50 Chapter 2 ColdFusion Tags cfelse br Searching cfif cfloop cfif...
Страница 101: ...cfdefaultcase 101 cfdefaultcase cfswitch cfoutput Your grade is grade cfoutput...
Страница 115: ...cfdocumentsection 115 cfdocumentsection cfoutput cfdocument...
Страница 311: ...cfNTauthenticate 311 Please Try again H2 cfif cfoutput cfinclude template loginform cfm cfabort cfif cfif cflogin...
Страница 411: ...cftable 411 cftable body html...
Страница 515: ...Chr 515 maxlength 5 p input type Submit name input type RESET cfform...
Страница 605: ...GetEncoding 605 WriteOutput The encoding is theEncoding cfscript cfif...
Страница 629: ...GetProfileString 629 tr td input type Submit name Submit value Submit td td td tr table form...
Страница 655: ...IIf 655 cfoutput IIf Hour Now GTE 12 DE It is afternoon or evening DE It is morning cfoutput b...
Страница 664: ...664 Chapter 3 ColdFusion Functions cfelse h3 Conversion error h3 cfif...
Страница 687: ...IsStruct 687 cfoutput cfquery cfif cfoutput hr Employee Add Complete cfoutput cfcase cfswitch...
Страница 693: ...IsWDDX 693 struct data wddxPacket hr xmp cfoutput packet xmp IsWDDX returns IsWDDX packet br cfoutput...
Страница 751: ...LSDateFormat 751 hr noshade cfoutput cfloop...
Страница 861: ...StructFind 861 cfquery cfif cfoutput hr Employee Add Complete cfoutput cfcase cfswitch...
Страница 869: ...StructIsEmpty 869 cfoutput cfquery cfif cfoutput hr Employee Add Complete cfoutput cfcase cfswitch...
Страница 903: ...Val 903 value Is the beginning numeric name form...
Страница 932: ...932 Chapter 3 ColdFusion Functions...
Страница 944: ...944 Chapter 4 ColdFusion MX Flash Form Style Reference...
Страница 962: ...962 Chapter 5 Application CFC Reference...
Страница 1008: ...1008 Chapter 6 ColdFusion MX Event Gateway Reference cfset retValue Reason reason cfreturn retValue cffunction...
Страница 1054: ...1054 Chapter 6 ColdFusion MX Event Gateway Reference...