Prevents other threads from simultaneously accessing a group of databases.
numero = 200[exclusivelock db=orders.db&db=lineitems.db&db=accesslog.db]...search, delete, or modify any of orders.db, lineitems.db, or accesslog.db while being assured that no other threads can modify any of these databases until the closing /exclusivelock tag is reached.[/exclusivelock]The list of database names is first alphabetized so as to maintain a consistent locking order (a technique which prevents internal deadlocks), then each database lock is acquired one at a time until all locks are acquired, then the interior WebDNA is executed. If any lock cannot be acquired, the other databases are unlocked, and the interior WebDNA is not executed. [exclusivelock database list]...WebDNA...[/exclusivelock]
[exclusivelock db=orders.db&db=lineitems.db&db=accesslog.db]
...search, delete, or modify any of orders.db, lineitems.db, or accesslog.db while being assured that no other threads can modify any of these databases until the closing /exclusivelock tag is reached.
[/exclusivelock]
DOWNLOAD WEBDNA NOW!
WebDNA applications...
AWS Raw WebDNA LAMP-Plus WebServerAmazon Web Services (AWS) README for Machine Image ID...
WebDNA LibrariesA list of available libraries for WebDNA...
WebDNA reference...
Technical Change HistoryThis Technical Change History provides a reverse chronological list of WebDNA changes...
Tips and TricksA list of user-submitted tips ...
This context displays HTML or executes WebDNA conditionally only if the expression is true...
[exclusivelock]Prevents other threads from simultaneously accessing a group of databases...
[switch]Executes the WebDNA inside the only [case] context which matches the given value...
[object]Embeds the results of an external function...
[SQLrelease]...
[!]Hides text...