Technical References - [exclusivelock]

Prevents other threads from simultaneously accessing a group of databases.

numero = 200
interpreted = N
texte = [exclusivelock database list]...WebDNA...[/exclusivelock] To prevent a group of databases from being modified by other threads (other 'hits' to the server, or other templates or triggers), wrap an [exclusivelock] context around the WebDNA code which will be making the important exclusive changes. Example:
[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]

To prevent a group of databases from being modified by other threads (other 'hits' to the server, or other templates or triggers), wrap an [exclusivelock] context around the WebDNA code which will be making the important exclusive changes.

Example:

[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.

DOWNLOAD WEBDNA NOW!

Top Articles:

Download WebDNA Applications

WebDNA applications...

WebDNA Modules

A list of the currently available modules...

Technical Change History

This Technical Change History provides a reverse chronological list of WebDNA changes...

WebDNA Libraries

A list of available libraries for WebDNA...

Tips and Tricks

A list of user-submitted tips ...

AWS Raw WebDNA LAMP-Plus WebServer

Amazon Web Services (AWS) README for Machine Image ID...

Related Readings:

[protect]

...

[array]

Array Operation...

[DOS]

Executes the DOS batch file commands contained in the context and displays the results...

[waitforfile]

The server waits until the file appears on disk...

[append]

[append db=base...

[loop]

Loops through the enclosing text the specified number of times...