X++ Server Threads

You can create threads in X++ to perform tasks in the background.  Here is a vey simple class that demonstrates the basics.

 

class ThreadDemo

{

    static server void main()

    {

        Thread t;

        ;

        new ExecutePermission().assert();

        //BP Deviation Documented

        t = new Thread();

        t.run(classnum(ThreadDemo), staticmethodstr(ThreadDemo, run));

    }

   

    static server void run(Thread t)

    {

        AsciiIo ai;

        // Change this to some path that your server will have access to

        str fileName = '\\t\\HelloWorld.txt';

        ;

        sleep(5000);

        new FileIOPermission(fileName, 'w').assert();

        //BP Deviation Documented

        ai = new AsciiIo(fileName, 'w');

        ai.write('Hello World!');

    }

}

 

I use the directory d:\t for temporary files.  You will have to either create the directory or change the example to point to some other directory.  In either case make sure that SYSTEM has read/write permission to the directory.

 

Create and run a simple job like this:

 

static void ThreadDemoJob(Args _args)

{

    ;

    ThreadDemo::main();

    print 'Ok';

    pause;

}

 

When you run the job it will return immediately.  Monitor the output directory and notice that the output file is created five seconds later.

 

One interesting quality of server side threads is that they have their own session block and that session block doesn’t have a client. This means that any attempt to instantiate a client side only class will fail. This can create some interesting bugs since almost no code does good error handling for when classes are not new-able.

Comments

• Anonymous
  February 18, 2007
  You have an outstanding good and well structured site. I enjoyed browsing through it.

• Anonymous
  March 28, 2007
  Vey interesting, but what are the ExecutePermission and FileIOPermission objects? My application does not recognize them.

• Anonymous
  March 28, 2007
  ExecutePermission and FileIOPermission are a part of the Code Access Security (CAS) framework added in version 4.0.  They serve a similar purpose and design with the .NET CAS system.