Re: polling IRQs in a thread's code

From:

=?ISO-8859-1?Q?Arne_Vajh=F8j?= <arne@vajhoej.dk>

Newsgroups:

comp.lang.java.programmer

Date:

Sun, 24 Mar 2013 19:06:54 -0400

Message-ID:

<514f870f$0$32108$14726298@news.sunsite.dk>

On 3/24/2013 6:45 PM, Stefan Ram wrote:

   I am new to multithreading in Java. In a thread's code, I write:

void run()
{ if( irq() )cleanup(); else
   { firstStep();
     if( irq() )cleanup1(); else
     { secondStep();
       ...

   The user can request the thread to end using a GUI button.
   The thread has to check often whether the user has requested
   this, and then has to stop.

   Now, all the thread's code is messed up with polling the
   status of the user request, before each and every other action.
   Writing and maintaining the code is more difficult. I cannot
   simply write

void run()
{ firstStep();
   secondStep();
   ...
   cleanup(); }

   but have to write the code as above.

   Is this the usual way to proceed? Or can I simplifiy this somehow?

Trying to affect the thread from another thread is known to
cause some problems.

So testing inside the code is common.

I would prefer a more common coding convention though.

public void run() {
     ...
     if(stopflag) { }
     ...
     if(stopflag) { }
     ...
     if(stopflag) { }
     ...
     if(stopflag) { }
     ...
}

Arne