IndependentModeler/src/cz/cvut/promod/services/Service.java

   1 package cz.cvut.promod.services;
   2
   3 /**
   4  * ProMod, master thesis project
   5  * User: Petr Zverina, petr.zverina@gmail.com
   6  * Date: 16:20:15, 10.10.2009
   7  */
   8
   9 /**
  10  * Common interface for all services.
  11  *
  12  * IMPORTANT NOTE! All services and their methods are supposed NOT to be used in (or by) a different thread
  13  * that Event Dispatcher Thread or Main Thread (during application start - init() method of any plugin).
  14  * Even all resources provided by services (generally ModelerSession), e.g. all instances of a ValueModel
  15  * interface etc., are supposed to be used only in Event Dispatcher Thread or Main Thread (during application start).
  16  *
  17  * One can use following code fragment if is not convinced about the thread identity:
  18  *
  19  * if(SwingUtilities.isEventDispatchThread()){
  20  *      usage of a service or a it's resource
  21  * }
  22  *
  23  * One can always delegate any program sequence to the Event Dispatcher thread too. Use:
  24  * 1) SwingUtilities.invokeAndWait(Runnable doRun) or
  25  * 2) SwingUtilities.invokeLater(Runnable doRun) - generally preferable solution.
  26  *
  27  * Usage of services and their resources form another thread than Event Dispatcher Thread can cause a
  28  * unpredictable inconsistency of application. One is supposed to always avoid using services and their
  29  * resources out of the Event Dispatcher Thread!
  30  *
  31  * @see cz.cvut.promod.services.ModelerSession
  32  * @see javax.swing.SwingUtilities
  33  */
  34 public interface Service {
  35
  36     /**
  37      * Is the common method for all services and is invoked by the IndependentModelerMain class
  38      * @see cz.cvut.promod.IndependentModelerMain
  39      *
  40      * This method is invoked during ProMod start to check availability and integrity of services.
  41
  42      * @return true if no error has occurred during check, false otherwise
  43      */
  44     public boolean check();
  45
  46 }