com.dautelle.realtime
Class LocalContext

java.lang.Object
  com.dautelle.realtime.Context
      com.dautelle.realtime.LocalContext

public final class LocalContext

extends Context

This class represents a local context; it is used to define locally scoped environment settings.

These settings are inherited by concurrent executions when performed within the scope of the local context. For example:

     LocalContext.enter(); // Enters local context scope.
     try {
         MY_VAR.setValue(myValue);
         ConcurrentContext.enter();
         try {
             // Concurrent executions inherit local setting of MY_VAR
             ConcurrentContext.execute(...);
             ConcurrentContext.execute(...); 
         } finally {
             ConcurrentContext.exit();
         }
     } finally {
         LocalContext.exit(); // End of local context scope.
     }
     static final LocalContext.Variable MY_VAR = new LocalContext.Variable();
     

Settings outside of a LocalContext scope, affects all threads (global default value). For example:

     public static final LocalContext.Variable DEBUG = new LocalContext.Variable();
     public static void main(String[] args) {
          DEBUG.setValue(new Boolean(true)); // Affects all threads.
          ...
     }

Locally scoped settings are typically wrapped by a static method. For example:

        LargeInteger.setModulus(m); // Performs integer operations modulo m.
        Length.showAs(NonSI.INCH); // Shows length in inches.
        RelativisticModel.select(); // Uses relativistic physical model.
        QuantityFormat.setInstance(format); // Changes current format.

Version:

6.0, May 02, 2004

Author:

Jean-Marie Dautelle

Nested Class Summary

static class

LocalContext.Variable This class represents a LocalContext variable.

Method Summary

static void	enter() Enters a LocalContext.
static void	exit() Exits the current LocalContext.

Methods inherited from class com.dautelle.realtime.Context

current, getInner, getOuter, getOwner, pop, push, push

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

enter

public static void enter()

Enters a LocalContext.

exit

public static void exit()

Exits the current LocalContext.

Throws:

java.lang.ClassCastException - if the current context is not a LocalContext.