ConcurrentContext.java

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/*
 * Javolution - Java(TM) Solution for Real-Time and Embedded Systems
 * Copyright (C) 2012 - Javolution (http://javolution.org/)
 * All rights reserved.
 * 
 * Permission to use, copy, modify, and distribute this software is
 * freely granted, provided that this notice is preserved.
 */
package javolution.context;
 
import javolution.lang.Configurable;
import javolution.lang.MathLib;
import javolution.osgi.internal.OSGiServices;
 
public abstract class ConcurrentContext extends AbstractContext {
 
    public static final Configurable<Integer> CONCURRENCY = new Configurable<Integer>() {
        @Override
        protected Integer getDefault() {
            return Runtime.getRuntime().availableProcessors() - 1;
        }
 
        @Override
        protected Integer initialized(Integer value) {
            return MathLib.min(value, 65536); // Hard-limiting
        }
 
        @Override
        protected Integer reconfigured(Integer oldCount, Integer newCount) {
            throw new UnsupportedOperationException(
                    "Concurrency reconfiguration not supported.");
        }
    };
 
    protected ConcurrentContext() {}
 
    public static ConcurrentContext enter() {
        ConcurrentContext ctx = current(ConcurrentContext.class);
        if (ctx == null) { // Root.
            ctx = OSGiServices.getConcurrentContext();
        }
        return (ConcurrentContext) ctx.enterInner();
    }
 
    public static void execute(Runnable... logics) {
        ConcurrentContext ctx = ConcurrentContext.enter();
        try {
            for (Runnable logic : logics) {
                ctx.execute(logic);
            }
        } finally {
            ctx.exit();
        }
    }
 
    public abstract void execute(Runnable logic);
 
    public abstract void setConcurrency(int concurrency);
 
    public abstract int getConcurrency();
 
    @Override
    public void exit() { // Redefine here for documentation purpose.
        super.exit();
    }
}