/*
 *                 Sun Public License Notice
 * 
 * The contents of this file are subject to the Sun Public License
 * Version 1.0 (the "License"). You may not use this file except in
 * compliance with the License. A copy of the License is available at
 * http://www.sun.com/
 * 
 * The Original Code is NetBeans. The Initial Developer of the Original
 * Code is Sun Microsystems, Inc. Portions Copyright 1997-2000 Sun
 * Microsystems, Inc. All Rights Reserved.
 */


/**
 * Does JVM implementation supports background threads by yielding?
 * 
 * @author  Petr Kuzel
 */
public class JVMPrioritiesTest {
    
    /** Creates a new instance of JVMPrioritiesTest */
    public JVMPrioritiesTest() {
    }
    
    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) throws Exception {
        
        final long start = System.currentTimeMillis();
        
        class Sprint implements Runnable {
            private String name;
            boolean back = false;
            
            Sprint(String name, boolean back) {
                this.name = name;
                this.back = back;
            }
            
            public void run() {
                
                StringBuffer cpuWork = new StringBuffer(500000);
                
                synchronized (JVMPrioritiesTest.class) {
                    System.err.println(name + " started.");
                }
                                                                
                for (int i = 0; i<100000; i++) {
                    cpuWork.append(i % 17);
                    for (int j = 0; j<1; j++) {
                        cpuWork.append(cpuWork.hashCode() % 2);
                        cpuWork.deleteCharAt(cpuWork.hashCode() % 2);
                    }
                    if (back) Thread.yield();
                }
                
                synchronized (JVMPrioritiesTest.class) {
                    System.err.println(name + " finished in " + (System.currentTimeMillis() - start) + "ms.");
                }                
            }
        };
        
        // HotSpot
        new Sprint("InitHostSpot", false).run();
        
        Thread background = new Thread(new Sprint("Background", true), "Background");        
        Thread foreground = new Thread(new Sprint("Foreground", false), "Foreground");
        
        synchronized (JVMPrioritiesTest.class) {
            background.setPriority(Thread.MIN_PRIORITY);            
            foreground.setPriority(Thread.MAX_PRIORITY);
            foreground.start();
            background.start();            
            System.err.print("Starter: prepare, ");
            Thread.sleep(1000); // let them allocate
            System.err.println("start!");
        }

// PIII@800        
        
// Linux 2.4.20
// InitHostSpot started.
// InitHostSpot finished in 26786ms.
// Starter: prepare, start!
// Foreground started.
// Background started.
// Foreground finished in 63179ms.
// Background finished in 97969ms.
       
    }
    
}