initial commit

timer/HRTimerResolution.java

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+import java.text.DecimalFormat;
+
+import com.vladium.utils.timing.ITimer;
+import com.vladium.utils.timing.TimerFactory;
+
+// ----------------------------------------------------------------------------
+/**
+ * A demo class to show off the higher resolution available from HRTimer class
+ * and to investigate the resolution offered by Java "time-related"
+ * methods other than System.currentTimeMillis().<P>
+ * 
+ * Make sure that hrtlib.dll JNI lib is in java.library.path or TimerFactory
+ * will fall back to the Java system timer:
+ * <PRE>
+ *  >java -Djava.library.path=(dir containing hrtlib.dll) HRTimerResolution
+ * </PRE>
+ * 
+ * @author (C) <a href="mailto:vroubtsov@illinoisalumni.org">Vlad Roubtsov</a>, 2002
+ */
+public class HRTimerResolution
+{
+    // public: ................................................................
+    
+    public static void main (final String [] args) throws Exception
+    {
+        final DecimalFormat format = new DecimalFormat ();
+        format.setMinimumFractionDigits (3);
+        format.setMaximumFractionDigits (3);
+        
+        // create an ITimer using the Factory class:
+        final ITimer timer = TimerFactory.newTimer ();
+        
+        // JIT/hotspot warmup:
+        for (int i = 0; i < 3000; ++ i)
+        {
+            timer.start ();
+            timer.stop ();
+            timer.getDuration ();
+            timer.reset ();
+        }
+        
+        final Object lock = new Object (); // this is used by monitor.wait() below
+        
+        for (int i = 0; i < 5; ++ i)
+        {
+            timer.start ();
+           
+            // uncomment various lines below to see the resolution
+            // offered by other Java time-related methods; with all
+            // lines commented out this loop reports time elapsed
+            // between successive calls to t.start() and t.stop(), thus
+            // providing an estimate for timer's raw resolution
+            
+            synchronized (lock) { lock.wait (1); }
+            //Thread.currentThread ().sleep (1);
+            //Thread.currentThread ().sleep (0, 500);
+            //Thread.currentThread ().join (1);
+    
+            timer.stop ();
+
+            System.out.println ("duration = "
+                + format.format (timer.getDuration ()) + " ms");            
+            timer.reset ();
+        }
+    } 
+
+} // end of class
+// ----------------------------------------------------------------------------