initial commit

timer/com/vladium/utils/timing/JavaSystemTimer.java

@@ -0,0 +1,74 @@
+
+package com.vladium.utils.timing;
+
+// ----------------------------------------------------------------------------
+/**
+ * A package-private implementation of {@link ITimer} based around Java system
+ * timer [<code>System.currentTimeMillis()</code> method]. It is used when
+ * <code>HRTimer</code> implementation is unavailable.<P> 
+ * 
+ * {@link TimerFactory} acts as the Factory for this class.<P>
+ * 
+ * MT-safety: an instance of this class is safe to be used within the same
+ * thread only.
+ * 
+ * @author (C) <a href="mailto:vroubtsov@illinoisalumni.org">Vlad Roubtsov</a>, 2002
+ */
+final class JavaSystemTimer implements ITimer, ITimerConstants 
+{
+    // public: ................................................................
+    
+    public void start ()
+    {
+        if (DO_STATE_CHECKS)
+        {
+            if (m_state != STATE_READY)
+                throw new IllegalStateException (this + ": start() must be called from READY state, current state is " + STATE_NAMES [m_state]);
+        }
+        
+        if (DO_STATE_CHECKS) m_state = STATE_STARTED;
+        m_data = System.currentTimeMillis ();
+    }
+    
+    public void stop ()
+    {
+        // latch stop time in a local var before doing anything else:
+        final long data = System.currentTimeMillis ();
+        
+        if (DO_STATE_CHECKS)
+        {
+            if (m_state != STATE_STARTED)
+                throw new IllegalStateException (this + ": stop() must be called from STARTED state, current state is " + STATE_NAMES [m_state]);
+        }
+        
+        m_data = data - m_data;
+        if (DO_STATE_CHECKS) m_state = STATE_STOPPED;
+    }
+    
+    public double getDuration ()
+    {
+        if (DO_STATE_CHECKS)
+        {
+            if (m_state != STATE_STOPPED)
+                throw new IllegalStateException (this + ": getDuration() must be called from STOPPED state, current state is " + STATE_NAMES [m_state]);
+        }
+        
+        return m_data;
+    }
+    
+    public void reset ()
+    {
+        if (DO_STATE_CHECKS) m_state = STATE_READY;
+    }
+    
+    // protected: .............................................................
+
+    // package: ...............................................................
+        
+    // private: ...............................................................
+    
+    private int m_state; // used to keep track of timer state
+    private long m_data; // timing data
+
+} // end of class
+// ----------------------------------------------------------------------------