From 303adb3117b3039aa4b0dbc91540627d06bcb07c Mon Sep 17 00:00:00 2001
From: wilderrodrigues <wrodrigues@schubergphilis.com>
Date: Mon, 22 Jun 2015 14:07:33 +0200
Subject: [PATCH 1/2] Replace System.currentTimeMillis() by System.nanoTime()

   - System.nanoTime() is the best way to measure elapsed time in Java.
   - It gives a resolution on the order of microseconds

The System.currentTimeMillis() is used when calculating absolut time.
---
 utils/src/com/cloud/utils/Profiler.java | 20 +++++++++-----------
 1 file changed, 9 insertions(+), 11 deletions(-)

diff --git a/utils/src/com/cloud/utils/Profiler.java b/utils/src/com/cloud/utils/Profiler.java
index e75da0efc574..6082a92157d6 100644
--- a/utils/src/com/cloud/utils/Profiler.java
+++ b/utils/src/com/cloud/utils/Profiler.java
@@ -23,24 +23,20 @@ public class Profiler {
     private Long startTickInMs;
     private Long stopTickInMs;
 
-    public Profiler() {
-        startTickInMs = null;
-        stopTickInMs = null;
-    }
-
     public long start() {
-        startTickInMs = System.currentTimeMillis();
+        startTickInMs = System.nanoTime();
         return startTickInMs.longValue();
     }
 
     public long stop() {
-        stopTickInMs = System.currentTimeMillis();
+        stopTickInMs = System.nanoTime();
         return stopTickInMs.longValue();
     }
 
     public long getDuration() {
-        if (startTickInMs != null && stopTickInMs != null)
+        if (startTickInMs != null && stopTickInMs != null) {
             return stopTickInMs.longValue() - startTickInMs.longValue();
+        }
 
         return -1;
     }
@@ -55,12 +51,14 @@ public boolean isStopped() {
 
     @Override
     public String toString() {
-        if (startTickInMs == null)
+        if (startTickInMs == null) {
             return "Not Started";
+        }
 
-        if (stopTickInMs == null)
+        if (stopTickInMs == null) {
             return "Started but not stopped";
+        }
 
         return "Done. Duration: " + getDuration() + "ms";
     }
-}
+}
\ No newline at end of file

From b8d46ff4f78f5996c68d86477ec894fea636e866 Mon Sep 17 00:00:00 2001
From: wilderrodrigues <wrodrigues@schubergphilis.com>
Date: Mon, 22 Jun 2015 16:05:15 +0200
Subject: [PATCH 2/2] Add unit tests to cover negative cases

   - Cover when the profile is not started/stopped
---
 utils/test/com/cloud/utils/TestProfiler.java | 32 ++++++++++++++++++--
 1 file changed, 29 insertions(+), 3 deletions(-)

diff --git a/utils/test/com/cloud/utils/TestProfiler.java b/utils/test/com/cloud/utils/TestProfiler.java
index 2690a262e76e..4323f1d3c717 100644
--- a/utils/test/com/cloud/utils/TestProfiler.java
+++ b/utils/test/com/cloud/utils/TestProfiler.java
@@ -32,11 +32,11 @@ public class TestProfiler extends Log4jEnabledTestCase {
     public void testProfiler() {
         s_logger.info("testProfiler() started");
 
-        Profiler pf = new Profiler();
+        final Profiler pf = new Profiler();
         pf.start();
         try {
             Thread.sleep(1000);
-        } catch (InterruptedException e) {
+        } catch (final InterruptedException e) {
         }
         pf.stop();
 
@@ -46,4 +46,30 @@ public void testProfiler() {
 
         s_logger.info("testProfiler() stopped");
     }
-}
+
+    @Test
+    public void testProfilerNoStart() {
+        final Profiler pf = new Profiler();
+        try {
+            Thread.sleep(20);
+        } catch (final InterruptedException e) {
+        }
+        pf.stop();
+
+        Assert.assertTrue(pf.getDuration() == -1);
+        Assert.assertFalse(pf.isStarted());
+    }
+
+    @Test
+    public void testProfilerNoStop() {
+        final Profiler pf = new Profiler();
+        pf.start();
+        try {
+            Thread.sleep(20);
+        } catch (final InterruptedException e) {
+        }
+
+        Assert.assertTrue(pf.getDuration() == -1);
+        Assert.assertFalse(pf.isStopped());
+    }
+}
\ No newline at end of file