tmf : Update the histogram to handle lost events correctly

Add a checkbox to toggle displaying the lost events
Display the lost events' bars in the histogram

Change-Id: Iba72f479455cadc4150efadf695f943a6572f3d2
Signed-off-by: Jean-Christian Kouamé <kadjo.gwandy.jean-christian.kouame@ericsson.com>
Signed-off-by: Simon Delisle <simon.delisle@ericsson.com>
Signed-off-by: Matthew Khouzam <matthew.khouzam@ericsson.com>
Signed-off-by: Patrick Tasse <patrick.tasse@gmail.com>
Reviewed-on: https://git.eclipse.org/r/15555

12 files changed, 664 insertions, 347 deletions

diff --git a/lttng/org.eclipse.linuxtools.lttng.help/doc/User-Guide.mediawiki b/lttng/org.eclipse.linuxtools.lttng.help/doc/User-Guide.mediawiki
index 215e8a0bf1..02bf777eff 100644
--- a/lttng/org.eclipse.linuxtools.lttng.help/doc/User-Guide.mediawiki
+++ b/lttng/org.eclipse.linuxtools.lttng.help/doc/User-Guide.mediawiki
@@ -524,6 +524,7 @@ The Histogram View displays the trace events distribution with respect to time.
 
 [[Image:images/HistogramView.png]]
 
+The '''Hide Lost Events''' toggle button [[Image:images/hide_lost_events.gif]] in the local toolbar allows to hide the bars of lost events. When the button is selected it can be toggled again to show the lost events.
 
 On the top left, there are two data controls:
 
diff --git a/lttng/org.eclipse.linuxtools.lttng.help/doc/images/hide_lost_events.gif b/lttng/org.eclipse.linuxtools.lttng.help/doc/images/hide_lost_events.gif
new file mode 100644
index 0000000000..bb46075ce4
--- /dev/null
+++ b/lttng/org.eclipse.linuxtools.lttng.help/doc/images/hide_lost_events.gif
diff --git a/lttng/org.eclipse.linuxtools.tmf.ui.tests/src/org/eclipse/linuxtools/tmf/ui/tests/histogram/HistogramDataModelTest.java b/lttng/org.eclipse.linuxtools.tmf.ui.tests/src/org/eclipse/linuxtools/tmf/ui/tests/histogram/HistogramDataModelTest.java
index e1304d2e3d..83d08740c2 100644
--- a/lttng/org.eclipse.linuxtools.tmf.ui.tests/src/org/eclipse/linuxtools/tmf/ui/tests/histogram/HistogramDataModelTest.java
+++ b/lttng/org.eclipse.linuxtools.tmf.ui.tests/src/org/eclipse/linuxtools/tmf/ui/tests/histogram/HistogramDataModelTest.java
@@ -15,10 +15,13 @@
 
 package org.eclipse.linuxtools.tmf.ui.tests.histogram;
 
+import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
+import org.eclipse.linuxtools.tmf.core.timestamp.ITmfTimestamp;
+import org.eclipse.linuxtools.tmf.core.timestamp.TmfTimeRange;
+import org.eclipse.linuxtools.tmf.core.timestamp.TmfTimestamp;
 import org.eclipse.linuxtools.tmf.ui.views.histogram.HistogramDataModel;
 import org.eclipse.linuxtools.tmf.ui.views.histogram.HistogramScaledData;
 import org.eclipse.linuxtools.tmf.ui.views.histogram.IHistogramModelListener;
@@ -37,13 +40,7 @@ public class HistogramDataModelTest {
     @Test
     public void testHistogramDataModel() {
         HistogramDataModel model = new HistogramDataModel();
-        assertTrue(model.getNbBuckets() == HistogramDataModel.DEFAULT_NUMBER_OF_BUCKETS);
-        assertTrue(model.getNbEvents() == 0);
-        assertTrue(model.getBucketDuration() == 1);
-        assertTrue(model.getFirstBucketTime() == 0);
-        assertTrue(model.getStartTime() == 0);
-        assertTrue(model.getEndTime() == 0);
-        assertTrue(model.getTimeLimit() == HistogramDataModel.DEFAULT_NUMBER_OF_BUCKETS);
+        testModelConsistency(model, HistogramDataModel.DEFAULT_NUMBER_OF_BUCKETS,0, 1, 0 , 0 , 0 , HistogramDataModel.DEFAULT_NUMBER_OF_BUCKETS);
     }
 
     /**
@@ -53,13 +50,7 @@ public class HistogramDataModelTest {
     public void testHistogramDataModelInt() {
         final int nbBuckets = 5 * 1000;
         HistogramDataModel model = new HistogramDataModel(nbBuckets);
-        assertTrue(model.getNbEvents() == 0);
-        assertTrue(model.getNbBuckets() == nbBuckets);
-        assertTrue(model.getBucketDuration() == 1);
-        assertTrue(model.getFirstBucketTime() == 0);
-        assertTrue(model.getStartTime() == 0);
-        assertTrue(model.getEndTime() == 0);
-        assertTrue(model.getTimeLimit() == nbBuckets);
+        testModelConsistency(model, nbBuckets, 0, 1, 0, 0, 0, nbBuckets);
     }
 
     /**
@@ -71,13 +62,7 @@ public class HistogramDataModelTest {
         HistogramDataModel model = new HistogramDataModel(nbBuckets);
         model.countEvent(0, -1);
 
-        assertTrue(model.getNbEvents() == 0);
-        assertTrue(model.getNbBuckets() == nbBuckets);
-        assertTrue(model.getBucketDuration() == 1);
-        assertTrue(model.getFirstBucketTime() == 0);
-        assertTrue(model.getStartTime() == 0);
-        assertTrue(model.getEndTime() == 0);
-        assertTrue(model.getTimeLimit() == nbBuckets);
+        testModelConsistency(model, nbBuckets, 0, 1, 0, 0, 0, nbBuckets);
     }
 
     /**
@@ -89,13 +74,7 @@ public class HistogramDataModelTest {
         HistogramDataModel model = new HistogramDataModel(nbBuckets);
         model.countEvent(0, -1);
 
-        assertTrue(model.getNbEvents() == 0);
-        assertTrue(model.getNbBuckets() == nbBuckets);
-        assertTrue(model.getBucketDuration() == 1);
-        assertTrue(model.getFirstBucketTime() == 0);
-        assertTrue(model.getStartTime() == 0);
-        assertTrue(model.getEndTime() == 0);
-        assertTrue(model.getTimeLimit() == nbBuckets);
+        testModelConsistency(model, nbBuckets, 0, 1, 0, 0, 0, nbBuckets);
     }
 
     /**
@@ -110,17 +89,12 @@ public class HistogramDataModelTest {
         HistogramDataModel model = new HistogramDataModel(nbBuckets);
 
         HistogramScaledData result = model.scaleTo(nbBuckets, maxHeight, 1);
+
         for (int i = 0; i < result.fData.length; i++) {
-            assertTrue(result.fData[i] == 0);
+            assertEquals(0, result.fData[i]);
         }
 
-        assertTrue(model.getNbEvents() == 0);
-        assertTrue(model.getNbBuckets() == nbBuckets);
-        assertTrue(model.getBucketDuration() == 1);
-        assertTrue(model.getFirstBucketTime() == 0);
-        assertTrue(model.getStartTime() == 0);
-        assertTrue(model.getEndTime() == 0);
-        assertTrue(model.getTimeLimit() == nbBuckets);
+        testModelConsistency(model, nbBuckets, 0, 1, 0, 0, 0, nbBuckets);
     }
 
     /**
@@ -136,18 +110,11 @@ public class HistogramDataModelTest {
         model.countEvent(0, 1);
 
         HistogramScaledData result = model.scaleTo(nbBuckets, maxHeight, 1);
-        assertTrue(result.fData[0] == 1);
-        for (int i = 1; i < result.fData.length; i++) {
-            assertTrue(result.fData[i] == 0);
-        }
+        assertEquals(1, result.fData[0]);
+
+        assertArrayEqualsInt(0, result.fData,1);
 
-        assertTrue(model.getNbEvents() == 1);
-        assertTrue(model.getNbBuckets() == nbBuckets);
-        assertTrue(model.getBucketDuration() == 1);
-        assertTrue(model.getFirstBucketTime() == 1);
-        assertTrue(model.getStartTime() == 1);
-        assertTrue(model.getEndTime() == 1);
-        assertTrue(model.getTimeLimit() == nbBuckets + 1);
+        testModelConsistency(model, nbBuckets, 1, 1, 1, 1, 1, nbBuckets + 1);
     }
 
     /**
@@ -160,22 +127,13 @@ public class HistogramDataModelTest {
         final int maxHeight = 10;
 
         HistogramDataModel model = new HistogramDataModel(nbBuckets);
-        for (int i = 0; i < nbBuckets; i++) {
-            model.countEvent(i, i);
-        }
+        countEventsInModel(nbBuckets, model);
 
         HistogramScaledData result = model.scaleTo(nbBuckets, maxHeight, 1);
-        for (int i = 0; i < result.fData.length; i++) {
-            assertTrue(result.fData[i] == 1);
-        }
 
-        assertTrue(model.getNbEvents() == nbBuckets);
-        assertTrue(model.getNbBuckets() == nbBuckets);
-        assertTrue(model.getBucketDuration() == 1);
-        assertTrue(model.getFirstBucketTime() == 0);
-        assertTrue(model.getStartTime() == 0);
-        assertTrue(model.getEndTime() == nbBuckets - 1);
-        assertTrue(model.getTimeLimit() == nbBuckets);
+        assertArrayEqualsInt(1, result.fData);
+
+        testModelConsistency(model, nbBuckets, nbBuckets, 1, 0, 0, nbBuckets - 1, nbBuckets);
     }
 
     /**
@@ -188,25 +146,20 @@ public class HistogramDataModelTest {
         final int maxHeight = 10;
 
         HistogramDataModel model = new HistogramDataModel(nbBuckets);
+        // to different to call elsewhere
         for (int i = 0; i < nbBuckets; i++) {
             model.countEvent(i, i);
-            model.countEvent(i+1, i);
+            model.countEvent(i + 1, i);
         }
 
         HistogramScaledData result = model.scaleTo(nbBuckets, maxHeight, 1);
-        for (int i = 0; i < result.fData.length; i++) {
-            assertTrue(result.fData[i] == 2);
-        }
 
-        assertTrue(model.getNbEvents() == 2 * nbBuckets);
-        assertTrue(model.getNbBuckets() == nbBuckets);
-        assertTrue(model.getBucketDuration() == 1);
-        assertTrue(model.getFirstBucketTime() == 0);
-        assertTrue(model.getStartTime() == 0);
-        assertTrue(model.getEndTime() == nbBuckets - 1);
-        assertTrue(model.getTimeLimit() == nbBuckets);
+        assertArrayEqualsInt(2, result.fData);
+
+        testModelConsistency(model, nbBuckets, 2 * nbBuckets, 1, 0, 0, nbBuckets- 1, nbBuckets);
     }
 
+
     /**
      * Test methods for {@link HistogramDataModel#countEvent(long,long)} and
      * {@link HistogramDataModel#scaleTo(int,int,int)}.
@@ -223,17 +176,10 @@ public class HistogramDataModelTest {
         }
 
         HistogramScaledData result = model.scaleTo(nbBuckets, maxHeight, 1);
-        for (int i = 0; i < result.fData.length; i++) {
-            assertTrue(result.fData[i] == 1);
-        }
 
-        assertTrue(model.getNbEvents() == nbBuckets);
-        assertTrue(model.getNbBuckets() == nbBuckets);
-        assertTrue(model.getBucketDuration() == 1);
-        assertTrue(model.getFirstBucketTime() == startTime);
-        assertTrue(model.getStartTime() == startTime);
-        assertTrue(model.getEndTime() == startTime + nbBuckets - 1);
-        assertTrue(model.getTimeLimit() == startTime + nbBuckets);
+        assertArrayEqualsInt(1, result.fData);
+
+        testModelConsistency(model, nbBuckets, nbBuckets, 1, startTime, startTime, startTime + nbBuckets- 1, startTime + nbBuckets);
     }
 
     /**
@@ -244,16 +190,13 @@ public class HistogramDataModelTest {
         HistogramDataModel model = new HistogramDataModel(10);
         try {
             model.scaleTo(10, 0, 1);
-        }
-        catch (AssertionError e1) {
+        } catch (AssertionError e1) {
             try {
                 model.scaleTo(0, 10, 1);
-            }
-            catch (AssertionError e2) {
+            } catch (AssertionError e2) {
                 try {
                     model.scaleTo(0, 0, 1);
-                }
-                catch (AssertionError e3) {
+                } catch (AssertionError e3) {
                     return;
                 }
             }
@@ -272,22 +215,13 @@ public class HistogramDataModelTest {
         final int[] expectedResult = new int[] { 1, 1, 1, 1, 1, 0, 0, 0, 0, 0 };
 
         HistogramDataModel model = new HistogramDataModel(nbBuckets);
-        for (int i = 0; i < nbEvents; i++) {
-            model.countEvent(i, i);
-        }
+        countEventsInModel(nbEvents, model);
 
         HistogramScaledData result = model.scaleTo(nbBuckets, maxHeight, 1);
-        for (int i = 0; i < result.fData.length; i++) {
-            assertTrue(result.fData[i] == expectedResult[i]);
-        }
 
-        assertTrue(model.getNbEvents() == nbEvents);
-        assertTrue(model.getNbBuckets() == nbBuckets);
-        assertTrue(model.getBucketDuration() == 1);
-        assertTrue(model.getFirstBucketTime() == 0);
-        assertTrue(model.getStartTime() == 0);
-        assertTrue(model.getEndTime() == nbEvents - 1);
-        assertTrue(model.getTimeLimit() == nbBuckets);
+        assertArrayEquals( expectedResult, result.fData);
+
+        testModelConsistency(model, nbBuckets, nbEvents, 1, 0, 0, nbEvents - 1, nbBuckets);
     }
 
     /**
@@ -301,22 +235,13 @@ public class HistogramDataModelTest {
         final int[] expectedResult = new int[] { 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 };
 
         HistogramDataModel model = new HistogramDataModel(nbBuckets);
-        for (int i = 0; i < nbEvents; i++) {
-            model.countEvent(i, i);
-        }
+        countEventsInModel(nbEvents, model);
 
         HistogramScaledData result = model.scaleTo(nbBuckets, maxHeight, 1);
-        for (int i = 0; i < result.fData.length; i++) {
-            assertTrue(result.fData[i] == expectedResult[i]);
-        }
 
-        assertTrue(model.getNbEvents() == nbEvents);
-        assertTrue(model.getNbBuckets() == nbBuckets);
-        assertTrue(model.getBucketDuration() == 1);
-        assertTrue(model.getFirstBucketTime() == 0);
-        assertTrue(model.getStartTime() == 0);
-        assertTrue(model.getEndTime() == nbEvents - 1);
-        assertTrue(model.getTimeLimit() == nbBuckets);
+        assertArrayEquals(expectedResult, result.fData);
+
+        testModelConsistency(model, nbBuckets, nbEvents, 1, 0, 0, nbEvents - 1, nbBuckets);
     }
 
     /**
@@ -330,22 +255,13 @@ public class HistogramDataModelTest {
         final int[] expectedResult = new int[] { 2, 2, 2, 2, 2, 2, 2, 2, 2, 2 };
 
         HistogramDataModel model = new HistogramDataModel(nbBuckets);
-        for (int i = 0; i < nbEvents; i++) {
-            model.countEvent(i, i);
-        }
+        countEventsInModel(nbEvents, model);
 
         HistogramScaledData result = model.scaleTo(nbBuckets, maxHeight, 1);
-        for (int i = 0; i < result.fData.length; i++) {
-            assertTrue(result.fData[i] == expectedResult[i]);
-        }
 
-        assertTrue(model.getNbEvents() == nbEvents);
-        assertTrue(model.getNbBuckets() == nbBuckets);
-        assertTrue(model.getBucketDuration() == 2);
-        assertTrue(model.getFirstBucketTime() == 0);
-        assertTrue(model.getStartTime() == 0);
-        assertTrue(model.getEndTime() == nbEvents - 1);
-        assertTrue(model.getTimeLimit() == 2 * nbBuckets);
+        assertArrayEquals(expectedResult, result.fData);
+
+        testModelConsistency(model, nbBuckets, nbEvents, 2, 0, 0, nbEvents - 1, 2 * nbBuckets);
     }
 
     /**
@@ -359,22 +275,13 @@ public class HistogramDataModelTest {
         final int[] expectedResult = new int[] { 4, 4, 4, 4, 4, 4, 4, 2, 0, 0 };
 
         HistogramDataModel model = new HistogramDataModel(nbBuckets);
-        for (int i = 0; i < nbEvents; i++) {
-            model.countEvent(i, i);
-        }
+        countEventsInModel(nbEvents, model);
 
         HistogramScaledData result = model.scaleTo(nbBuckets, maxHeight, 1);
-        for (int i = 0; i < result.fData.length; i++) {
-            assertTrue(result.fData[i] == expectedResult[i]);
-        }
 
-        assertTrue(model.getNbEvents() == nbEvents);
-        assertTrue(model.getNbBuckets() == nbBuckets);
-        assertTrue(model.getBucketDuration() == 4);
-        assertTrue(model.getFirstBucketTime() == 0);
-        assertTrue(model.getStartTime() == 0);
-        assertTrue(model.getEndTime() == nbEvents - 1);
-        assertTrue(model.getTimeLimit() == 4 * nbBuckets);
+        assertArrayEquals(expectedResult, result.fData);
+
+        testModelConsistency(model, nbBuckets, nbEvents, 4, 0, 0, nbEvents - 1, 4 * nbBuckets);
     }
 
     /**
@@ -388,21 +295,13 @@ public class HistogramDataModelTest {
         final int[] expectedResult = new int[] { 20, 20, 20, 20, 20, 20, 20, 20, 20, 20 };
 
         HistogramDataModel model = new HistogramDataModel(nbBuckets);
-        for (int i = 0; i < nbEvents; i++) {
-            model.countEvent(i, i);
-        }
+        countEventsInModel(nbEvents, model);
 
         HistogramScaledData result = model.scaleTo(10, maxHeight, 1);
-        for (int i = 0; i < result.fData.length; i++) {
-            assertTrue(result.fData[i] == expectedResult[i]);
-        }
 
-        assertTrue(model.getNbEvents() == nbEvents);
-        assertTrue(model.getNbBuckets() == nbBuckets);
-        assertTrue(model.getBucketDuration() == 2);
-        assertTrue(model.getFirstBucketTime() == 0);
-        assertTrue(model.getEndTime() == nbEvents - 1);
-        assertTrue(model.getTimeLimit() == 2 * nbBuckets);
+        assertArrayEquals(expectedResult, result.fData);
+
+        testModelConsistency(model, nbBuckets, nbEvents, 2, 0, 0, nbEvents - 1, 2 * nbBuckets);
     }
 
     /**
@@ -416,22 +315,13 @@ public class HistogramDataModelTest {
         final int[] expectedResult = new int[] { 24, 24, 24, 24, 24, 24, 24, 24, 9, 0 };
 
         HistogramDataModel model = new HistogramDataModel(nbBuckets);
-        for (int i = 0; i < nbEvents; i++) {
-            model.countEvent(i, i);
-        }
+        countEventsInModel(nbEvents, model);
 
         HistogramScaledData result = model.scaleTo(10, maxHeight, 1);
-        for (int i = 0; i < result.fData.length; i++) {
-            assertTrue(result.fData[i] == expectedResult[i]);
-        }
 
-        assertTrue(model.getNbEvents() == nbEvents);
-        assertTrue(model.getNbBuckets() == nbBuckets);
-        assertTrue(model.getBucketDuration() == 4);
-        assertTrue(model.getFirstBucketTime() == 0);
-        assertTrue(model.getStartTime() == 0);
-        assertTrue(model.getEndTime() == nbEvents - 1);
-        assertTrue(model.getTimeLimit() == 4 * nbBuckets);
+        assertArrayEquals(expectedResult, result.fData);
+
+        testModelConsistency(model, nbBuckets, nbEvents, 4, 0, 0, nbEvents - 1, 4 * nbBuckets);
     }
 
     /**
@@ -449,16 +339,15 @@ public class HistogramDataModelTest {
         // (int)(width / barWith) = 2
         // -> 2 bars -> expected result needs two buckets (scaled data)
         //
-        // buckets (in model) per bar = last bucket id / nbBars + 1 (plus 1 to cover all used buckets)
+        // buckets (in model) per bar = last bucket id / nbBars + 1 (plus 1 to
+        // cover all used buckets)
         // -> buckets per bar = 50 / 2 + 1 = 26
         // -> first entry in expected result is 26 * 4 = 104
         // -> second entry in expected result is 22 * 4 + 9 = 97
         final int[] expectedResult = new int[] { 104, 97 };
 
         HistogramDataModel model = new HistogramDataModel(nbBuckets);
-        for (int i = 0; i < nbEvents; i++) {
-            model.countEvent(i, i);
-        }
+        countEventsInModel(nbEvents, model);
 
         // verify scaled data
         HistogramScaledData result = model.scaleTo(width, maxHeight, barWidth);
@@ -470,23 +359,15 @@ public class HistogramDataModelTest {
         assertEquals(0, result.fFirstEventTime);
         assertEquals(1, result.fLastBucket);
         assertEquals(104, result.fMaxValue);
-        assertEquals((double)maxHeight/104, result.fScalingFactor, DELTA);
+        assertEquals((double) maxHeight / 104, result.fScalingFactor, DELTA);
         assertEquals(maxHeight, result.fHeight);
         assertEquals(width, result.fWidth);
         assertEquals(barWidth, result.fBarWidth);
 
-        for (int i = 0; i < result.fData.length; i++) {
-            assertEquals(expectedResult[i], result.fData[i]);
-        }
+        assertArrayEquals(expectedResult, result.fData);
 
         // verify model
-        assertEquals(nbEvents, model.getNbEvents());
-        assertEquals(nbBuckets, model.getNbBuckets());
-        assertEquals(4, model.getBucketDuration());
-        assertEquals(0, model.getFirstBucketTime());
-        assertEquals(0, model.getStartTime());
-        assertEquals(nbEvents - 1, model.getEndTime());
-        assertEquals(4 * nbBuckets, model.getTimeLimit());
+        testModelConsistency(model, nbBuckets, nbEvents, 4, 0, 0, nbEvents - 1, 4 * nbBuckets);
     }
 
     /**
@@ -503,14 +384,13 @@ public class HistogramDataModelTest {
         // (int)(width / barWith) = 10
         // -> 10 bars -> expected result needs 10 buckets (scaled data)
         //
-        // buckets in (model) per bar = last bucket id / nbBars + 1 (plus 1 to cover all used buckets)
+        // buckets in (model) per bar = last bucket id / nbBars + 1 (plus 1 to
+        // cover all used buckets)
         // -> buckets per bar = 50 / 10 + 1 = 6
         final int[] expectedResult = new int[] { 21, 24, 24, 24, 24, 24, 24, 24, 12, 0 };
 
         HistogramDataModel model = new HistogramDataModel(nbBuckets);
-        for (int i = nbEvents - 1; i >= 0; i--) {
-            model.countEvent(i, i);
-        }
+        countInvertedEvents(nbEvents, model);
 
         // verify scaled data
         HistogramScaledData result = model.scaleTo(width, maxHeight, barWidth);
@@ -518,27 +398,26 @@ public class HistogramDataModelTest {
         assertEquals(4 * 6, result.fBucketDuration);
         assertEquals(0, result.fSelectionBeginBucket);
         assertEquals(0, result.fSelectionEndBucket);
-        assertEquals(-3, result.fFirstBucketTime); // negative is correct, can happen when reverse
+        assertEquals(-3, result.fFirstBucketTime); // negative is correct, can
+                                                   // happen when reverse
         assertEquals(0, result.fFirstEventTime);
         assertEquals(9, result.fLastBucket);
         assertEquals(24, result.fMaxValue);
-        assertEquals((double)maxHeight/24, result.fScalingFactor, DELTA);
+        assertEquals((double) maxHeight / 24, result.fScalingFactor, DELTA);
         assertEquals(maxHeight, result.fHeight);
         assertEquals(width, result.fWidth);
         assertEquals(barWidth, result.fBarWidth);
 
-        for (int i = 0; i < result.fData.length; i++) {
-            assertEquals(expectedResult[i], result.fData[i]);
-        }
+        assertArrayEquals(expectedResult, result.fData);
 
         // verify model
-        assertEquals(nbEvents, model.getNbEvents());
-        assertEquals(nbBuckets, model.getNbBuckets());
-        assertEquals(4, model.getBucketDuration());
-        assertEquals(-3, model.getFirstBucketTime());
-        assertEquals(0, model.getStartTime());
-        assertEquals(nbEvents - 1, model.getEndTime());
-        assertEquals(-3 + 4 * nbBuckets, model.getTimeLimit());
+        testModelConsistency(model, nbBuckets, nbEvents, 4, -3, 0, nbEvents - 1, -3 + 4 * nbBuckets);
+    }
+
+    private static void countInvertedEvents(final int nbEvents, HistogramDataModel model) {
+        for (int i = nbEvents - 1; i >= 0; i--) {
+            model.countEvent(i, i);
+        }
     }
 
     /**
@@ -554,29 +433,20 @@ public class HistogramDataModelTest {
         final int nbEvents = 2 * nbBuckets;
 
         HistogramDataModel model = new HistogramDataModel(nbBuckets);
-        for (int i = 0; i < nbEvents; i++) {
-            model.countEvent(i, i);
-        }
+        countEventsInModel(nbEvents, model);
 
         HistogramScaledData result = model.scaleTo(width, maxHeight, barWidth);
 
         model.clear();
 
-        for (int i = nbEvents -1; i >= 0; i--) {
-            model.countEvent(i, i);
-        }
+        countInvertedEvents(nbEvents, model);
 
         HistogramScaledData revResult = model.scaleTo(width, maxHeight, barWidth);
 
-        assertEquals(nbEvents, model.getNbEvents());
-        assertEquals(nbBuckets, model.getNbBuckets());
-        assertEquals(2, model.getBucketDuration());
-        assertEquals(0, model.getFirstBucketTime());
-        assertEquals(0, model.getStartTime());
-        assertEquals(nbEvents - 1, model.getEndTime());
-        assertEquals(2 * nbBuckets, model.getTimeLimit());
+        testModelConsistency(model, nbBuckets, nbEvents, 2, 0, 0, nbEvents - 1, 2 * nbBuckets);
 
         // For the above number of events, result and revResult are exactly the same.
+
         assertEquals(result.fBucketDuration, revResult.fBucketDuration);
         assertEquals(result.fSelectionBeginBucket, revResult.fSelectionBeginBucket);
         assertEquals(result.fSelectionEndBucket, revResult.fSelectionEndBucket);
@@ -587,9 +457,7 @@ public class HistogramDataModelTest {
         assertEquals(result.getBucketEndTime(0), revResult.getBucketEndTime(0));
         assertEquals(result.getBucketStartTime(0), revResult.getBucketStartTime(0));
 
-        for (int i = 0; i < result.fData.length; i++) {
-            assertTrue(result.fData[i] == revResult.fData[i]);
-        }
+        assertArrayEquals(revResult.fData, result.fData);
     }
 
     /**
@@ -600,7 +468,7 @@ public class HistogramDataModelTest {
         final int nbBuckets = 2000;
         final int nbEvents = 10 * nbBuckets + 256;
         final int[] count = new int[1];
-        count [0] = 0;
+        count[0] = 0;
 
         // Test add listener and call of listener
         IHistogramModelListener listener = new IHistogramModelListener() {
@@ -613,28 +481,203 @@ public class HistogramDataModelTest {
         // Test that the listener interface is called every 16000 events.
         HistogramDataModel model = new HistogramDataModel(nbBuckets);
         model.addHistogramListener(listener);
-        for (int i = 0; i < nbEvents; i++) {
-            model.countEvent(i+1, i);
-        }
 
-        assertTrue(count[0] == 1);
+        countEventsInModel(nbEvents, model, 1);
+
+        assertEquals(1, count[0]);
 
         // Test that the listener interface is called when complete is called.
         model.complete();
-        assertTrue(count[0] == 2);
+        assertEquals(2, count[0]);
 
         // Test that clear triggers call of listener interface
         model.clear();
-        assertTrue(count[0] == 3);
+        assertEquals(3, count[0]);
 
         // Test remove listener
         count[0] = 0;
         model.removeHistogramListener(listener);
 
-        for (int i = 0; i < nbEvents; i++) {
-            model.countEvent(i, i);
-        }
+        countEventsInModel(nbEvents, model);
         model.complete();
-        assertTrue(count[0] == 0);
+        assertEquals(0, count[0]);
+    }
+
+    /**
+     * Test method for {@link HistogramDataModel#scaleTo(int,int,int)}.
+     */
+    @Test
+    public void testLostEventsScaleTo_0() {
+        final int nbBuckets = 10;
+        final int maxHeight = 10;
+        final int nbEvents = 3 * nbBuckets;
+        final int nbLostEvents_0 = 4;
+        final int nbLostEvents_1 = 9;
+        final int nbCombinedEvents = nbEvents + 2;
+        final int[] expectedResult = new int[] { 4, 4, 4, 4, 4, 4, 4, 2, 0, 0 };
+        final int[] expectedLostEventsResult = new int[] { 0, 2, 2, 0, 3, 3, 3, 0, 0, 0 };
+
+        HistogramDataModel model = new HistogramDataModel(nbBuckets);
+        countEventsInModel(nbEvents, model);
+
+        final TmfTimeRange timeRange_0 = new TmfTimeRange(
+                new TmfTimestamp(5L, ITmfTimestamp.NANOSECOND_SCALE),
+                new TmfTimestamp(10L, ITmfTimestamp.NANOSECOND_SCALE));
+        model.countLostEvent(timeRange_0, nbLostEvents_0, false);
+
+        final TmfTimeRange timeRange_1 = new TmfTimeRange(
+                new TmfTimestamp(18L, ITmfTimestamp.NANOSECOND_SCALE),
+                new TmfTimestamp(27L, ITmfTimestamp.NANOSECOND_SCALE));
+        model.countLostEvent(timeRange_1, nbLostEvents_1, false);
+
+        HistogramScaledData result = model.scaleTo(nbBuckets, maxHeight, 1);
+
+        assertArrayEquals(expectedResult, result.fData);
+
+        assertArrayEquals(expectedLostEventsResult, result.fLostEventsData);
+
+        testModelConsistency(model, nbBuckets, nbCombinedEvents, 4, 0, 0, nbEvents - 1, 4 * nbBuckets);
+        assertEquals(7, result.fMaxCombinedValue);
+    }
+
+    /**
+     * Test method for {@link HistogramDataModel#scaleTo(int,int,int)}.
+     */
+    @Test
+    public void testLostEventsScaleTo_1() {
+        final int nbBuckets = 10;
+        final int maxHeight = 10;
+        final int nbEvents = 3 * nbBuckets;
+        final int nbLostEvents_0 = 4;
+        final int nbLostEvents_1 = 9;
+        final int nbCombinedEvents = nbEvents + 2;
+        final int[] expectedLostEventsResult = new int[] { 0, 2, 5, 3, 3, 0, 0, 0, 0, 0 };
+
+        HistogramDataModel model = new HistogramDataModel(nbBuckets);
+        countEventsInModel(nbEvents, model);
+
+        final TmfTimeRange timeRange_0 = new TmfTimeRange(
+                new TmfTimestamp(5L, ITmfTimestamp.NANOSECOND_SCALE),
+                new TmfTimestamp(10L, ITmfTimestamp.NANOSECOND_SCALE));
+        model.countLostEvent(timeRange_0, nbLostEvents_0, false);
+
+        final TmfTimeRange timeRange_1 = new TmfTimeRange(
+                new TmfTimestamp(11L, ITmfTimestamp.NANOSECOND_SCALE),
+                new TmfTimestamp(18L, ITmfTimestamp.NANOSECOND_SCALE));
+        model.countLostEvent(timeRange_1, nbLostEvents_1, false);
+
+        HistogramScaledData result = model.scaleTo(nbBuckets, maxHeight, 1);
+
+        assertArrayEquals(expectedLostEventsResult, result.fLostEventsData);
+
+        testModelConsistency(model, nbBuckets, nbCombinedEvents, 4, 0, 0, nbEvents - 1, 4 * nbBuckets);
+        assertEquals(9, result.fMaxCombinedValue);
     }
+
+    /**
+     * Test method for {@link HistogramDataModel#scaleTo(int,int,int)}.
+     */
+    @Test
+    public void testLostEventsScaleTo_2() {
+        final int nbBuckets = 10;
+        final int maxHeight = 10;
+        final int nbEvents = 3 * nbBuckets;
+        final int nbLostEvents_0 = 5;
+        final int nbLostEvents_1 = 15;
+        final int nbLostEvents_2 = 2;
+        final int nbCombinedEvents = nbEvents + 3;
+        final int[] expectedLostEventsResult = new int[] { 0, 0, 3, 3, 6, 5, 3, 2, 0, 0 };
+
+        HistogramDataModel model = new HistogramDataModel(nbBuckets);
+        countEventsInModel(nbEvents, model);
+
+        final TmfTimeRange timeRange_0 = new TmfTimeRange(
+                new TmfTimestamp(18L, ITmfTimestamp.NANOSECOND_SCALE),
+                new TmfTimestamp(22L, ITmfTimestamp.NANOSECOND_SCALE));
+        model.countLostEvent(timeRange_0, nbLostEvents_0, false);
+
+        final TmfTimeRange timeRange_2 = new TmfTimeRange(
+                new TmfTimestamp(28L, ITmfTimestamp.NANOSECOND_SCALE),
+                new TmfTimestamp(29L, ITmfTimestamp.NANOSECOND_SCALE));
+        model.countLostEvent(timeRange_2, nbLostEvents_2, false);
+
+        final TmfTimeRange timeRange_1 = new TmfTimeRange(
+                new TmfTimestamp(11L, ITmfTimestamp.NANOSECOND_SCALE),
+                new TmfTimestamp(26L, ITmfTimestamp.NANOSECOND_SCALE));
+        model.countLostEvent(timeRange_1, nbLostEvents_1, false);
+
+        HistogramScaledData result = model.scaleTo(nbBuckets, maxHeight, 1);
+
+        assertArrayEquals(expectedLostEventsResult, result.fLostEventsData );
+
+        testModelConsistency(model, nbBuckets, nbCombinedEvents, 4, 0, 0, nbEvents - 1, 4 * nbBuckets);
+        assertEquals(10, result.fMaxCombinedValue);
+    }
+
+    /**
+     * Test method for {@link HistogramDataModel#scaleTo(int,int,int)}.
+     */
+    @Test
+    public void testLostEventsScaleTo_3() {
+        final int nbBuckets = 10;
+        final int maxHeight = 10;
+        final int nbEvents = 3 * nbBuckets;
+        final int nbLostEvents_0 = 23;
+        final int nbCombinedEvents = nbEvents + 1;
+        final int[] expectedLostEventsResult = new int[] { 0, 0, 5, 5, 5, 5, 3, 0, 0, 0 };
+
+        HistogramDataModel model = new HistogramDataModel(nbBuckets);
+        countEventsInModel(nbEvents, model);
+
+        final TmfTimeRange timeRange_0 = new TmfTimeRange(
+                new TmfTimestamp(11L, ITmfTimestamp.NANOSECOND_SCALE),
+                new TmfTimestamp(26L, ITmfTimestamp.NANOSECOND_SCALE));
+        model.countLostEvent(timeRange_0, nbLostEvents_0, false);
+
+        HistogramScaledData result = model.scaleTo(nbBuckets, maxHeight, 1);
+
+        assertArrayEquals(expectedLostEventsResult, result.fLostEventsData );
+
+        testModelConsistency(model, nbBuckets, nbCombinedEvents, 4, 0, 0, nbEvents - 1, 4 * nbBuckets);
+        assertEquals(9, result.fMaxCombinedValue);
+    }
+
+    /*
+     * helpers
+     */
+
+    private static void countEventsInModel(final int nbEvents, HistogramDataModel model) {
+        countEventsInModel(nbEvents, model, 0);
+    }
+
+    private static void countEventsInModel(final int nbEvents, HistogramDataModel model, int offset) {
+        countEventsInModel(nbEvents, model, offset, 0);
+    }
+
+    private static void countEventsInModel(final int nbEvents, HistogramDataModel model, int offset, int startTime) {
+        for (int i = startTime; i < nbEvents + startTime; i++) {
+            model.countEvent(i + offset, i);
+        }
+    }
+
+    private static void testModelConsistency(HistogramDataModel model, int numberOfBuckets,int nbEvents, int bucketduration,int firstBucketTime, int startTime, int endTime, int timeLimit) {
+        assertEquals(numberOfBuckets, model.getNbBuckets());
+        assertEquals(nbEvents, model.getNbEvents());
+        assertEquals(bucketduration, model.getBucketDuration());
+        assertEquals(firstBucketTime, model.getFirstBucketTime());
+        assertEquals(startTime, model.getStartTime());
+        assertEquals(endTime, model.getEndTime());
+        assertEquals(timeLimit, model.getTimeLimit());
+    }
+
+    private static void assertArrayEqualsInt(final int val , int[] result) {
+        assertArrayEqualsInt(val, result, 0);
+    }
+
+    private static void assertArrayEqualsInt(final int val , int[] result, int startVal ) {
+        for (int i = startVal; i < result.length; i++) {
+            assertEquals(val, result[i]);
+        }
+    }
+
 }
diff --git a/lttng/org.eclipse.linuxtools.tmf.ui/icons/elcl16/hide_lost_events.gif b/lttng/org.eclipse.linuxtools.tmf.ui/icons/elcl16/hide_lost_events.gif
new file mode 100644
index 0000000000..bb46075ce4
--- /dev/null
+++ b/lttng/org.eclipse.linuxtools.tmf.ui/icons/elcl16/hide_lost_events.gif
diff --git a/lttng/org.eclipse.linuxtools.tmf.ui/src/org/eclipse/linuxtools/internal/tmf/ui/ITmfImageConstants.java b/lttng/org.eclipse.linuxtools.tmf.ui/src/org/eclipse/linuxtools/internal/tmf/ui/ITmfImageConstants.java
index b298260552..1d1f450e45 100755
--- a/lttng/org.eclipse.linuxtools.tmf.ui/src/org/eclipse/linuxtools/internal/tmf/ui/ITmfImageConstants.java
+++ b/lttng/org.eclipse.linuxtools.tmf.ui/src/org/eclipse/linuxtools/internal/tmf/ui/ITmfImageConstants.java
@@ -45,6 +45,7 @@ public interface ITmfImageConstants {
     public static final String IMG_UI_HIDE_ARROWS = ICONS_PATH + "elcl16/hide_arrows.gif";
     public static final String IMG_UI_FOLLOW_ARROW_FORWARD = ICONS_PATH + "elcl16/follow_arrow_fwd.gif";
     public static final String IMG_UI_FOLLOW_ARROW_BACKWARD = ICONS_PATH + "elcl16/follow_arrow_bwd.gif";
+    public static final String IMG_UI_SHOW_LOST_EVENTS = ICONS_PATH + "elcl16/hide_lost_events.gif";
 
     /* eview16 */
     public static final String IMG_UI_SEQ_DIAGRAM_OBJ = ICONS_PATH + "eview16/sequencediagram_view.gif";
diff --git a/lttng/org.eclipse.linuxtools.tmf.ui/src/org/eclipse/linuxtools/tmf/ui/views/histogram/Histogram.java b/lttng/org.eclipse.linuxtools.tmf.ui/src/org/eclipse/linuxtools/tmf/ui/views/histogram/Histogram.java
index 890158d843..6a8cb73c84 100644
--- a/lttng/org.eclipse.linuxtools.tmf.ui/src/org/eclipse/linuxtools/tmf/ui/views/histogram/Histogram.java
+++ b/lttng/org.eclipse.linuxtools.tmf.ui/src/org/eclipse/linuxtools/tmf/ui/views/histogram/Histogram.java
@@ -99,6 +99,7 @@ public abstract class Histogram implements ControlListener, PaintListener, KeyLi
     private final Color fSelectionBackgroundColor = Display.getCurrent().getSystemColor(SWT.COLOR_WIDGET_BACKGROUND);
     private final Color fLastEventColor = Display.getCurrent().getSystemColor(SWT.COLOR_DARK_RED);
     private final Color fHistoBarColor = new Color(Display.getDefault(), 74, 112, 139);
+    private final Color fLostEventColor = new Color(Display.getCurrent(), 208, 62, 120);
 
     // ------------------------------------------------------------------------
     // Attributes
@@ -119,12 +120,12 @@ public abstract class Histogram implements ControlListener, PaintListener, KeyLi
     private Text fTimeRangeEndText;
 
     /**
-     *  Histogram drawing area
+     * Histogram drawing area
      */
     protected Canvas fCanvas;
 
     /**
-     *  The histogram data model.
+     * The histogram data model.
      */
     protected final HistogramDataModel fDataModel;
 
@@ -182,6 +183,7 @@ public abstract class Histogram implements ControlListener, PaintListener, KeyLi
         TmfSignalManager.deregister(this);
 
         fHistoBarColor.dispose();
+        fLastEventColor.dispose();
         fDataModel.removeHistogramListener(this);
     }
 
@@ -332,6 +334,16 @@ public abstract class Histogram implements ControlListener, PaintListener, KeyLi
         return fDataModel;
     }
 
+    /**
+     * Returns the text control for the maximum of events in one bar
+     *
+     * @return the text control
+     * @since 2.1
+     */
+    public Text getMaxNbEventsText() {
+        return fMaxNbEventsText;
+    }
+
     // ------------------------------------------------------------------------
     // Operations
     // ------------------------------------------------------------------------
@@ -355,10 +367,8 @@ public abstract class Histogram implements ControlListener, PaintListener, KeyLi
     /**
      * Increase the histogram bucket corresponding to [timestamp]
      *
-     * @param eventCount
-     *            The new event count
-     * @param timestamp
-     *            The latest timestamp
+     * @param eventCount The new event count
+     * @param timestamp The latest timestamp
      */
     public void countEvent(final long eventCount, final long timestamp) {
         fDataModel.countEvent(eventCount, timestamp);
@@ -367,8 +377,7 @@ public abstract class Histogram implements ControlListener, PaintListener, KeyLi
     /**
      * Sets the current event time and refresh the display
      *
-     * @param timestamp
-     *            The time of the current event
+     * @param timestamp The time of the current event
      * @deprecated As of 2.1, use {@link #setSelection(long, long)}
      */
     @Deprecated
@@ -381,10 +390,8 @@ public abstract class Histogram implements ControlListener, PaintListener, KeyLi
     /**
      * Sets the current selection time range and refresh the display
      *
-     * @param beginTime
-     *            The begin time of the current selection
-     * @param endTime
-     *            The end time of the current selection
+     * @param beginTime The begin time of the current selection
+     * @param endTime The end time of the current selection
      * @since 2.1
      */
     public void setSelection(final long beginTime, final long endTime) {
@@ -431,48 +438,48 @@ public abstract class Histogram implements ControlListener, PaintListener, KeyLi
         int index;
         switch (keyCode) {
 
-            case SWT.HOME:
-                index = 0;
-                while (index < fScaledData.fLastBucket && fScaledData.fData[index] == 0) {
-                    index++;
-                }
-                if (index < fScaledData.fLastBucket) {
-                    fScaledData.fSelectionBeginBucket = index;
-                }
-                break;
+        case SWT.HOME:
+            index = 0;
+            while (index < fScaledData.fLastBucket && fScaledData.fData[index] == 0) {
+                index++;
+            }
+            if (index < fScaledData.fLastBucket) {
+                fScaledData.fSelectionBeginBucket = index;
+            }
+            break;
 
-            case SWT.ARROW_RIGHT:
-                index = Math.max(0, fScaledData.fSelectionBeginBucket + 1);
-                while (index < fScaledData.fWidth && fScaledData.fData[index] == 0) {
-                    index++;
-                }
-                if (index < fScaledData.fLastBucket) {
-                    fScaledData.fSelectionBeginBucket = index;
-                }
-                break;
+        case SWT.ARROW_RIGHT:
+            index = Math.max(0, fScaledData.fSelectionBeginBucket + 1);
+            while (index < fScaledData.fWidth && fScaledData.fData[index] == 0) {
+                index++;
+            }
+            if (index < fScaledData.fLastBucket) {
+                fScaledData.fSelectionBeginBucket = index;
+            }
+            break;
 
-            case SWT.END:
-                index = fScaledData.fLastBucket;
-                while (index >= 0 && fScaledData.fData[index] == 0) {
-                    index--;
-                }
-                if (index >= 0) {
-                    fScaledData.fSelectionBeginBucket = index;
-                }
-                break;
+        case SWT.END:
+            index = fScaledData.fLastBucket;
+            while (index >= 0 && fScaledData.fData[index] == 0) {
+                index--;
+            }
+            if (index >= 0) {
+                fScaledData.fSelectionBeginBucket = index;
+            }
+            break;
 
-            case SWT.ARROW_LEFT:
-                index = Math.min(fScaledData.fLastBucket - 1, fScaledData.fSelectionBeginBucket - 1);
-                while (index >= 0 && fScaledData.fData[index] == 0) {
-                    index--;
-                }
-                if (index >= 0) {
-                    fScaledData.fSelectionBeginBucket = index;
-                }
-                break;
+        case SWT.ARROW_LEFT:
+            index = Math.min(fScaledData.fLastBucket - 1, fScaledData.fSelectionBeginBucket - 1);
+            while (index >= 0 && fScaledData.fData[index] == 0) {
+                index--;
+            }
+            if (index >= 0) {
+                fScaledData.fSelectionBeginBucket = index;
+            }
+            break;
 
-            default:
-                return;
+        default:
+            return;
         }
 
         fScaledData.fSelectionEndBucket = fScaledData.fSelectionBeginBucket;
@@ -499,18 +506,20 @@ public abstract class Histogram implements ControlListener, PaintListener, KeyLi
                         }
                         fDataModel.setSelection(fSelectionBegin, fSelectionEnd);
                         fScaledData = fDataModel.scaleTo(canvasWidth, canvasHeight, 1);
-                        synchronized(fDataModel) {
+                        synchronized (fDataModel) {
                             if (fScaledData != null) {
                                 fCanvas.redraw();
                                 if (fDataModel.getNbEvents() != 0) {
-                                    // Display histogram and update X-,Y-axis labels
+                                    // Display histogram and update X-,Y-axis
+                                    // labels
                                     fTimeRangeStartText.setText(TmfTimestampFormat.getDefaulTimeFormat().format(fDataModel.getFirstBucketTime()));
                                     fTimeRangeEndText.setText(TmfTimestampFormat.getDefaulTimeFormat().format(fDataModel.getEndTime()));
                                 } else {
                                     fTimeRangeStartText.setText(""); //$NON-NLS-1$
                                     fTimeRangeEndText.setText(""); //$NON-NLS-1$
                                 }
-                                fMaxNbEventsText.setText(Long.toString(fScaledData.fMaxValue));
+                                long maxNbEvents = HistogramScaledData.hideLostEvents ? fScaledData.fMaxValue : fScaledData.fMaxCombinedValue;
+                                fMaxNbEventsText.setText(Long.toString(maxNbEvents));
                                 // The Y-axis area might need to be re-sized
                                 fMaxNbEventsText.getParent().layout();
                             }
@@ -599,11 +608,26 @@ public abstract class Histogram implements ControlListener, PaintListener, KeyLi
             imageGC.fillRectangle(0, 0, image.getBounds().width + 1, image.getBounds().height + 1);
 
             // Draw the histogram bars
-            imageGC.setBackground(fHistoBarColor);
             final int limit = width < scaledData.fWidth ? width : scaledData.fWidth;
+            double factor = HistogramScaledData.hideLostEvents ? scaledData.fScalingFactor : scaledData.fScalingFactorCombined;
             for (int i = 0; i < limit; i++) {
-                final int value = (int) Math.ceil(scaledData.fData[i] * scaledData.fScalingFactor);
-                imageGC.fillRectangle(i, height - value, 1, value);
+                imageGC.setForeground(fHistoBarColor);
+                final int value = (int) Math.ceil(scaledData.fData[i] * factor);
+                imageGC.drawLine(i, height - value, i, height);
+
+                if (!HistogramScaledData.hideLostEvents) {
+                    imageGC.setForeground(fLostEventColor);
+                    final int lostEventValue = (int) Math.ceil(scaledData.fLostEventsData[i] * factor);
+                    if (lostEventValue != 0) {
+                        if (lostEventValue == 1) {
+                            // in linux, a line from x to x is not drawn, in windows it is.
+                            imageGC.drawPoint(i, height - value - 1);
+                        } else {
+                            // drawing a line is inclusive, so we need to remove 1 from the destination to have the correct length
+                            imageGC.drawLine(i, height - value - lostEventValue, i, height - value - 1);
+                        }
+                    }
+                }
             }
 
             // Add a dashed line as a delimiter (at the right of the last bar)
@@ -730,15 +754,22 @@ public abstract class Histogram implements ControlListener, PaintListener, KeyLi
         }
         final long endTime = fScaledData.getBucketEndTime(index);
         final int nbEvents = (index >= 0) ? fScaledData.fData[index] : 0;
-
+        final String newLine = System.getProperty("line.separator"); //$NON-NLS-1$
         final StringBuffer buffer = new StringBuffer();
         buffer.append("Range = ["); //$NON-NLS-1$
         buffer.append(new TmfTimestamp(startTime, ITmfTimestamp.NANOSECOND_SCALE).toString());
-        buffer.append(","); //$NON-NLS-1$
+        buffer.append(',');
         buffer.append(new TmfTimestamp(endTime, ITmfTimestamp.NANOSECOND_SCALE).toString());
-        buffer.append(")\n"); //$NON-NLS-1$
+        buffer.append(')');
+        buffer.append(newLine);
         buffer.append("Event count = "); //$NON-NLS-1$
         buffer.append(nbEvents);
+        if (!HistogramScaledData.hideLostEvents) {
+            final int nbLostEvents = (index >= 0) ? fScaledData.fLostEventsData[index] : 0;
+            buffer.append(newLine);
+            buffer.append("Lost events count = "); //$NON-NLS-1$
+            buffer.append(nbLostEvents);
+        }
         return buffer.toString();
     }
 
@@ -763,7 +794,8 @@ public abstract class Histogram implements ControlListener, PaintListener, KeyLi
     /**
      * Format the timestamp and update the display
      *
-     * @param signal the incoming signal
+     * @param signal
+     *            the incoming signal
      * @since 2.0
      */
     @TmfSignalHandler
diff --git a/lttng/org.eclipse.linuxtools.tmf.ui/src/org/eclipse/linuxtools/tmf/ui/views/histogram/HistogramDataModel.java b/lttng/org.eclipse.linuxtools.tmf.ui/src/org/eclipse/linuxtools/tmf/ui/views/histogram/HistogramDataModel.java
index a59b178fa5..f14b1b2a1f 100644
--- a/lttng/org.eclipse.linuxtools.tmf.ui/src/org/eclipse/linuxtools/tmf/ui/views/histogram/HistogramDataModel.java
+++ b/lttng/org.eclipse.linuxtools.tmf.ui/src/org/eclipse/linuxtools/tmf/ui/views/histogram/HistogramDataModel.java
@@ -13,6 +13,7 @@
  *   Francois Chouinard - Moved from LTTng to TMF
  *   Francois Chouinard - Added support for empty initial buckets
  *   Patrick Tasse - Support selection range
+ *   Jean-Christian Kouamé, Simon Delisle - Added support to manage lost events
  *******************************************************************************/
 
 package org.eclipse.linuxtools.tmf.ui.views.histogram;
@@ -20,6 +21,7 @@ package org.eclipse.linuxtools.tmf.ui.views.histogram;
 import java.util.Arrays;
 
 import org.eclipse.core.runtime.ListenerList;
+import org.eclipse.linuxtools.tmf.core.timestamp.TmfTimeRange;
 
 /**
  * Histogram-independent data model.
@@ -49,10 +51,10 @@ import org.eclipse.core.runtime.ListenerList;
  * be fed to the model in any order. If an event has a timestamp less than the
  * <i>basetime</i>, the buckets will be moved to the right to account for the
  * new smaller timestamp. The new <i>basetime</i> is a multiple of the bucket
- * duration smaller then the previous <i>basetime</i>. Note that the <i>basetime</i>
- * might not be anymore a timestamp of an event. If necessary, the buckets will
- * be compacted before moving to the right. This might be necessary to not
- * loose any event counts at the end of the buckets array.
+ * duration smaller then the previous <i>basetime</i>. Note that the
+ * <i>basetime</i> might no longer be the timestamp of an event. If necessary,
+ * the buckets will be compacted before moving to the right. This might be
+ * necessary to not lose any event counts at the end of the buckets array.
  * <p>
  * The mapping from the model to the UI is performed by the <i>scaleTo()</i>
  * method. By keeping the number of buckets <i>n</i> relatively large with
@@ -70,7 +72,7 @@ public class HistogramDataModel implements IHistogramDataModel {
     // ------------------------------------------------------------------------
 
     /**
-     *  The default number of buckets
+     * The default number of buckets
      */
     public static final int DEFAULT_NUMBER_OF_BUCKETS = 16 * 1000;
 
@@ -86,6 +88,7 @@ public class HistogramDataModel implements IHistogramDataModel {
     // Bucket management
     private final int fNbBuckets;
     private final long[] fBuckets;
+    private final long[] fLostEventsBuckets;
     private long fBucketDuration;
     private long fNbEvents;
     private int fLastBucket;
@@ -114,7 +117,9 @@ public class HistogramDataModel implements IHistogramDataModel {
 
     /**
      * Default constructor with default number of buckets.
-     * @param startTime The histogram start time
+     *
+     * @param startTime
+     *            The histogram start time
      * @since 2.0
      */
     public HistogramDataModel(long startTime) {
@@ -123,7 +128,9 @@ public class HistogramDataModel implements IHistogramDataModel {
 
     /**
      * Constructor with non-default number of buckets.
-     * @param nbBuckets A number of buckets.
+     *
+     * @param nbBuckets
+     *            A number of buckets.
      */
     public HistogramDataModel(int nbBuckets) {
         this(0, nbBuckets);
@@ -131,25 +138,32 @@ public class HistogramDataModel implements IHistogramDataModel {
 
     /**
      * Constructor with non-default number of buckets.
-     * @param startTime the histogram start time
-     * @param nbBuckets A number of buckets.
+     *
+     * @param startTime
+     *            the histogram start time
+     * @param nbBuckets
+     *            A number of buckets.
      * @since 2.0
      */
     public HistogramDataModel(long startTime, int nbBuckets) {
         fFirstBucketTime = fFirstEventTime = fLastEventTime = startTime;
         fNbBuckets = nbBuckets;
         fBuckets = new long[nbBuckets];
+        fLostEventsBuckets = new long[nbBuckets];
         fModelListeners = new ListenerList();
         clear();
     }
 
     /**
      * Copy constructor.
-     * @param other A model to copy.
+     *
+     * @param other
+     *            A model to copy.
      */
     public HistogramDataModel(HistogramDataModel other) {
         fNbBuckets = other.fNbBuckets;
         fBuckets = Arrays.copyOf(other.fBuckets, fNbBuckets);
+        fLostEventsBuckets = Arrays.copyOf(other.fLostEventsBuckets, fNbBuckets);
         fBucketDuration = Math.max(other.fBucketDuration, 1);
         fNbEvents = other.fNbEvents;
         fLastBucket = other.fLastBucket;
@@ -172,6 +186,7 @@ public class HistogramDataModel implements IHistogramDataModel {
 
     /**
      * Returns the number of events in the data model.
+     *
      * @return number of events.
      */
     public long getNbEvents() {
@@ -180,22 +195,25 @@ public class HistogramDataModel implements IHistogramDataModel {
 
     /**
      * Returns the number of buckets in the model.
+     *
      * @return number of buckets.
      */
     public int getNbBuckets() {
         return fNbBuckets;
     }
 
-   /**
-    * Returns the current bucket duration.
-    * @return bucket duration
-    */
+    /**
+     * Returns the current bucket duration.
+     *
+     * @return bucket duration
+     */
     public long getBucketDuration() {
         return fBucketDuration;
     }
 
     /**
      * Returns the time value of the first bucket in the model.
+     *
      * @return time of first bucket.
      */
     public long getFirstBucketTime() {
@@ -204,6 +222,7 @@ public class HistogramDataModel implements IHistogramDataModel {
 
     /**
      * Returns the time of the first event in the model.
+     *
      * @return time of first event.
      */
     public long getStartTime() {
@@ -212,8 +231,11 @@ public class HistogramDataModel implements IHistogramDataModel {
 
     /**
      * Sets the model start time
-     * @param startTime the histogram range start time
-     * @param endTime the histogram range end time
+     *
+     * @param startTime
+     *            the histogram range start time
+     * @param endTime
+     *            the histogram range end time
      * @since 2.0
      */
     public void setTimeRange(long startTime, long endTime) {
@@ -227,6 +249,7 @@ public class HistogramDataModel implements IHistogramDataModel {
 
     /**
      * Returns the time of the last event in the model.
+     *
      * @return the time of last event.
      */
     public long getEndTime() {
@@ -235,8 +258,10 @@ public class HistogramDataModel implements IHistogramDataModel {
 
     /**
      * Returns the time of the current event in the model.
+     *
      * @return the time of the current event.
-     * @deprecated As of 2.1, use {@link #getSelectionBegin()} and {@link #getSelectionEnd()}
+     * @deprecated As of 2.1, use {@link #getSelectionBegin()} and
+     *             {@link #getSelectionEnd()}
      */
     @Deprecated
     public long getCurrentEventTime() {
@@ -245,6 +270,7 @@ public class HistogramDataModel implements IHistogramDataModel {
 
     /**
      * Returns the begin time of the current selection in the model.
+     *
      * @return the begin time of the current selection.
      * @since 2.1
      */
@@ -254,6 +280,7 @@ public class HistogramDataModel implements IHistogramDataModel {
 
     /**
      * Returns the end time of the current selection in the model.
+     *
      * @return the end time of the current selection.
      * @since 2.1
      */
@@ -263,6 +290,7 @@ public class HistogramDataModel implements IHistogramDataModel {
 
     /**
      * Returns the time limit with is: start time + nbBuckets * bucketDuration
+     *
      * @return the time limit.
      */
     public long getTimeLimit() {
@@ -275,7 +303,9 @@ public class HistogramDataModel implements IHistogramDataModel {
 
     /**
      * Add a listener to the model to be informed about model changes.
-     * @param listener A listener to add.
+     *
+     * @param listener
+     *            A listener to add.
      */
     public void addHistogramListener(IHistogramModelListener listener) {
         fModelListeners.add(listener);
@@ -283,7 +313,9 @@ public class HistogramDataModel implements IHistogramDataModel {
 
     /**
      * Remove a given model listener.
-     * @param listener A listener to remove.
+     *
+     * @param listener
+     *            A listener to remove.
      */
     public void removeHistogramListener(IHistogramModelListener listener) {
         fModelListeners.remove(listener);
@@ -316,11 +348,13 @@ public class HistogramDataModel implements IHistogramDataModel {
 
     /**
      * Clear the histogram model.
+     *
      * @see org.eclipse.linuxtools.tmf.ui.views.distribution.model.IBaseDistributionModel#clear()
      */
     @Override
     public void clear() {
         Arrays.fill(fBuckets, 0);
+        Arrays.fill(fLostEventsBuckets, 0);
         fNbEvents = 0;
         fFirstBucketTime = 0;
         fLastEventTime = 0;
@@ -335,7 +369,8 @@ public class HistogramDataModel implements IHistogramDataModel {
     /**
      * Sets the current event time (no notification of listeners)
      *
-     * @param timestamp A time stamp to set.
+     * @param timestamp
+     *            A time stamp to set.
      * @deprecated As of 2.1, use {@link #setSelection(long, long)}
      */
     @Deprecated
@@ -347,8 +382,10 @@ public class HistogramDataModel implements IHistogramDataModel {
     /**
      * Sets the current event time with notification of listeners
      *
-     * @param timestamp A time stamp to set.
-     * @deprecated As of 2.1, use {@link #setSelectionNotifyListeners(long, long)}
+     * @param timestamp
+     *            A time stamp to set.
+     * @deprecated As of 2.1, use
+     *             {@link #setSelectionNotifyListeners(long, long)}
      */
     @Deprecated
     public void setCurrentEventNotifyListeners(long timestamp) {
@@ -360,8 +397,10 @@ public class HistogramDataModel implements IHistogramDataModel {
     /**
      * Sets the current selection time range (no notification of listeners)
      *
-     * @param beginTime The selection begin time.
-     * @param endTime The selection end time.
+     * @param beginTime
+     *            The selection begin time.
+     * @param endTime
+     *            The selection end time.
      * @since 2.1
      */
     public void setSelection(long beginTime, long endTime) {
@@ -372,8 +411,10 @@ public class HistogramDataModel implements IHistogramDataModel {
     /**
      * Sets the current selection time range with notification of listeners
      *
-     * @param beginTime The selection begin time.
-     * @param endTime The selection end time.
+     * @param beginTime
+     *            The selection begin time.
+     * @param endTime
+     *            The selection end time.
      * @since 2.1
      */
     public void setSelectionNotifyListeners(long beginTime, long endTime) {
@@ -385,8 +426,10 @@ public class HistogramDataModel implements IHistogramDataModel {
     /**
      * Add event to the correct bucket, compacting the if needed.
      *
-     * @param eventCount The current event Count (for notification purposes)
-     * @param timestamp The timestamp of the event to count
+     * @param eventCount
+     *            The current event Count (for notification purposes)
+     * @param timestamp
+     *            The timestamp of the event to count
      *
      */
     @Override
@@ -425,7 +468,7 @@ public class HistogramDataModel implements IHistogramDataModel {
             int offset = getOffset(timestamp);
 
             // Compact as needed
-            while((fLastBucket + offset) >= fNbBuckets) {
+            while ((fLastBucket + offset) >= fNbBuckets) {
                 mergeBuckets();
                 offset = getOffset(timestamp);
             }
@@ -434,7 +477,7 @@ public class HistogramDataModel implements IHistogramDataModel {
 
             fLastBucket = fLastBucket + offset;
 
-            fFirstBucketTime = fFirstBucketTime - (offset*fBucketDuration);
+            fFirstBucketTime = fFirstBucketTime - (offset * fBucketDuration);
             updateEndTime();
         }
 
@@ -450,20 +493,71 @@ public class HistogramDataModel implements IHistogramDataModel {
     }
 
     /**
+     * Add lost event to the correct bucket, compacting the if needed.
+     *
+     * @param timeRange
+     *            time range of a lost event
+     * @param nbLostEvents
+     *            the number of lost events
+     * @param fullRange
+     *            Full range or time range for histogram request
+     * @since 2.1
+     */
+    public void countLostEvent(TmfTimeRange timeRange, long nbLostEvents, boolean fullRange) {
+
+        // Validate
+        if (timeRange.getStartTime().getValue() < 0 || timeRange.getEndTime().getValue() < 0) {
+            return;
+        }
+
+        // Compact as needed
+        if (fullRange) {
+            while (timeRange.getEndTime().getValue() >= fTimeLimit) {
+                mergeBuckets();
+            }
+        }
+
+        int indexStart = (int) ((timeRange.getStartTime().getValue() - fFirstBucketTime) / fBucketDuration);
+        int indexEnd = (int) ((timeRange.getEndTime().getValue() - fFirstBucketTime) / fBucketDuration);
+        int nbBucketRange = (indexEnd - indexStart) + 1;
+
+        int lostEventPerBucket = (int) Math.ceil((double) nbLostEvents / nbBucketRange);
+        long lastLostCol = Math.max(1, nbLostEvents - lostEventPerBucket * (nbBucketRange - 1));
+
+        // Increment the right bucket, bear in mind that ranges make it almost certain that some lost events are out of range
+        for (int index = indexStart; index <= indexEnd && index < fLostEventsBuckets.length; index++) {
+            if (index == (indexStart + nbBucketRange - 1)) {
+                fLostEventsBuckets[index] += lastLostCol;
+            } else {
+                fLostEventsBuckets[index] += lostEventPerBucket;
+            }
+        }
+
+        fNbEvents++;
+
+        fireModelUpdateNotification(nbLostEvents);
+    }
+
+    /**
      * Scale the model data to the width, height and bar width requested.
      *
-     * @param width A width of the histogram canvas
-     * @param height A height of the histogram canvas
-     * @param barWidth A width (in pixel) of a histogram bar
-     * @return the result array of size [width] and where the highest value doesn't exceed [height]
+     * @param width
+     *            A width of the histogram canvas
+     * @param height
+     *            A height of the histogram canvas
+     * @param barWidth
+     *            A width (in pixel) of a histogram bar
+     * @return the result array of size [width] and where the highest value
+     *         doesn't exceed [height]
      *
-     * @see org.eclipse.linuxtools.tmf.ui.views.histogram.IHistogramDataModel#scaleTo(int, int, int)
+     * @see org.eclipse.linuxtools.tmf.ui.views.histogram.IHistogramDataModel#scaleTo(int,
+     *      int, int)
      */
     @Override
     public HistogramScaledData scaleTo(int width, int height, int barWidth) {
         // Basic validation
-        if ((width <= 0) ||  (height <= 0) || (barWidth <= 0))
-         {
+        if ((width <= 0) || (height <= 0) || (barWidth <= 0))
+        {
             throw new AssertionError("Invalid histogram dimensions (" + width + "x" + height + ", barWidth=" + barWidth + ")"); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$
         }
 
@@ -475,26 +569,35 @@ public class HistogramDataModel implements IHistogramDataModel {
 
         int nbBars = width / barWidth;
         int bucketsPerBar = (fLastBucket / nbBars) + 1;
-        result.fBucketDuration = Math.max(bucketsPerBar * fBucketDuration,1);
+        result.fBucketDuration = Math.max(bucketsPerBar * fBucketDuration, 1);
         for (int i = 0; i < nbBars; i++) {
             int count = 0;
+            int countLostEvent = 0;
             for (int j = i * bucketsPerBar; j < ((i + 1) * bucketsPerBar); j++) {
                 if (fNbBuckets <= j) {
                     break;
                 }
                 count += fBuckets[j];
+                countLostEvent += fLostEventsBuckets[j];
             }
             result.fData[i] = count;
+            result.fLostEventsData[i] = countLostEvent;
             result.fLastBucket = i;
             if (result.fMaxValue < count) {
                 result.fMaxValue = count;
             }
+            if (result.fMaxCombinedValue < count + countLostEvent) {
+                result.fMaxCombinedValue = count + countLostEvent;
+            }
         }
 
         // Scale vertically
         if (result.fMaxValue > 0) {
             result.fScalingFactor = (double) height / result.fMaxValue;
         }
+        if (result.fMaxCombinedValue > 0) {
+            result.fScalingFactorCombined = (double) height / result.fMaxCombinedValue;
+        }
 
         fBucketDuration = Math.max(fBucketDuration, 1);
         // Set selection begin and end index in the scaled histogram
@@ -529,20 +632,24 @@ public class HistogramDataModel implements IHistogramDataModel {
     private void mergeBuckets() {
         for (int i = 0; i < (fNbBuckets / 2); i++) {
             fBuckets[i] = fBuckets[2 * i] + fBuckets[(2 * i) + 1];
+            fLostEventsBuckets[i] = fLostEventsBuckets[2 * i] + fLostEventsBuckets[(2 * i) + 1];
         }
         Arrays.fill(fBuckets, fNbBuckets / 2, fNbBuckets, 0);
+        Arrays.fill(fLostEventsBuckets, fNbBuckets / 2, fNbBuckets, 0);
         fBucketDuration *= 2;
         updateEndTime();
         fLastBucket = (fNbBuckets / 2) - 1;
     }
 
     private void moveBuckets(int offset) {
-        for(int i = fNbBuckets - 1; i >= offset; i--) {
-            fBuckets[i] = fBuckets[i-offset];
+        for (int i = fNbBuckets - 1; i >= offset; i--) {
+            fBuckets[i] = fBuckets[i - offset];
+            fLostEventsBuckets[i] = fLostEventsBuckets[i - offset];
         }
 
         for (int i = 0; i < offset; i++) {
             fBuckets[i] = 0;
+            fLostEventsBuckets[i] = 0;
         }
     }
 
@@ -553,5 +660,4 @@ public class HistogramDataModel implements IHistogramDataModel {
         }
         return offset;
     }
-
 }
diff --git a/lttng/org.eclipse.linuxtools.tmf.ui/src/org/eclipse/linuxtools/tmf/ui/views/histogram/HistogramRequest.java b/lttng/org.eclipse.linuxtools.tmf.ui/src/org/eclipse/linuxtools/tmf/ui/views/histogram/HistogramRequest.java
index 7df67cb160..3bfe26d372 100644
--- a/lttng/org.eclipse.linuxtools.tmf.ui/src/org/eclipse/linuxtools/tmf/ui/views/histogram/HistogramRequest.java
+++ b/lttng/org.eclipse.linuxtools.tmf.ui/src/org/eclipse/linuxtools/tmf/ui/views/histogram/HistogramRequest.java
@@ -11,11 +11,13 @@
  *   Yuriy Vashchuk - Heritage correction.
  *   Francois Chouinard - Cleanup and refactoring
  *   Francois Chouinard - Moved from LTTng to TMF
+ *   Simon Delisle - Added a new parameter to the constructor
  *******************************************************************************/
 
 package org.eclipse.linuxtools.tmf.ui.views.histogram;
 
 import org.eclipse.linuxtools.tmf.core.event.ITmfEvent;
+import org.eclipse.linuxtools.tmf.core.event.ITmfLostEvent;
 import org.eclipse.linuxtools.tmf.core.request.ITmfDataRequest;
 import org.eclipse.linuxtools.tmf.core.request.TmfEventRequest;
 import org.eclipse.linuxtools.tmf.core.timestamp.ITmfTimestamp;
@@ -23,11 +25,12 @@ import org.eclipse.linuxtools.tmf.core.timestamp.TmfTimeRange;
 import org.eclipse.linuxtools.tmf.core.trace.ITmfTrace;
 
 /**
- * Class to request events for given time range from a trace to fill a HistogramDataModel and HistogramView.
+ * Class to request events for given time range from a trace to fill a
+ * HistogramDataModel and HistogramView.
  *
  * @version 1.0
  * @author Francois Chouinard
- * <p>
+ *         <p>
  */
 public class HistogramRequest extends TmfEventRequest {
 
@@ -40,6 +43,8 @@ public class HistogramRequest extends TmfEventRequest {
      */
     protected final HistogramDataModel fHistogram;
 
+    private final boolean fFullRange;
+
     // ------------------------------------------------------------------------
     // Constructor
     // ------------------------------------------------------------------------
@@ -62,6 +67,7 @@ public class HistogramRequest extends TmfEventRequest {
      * @since 2.0
      *
      */
+    @Deprecated
     public HistogramRequest(HistogramDataModel histogram, TmfTimeRange range,
             int rank, int nbEvents, int blockSize,
             ITmfDataRequest.ExecutionType execType) {
@@ -69,6 +75,41 @@ public class HistogramRequest extends TmfEventRequest {
                 (blockSize > 0) ? blockSize : ITmfTrace.DEFAULT_TRACE_CACHE_SIZE,
                 execType);
         fHistogram = histogram;
+        if (execType == ExecutionType.FOREGROUND) {
+            fFullRange = false;
+        } else {
+            fFullRange = true;
+        }
+    }
+
+    /**
+     * Constructor
+     *
+     * @param histogram
+     *            The histogram data model
+     * @param range
+     *            The time range to request data
+     * @param rank
+     *            The index of the first event to retrieve
+     * @param nbEvents
+     *            The number of events requested
+     * @param blockSize
+     *            The number of events per block
+     * @param execType
+     *            The requested execution priority
+     * @param fullRange
+     *            Full range or time range for histogram request
+     * @since 2.1
+     *
+     */
+    public HistogramRequest(HistogramDataModel histogram, TmfTimeRange range,
+            int rank, int nbEvents, int blockSize,
+            ITmfDataRequest.ExecutionType execType, boolean fullRange) {
+        super(ITmfEvent.class, range, rank, nbEvents,
+                (blockSize > 0) ? blockSize : ITmfTrace.DEFAULT_TRACE_CACHE_SIZE,
+                execType);
+        fHistogram = histogram;
+        fFullRange = fullRange;
     }
 
     // ------------------------------------------------------------------------
@@ -78,20 +119,29 @@ public class HistogramRequest extends TmfEventRequest {
     /**
      * Handle the event from the trace by updating the histogram data model.
      *
-     * @param event a event from the trace
+     * @param event
+     *            a event from the trace
      * @see org.eclipse.linuxtools.tmf.core.request.TmfDataRequest#handleData(org.eclipse.linuxtools.tmf.core.event.ITmfEvent)
      */
     @Override
     public void handleData(ITmfEvent event) {
         super.handleData(event);
         if (event != null) {
-            long timestamp = event.getTimestamp().normalize(0, ITmfTimestamp.NANOSECOND_SCALE).getValue();
-            fHistogram.countEvent(getNbRead(), timestamp);
+            if (event instanceof ITmfLostEvent) {
+                ITmfLostEvent lostEvents = (ITmfLostEvent) event;
+                /* clear the old data when it is a new request */
+                fHistogram.countLostEvent(lostEvents.getTimeRange(), lostEvents.getNbLostEvents(), fFullRange);
+
+            } else { /* handle lost event */
+                long timestamp = event.getTimestamp().normalize(0, ITmfTimestamp.NANOSECOND_SCALE).getValue();
+                fHistogram.countEvent(getNbRead(), timestamp);
+            }
         }
     }
 
     /**
-     * Complete the request. It also notifies the histogram model about the completion.
+     * Complete the request. It also notifies the histogram model about the
+     * completion.
      *
      * @see org.eclipse.linuxtools.tmf.core.request.TmfDataRequest#handleCompleted()
      */
diff --git a/lttng/org.eclipse.linuxtools.tmf.ui/src/org/eclipse/linuxtools/tmf/ui/views/histogram/HistogramScaledData.java b/lttng/org.eclipse.linuxtools.tmf.ui/src/org/eclipse/linuxtools/tmf/ui/views/histogram/HistogramScaledData.java
index 52487a7b6a..491529ac6a 100644
--- a/lttng/org.eclipse.linuxtools.tmf.ui/src/org/eclipse/linuxtools/tmf/ui/views/histogram/HistogramScaledData.java
+++ b/lttng/org.eclipse.linuxtools.tmf.ui/src/org/eclipse/linuxtools/tmf/ui/views/histogram/HistogramScaledData.java
@@ -11,6 +11,7 @@
  *   Bernd Hufmann - Added setter and getter and bar width support
  *   Francois Chouinard - Moved from LTTng to TMF
  *   Patrick Tasse - Support selection range
+ *   Jean-Christian Kouamé - Support to manage lost events
  *******************************************************************************/
 
 package org.eclipse.linuxtools.tmf.ui.views.histogram;
@@ -54,6 +55,12 @@ public class HistogramScaledData {
      */
     public int[] fData;
     /**
+     * Array of scaled values combined including the lost events.
+     * This array contains the number of lost events for each bar in the histogram
+     * @since 2.1
+     */
+    public final int[] fLostEventsData;
+    /**
      * The bucket duration of a scaled data bucket.
      */
     public long fBucketDuration;
@@ -62,6 +69,11 @@ public class HistogramScaledData {
      */
     public long fMaxValue;
     /**
+     * the maximum of events of all buckets including the lost events
+     * @since 2.1
+     */
+    public long fMaxCombinedValue;
+    /**
      * The index of the current bucket.
      */
     @Deprecated
@@ -85,6 +97,14 @@ public class HistogramScaledData {
      */
     public double fScalingFactor;
     /**
+     * The scaling factor used to fill the scaled data including the lost events.
+     * @since 2.1
+     */
+    public double fScalingFactorCombined;
+    /**
+     * The scaling factor used to fill the combining scaled data including lost events
+     */
+    /**
      * Time of first bucket.
      */
     public long fFirstBucketTime;
@@ -92,7 +112,11 @@ public class HistogramScaledData {
      * The time of the first event.
      */
     public long fFirstEventTime;
-
+    /**
+     * show the lost events or not
+     * @since 2.1
+     */
+    public static volatile boolean hideLostEvents = false;
     // ------------------------------------------------------------------------
     // Constructor
     // ------------------------------------------------------------------------
@@ -107,14 +131,16 @@ public class HistogramScaledData {
         fWidth = width;
         fHeight = height;
         fBarWidth = barWidth;
-        fData = new int[width/fBarWidth];
-        Arrays.fill(fData, 0);
+        fData = new int[width / fBarWidth];
+        fLostEventsData = new int[width / fBarWidth];
         fBucketDuration = 1;
         fMaxValue = 0;
+        fMaxCombinedValue = 0;
         fSelectionBeginBucket = 0;
         fSelectionEndBucket = 0;
         fLastBucket = 0;
         fScalingFactor = 1;
+        fScalingFactorCombined = 1;
         fFirstBucketTime = 0;
     }
 
@@ -126,13 +152,16 @@ public class HistogramScaledData {
         fWidth = other.fWidth;
         fHeight = other.fHeight;
         fBarWidth = other.fBarWidth;
-        fData = Arrays.copyOf(other.fData, fWidth);
+        fData = Arrays.copyOf(other.fData, other.fData.length);
+        fLostEventsData  = Arrays.copyOf(other.fLostEventsData, other.fLostEventsData.length);
         fBucketDuration = other.fBucketDuration;
         fMaxValue = other.fMaxValue;
+        fMaxCombinedValue = other.fMaxCombinedValue;
         fSelectionBeginBucket = other.fSelectionBeginBucket;
         fSelectionEndBucket = other.fSelectionEndBucket;
         fLastBucket = other.fLastBucket;
         fScalingFactor = other.fScalingFactor;
+        fScalingFactorCombined = other.fScalingFactorCombined;
         fFirstBucketTime = other.fFirstBucketTime;
     }
 
@@ -181,4 +210,4 @@ public class HistogramScaledData {
     public long getBucketEndTime(int index) {
         return getBucketStartTime(index) + fBucketDuration;
     }
-}
\ No newline at end of file
+}
diff --git a/lttng/org.eclipse.linuxtools.tmf.ui/src/org/eclipse/linuxtools/tmf/ui/views/histogram/HistogramView.java b/lttng/org.eclipse.linuxtools.tmf.ui/src/org/eclipse/linuxtools/tmf/ui/views/histogram/HistogramView.java
index e41d14c6c3..e286232999 100644
--- a/lttng/org.eclipse.linuxtools.tmf.ui/src/org/eclipse/linuxtools/tmf/ui/views/histogram/HistogramView.java
+++ b/lttng/org.eclipse.linuxtools.tmf.ui/src/org/eclipse/linuxtools/tmf/ui/views/histogram/HistogramView.java
@@ -18,6 +18,11 @@
 
 package org.eclipse.linuxtools.tmf.ui.views.histogram;
 
+import org.eclipse.jface.action.Action;
+import org.eclipse.jface.action.IAction;
+import org.eclipse.jface.action.Separator;
+import org.eclipse.linuxtools.internal.tmf.ui.Activator;
+import org.eclipse.linuxtools.internal.tmf.ui.ITmfImageConstants;
 import org.eclipse.linuxtools.tmf.core.request.ITmfDataRequest.ExecutionType;
 import org.eclipse.linuxtools.tmf.core.request.TmfDataRequest;
 import org.eclipse.linuxtools.tmf.core.signal.TmfRangeSynchSignal;
@@ -39,6 +44,7 @@ import org.eclipse.swt.events.MouseWheelListener;
 import org.eclipse.swt.layout.GridData;
 import org.eclipse.swt.layout.GridLayout;
 import org.eclipse.swt.widgets.Composite;
+import org.eclipse.ui.IActionBars;
 
 /**
  * The purpose of this view is to provide graphical time distribution statistics about the trace events.
@@ -101,6 +107,9 @@ public class HistogramView extends TmfView {
     private final TmfSignalThrottler fTimeSyncThrottle;
     private final TmfSignalThrottler fTimeRangeSyncThrottle;
 
+    // Action for toggle showing the lost events
+    private Action hideLostEventsAction;
+
     // ------------------------------------------------------------------------
     // Constructor
     // ------------------------------------------------------------------------
@@ -251,6 +260,10 @@ public class HistogramView extends TmfView {
         MouseWheelListener listener = fFullTraceHistogram.getZoom();
         fTimeSpanControl.addMouseWheelListener(listener);
 
+
+        // View Action Handling
+        contributeToActionBars();
+
         ITmfTrace trace = getActiveTrace();
         if (trace != null) {
             traceSelected(new TmfTraceSelectedSignal(this, trace));
@@ -292,6 +305,36 @@ public class HistogramView extends TmfView {
                 new TmfTimestamp(fWindowEndTime, ITmfTimestamp.NANOSECOND_SCALE));
     }
 
+    /**
+     * get the show lost events action
+     *
+     * @return The action object
+     * @since 2.1
+     */
+    public Action getShowLostEventsAction() {
+        if (hideLostEventsAction == null) {
+            /* show lost events */
+            hideLostEventsAction = new Action(Messages.HistogramView_hideLostEvents, IAction.AS_CHECK_BOX) {
+                @Override
+                public void run() {
+                    HistogramScaledData.hideLostEvents = hideLostEventsAction.isChecked();
+                    long maxNbEvents = HistogramScaledData.hideLostEvents ? fFullTraceHistogram.fScaledData.fMaxValue : fFullTraceHistogram.fScaledData.fMaxCombinedValue;
+                    fFullTraceHistogram.getMaxNbEventsText().setText(Long.toString(maxNbEvents));
+                    fFullTraceHistogram.getMaxNbEventsText().getParent().layout();
+                    fFullTraceHistogram.fCanvas.redraw();
+                    maxNbEvents = HistogramScaledData.hideLostEvents ? fTimeRangeHistogram.fScaledData.fMaxValue : fTimeRangeHistogram.fScaledData.fMaxCombinedValue;
+                    fTimeRangeHistogram.getMaxNbEventsText().setText(Long.toString(maxNbEvents));
+                    fTimeRangeHistogram.getMaxNbEventsText().getParent().layout();
+                    fTimeRangeHistogram.fCanvas.redraw();
+                }
+            };
+            hideLostEventsAction.setText(Messages.HistogramView_hideLostEvents);
+            hideLostEventsAction.setToolTipText(Messages.HistogramView_hideLostEvents);
+            hideLostEventsAction.setImageDescriptor(Activator.getDefault().getImageDescripterFromPath(ITmfImageConstants.IMG_UI_SHOW_LOST_EVENTS));
+        }
+        return hideLostEventsAction;
+    }
+
     // ------------------------------------------------------------------------
     // Operations
     // ------------------------------------------------------------------------
@@ -615,7 +658,7 @@ public class HistogramView extends TmfView {
         fTimeRangeHistogram.setTimeRange(startTime, endTime - startTime);
 
         int cacheSize = fTrace.getCacheSize();
-        fTimeRangeRequest = new HistogramRequest(fTimeRangeHistogram.getDataModel(), timeRange, 0, TmfDataRequest.ALL_DATA, cacheSize, ExecutionType.FOREGROUND);
+        fTimeRangeRequest = new HistogramRequest(fTimeRangeHistogram.getDataModel(), timeRange, 0, TmfDataRequest.ALL_DATA, cacheSize, ExecutionType.FOREGROUND, false);
         fTrace.sendRequest(fTimeRangeRequest);
     }
 
@@ -625,8 +668,14 @@ public class HistogramView extends TmfView {
         }
         int cacheSize = fTrace.getCacheSize();
         fFullTraceRequest = new HistogramRequest(fFullTraceHistogram.getDataModel(), fullRange, (int) fFullTraceHistogram.fDataModel.getNbEvents(),
-                TmfDataRequest.ALL_DATA, cacheSize, ExecutionType.BACKGROUND);
+                TmfDataRequest.ALL_DATA, cacheSize, ExecutionType.BACKGROUND, true);
         fTrace.sendRequest(fFullTraceRequest);
     }
 
+    private void contributeToActionBars() {
+        IActionBars bars = getViewSite().getActionBars();
+        bars.getToolBarManager().add(getShowLostEventsAction());
+        bars.getToolBarManager().add(new Separator());
+    }
+
 }
diff --git a/lttng/org.eclipse.linuxtools.tmf.ui/src/org/eclipse/linuxtools/tmf/ui/views/histogram/Messages.java b/lttng/org.eclipse.linuxtools.tmf.ui/src/org/eclipse/linuxtools/tmf/ui/views/histogram/Messages.java
index e5c520ec91..fbb626ecfe 100644
--- a/lttng/org.eclipse.linuxtools.tmf.ui/src/org/eclipse/linuxtools/tmf/ui/views/histogram/Messages.java
+++ b/lttng/org.eclipse.linuxtools.tmf.ui/src/org/eclipse/linuxtools/tmf/ui/views/histogram/Messages.java
@@ -19,6 +19,7 @@ import org.eclipse.osgi.util.NLS;
 /**
  * Messages file for the histogram widgets.
  * <p>
+ *
  * @version 1.0
  * @author Francois Chouinard
  */
@@ -28,15 +29,19 @@ public class Messages extends NLS {
     // Constants
     // ------------------------------------------------------------------------
 
-	private static final String BUNDLE_NAME = "org.eclipse.linuxtools.tmf.ui.views.histogram.messages"; //$NON-NLS-1$
-
-	/**
-	 * The label for the current event time
-	 */
-	public static String HistogramView_currentEventLabel;
-	/**
-	 * The label for the window span.
-	 */
+    private static final String BUNDLE_NAME = "org.eclipse.linuxtools.tmf.ui.views.histogram.messages"; //$NON-NLS-1$
+
+    /**
+     * @since 2.1
+     */
+    public static String HistogramView_hideLostEvents;
+    /**
+     * The label for the current event time
+     */
+    public static String HistogramView_currentEventLabel;
+    /**
+     * The label for the window span.
+     */
     public static String HistogramView_windowSpanLabel;
 
     // ------------------------------------------------------------------------
diff --git a/lttng/org.eclipse.linuxtools.tmf.ui/src/org/eclipse/linuxtools/tmf/ui/views/histogram/messages.properties b/lttng/org.eclipse.linuxtools.tmf.ui/src/org/eclipse/linuxtools/tmf/ui/views/histogram/messages.properties
index 0bba1e6fd9..89e95bb6a8 100644
--- a/lttng/org.eclipse.linuxtools.tmf.ui/src/org/eclipse/linuxtools/tmf/ui/views/histogram/messages.properties
+++ b/lttng/org.eclipse.linuxtools.tmf.ui/src/org/eclipse/linuxtools/tmf/ui/views/histogram/messages.properties
@@ -10,5 +10,6 @@
 #     Ericsson - Initial API and implementation
 ###############################################################################
 
+HistogramView_hideLostEvents=Hide Lost Events
 HistogramView_currentEventLabel=Current Event
-HistogramView_windowSpanLabel=Window Span
+HistogramView_windowSpanLabel=Window Span
\ No newline at end of file