Ignore trailing sleeping samples for duration estimation (#413)

2 files changed, 12 insertions, 2 deletions

diff --git a/spark-common/src/main/java/me/lucko/spark/common/sampler/java/JavaDataAggregator.java b/spark-common/src/main/java/me/lucko/spark/common/sampler/java/JavaDataAggregator.java
index c51ec05..b7b841e 100644
--- a/spark-common/src/main/java/me/lucko/spark/common/sampler/java/JavaDataAggregator.java
+++ b/spark-common/src/main/java/me/lucko/spark/common/sampler/java/JavaDataAggregator.java
@@ -99,7 +99,7 @@ public abstract class JavaDataAggregator extends AbstractDataAggregator {
         return super.exportData();
     }
 
-    private static boolean isSleeping(ThreadInfo thread) {
+    static boolean isSleeping(ThreadInfo thread) {
         if (thread.getThreadState() == Thread.State.WAITING || thread.getThreadState() == Thread.State.TIMED_WAITING) {
             return true;
         }
diff --git a/spark-common/src/main/java/me/lucko/spark/common/sampler/java/TickedDataAggregator.java b/spark-common/src/main/java/me/lucko/spark/common/sampler/java/TickedDataAggregator.java
index 08cb719..f24af3f 100644
--- a/spark-common/src/main/java/me/lucko/spark/common/sampler/java/TickedDataAggregator.java
+++ b/spark-common/src/main/java/me/lucko/spark/common/sampler/java/TickedDataAggregator.java
@@ -110,7 +110,7 @@ public class TickedDataAggregator extends JavaDataAggregator {
         }
 
         // approximate how long the tick lasted
-        int tickLengthMicros = currentData.getList().size() * this.interval;
+        int tickLengthMicros = currentData.sizeWithoutTrailingSleeping() * this.interval;
 
         // don't push data below the threshold
         if (tickLengthMicros < this.tickLengthThreshold) {
@@ -151,6 +151,16 @@ public class TickedDataAggregator extends JavaDataAggregator {
             return this.list;
         }
 
+        public int sizeWithoutTrailingSleeping() {
+            // find the last index at which the thread wasn't sleeping
+            for (int i = this.list.size() - 1; i >= 0; i--) {
+                if (!isSleeping(this.list.get(i))) {
+                    return i + 1; // add one to go from index to size
+                }
+            }
+            return 0;
+        }
+
         public void addData(ThreadInfo data) {
             this.list.add(data);
         }