[#8663] Fix to generate DummySpanEvent on stack overflow of callstack

profiler/src/main/java/com/navercorp/pinpoint/profiler/context/CallStack.java

@@ -36,6 +36,8 @@ public interface CallStack<T> {
 
     int getMaxSequence();
 
+    T newInstance();
+
     Factory<T> getFactory();
 
     interface Factory<T> {

profiler/src/main/java/com/navercorp/pinpoint/profiler/context/DefaultCallStack.java

@@ -165,6 +165,15 @@ private boolean isSequenceOverflow() {
         return maxSequence != -1 && maxSequence <= sequence;
     }
 
+    @Override
+    public T newInstance() {
+        if (isOverflow()) {
+            return factory.dummyInstance();
+        } else {
+            return factory.newInstance();
+        }
+    }
+
     @Override
     public Factory<T> getFactory() {
         return factory;

profiler/src/main/java/com/navercorp/pinpoint/profiler/context/DefaultTrace.java

@@ -273,7 +273,7 @@ public SpanEventRecorder currentSpanEventRecorder() {
     }
 
     private SpanEvent newSpanEvent(int stackId) {
-        final SpanEvent spanEvent = callStack.getFactory().newInstance();
+        final SpanEvent spanEvent = callStack.newInstance();
         spanEvent.markStartTime();
         spanEvent.setStackId(stackId);
         return spanEvent;

profiler/src/test/java/com/navercorp/pinpoint/profiler/context/CallStackTest.java

@@ -103,7 +103,17 @@ public void testPop_Fail() {
         callStack.pop();
         assertNull(callStack.pop());
     }
-
+
+    @Test
+    public void newInstance() {
+        CallStack<SpanEvent> callStack = newCallStack(0);
+        SpanEvent spanEvent1 = callStack.newInstance();
+        callStack.push(spanEvent1);
+
+        SpanEvent spanEvent2 = callStack.newInstance();
+        Assert.assertTrue(callStack.getFactory().isDummy(spanEvent2));
+    }
+
     @Test
     public void overflow() {
         final int maxDepth = 3;