From a8cce319dbb22fe70fbd8cb1ac81bf328096e5e3 Mon Sep 17 00:00:00 2001
From: Wojciech Baran <wojciech.baran@tomtom.com>
Date: Thu, 5 Jul 2018 14:06:42 +0200
Subject: [PATCH] Fixed the wrong calculation of methodExecutionTime

---
 .../newagent/MethodExecutionTimeHelper.java   | 47 +++++++++++++++++++
 .../james/newagent/james/GroovyJames.java     | 11 ++---
 2 files changed, 51 insertions(+), 7 deletions(-)
 create mode 100644 james-agent/src/main/java/com/tomtom/james/newagent/MethodExecutionTimeHelper.java

diff --git a/james-agent/src/main/java/com/tomtom/james/newagent/MethodExecutionTimeHelper.java b/james-agent/src/main/java/com/tomtom/james/newagent/MethodExecutionTimeHelper.java
new file mode 100644
index 0000000..13353a7
--- /dev/null
+++ b/james-agent/src/main/java/com/tomtom/james/newagent/MethodExecutionTimeHelper.java
@@ -0,0 +1,47 @@
+/*
+ * Copyright 2017 TomTom International B.V.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.tomtom.james.newagent;
+
+import java.util.ArrayDeque;
+import java.util.Deque;
+import java.util.function.Supplier;
+
+public final class MethodExecutionTimeHelper {
+
+    private static ThreadLocal<ArrayDeque<Long>> startTimeStack = ThreadLocal.withInitial(new Supplier<ArrayDeque<Long>>() {
+        @Override
+        public ArrayDeque<Long> get() {
+            return new ArrayDeque<Long>(8);
+        }
+    });
+
+    public static long executionStarted() {
+        final long startTime = System.nanoTime();
+        startTimeStack.get().push(startTime);
+        return startTime;
+    }
+
+    public static long getStartTime() {
+        long startTime = startTimeStack.get().peek();
+        return startTime;
+    }
+
+    public static long executionFinished() {
+        long startTime = startTimeStack.get().pop();
+        return startTime;
+    }
+}
diff --git a/james-agent/src/main/java/com/tomtom/james/newagent/james/GroovyJames.java b/james-agent/src/main/java/com/tomtom/james/newagent/james/GroovyJames.java
index e18de64..106a408 100644
--- a/james-agent/src/main/java/com/tomtom/james/newagent/james/GroovyJames.java
+++ b/james-agent/src/main/java/com/tomtom/james/newagent/james/GroovyJames.java
@@ -25,17 +25,15 @@ private String escapeScriptString(String script) {
     }
 
     protected void insertBefore(CtMethod method, ExtendedInformationPoint informationPoint) throws CannotCompileException {
-        method.addLocalVariable("_startTime", CtClass.longType);
         StringBuilder s = new StringBuilder("");
-        s.append(" _startTime = System.nanoTime();"); // we put nanoTime into local variable ...
-        s.append(" com.tomtom.james.newagent.GlobalValueStore.put(\"" + informationPoint + "\", _startTime); "); // and into the GlobalValueStore in case of Exception, because in finally block local variable is not visible
+        s.append(" com.tomtom.james.newagent.MethodExecutionTimeHelper.executionStarted();");
         method.insertBefore(s.toString());
     }
 
     protected void insertAfter(CtMethod method, ExtendedInformationPoint informationPoint) throws CannotCompileException {
         String script = escapeScriptString(informationPoint.getScript().get());
         StringBuilder s = new StringBuilder();
-        s.append(" com.tomtom.james.informationpoint.advice.ContextAwareAdvice.onExit( _startTime, \n");
+        s.append(" com.tomtom.james.informationpoint.advice.ContextAwareAdvice.onExit( com.tomtom.james.newagent.MethodExecutionTimeHelper.getStartTime(), \n");
         s.append("\"" + informationPoint.getClassName() + "\", ");
         s.append("\"" + informationPoint.getMethodName() + "\", ");
         s.append("\"" + script + "\", ");
@@ -59,8 +57,7 @@ protected void insertAfter(CtMethod method, ExtendedInformationPoint information
     protected void addCatch(ClassPool pool, CtMethod method, ExtendedInformationPoint informationPoint) throws CannotCompileException, NotFoundException {
         String script = escapeScriptString(informationPoint.getScript().get());
         StringBuilder s = new StringBuilder();
-        s.append(" long _methodStartTime = com.tomtom.james.newagent.GlobalValueStore.get(\"" + informationPoint + "\"); ");
-        s.append(" com.tomtom.james.informationpoint.advice.ContextAwareAdvice.onExit( _methodStartTime, ");
+        s.append(" com.tomtom.james.informationpoint.advice.ContextAwareAdvice.onExit( com.tomtom.james.newagent.MethodExecutionTimeHelper.getStartTime(), ");
         s.append("\"" + informationPoint.getClassName() + "\", ");
         s.append("\"" + informationPoint.getMethodName() + "\", ");
         s.append("\"" + script + "\", ");
@@ -83,7 +80,7 @@ protected void addCatch(ClassPool pool, CtMethod method, ExtendedInformationPoin
 
         // finally block
         StringBuilder f = new StringBuilder("");
-        f.append(" com.tomtom.james.newagent.GlobalValueStore.getAndRemove(\"" + informationPoint + "\"); \n");
+        f.append(" com.tomtom.james.newagent.MethodExecutionTimeHelper.executionFinished(); \n");
         method.insertAfter(f.toString(), true);
     }
 }