Merge pull request #2088 from newrelic/lazy-guid-init

Lazy init of GUIDs on DefaultTracers

Author: jtduffy

newrelic-agent/src/main/java/com/newrelic/agent/trace/TransactionGuidFactory.java

@@ -10,6 +10,7 @@
 import java.util.concurrent.ThreadLocalRandom;
 
 public class TransactionGuidFactory {
+    private static final char[] hexchars = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
 
     private TransactionGuidFactory() {
     }
@@ -21,7 +22,6 @@ public static String generate16CharGuid() {
         // return Long.toHexString(Math.abs(randomHolder.get().nextLong()))
         // In addition, this one returns 16 useful digits, while the obvious one returns slightly fewer.
         // Note that the digits are generated in "reverse order", which is perfectly fine here.
-        final char[] hexchars = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
         long random = ThreadLocalRandom.current().nextLong();
         char[] result = new char[16];
         for (int i = 0; i < 16; ++i) {

newrelic-agent/src/main/java/com/newrelic/agent/tracers/DefaultTracer.java

@@ -145,7 +145,6 @@ public DefaultTracer(TransactionActivity txa, ClassMethodSignature sig, Object o
         }
 
         this.tracerFlags = (byte) tracerFlags;
-        this.guid = TransactionGuidFactory.generate16CharGuid();
     }
 
     public DefaultTracer(TransactionActivity txa, ClassMethodSignature sig, Object object,
@@ -169,7 +168,10 @@ public void removeTransactionSegment() {
 
     @Override
     public String getGuid() {
-        return guid;
+        if (this.guid == null) {
+            this.guid = TransactionGuidFactory.generate16CharGuid();
+        }
+        return this.guid;
     }
 
     @Override