HTRACE-119. Detaching or closing the NullScope singleton should not fail (iwasakims via cmccabe)
diff --git a/htrace-core/src/main/java/org/apache/htrace/NullScope.java b/htrace-core/src/main/java/org/apache/htrace/NullScope.java
index 32963a8..ff9a42c 100644
--- a/htrace-core/src/main/java/org/apache/htrace/NullScope.java
+++ b/htrace-core/src/main/java/org/apache/htrace/NullScope.java
@@ -28,6 +28,16 @@
}
@Override
+ public Span detach() {
+ return null;
+ }
+
+ @Override
+ public void close() {
+ return;
+ }
+
+ @Override
public String toString() {
return "NullScope";
}
diff --git a/htrace-core/src/main/java/org/apache/htrace/TraceScope.java b/htrace-core/src/main/java/org/apache/htrace/TraceScope.java
index 3546e69..ab36feb 100644
--- a/htrace-core/src/main/java/org/apache/htrace/TraceScope.java
+++ b/htrace-core/src/main/java/org/apache/htrace/TraceScope.java
@@ -81,7 +81,7 @@
@Override
public void close() {
- if ((span == null) || detached) {
+ if (detached) {
return;
}
detached = true;
diff --git a/htrace-core/src/test/java/org/apache/htrace/TestNullScope.java b/htrace-core/src/test/java/org/apache/htrace/TestNullScope.java
new file mode 100644
index 0000000..26b1cba
--- /dev/null
+++ b/htrace-core/src/test/java/org/apache/htrace/TestNullScope.java
@@ -0,0 +1,37 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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 org.apache.htrace;
+
+import org.apache.htrace.Trace;
+import org.apache.htrace.TraceScope;
+import org.apache.htrace.NullScope;
+import org.junit.Assert;
+import org.junit.Test;
+
+public class TestNullScope {
+ @Test
+ public void testNullScope() {
+ Assert.assertTrue(!Trace.isTracing());
+ TraceScope tc = Trace.startSpan("NullScopeSingleton");
+ Assert.assertTrue(tc == NullScope.INSTANCE);
+ tc.detach();
+ tc.detach(); // should not fail even if called multiple times.
+ Assert.assertFalse(tc.isDetached());
+ tc.close();
+ tc.close(); // should not fail even if called multiple times.
+ }
+}
