benchmarks: add initial context benchmarks

benchmarks/src/jmh/java/io/grpc/context/ContextBenchmark.java

@@ -0,0 +1,52 @@
+/*
+ * Copyright 2016, gRPC Authors All rights reserved.
+ *
+ * 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 io.grpc.context;
+
+import io.grpc.Context;
+import io.grpc.Context.Key;
+import java.util.concurrent.TimeUnit;
+import org.openjdk.jmh.annotations.Benchmark;
+import org.openjdk.jmh.annotations.BenchmarkMode;
+import org.openjdk.jmh.annotations.GroupThreads;
+import org.openjdk.jmh.annotations.Mode;
+import org.openjdk.jmh.annotations.OutputTimeUnit;
+import org.openjdk.jmh.annotations.Scope;
+import org.openjdk.jmh.annotations.State;
+
+/** StatusBenchmark. */
+@State(Scope.Benchmark)
+public class ContextBenchmark {
+
+  private final Key<Integer> key = Context.keyWithDefault("key", 9999);
+  private final Context cu = Context.current().withValue(key, 8888);
+
+  /**
+   * Javadoc comment.
+   */
+  @Benchmark
+  @BenchmarkMode(Mode.SampleTime)
+  @OutputTimeUnit(TimeUnit.NANOSECONDS)
+  @GroupThreads(6)
+  public int attachDetach() {
+    Context old = cu.attach();
+    try {
+      return key.get();
+    } finally {
+      Context.current().detach(old);
+    }
+  }
+}