[JBTM-4014] Reduce allocation pressure on Uid

narayana/ArjunaCore/arjuna/tests/classes/com/hp/mwtests/ts/arjuna/performance/UidBenchmark.java

@@ -0,0 +1,61 @@
+/*
+ * Copyright The Narayana Authors
+ * SPDX short identifier: Apache-2.0
+ */
+
+package com.hp.mwtests.ts.arjuna.performance;
+
+import java.util.concurrent.TimeUnit;
+
+import org.openjdk.jmh.annotations.Benchmark;
+import org.openjdk.jmh.annotations.BenchmarkMode;
+import org.openjdk.jmh.annotations.Fork;
+import org.openjdk.jmh.annotations.Measurement;
+import org.openjdk.jmh.annotations.Mode;
+import org.openjdk.jmh.annotations.OutputTimeUnit;
+import org.openjdk.jmh.annotations.Scope;
+import org.openjdk.jmh.annotations.Setup;
+import org.openjdk.jmh.annotations.State;
+import org.openjdk.jmh.annotations.Warmup;
+import org.openjdk.jmh.infra.Blackhole;
+
+import com.arjuna.ats.arjuna.common.Uid;
+
+@State(Scope.Benchmark)
+@BenchmarkMode(Mode.AverageTime)
+@OutputTimeUnit(TimeUnit.NANOSECONDS)
+@Fork(2)
+@Warmup(iterations = 10, time = 1, timeUnit = TimeUnit.SECONDS)
+@Measurement(iterations = 10, time = 1, timeUnit = TimeUnit.SECONDS)
+public class UidBenchmark {
+
+   private byte[] byteForm;
+   private Uid toCopy;
+
+   @Setup
+   public void setup() {
+      toCopy = Uid.maxUid();
+      byteForm = toCopy.getBytes();
+   }
+
+   @Benchmark
+   public Uid fromByteForm() {
+      return new Uid(byteForm);
+   }
+
+   @Benchmark
+   public byte[] getBytes(Blackhole bh) {
+      var uid = new Uid(toCopy);
+      // this should enable uid barriers to still materialize
+      bh.consume(uid);
+      return uid.getBytes();
+   }
+
+   @Benchmark
+   public String stringForm(Blackhole bh) {
+      var uid = new Uid(toCopy);
+      bh.consume(uid);
+      return uid.stringForm();
+   }
+
+}