chore: add support for macos

.github/workflows/ci.yml

@@ -102,6 +102,25 @@ jobs:
           mode: walltime
           run: ./gradlew :examples:example-gradle:jmh
 
+  walltime-benchmarks-flamegraph:
+    runs-on: codspeed-macro
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          submodules: true
+      - uses: actions/setup-java@v4
+        with:
+          distribution: temurin
+          java-version: 21
+          cache: 'gradle'
+      - name: Run FibFlamegraphBenchmark
+        uses: CodSpeedHQ/action@main
+        env:
+          CODSPEED_BENCH_GROUP: flamegraph
+        with:
+          mode: walltime
+          run: ./gradlew :examples:example-gradle:jmh
+
   check:
     runs-on: ubuntu-latest
     if: always()
@@ -111,6 +130,7 @@ jobs:
       - build-and-run-gradle
       - build-and-run-maven
       - walltime-benchmarks
+      - walltime-benchmarks-flamegraph
     steps:
       - uses: re-actors/alls-green@release/v1
         with:

examples/example-gradle/build.gradle.kts

@@ -29,9 +29,17 @@ jmh {
         // me.champeau.jmh joins `includes` with commas into a single positional
         // regex passed to JMH, so multiple entries collapse to one pattern with
         // literal commas and match nothing. Use a single alternation instead.
-        includes.set(listOf(
-            ".*(SleepBenchmark|BacktrackingBenchmark|FibBenchmark).*",
-        ))
+        //
+        // CODSPEED_BENCH_GROUP=flamegraph selects the macOS-only
+        // FibFlamegraphBenchmark used to exercise the flamegraph pipeline.
+        // Default is the regular benchmark set.
+        // TODO(COD-2715): Run all benches on MacOS
+        val pattern = if (System.getenv("CODSPEED_BENCH_GROUP") == "flamegraph") {
+            ".*FibFlamegraphBenchmark.*"
+        } else {
+            ".*(SleepBenchmark|BacktrackingBenchmark|FibBenchmark).*"
+        }
+        includes.set(listOf(pattern))
     }
 }
 

examples/example-gradle/src/jmh/java/bench/FibFlamegraphBenchmark.java

@@ -0,0 +1,27 @@
+package bench;
+
+import java.util.concurrent.TimeUnit;
+import org.openjdk.jmh.annotations.*;
+
+/**
+ * macOS-only benchmark whose recursion shape produces an easily-recognisable flamegraph. Gated to
+ * macOS via Gradle excludes in {@code build.gradle.kts}.
+ */
+@BenchmarkMode(Mode.AverageTime)
+@OutputTimeUnit(TimeUnit.NANOSECONDS)
+@State(Scope.Benchmark)
+public class FibFlamegraphBenchmark {
+
+  @Param({"30"})
+  private int n;
+
+  @Benchmark
+  public long fib() {
+    return fib(n);
+  }
+
+  private static long fib(int n) {
+    if (n <= 1) return n;
+    return fib(n - 1) + fib(n - 2);
+  }
+}