bench(gradle): configure JMH via plugin for CI-appropriate defaults

Author: not-matthias

examples/example-gradle/build.gradle.kts

@@ -9,10 +9,30 @@ version = "1.0-SNAPSHOT"
 jmh {
     jmhVersion.set("0.1.0")
 
+    benchmarkMode.set(listOf("avgt"))
+    timeUnit.set("ns")
+    warmupIterations.set(2)
+    warmup.set("1s")
+    iterations.set(3)
+    timeOnIteration.set("1s")
+    fork.set(3)
+    resultFormat.set("JSON")
+
     // Force a System.gc() between iterations so heap state is reset before each
     // measurement starts. Without this, a GC pause can land inside the measurement
     // window and show up as a spurious regression in CI.
     forceGC = true
+
+    // Run subset of the benchmarks to avoid long CI runtimes
+    if (System.getenv("CODSPEED_ENV") != null) {
+        logger.lifecycle("CODSPEED_ENV detected — running curated CI benchmark subset")
+        // 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).*",
+        ))
+    }
 }
 
 sourceSets {