remove sun.misc.unsafe leftover in the test and benchmark code

Removed the usage from a unit test that requires a predictable
ThreadLocalRandom result. This now uses reflection and the runner must
explicitly open the module for access.

Removed from a benchmark comparing table lookup mechanisms and the
cache currently uses the VarHandles approach,

Removed JDK 7's ConcurrentHashMap as this was only useful for
judging the performance benefit of the Java 8 rewrite when trying to
set baseline expectations during the library's initial development.

.github/workflows/analysis.yml

@@ -23,7 +23,7 @@ jobs:
   forbiddenApis:
     runs-on: ubuntu-latest
     env:
-      JAVA_VERSION: 22
+      JAVA_VERSION: 23
     steps:
       - name: Harden Runner
         uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2

caffeine/build.gradle.kts

@@ -255,11 +255,11 @@ tasks.named<CheckForbiddenApis>("forbiddenApisJavaPoet").configure {
 }
 
 tasks.named<CheckForbiddenApis>("forbiddenApisTest").configure {
-  bundledSignatures.add("jdk-deprecated-18")
+  bundledSignatures.addAll(listOf("jdk-deprecated-18", "jdk-unsafe"))
 }
 
 tasks.named<CheckForbiddenApis>("forbiddenApisJmh").configure {
-  bundledSignatures.addAll(listOf("jdk-deprecated-18", "jdk-reflection"))
+  bundledSignatures.addAll(listOf("jdk-deprecated-18", "jdk-reflection", "jdk-unsafe"))
 }
 
 tasks.register<JavaExec>("memoryOverhead") {
@@ -314,7 +314,8 @@ for (scenario in Scenario.all()) {
         } else {
           parallel = "methods"
           excludeGroups("slow", "isolated", "lincheck")
-          jvmArgs("-XX:+UseG1GC", "-XX:+ParallelRefProcEnabled")
+          jvmArgs("-XX:+UseG1GC", "-XX:+ParallelRefProcEnabled",
+            "--add-opens", "java.base/java.lang=ALL-UNNAMED")
           threadCount = max(6, Runtime.getRuntime().availableProcessors() - 1)
         }
       }

caffeine/src/jmh/java/com/github/benmanes/caffeine/SlotLookupBenchmark.java

@@ -20,7 +20,6 @@
 import java.util.concurrent.ThreadLocalRandom;
 import java.util.stream.LongStream;
 
-import org.jctools.util.UnsafeAccess;
 import org.openjdk.jmh.annotations.Benchmark;
 import org.openjdk.jmh.annotations.Scope;
 import org.openjdk.jmh.annotations.Setup;
@@ -55,7 +54,6 @@ public class SlotLookupBenchmark {
   static final VarHandle PROBE;
 
   ThreadLocal<Integer> threadLocal;
-  long probeOffset;
   long[] array;
 
   @Setup
@@ -75,11 +73,6 @@ public void setupBinarySearch() {
     array = LongStream.range(0, ARENA_SIZE).toArray();
   }
 
-  @Setup
-  public void setupStriped64() {
-    probeOffset = UnsafeAccess.fieldOffset(Thread.class, "threadLocalRandomProbe");
-  }
-
   @Benchmark
   public int threadLocal() {
     // Emulates holding the arena slot in a thread-local
@@ -113,32 +106,6 @@ private static int mix32(int x) {
     return (x >>> 16) ^ x;
   }
 
-  @Benchmark
-  public long striped64_unsafe(Blackhole blackhole) {
-    // Emulates finding the arena slot by reusing the thread-local random seed (j.u.c.a.Striped64)
-    int hash = getProbe_unsafe();
-    if (hash == 0) {
-      blackhole.consume(ThreadLocalRandom.current()); // force initialization
-      hash = getProbe_unsafe();
-    }
-    advanceProbe_unsafe(hash);
-    int index = selectSlot(hash);
-    return array[index];
-  }
-
-  @SuppressWarnings("SunApi")
-  private int getProbe_unsafe() {
-    return UnsafeAccess.UNSAFE.getInt(Thread.currentThread(), probeOffset);
-  }
-
-  @SuppressWarnings("SunApi")
-  private void advanceProbe_unsafe(int probe) {
-    probe ^= probe << 13; // xorshift
-    probe ^= probe >>> 17;
-    probe ^= probe << 5;
-    UnsafeAccess.UNSAFE.putInt(Thread.currentThread(), probeOffset, probe);
-  }
-
   @Benchmark
   public long striped64_varHandle(Blackhole blackhole) {
     // Emulates finding the arena slot by reusing the thread-local random seed (j.u.c.a.Striped64)

caffeine/src/jmh/java/com/github/benmanes/caffeine/cache/CacheType.java

@@ -23,7 +23,6 @@
 import com.github.benmanes.caffeine.cache.impl.Cache2k;
 import com.github.benmanes.caffeine.cache.impl.CaffeineCache;
 import com.github.benmanes.caffeine.cache.impl.CoherenceCache;
-import com.github.benmanes.caffeine.cache.impl.ConcurrentHashMapV7;
 import com.github.benmanes.caffeine.cache.impl.ConcurrentMapCache;
 import com.github.benmanes.caffeine.cache.impl.Ehcache3;
 import com.github.benmanes.caffeine.cache.impl.GuavaCache;
@@ -47,12 +46,6 @@ public enum CacheType {
 
   /* --------------- Unbounded --------------- */
 
-  ConcurrentHashMapV7 { // see OpenJDK/7u40-b43
-    @Override public <K, V> BasicCache<K, V> create(int maximumSize) {
-      return new ConcurrentMapCache<>(
-          new ConcurrentHashMapV7<>(maximumSize, 0.75f, CONCURRENCY_LEVEL));
-    }
-  },
   ConcurrentHashMap {
     @Override public <K, V> BasicCache<K, V> create(int maximumSize) {
       return new ConcurrentMapCache<>(new ConcurrentHashMap<>(maximumSize));