Prefer method handles over reflection [skip ci]

This restores an optimization that was removed in #222 due to a memory
leak in older JDKs.

caffeine/src/javaPoet/java/com/github/benmanes/caffeine/cache/LocalCacheFactoryGenerator.java

@@ -16,7 +16,9 @@
 package com.github.benmanes.caffeine.cache;
 
 import static com.github.benmanes.caffeine.cache.Specifications.BOUNDED_LOCAL_CACHE;
+import static com.github.benmanes.caffeine.cache.Specifications.BUILDER;
 import static com.github.benmanes.caffeine.cache.Specifications.BUILDER_PARAM;
+import static com.github.benmanes.caffeine.cache.Specifications.CACHE_LOADER;
 import static com.github.benmanes.caffeine.cache.Specifications.CACHE_LOADER_PARAM;
 import static com.github.benmanes.caffeine.cache.Specifications.kTypeVar;
 import static com.github.benmanes.caffeine.cache.Specifications.vTypeVar;
@@ -25,6 +27,8 @@
 import static java.util.stream.Collectors.toList;
 
 import java.io.IOException;
+import java.lang.invoke.MethodHandles;
+import java.lang.invoke.MethodType;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
@@ -67,6 +71,7 @@
 import com.google.googlejavaformat.java.Formatter;
 import com.google.googlejavaformat.java.FormatterException;
 import com.squareup.javapoet.ClassName;
+import com.squareup.javapoet.FieldSpec;
 import com.squareup.javapoet.JavaFile;
 import com.squareup.javapoet.MethodSpec;
 import com.squareup.javapoet.ParameterizedTypeName;
@@ -79,6 +84,16 @@
  * @author [email protected] (Ben Manes)
  */
 public final class LocalCacheFactoryGenerator {
+  static final FieldSpec LOOKUP = FieldSpec.builder(MethodHandles.Lookup.class, "LOOKUP")
+      .initializer("$T.lookup()", MethodHandles.class)
+      .addModifiers(Modifier.PUBLIC, Modifier.STATIC, Modifier.FINAL)
+      .build();
+  static final FieldSpec FACTORY = FieldSpec.builder(MethodType.class, "FACTORY")
+      .initializer("$T.methodType($T.class, $T.class, $T.class, $T.class)",
+          MethodType.class, void.class, BUILDER, CACHE_LOADER.rawType, TypeName.BOOLEAN)
+      .addModifiers(Modifier.PUBLIC, Modifier.STATIC, Modifier.FINAL)
+      .build();
+
   final Feature[] featureByIndex = { null, null, Feature.LISTENING, Feature.STATS,
       Feature.MAXIMUM_SIZE, Feature.MAXIMUM_WEIGHT, Feature.EXPIRE_ACCESS,
       Feature.EXPIRE_WRITE, Feature.REFRESH_WRITE};
@@ -105,6 +120,7 @@ void generate() throws IOException {
         .addModifiers(Modifier.FINAL)
         .addMethod(MethodSpec.constructorBuilder().addModifiers(Modifier.PRIVATE).build());
     addClassJavaDoc();
+    addConstants();
     generateLocalCaches();
     addFactoryMethods();
     writeJavaFile();
@@ -228,6 +244,11 @@ private void addClassJavaDoc() {
         .addJavadoc("\n@author [email protected] (Ben Manes)\n");
   }
 
+  private void addConstants() {
+    factory.addField(LOOKUP);
+    factory.addField(FACTORY);
+  }
+
   /** Returns an encoded form of the class name for compact use. */
   private static String encode(String className) {
     return Feature.makeEnumName(className)

caffeine/src/javaPoet/java/com/github/benmanes/caffeine/cache/LocalCacheSelectorCode.java

@@ -15,15 +15,14 @@
  */
 package com.github.benmanes.caffeine.cache;
 
+import static com.github.benmanes.caffeine.cache.LocalCacheFactoryGenerator.FACTORY;
+import static com.github.benmanes.caffeine.cache.LocalCacheFactoryGenerator.LOOKUP;
 import static com.github.benmanes.caffeine.cache.Specifications.BOUNDED_LOCAL_CACHE;
-import static com.github.benmanes.caffeine.cache.Specifications.BUILDER;
-import static com.github.benmanes.caffeine.cache.Specifications.CACHE_LOADER;
 import static com.github.benmanes.caffeine.cache.Specifications.LOCAL_CACHE_FACTORY;
 
-import java.lang.reflect.Constructor;
+import java.lang.invoke.MethodHandle;
 
 import com.squareup.javapoet.CodeBlock;
-import com.squareup.javapoet.TypeName;
 
 /**
  * @author [email protected] (Ben Manes)
@@ -100,15 +99,15 @@ private LocalCacheSelectorCode selector() {
         .beginControlFlow("try")
             .addStatement("$T<?> clazz = $T.class.getClassLoader().loadClass(sb.toString())",
                 Class.class, LOCAL_CACHE_FACTORY)
-            .addStatement("$T<?> ctor = clazz.getDeclaredConstructor($T.class, $T.class, $T.class)",
-                Constructor.class, BUILDER, CACHE_LOADER.rawType, TypeName.BOOLEAN)
-            .add("@SuppressWarnings($S)\n", "unchecked")
-            .addStatement("$1T factory = ($1T) ctor.newInstance(builder, cacheLoader, async)",
+            .addStatement("$T handle = $N.findConstructor(clazz, $N)",
+                MethodHandle.class, LOOKUP, FACTORY)
+            .addStatement("return ($T) handle.invoke(builder, cacheLoader, async)",
                 BOUNDED_LOCAL_CACHE)
-            .addStatement("return factory")
-        .nextControlFlow("catch ($T e)", ReflectiveOperationException.class)
-            .addStatement("throw new $T(sb.toString(), e)", IllegalStateException.class)
-      .endControlFlow();
+            .nextControlFlow("catch ($T | $T e)", RuntimeException.class, Error.class)
+                .addStatement("throw e")
+            .nextControlFlow("catch ($T t)", Throwable.class)
+                .addStatement("throw new $T(sb.toString(), t)", IllegalStateException.class)
+        .endControlFlow();
     return this;
   }
 

caffeine/src/javaPoet/java/com/github/benmanes/caffeine/cache/NodeFactoryGenerator.java

@@ -39,6 +39,8 @@
 import static java.util.stream.Collectors.toList;
 
 import java.io.IOException;
+import java.lang.invoke.MethodHandles;
+import java.lang.invoke.MethodType;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
@@ -101,6 +103,15 @@
  */
 @SuppressWarnings("PMD.AvoidDuplicateLiterals")
 public final class NodeFactoryGenerator {
+  static final FieldSpec LOOKUP = FieldSpec.builder(MethodHandles.Lookup.class, "LOOKUP")
+      .initializer("$T.lookup()", MethodHandles.class)
+      .addModifiers(Modifier.PUBLIC, Modifier.STATIC, Modifier.FINAL)
+      .build();
+  static final FieldSpec FACTORY = FieldSpec.builder(MethodType.class, "FACTORY")
+      .initializer("$T.methodType($T.class)", MethodType.class, void.class)
+      .addModifiers(Modifier.PUBLIC, Modifier.STATIC, Modifier.FINAL)
+      .build();
+
   final List<NodeRule> rules = ImmutableList.of(new AddSubtype(), new AddConstructors(),
       new AddKey(), new AddValue(), new AddMaximum(), new AddExpiration(), new AddDeques(),
       new AddFactoryMethods(),  new AddHealth(), new Finalize());
@@ -194,6 +205,9 @@ private void addConstants() {
     nodeFactory.addField(FieldSpec.builder(rawReferenceKeyType, DEAD_WEAK_KEY, modifiers)
         .initializer("new $T(null, null)", rawReferenceKeyType)
         .build());
+
+    nodeFactory.addField(FACTORY);
+    nodeFactory.addField(LOOKUP);
   }
 
   private void addKeyMethods() {

caffeine/src/javaPoet/java/com/github/benmanes/caffeine/cache/NodeSelectorCode.java

@@ -15,8 +15,12 @@
  */
 package com.github.benmanes.caffeine.cache;
 
+import static com.github.benmanes.caffeine.cache.NodeFactoryGenerator.FACTORY;
+import static com.github.benmanes.caffeine.cache.NodeFactoryGenerator.LOOKUP;
 import static com.github.benmanes.caffeine.cache.Specifications.NODE_FACTORY;
 
+import java.lang.invoke.MethodHandle;
+
 import com.squareup.javapoet.CodeBlock;
 
 /**
@@ -96,12 +100,13 @@ private NodeSelectorCode selector() {
         .beginControlFlow("try")
             .addStatement("$T<?> clazz = $T.class.getClassLoader().loadClass(sb.toString())",
                 Class.class, NODE_FACTORY.rawType)
-            .add("@SuppressWarnings($S)\n", "unchecked")
-            .addStatement("$1T factory = ($1T) clazz.getDeclaredConstructor().newInstance()",
-                NODE_FACTORY)
-            .addStatement("return factory")
-        .nextControlFlow("catch ($T e)", ReflectiveOperationException.class)
-            .addStatement("throw new $T(sb.toString(), e)", IllegalStateException.class)
+            .addStatement("$T handle = $N.findConstructor(clazz, $N)",
+                MethodHandle.class, LOOKUP, FACTORY)
+            .addStatement("return ($T) handle.invoke()", NODE_FACTORY)
+        .nextControlFlow("catch ($T | $T e)", RuntimeException.class, Error.class)
+            .addStatement("throw e")
+        .nextControlFlow("catch ($T t)", Throwable.class)
+            .addStatement("throw new $T(sb.toString(), t)", IllegalStateException.class)
         .endControlFlow();
     return this;
   }

caffeine/src/javaPoet/java/com/github/benmanes/caffeine/cache/node/AddExpiration.java

@@ -114,7 +114,7 @@ private void addAccessExpiration() {
         .addField(long.class, "accessTime", Modifier.VOLATILE)
         .addMethod(newGetter(Strength.STRONG, TypeName.LONG, "accessTime", Visibility.PLAIN))
         .addMethod(newSetter(TypeName.LONG, "accessTime", Visibility.PLAIN));
-    addVarHandle("accessTime", long.class);
+    addVarHandle("accessTime", TypeName.get(long.class));
     addTimeConstructorAssignment(context.constructorByKey, "accessTime");
     addTimeConstructorAssignment(context.constructorByKeyRef, "accessTime");
   }
@@ -126,7 +126,7 @@ private void addWriteExpiration() {
           .addField(long.class, "writeTime", Modifier.VOLATILE)
           .addMethod(newGetter(Strength.STRONG, TypeName.LONG, "writeTime", Visibility.PLAIN))
           .addMethod(newSetter(TypeName.LONG, "writeTime", Visibility.PLAIN));
-      addVarHandle("writeTime", long.class);
+      addVarHandle("writeTime", TypeName.get(long.class));
       addTimeConstructorAssignment(context.constructorByKey, "writeTime");
       addTimeConstructorAssignment(context.constructorByKeyRef, "writeTime");
     }

caffeine/src/javaPoet/java/com/github/benmanes/caffeine/cache/node/AddKey.java

@@ -19,6 +19,7 @@
 
 import javax.lang.model.element.Modifier;
 
+import com.squareup.javapoet.ClassName;
 import com.squareup.javapoet.FieldSpec;
 
 /**
@@ -40,7 +41,9 @@ protected void execute() {
         .addField(newKeyField())
         .addMethod(newGetter(keyStrength(), kTypeVar, "key", Visibility.PLAIN))
         .addMethod(newGetRef("key"));
-    addVarHandle("key", Object.class);
+    addVarHandle("key", isStrongKeys()
+        ? ClassName.get(Object.class)
+        : keyReferenceType().rawType);
   }
 
   private FieldSpec newKeyField() {

caffeine/src/javaPoet/java/com/github/benmanes/caffeine/cache/node/AddValue.java

@@ -23,6 +23,7 @@
 
 import javax.lang.model.element.Modifier;
 
+import com.squareup.javapoet.ClassName;
 import com.squareup.javapoet.FieldSpec;
 import com.squareup.javapoet.MethodSpec;
 
@@ -47,7 +48,9 @@ protected void execute() {
         .addMethod(newGetRef("value"))
         .addMethod(makeSetValue())
         .addMethod(makeContainsValue());
-    addVarHandle("value", Object.class);
+    addVarHandle("value", isStrongValues()
+        ? ClassName.get(Object.class)
+        : valueReferenceType().rawType);
   }
 
   private FieldSpec newValueField() {

caffeine/src/javaPoet/java/com/github/benmanes/caffeine/cache/node/NodeRule.java

@@ -85,13 +85,13 @@ protected boolean isStrongValues() {
         || context.generateFeatures.contains(Feature.STRONG_VALUES);
   }
 
-  protected TypeName keyReferenceType() {
+  protected ParameterizedTypeName keyReferenceType() {
     checkState(context.generateFeatures.contains(Feature.WEAK_KEYS));
     return ParameterizedTypeName.get(
         ClassName.get(PACKAGE_NAME + ".References", "WeakKeyReference"), kTypeVar);
   }
 
-  protected TypeName valueReferenceType() {
+  protected ParameterizedTypeName valueReferenceType() {
     checkState(!context.generateFeatures.contains(Feature.STRONG_VALUES));
     String clazz = context.generateFeatures.contains(Feature.WEAK_VALUES)
         ? "WeakValueReference"
@@ -105,7 +105,7 @@ protected String varHandleName(String varName) {
   }
 
   /** Creates a VarHandle to the instance field. */
-  public void addVarHandle(String varName, Class<?> type) {
+  public void addVarHandle(String varName, TypeName type) {
     String fieldName = varHandleName(varName);
     context.nodeSubtype.addField(FieldSpec.builder(VarHandle.class, fieldName,
         Modifier.PROTECTED, Modifier.STATIC, Modifier.FINAL).build());
@@ -177,7 +177,7 @@ private Strength strengthOf(Feature feature) {
   }
 
   protected enum Strength {
-    STRONG, WEAK, SOFT,
+    STRONG, WEAK, SOFT;
   }
 
   protected enum Visibility {

caffeine/src/main/java/com/github/benmanes/caffeine/cache/StripedBuffer.java

@@ -287,7 +287,7 @@ final void expandOrRetry(E e, boolean wasUncontended) {
       try {
         probe = supplier.get();
         break;
-      } catch (Throwable ignored) {}
+      } catch (Throwable ignored) { /* Try next strategy */ }
     }
     PROBE = requireNonNull(probe, "Unable to determine a probe strategy");
   }