1 /*
   2  * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package jdk.experimental.value;
  27 
  28 import java.lang.invoke.MethodHandle;
  29 import java.lang.invoke.MethodHandles;
  30 import java.lang.invoke.MethodHandles.Lookup;
  31 import java.lang.invoke.MethodType;
  32 import java.lang.reflect.Field;
  33 import java.lang.reflect.Method;
  34 import java.lang.reflect.Modifier;
  35 import java.util.Arrays;
  36 import java.util.List;
  37 import java.util.Map;
  38 import java.util.Objects;
  39 import java.util.Optional;
  40 import java.util.concurrent.ConcurrentHashMap;
  41 import java.util.stream.Stream;
  42 
  43 import jdk.experimental.value.ValueType.ValueHandleKind.ValueHandleKey;
  44 import jdk.experimental.bytecode.MacroCodeBuilder.CondKind;
  45 import jdk.experimental.bytecode.TypeTag;
  46 import jdk.internal.misc.Unsafe;
  47 import sun.invoke.util.BytecodeDescriptor;
  48 import sun.invoke.util.Wrapper;
  49 import valhalla.shady.MinimalValueTypes_1_0;
  50 
  51 // Rough place holder just now...
  52 public class ValueType<T> {
  53 
  54     static final Unsafe UNSAFE = Unsafe.getUnsafe();
  55 
  56     enum ValueHandleKind {
  57         BOX,
  58         UNBOX,
  59         DEFAULT,
  60         EQ,
  61         HASH,
  62         WITHER() {
  63             @Override
  64             ValueHandleKey key(Object fieldName) {
  65                return new ValueHandleKey(this, fieldName);
  66             }
  67         },
  68         NEWARRAY,
  69         VALOAD,
  70         VASTORE,
  71         MULTINEWARRAY() {
  72             @Override
  73             ValueHandleKey key(Object dims) {
  74                return new ValueHandleKey(this, dims);
  75             }
  76         },
  77         IDENTITY,
  78         GETTER() {
  79             @Override
  80             ValueHandleKey key(Object fieldName) {
  81                return new ValueHandleKey(this, fieldName);
  82             }
  83         };
  84 
  85         ValueHandleKey key() {
  86             return new ValueHandleKey(this, null);
  87         }
  88 
  89         ValueHandleKey key(Object optArg) {
  90             throw new IllegalStateException();
  91         }
  92 
  93         static class ValueHandleKey {
  94             ValueHandleKind kind;
  95             Optional<Object> optArg;
  96 
  97             ValueHandleKey(ValueHandleKind kind, Object optArg) {
  98                 this.kind = kind;
  99                 this.optArg = Optional.ofNullable(optArg);
 100             }
 101 
 102             @Override
 103             public boolean equals(Object obj) {
 104                 if (obj instanceof ValueHandleKey) {
 105                     ValueHandleKey that = (ValueHandleKey)obj;
 106                     return Objects.equals(kind, that.kind) &&
 107                             Objects.equals(optArg, that.optArg);
 108                 } else {
 109                     return false;
 110                 }
 111             }
 112 
 113             @Override
 114             public int hashCode() {
 115                 return Objects.hashCode(kind) * 31 + Objects.hashCode(optArg);
 116             }
 117         }
 118     }
 119 
 120     private static final Lookup IMPL_LOOKUP;
 121 
 122     static {
 123         try {
 124             Field f = Lookup.class.getDeclaredField("IMPL_LOOKUP");
 125             f.setAccessible(true);
 126             IMPL_LOOKUP = (Lookup)f.get(null);
 127         } catch (ReflectiveOperationException ex) {
 128             throw new AssertionError(ex);
 129         }
 130     }
 131 
 132     private static final ConcurrentHashMap<Class<?>, ValueType<?>> BOX_TO_VT = new ConcurrentHashMap<>();
 133 
 134     public static boolean classHasValueType(Class<?> x) {
 135         return MinimalValueTypes_1_0.classHasValueType(x);



 136     }
 137 
 138     @SuppressWarnings("unchecked")
 139     public static <T> ValueType<T> forClass(Class<T> x) {




 140         ValueType<T> vt = (ValueType<T>) BOX_TO_VT.get(x);
 141         if (vt != null) {
 142             return vt;
 143         }
 144 
 145         try {
 146             Class<T> valueClass = (Class<T>) MinimalValueTypes_1_0.getValueTypeClass(x);
 147             vt = new ValueType<T>(x, valueClass);
 148             ValueType<T> old = (ValueType<T>) BOX_TO_VT.putIfAbsent(x, vt);
 149             if (old != null) {
 150                 vt = old;
 151             }
 152             return vt;
 153         }
 154         catch (ClassNotFoundException cne) {
 155             throw new IllegalArgumentException("Class " + x + " not bound to ValueType", cne);
 156         }
 157     }
 158 
 159     private Lookup boxLookup;
 160     private Lookup valueLookup;
 161     private Map<ValueHandleKind.ValueHandleKey, MethodHandle> handleMap = new ConcurrentHashMap<>();
 162 
 163     private ValueType(Class<T> boxClass, Class<T> valueClass) {
 164         this.boxLookup = IMPL_LOOKUP.in(boxClass);
 165         this.valueLookup = IMPL_LOOKUP.in(valueClass);
 166     }
 167 
 168     @SuppressWarnings("unchecked")
 169     public Class<T> boxClass() {
 170         return (Class<T>)boxLookup.lookupClass();
 171     }
 172 
 173     public Class<?> sourceClass() {
 174         return boxClass();
 175     }
 176 
 177     public Class<?> valueClass() {
 178         return valueLookup.lookupClass();
 179     }
 180 
 181     public Class<?> arrayValueClass() {
 182         return arrayValueClass(1);
 183     }
 184 
 185     public Class<?> arrayValueClass(int dims) {
 186         try {
 187             String dimsStr = "[[[[[[[[[[[[[[[[";
 188             if (dims < 1 || dims > 16) {
 189                 throw new IllegalArgumentException("cannot create array class for dimension > 16");
 190             }
 191             return Class.forName(dimsStr.substring(0, dims) + "Q" + valueClass().getName() + ";", false, boxLookup.lookupClass().getClassLoader());
 192         } catch (ClassNotFoundException ex) {
 193             throw new IllegalStateException(ex);
 194         }
 195     }
 196 
 197     public String toString() {
 198         return "ValueType boxClass=" + boxClass() + " valueClass=" + valueClass();
 199     }
 200 
 201     String mhName(String opName) {
 202         return sourceClass().getName() + "_" + opName;
 203     }
 204 
 205     public MethodHandle defaultValueConstant() {
 206         ValueHandleKey key = ValueHandleKind.DEFAULT.key();
 207         MethodHandle result = handleMap.get(key);
 208         if (result == null) {
 209             result = MethodHandleBuilder.loadCode(boxLookup, mhName("default"), MethodType.methodType(valueClass()),
 210                     C -> {
 211                         C.vdefault(valueClass()).vreturn();
 212                     });
 213             handleMap.put(key, result);
 214         }
 215         return result;
 216     }
 217 
 218     public MethodHandle substitutabilityTest() {
 219         ValueHandleKey key = ValueHandleKind.EQ.key();
 220         MethodHandle result = handleMap.get(key);
 221         if (result == null) {
 222             result = MethodHandleBuilder.loadCode(valueLookup, mhName("subTest"), MethodType.methodType(boolean.class, valueClass(), valueClass()),
 223                     C -> {
 224                         for (Field f : valueFields()) {
 225                             String fDesc = BytecodeDescriptor.unparse(f.getType());
 226                             C.vload(0).vgetfield(valueClass(), f.getName(), fDesc);
 227                             C.vload(1).vgetfield(valueClass(), f.getName(), fDesc);
 228                             if (f.getType().isPrimitive()) {
 229                                 C.ifcmp(fDesc, CondKind.NE, "fail");
 230                             } else {
 231                                 C.invokestatic(Objects.class, "equals", "(Ljava/lang/Object;Ljava/lang/Object;)Z", false);
 232                                 C.const_(0).ifcmp(TypeTag.I, CondKind.EQ, "fail");
 233                             }
 234                         }
 235                         C.const_(1);
 236                         C.ireturn();
 237                         C.label("fail");
 238                         C.const_(0);
 239                         C.ireturn();
 240                     });
 241             handleMap.put(key, result);
 242         }
 243         return result;
 244     }
 245 
 246     public MethodHandle substitutabilityHashCode() {
 247         ValueHandleKey key = ValueHandleKind.HASH.key();
 248         MethodHandle result = handleMap.get(key);
 249         if (result == null) {
 250             result = MethodHandleBuilder.loadCode(valueLookup, mhName("subHash"), MethodType.methodType(int.class, valueClass()),
 251                     C -> {
 252                         C.withLocal("res", "I");
 253                         C.const_(1).store("res");
 254                         for (Field f : valueFields()) {
 255                             String desc = BytecodeDescriptor.unparse(f.getType());
 256                             C.vload(0).vgetfield(valueClass(), f.getName(), desc);
 257                             if (f.getType().isPrimitive()) {
 258                                 C.invokestatic(Wrapper.asWrapperType(f.getType()), "hashCode", "(" + desc + ")I", false);
 259                             } else {
 260                                 C.invokestatic(Objects.class, "hashCode", "(Ljava/lang/Object;)I", false);
 261                             }
 262                             C.load("res").const_(31).imul();
 263                             C.iadd().store("res");
 264                         }
 265                         C.load("res").ireturn();
 266                     });
 267             handleMap.put(key, result);
 268         }
 269         return result;
 270     }
 271 
 272     //Todo: when 'vwithfield' is ready, this handle could be greatly simplified
 273     public MethodHandle findWither(Lookup lookup, String name, Class<?> type) throws NoSuchFieldException, IllegalAccessException {
 274         ValueHandleKey key = ValueHandleKind.WITHER.key(List.of(name, type));
 275         MethodHandle result = handleMap.get(key);
 276         if (result == null) {
 277             MethodHandle mh = boxLookup.findGetter(boxClass(), name, type);
 278             Field field = MethodHandles.reflectAs(Field.class, mh);
 279             Class<?> erasedType = type.isPrimitive() ?
 280                     type : Object.class;
 281             Method unsafeMethod = Stream.of(UNSAFE.getClass().getDeclaredMethods())
 282                     .filter(m -> m.getName().startsWith("put") &&
 283                             Arrays.asList(m.getParameterTypes()).equals(Arrays.asList(Object.class, long.class, erasedType)))
 284                     .findFirst().get();
 285             long fieldOffset = UNSAFE.objectFieldOffset(field);
 286             result = MethodHandleBuilder.loadCode(boxLookup, mhName("wither$" + name), MethodType.methodType(valueClass(), MethodHandle.class, valueClass(), type),
 287                     C -> {
 288                         C.withLocal("boxedVal", BytecodeDescriptor.unparse(boxClass()))
 289                          .load(1)
 290                          .vbox(boxClass())
 291                          .store("boxedVal")
 292                          .load(0)
 293                          .load("boxedVal")
 294                          .const_(fieldOffset)
 295                          .load(2);
 296                          MethodType unsafeMT = MethodType.methodType(unsafeMethod.getReturnType(), unsafeMethod.getParameterTypes());
 297                          C.invokevirtual(MethodHandle.class, "invokeExact", BytecodeDescriptor.unparse(unsafeMT), false)
 298                           .load("boxedVal")
 299                           .vunbox(valueClass())
 300                           .vreturn();
 301                     }).bindTo(MethodHandles.lookup().unreflect(unsafeMethod).bindTo(UNSAFE));
 302             handleMap.put(key, result);
 303         }
 304         //force access-check
 305         lookup.findGetter(boxClass(), name, type);
 306         return result;
 307     }
 308 
 309     public MethodHandle unbox() {
 310         ValueHandleKey key = ValueHandleKind.UNBOX.key();
 311         MethodHandle result = handleMap.get(key);
 312         if (result == null) {
 313             result = MethodHandleBuilder.loadCode(boxLookup, mhName("unbox"), MethodType.methodType(valueClass(), boxClass()),
 314                     C -> {
 315                         C.load(0).vunbox(valueClass()).vreturn();
 316                     });
 317             handleMap.put(key, result);
 318         }
 319         return result;
 320     }
 321 
 322     public MethodHandle box() {
 323         ValueHandleKey key = ValueHandleKind.BOX.key();
 324         MethodHandle result = handleMap.get(key);
 325         if (result == null) {
 326             result = MethodHandleBuilder.loadCode(boxLookup, mhName("box"), MethodType.methodType(boxClass(), valueClass()),
 327                     C -> {
 328                         C.vload(0).vbox(boxClass()).areturn();
 329                     });
 330             handleMap.put(key, result);
 331         }
 332         return result;
 333     }
 334 
 335     public MethodHandle newArray() {
 336         Class<?> arrayValueClass = arrayValueClass();
 337         ValueHandleKey key = ValueHandleKind.NEWARRAY.key();
 338         MethodHandle result = handleMap.get(key);
 339         if (result == null) {
 340             result = MethodHandleBuilder.loadCode(boxLookup, mhName("newArray"), MethodType.methodType(arrayValueClass, int.class),
 341                     C -> {
 342                         C.load(0).anewarray(valueClass()).areturn();
 343                     });
 344             handleMap.put(key, result);
 345         }
 346         return result;
 347     }
 348 
 349     public MethodHandle arrayGetter() {
 350         Class<?> arrayValueClass = arrayValueClass();
 351         ValueHandleKey key = ValueHandleKind.VALOAD.key();
 352         MethodHandle result = handleMap.get(key);
 353         if (result == null) {
 354             result = MethodHandleBuilder.loadCode(boxLookup, mhName("arrayGet"), MethodType.methodType(valueClass(), arrayValueClass, int.class),
 355                     C -> {
 356                         C.load(0).load(1).vaload().vreturn();
 357                     });
 358             handleMap.put(key, result);
 359         }
 360         return result;
 361     }
 362 
 363     public MethodHandle arraySetter() {
 364         Class<?> arrayValueClass = arrayValueClass();
 365         ValueHandleKey key = ValueHandleKind.VASTORE.key();
 366         MethodHandle result = handleMap.get(key);
 367         if (result == null) {
 368             result = MethodHandleBuilder.loadCode(boxLookup, mhName("arraySet"), MethodType.methodType(void.class, arrayValueClass, int.class, valueClass()),
 369                     C -> {
 370                         C.load(0).load(1).load(2).vastore().return_();
 371                     });
 372             handleMap.put(key, result);
 373         }
 374         return result;
 375     }
 376 
 377     public MethodHandle newMultiArray(int dims) {
 378         Class<?> arrayValueClass = arrayValueClass(dims);
 379         ValueHandleKey key = ValueHandleKind.MULTINEWARRAY.key(dims);
 380         MethodHandle result = handleMap.get(key);
 381         Class<?>[] params = new Class<?>[dims];
 382         Arrays.fill(params, int.class);
 383         if (result == null) {
 384             result = MethodHandleBuilder.loadCode(boxLookup, mhName("newMultiArray"), MethodType.methodType(arrayValueClass, params),
 385                     C -> {
 386                         for (int i = 0 ; i < dims ; i++) {
 387                             C.load(i);
 388                         }
 389                         C.multianewarray(arrayValueClass, (byte)dims).areturn();
 390                     });
 391             handleMap.put(key, result);
 392         }
 393         return result;
 394     }
 395 
 396     public MethodHandle identity() {
 397         ValueHandleKey key = ValueHandleKind.IDENTITY.key();
 398         MethodHandle result = handleMap.get(key);
 399         if (result == null) {
 400             result = MethodHandleBuilder.loadCode(boxLookup, mhName("identity"), MethodType.methodType(valueClass(), valueClass()),
 401                     C -> C.vload(0).vreturn());
 402             handleMap.put(key, result);
 403         }
 404         return result;
 405     }
 406 
 407     public MethodHandle findGetter(Lookup lookup, String name, Class<?> type) throws NoSuchFieldException, IllegalAccessException {
 408         ValueHandleKey key = ValueHandleKind.GETTER.key(List.of(name, type));
 409         MethodHandle result = handleMap.get(key);
 410         if (result == null) {
 411             String fieldType = BytecodeDescriptor.unparse(type);
 412             result = MethodHandleBuilder.loadCode(boxLookup, mhName("getter$" + name), MethodType.methodType(type, valueClass()),
 413                     C -> C.vload(0).vgetfield(valueClass(), name, fieldType).return_(fieldType));
 414             handleMap.put(key, result);
 415         }
 416         //force access-check
 417         lookup.findGetter(boxClass(), name, type);
 418         return result;
 419     }
 420 
 421     private Field[] valueFields() {
 422         int valFieldMask = Modifier.FINAL;
 423         return Stream.of(sourceClass().getDeclaredFields())
 424                 .filter(f -> (f.getModifiers() & (valFieldMask | Modifier.STATIC)) == valFieldMask)
 425                 .toArray(Field[]::new);
 426     }
 427 
 428 }
--- EOF ---