1 /*
   2  * Copyright (c) 2014, 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 /*
  27  * @test TestStableDouble
  28  * @summary tests on stable fields and arrays
  29  * @library /testlibrary
  30  * @compile -XDignore.symbol.file TestStableDouble.java
  31  * @run main ClassFileInstaller
  32  *           java/lang/invoke/TestStableDouble
  33  *           java/lang/invoke/TestStableDouble$DoubleStable
  34  *           java/lang/invoke/TestStableDouble$StaticDoubleStable
  35  *           java/lang/invoke/TestStableDouble$VolatileDoubleStable
  36  *           java/lang/invoke/TestStableDouble$DoubleArrayDim1
  37  *           java/lang/invoke/TestStableDouble$DoubleArrayDim2
  38  *           java/lang/invoke/TestStableDouble$DoubleArrayDim3
  39  *           java/lang/invoke/TestStableDouble$DoubleArrayDim4
  40  *           java/lang/invoke/TestStableDouble$ObjectArrayLowerDim0
  41  *           java/lang/invoke/TestStableDouble$ObjectArrayLowerDim1
  42  *           java/lang/invoke/TestStableDouble$NestedStableField
  43  *           java/lang/invoke/TestStableDouble$NestedStableField$A
  44  *           java/lang/invoke/TestStableDouble$NestedStableField1
  45  *           java/lang/invoke/TestStableDouble$NestedStableField1$A
  46  *           java/lang/invoke/TestStableDouble$NestedStableField2
  47  *           java/lang/invoke/TestStableDouble$NestedStableField2$A
  48  *           java/lang/invoke/TestStableDouble$NestedStableField3
  49  *           java/lang/invoke/TestStableDouble$NestedStableField3$A
  50  *           java/lang/invoke/TestStableDouble$DefaultValue
  51  *           java/lang/invoke/TestStableDouble$ObjectArrayLowerDim2
  52  *
  53  * @run main/othervm -Xbootclasspath/a:. -XX:+IgnoreUnrecognizedVMOptions
  54  *                   -XX:+UnlockDiagnosticVMOptions -XX:+FoldStableValues -XX:+UseCompressedOop
  55  *                   -server -XX:-TieredCompilation -Xcomp
  56  *                   -XX:CompileOnly=::get,::get1,::get2,::get3,::get4
  57  *                   java.lang.invoke.TestStableDouble
  58  *
  59  * @run main/othervm -Xbootclasspath/a:. -XX:+IgnoreUnrecognizedVMOptions
  60  *                   -XX:+UnlockDiagnosticVMOptions -XX:+FoldStableValues -XX:-UseCompressedOop
  61  *                   -server -XX:-TieredCompilation -Xcomp
  62  *                   -XX:CompileOnly=::get,::get1,::get2,::get3,::get4
  63  *                   java.lang.invoke.TestStableDouble
  64  *
  65  * @run main/othervm -Xbootclasspath/a:. -XX:+IgnoreUnrecognizedVMOptions
  66  *                   -XX:+UnlockDiagnosticVMOptions -XX:-FoldStableValues -XX:+UseCompressedOop
  67  *                   -server -XX:-TieredCompilation -Xcomp
  68  *                   -XX:CompileOnly=::get,::get1,::get2,::get3,::get4
  69  *                   java.lang.invoke.TestStableDouble
  70  *
  71  * @run main/othervm -Xbootclasspath/a:. -XX:+IgnoreUnrecognizedVMOptions
  72  *                   -XX:+UnlockDiagnosticVMOptions -XX:-FoldStableValues -XX:-UseCompressedOop
  73  *                   -server -XX:-TieredCompilation -Xcomp
  74  *                   -XX:CompileOnly=::get,::get1,::get2,::get3,::get4
  75  *                   java.lang.invoke.TestStableDouble
  76  */
  77 package java.lang.invoke;
  78 
  79 import com.sun.management.HotSpotDiagnosticMXBean;
  80 import com.sun.management.VMOption;
  81 import sun.management.ManagementFactoryHelper;
  82 import java.lang.reflect.InvocationTargetException;
  83 
  84 public class TestStableDouble {
  85     public static void main(String[] args) throws Exception {
  86         System.out.println("@Stable enabled: "+isStableEnabled);
  87         System.out.println();
  88 
  89         run(DefaultValue.class);
  90         run(DoubleStable.class);
  91         run(StaticDoubleStable.class);
  92         run(VolatileDoubleStable.class);
  93 
  94         // @Stable arrays: Dim 1-4
  95         run(DoubleArrayDim1.class);
  96         run(DoubleArrayDim2.class);
  97         run(DoubleArrayDim3.class);
  98         run(DoubleArrayDim4.class);
  99 
 100         // @Stable Object field: dynamic arrays
 101         run(ObjectArrayLowerDim0.class);
 102         run(ObjectArrayLowerDim1.class);
 103         run(ObjectArrayLowerDim2.class);
 104 
 105         // Nested @Stable fields
 106         run(NestedStableField.class);
 107         run(NestedStableField1.class);
 108         run(NestedStableField2.class);
 109         run(NestedStableField3.class);
 110 
 111         if (failed) {
 112             throw new Error("TEST FAILED");
 113         }
 114     }
 115 
 116     /* ==================================================== */
 117 
 118     static class DefaultValue {
 119         public @Stable double v;
 120 
 121         public static final DefaultValue c = new DefaultValue();
 122         public static double get() { return c.v; }
 123         public static void test() throws Exception {
 124                        double val1 = get();
 125             c.v = 1.0; double val2 = get();
 126             assertEquals(val1, 0);
 127             assertEquals(val2, 1.0);
 128         }
 129     }
 130 
 131     /* ==================================================== */
 132 
 133     static class DoubleStable {
 134         public @Stable double v;
 135 
 136         public static final DoubleStable c = new DoubleStable();
 137         public static double get() { return c.v; }
 138         public static void test() throws Exception {
 139             c.v = 1.0; double val1 = get();
 140             c.v = Double.MAX_VALUE; double val2 = get();
 141             assertEquals(val1, 1.0);
 142             assertEquals(val2, (isStableEnabled ? 1.0 : Double.MAX_VALUE));
 143         }
 144     }
 145 
 146     /* ==================================================== */
 147 
 148     static class StaticDoubleStable {
 149         public static @Stable double v;
 150 
 151         public static final StaticDoubleStable c = new StaticDoubleStable();
 152         public static double get() { return c.v; }
 153         public static void test() throws Exception {
 154             c.v = 1.0; double val1 = get();
 155             c.v = Double.MAX_VALUE; double val2 = get();
 156             assertEquals(val1, 1.0);
 157             assertEquals(val2, (isStableEnabled ? 1.0 : Double.MAX_VALUE));
 158         }
 159     }
 160 
 161     /* ==================================================== */
 162 
 163     static class VolatileDoubleStable {
 164         public @Stable double v;
 165 
 166         public static final VolatileDoubleStable c = new VolatileDoubleStable();
 167         public static double get() { return c.v; }
 168         public static void test() throws Exception {
 169             c.v = 1.0; double val1 = get();
 170             c.v = Double.MAX_VALUE; double val2 = get();
 171             assertEquals(val1, 1.0);
 172             assertEquals(val2, (isStableEnabled ? 1.0 : Double.MAX_VALUE));
 173         }
 174     }
 175 
 176     /* ==================================================== */
 177     // @Stable array == field && all components are stable
 178 
 179     static class DoubleArrayDim1 {
 180         public @Stable double[] v;
 181 
 182         public static final DoubleArrayDim1 c = new DoubleArrayDim1();
 183         public static double get() { return c.v[0]; }
 184         public static double get1() { return c.v[10]; }
 185         public static double[] get2() { return c.v; }
 186         public static void test() throws Exception {
 187             {
 188                 c.v = new double[1]; c.v[0] = 1.0; double val1 = get();
 189                                      c.v[0] = 2.0; double val2 = get();
 190                 assertEquals(val1, 1.0);
 191                 assertEquals(val2, (isStableEnabled ? 1.0 : 2.0));
 192 
 193                 c.v = new double[1]; c.v[0] = 3.0; double val3 = get();
 194                 assertEquals(val3, (isStableEnabled ? 1.0 : 3.0));
 195             }
 196 
 197             {
 198                 c.v = new double[20]; c.v[10] = 1.0; double val1 = get1();
 199                                       c.v[10] = 2.0; double val2 = get1();
 200                 assertEquals(val1, 1.0);
 201                 assertEquals(val2, (isStableEnabled ? 1.0 : 2.0));
 202 
 203                 c.v = new double[20]; c.v[10] = 3.0; double val3 = get1();
 204                 assertEquals(val3, (isStableEnabled ? 1.0 : 3.0));
 205             }
 206 
 207             {
 208                 c.v = new double[1]; double[] val1 = get2();
 209                 c.v = new double[1]; double[] val2 = get2();
 210                 assertTrue((isStableEnabled ? (val1 == val2) : (val1 != val2)));
 211             }
 212         }
 213     }
 214 
 215     /* ==================================================== */
 216 
 217     static class DoubleArrayDim2 {
 218         public @Stable double[][] v;
 219 
 220         public static final DoubleArrayDim2 c = new DoubleArrayDim2();
 221         public static double get() { return c.v[0][0]; }
 222         public static double[] get1() { return c.v[0]; }
 223         public static double[][] get2() { return c.v; }
 224         public static void test() throws Exception {
 225             {
 226                 c.v = new double[1][1]; c.v[0][0] = 1.0; double val1 = get();
 227                                         c.v[0][0] = 2.0; double val2 = get();
 228                 assertEquals(val1, 1.0);
 229                 assertEquals(val2, (isStableEnabled ? 1.0 : 2.0));
 230 
 231                 c.v = new double[1][1]; c.v[0][0] = 3.0; double val3 = get();
 232                 assertEquals(val3, (isStableEnabled ? 1.0 : 3.0));
 233 
 234                 c.v[0] = new double[1]; c.v[0][0] = 4.0; double val4 = get();
 235                 assertEquals(val4, (isStableEnabled ? 1.0 : 4.0));
 236             }
 237 
 238             {
 239                 c.v = new double[1][1]; double[] val1 = get1();
 240                 c.v[0] = new double[1]; double[] val2 = get1();
 241                 assertTrue((isStableEnabled ? (val1 == val2) : (val1 != val2)));
 242             }
 243 
 244             {
 245                 c.v = new double[1][1]; double[][] val1 = get2();
 246                 c.v = new double[1][1]; double[][] val2 = get2();
 247                 assertTrue((isStableEnabled ? (val1 == val2) : (val1 != val2)));
 248             }
 249         }
 250     }
 251 
 252     /* ==================================================== */
 253 
 254     static class DoubleArrayDim3 {
 255         public @Stable double[][][] v;
 256 
 257         public static final DoubleArrayDim3 c = new DoubleArrayDim3();
 258         public static double get() { return c.v[0][0][0]; }
 259         public static double[] get1() { return c.v[0][0]; }
 260         public static double[][] get2() { return c.v[0]; }
 261         public static double[][][] get3() { return c.v; }
 262         public static void test() throws Exception {
 263             {
 264                 c.v = new double[1][1][1]; c.v[0][0][0] = 1.0; double val1 = get();
 265                                            c.v[0][0][0] = 2.0; double val2 = get();
 266                 assertEquals(val1, 1.0);
 267                 assertEquals(val2, (isStableEnabled ? 1.0 : 2.0));
 268 
 269                 c.v = new double[1][1][1]; c.v[0][0][0] = 3.0; double val3 = get();
 270                 assertEquals(val3, (isStableEnabled ? 1.0 : 3.0));
 271 
 272                 c.v[0] = new double[1][1]; c.v[0][0][0] = 4.0; double val4 = get();
 273                 assertEquals(val4, (isStableEnabled ? 1.0 : 4.0));
 274 
 275                 c.v[0][0] = new double[1]; c.v[0][0][0] = 5.0; double val5 = get();
 276                 assertEquals(val5, (isStableEnabled ? 1.0 : 5.0));
 277             }
 278 
 279             {
 280                 c.v = new double[1][1][1]; double[] val1 = get1();
 281                 c.v[0][0] = new double[1]; double[] val2 = get1();
 282                 assertTrue((isStableEnabled ? (val1 == val2) : (val1 != val2)));
 283             }
 284 
 285             {
 286                 c.v = new double[1][1][1]; double[][] val1 = get2();
 287                 c.v[0] = new double[1][1]; double[][] val2 = get2();
 288                 assertTrue((isStableEnabled ? (val1 == val2) : (val1 != val2)));
 289             }
 290 
 291             {
 292                 c.v = new double[1][1][1]; double[][][] val1 = get3();
 293                 c.v = new double[1][1][1]; double[][][] val2 = get3();
 294                 assertTrue((isStableEnabled ? (val1 == val2) : (val1 != val2)));
 295             }
 296         }
 297     }
 298 
 299     /* ==================================================== */
 300 
 301     static class DoubleArrayDim4 {
 302         public @Stable double[][][][] v;
 303 
 304         public static final DoubleArrayDim4 c = new DoubleArrayDim4();
 305         public static double get() { return c.v[0][0][0][0]; }
 306         public static double[] get1() { return c.v[0][0][0]; }
 307         public static double[][] get2() { return c.v[0][0]; }
 308         public static double[][][] get3() { return c.v[0]; }
 309         public static double[][][][] get4() { return c.v; }
 310         public static void test() throws Exception {
 311             {
 312                 c.v = new double[1][1][1][1]; c.v[0][0][0][0] = 1.0; double val1 = get();
 313                                               c.v[0][0][0][0] = 2.0; double val2 = get();
 314                 assertEquals(val1, 1.0);
 315                 assertEquals(val2, (isStableEnabled ? 1.0 : 2.0));
 316 
 317                 c.v = new double[1][1][1][1]; c.v[0][0][0][0] = 3.0; double val3 = get();
 318                 assertEquals(val3, (isStableEnabled ? 1.0 : 3.0));
 319 
 320                 c.v[0] = new double[1][1][1]; c.v[0][0][0][0] = 4.0; double val4 = get();
 321                 assertEquals(val4, (isStableEnabled ? 1.0 : 4.0));
 322 
 323                 c.v[0][0] = new double[1][1]; c.v[0][0][0][0] = 5.0; double val5 = get();
 324                 assertEquals(val5, (isStableEnabled ? 1.0 : 5.0));
 325 
 326                 c.v[0][0][0] = new double[1]; c.v[0][0][0][0] = 6.0; double val6 = get();
 327                 assertEquals(val6, (isStableEnabled ? 1.0 : 6.0));
 328             }
 329 
 330             {
 331                 c.v = new double[1][1][1][1]; double[] val1 = get1();
 332                 c.v[0][0][0] = new double[1]; double[] val2 = get1();
 333                 assertTrue((isStableEnabled ? (val1 == val2) : (val1 != val2)));
 334             }
 335 
 336             {
 337                 c.v = new double[1][1][1][1]; double[][] val1 = get2();
 338                 c.v[0][0] = new double[1][1]; double[][] val2 = get2();
 339                 assertTrue((isStableEnabled ? (val1 == val2) : (val1 != val2)));
 340             }
 341 
 342             {
 343                 c.v = new double[1][1][1][1]; double[][][] val1 = get3();
 344                 c.v[0] = new double[1][1][1]; double[][][] val2 = get3();
 345                 assertTrue((isStableEnabled ? (val1 == val2) : (val1 != val2)));
 346             }
 347 
 348             {
 349                 c.v = new double[1][1][1][1]; double[][][][] val1 = get4();
 350                 c.v = new double[1][1][1][1]; double[][][][] val2 = get4();
 351                 assertTrue((isStableEnabled ? (val1 == val2) : (val1 != val2)));
 352             }
 353 
 354         }
 355     }
 356 
 357     /* ==================================================== */
 358     // Dynamic Dim is higher than static
 359 
 360     static class ObjectArrayLowerDim0 {
 361         public @Stable Object v;
 362 
 363         public static final ObjectArrayLowerDim0 c = new ObjectArrayLowerDim0();
 364         public static double get() { return ((double[])c.v)[0]; }
 365         public static double[] get1() { return (double[])c.v; }
 366 
 367         public static void test() throws Exception {
 368             {
 369                 c.v = new double[1]; ((double[])c.v)[0] = 1.0; double val1 = get();
 370                                      ((double[])c.v)[0] = 2.0; double val2 = get();
 371 
 372                 assertEquals(val1, 1.0);
 373                 assertEquals(val2, 2.0);
 374             }
 375 
 376             {
 377                 c.v = new double[1]; double[] val1 = get1();
 378                 c.v = new double[1]; double[] val2 = get1();
 379                 assertTrue((isStableEnabled ? (val1 == val2) : (val1 != val2)));
 380             }
 381         }
 382     }
 383 
 384     /* ==================================================== */
 385 
 386     static class ObjectArrayLowerDim1 {
 387         public @Stable Object[] v;
 388 
 389         public static final ObjectArrayLowerDim1 c = new ObjectArrayLowerDim1();
 390         public static double get() { return ((double[][])c.v)[0][0]; }
 391         public static double[] get1() { return (double[])(c.v[0]); }
 392         public static Object[] get2() { return c.v; }
 393 
 394         public static void test() throws Exception {
 395             {
 396                 c.v = new double[1][1]; ((double[][])c.v)[0][0] = 1.0; double val1 = get();
 397                                         ((double[][])c.v)[0][0] = 2.0; double val2 = get();
 398 
 399                 assertEquals(val1, 1.0);
 400                 assertEquals(val2, 2.0);
 401             }
 402 
 403             {
 404                 c.v = new double[1][1]; c.v[0] = new double[0]; double[] val1 = get1();
 405                                         c.v[0] = new double[0]; double[] val2 = get1();
 406 
 407                 assertTrue((isStableEnabled ? (val1 == val2) : (val1 != val2)));
 408             }
 409 
 410             {
 411                 c.v = new double[0][0]; Object[] val1 = get2();
 412                 c.v = new double[0][0]; Object[] val2 = get2();
 413 
 414                 assertTrue((isStableEnabled ? (val1 == val2) : (val1 != val2)));
 415             }
 416         }
 417     }
 418 
 419     /* ==================================================== */
 420 
 421     static class ObjectArrayLowerDim2 {
 422         public @Stable Object[][] v;
 423 
 424         public static final ObjectArrayLowerDim2 c = new ObjectArrayLowerDim2();
 425         public static double get() { return ((double[][][])c.v)[0][0][0]; }
 426         public static double[] get1() { return (double[])(c.v[0][0]); }
 427         public static double[][] get2() { return (double[][])(c.v[0]); }
 428         public static Object[][] get3() { return c.v; }
 429 
 430         public static void test() throws Exception {
 431             {
 432                 c.v = new double[1][1][1]; ((double[][][])c.v)[0][0][0] = 1.0; double val1 = get();
 433                                            ((double[][][])c.v)[0][0][0] = 2.0; double val2 = get();
 434 
 435                 assertEquals(val1, 1.0);
 436                 assertEquals(val2, 2.0);
 437             }
 438 
 439             {
 440                 c.v = new double[1][1][1]; c.v[0][0] = new double[0]; double[] val1 = get1();
 441                                            c.v[0][0] = new double[0]; double[] val2 = get1();
 442 
 443                 assertTrue((isStableEnabled ? (val1 == val2) : (val1 != val2)));
 444             }
 445 
 446             {
 447                 c.v = new double[1][1][1]; c.v[0] = new double[0][0]; double[][] val1 = get2();
 448                                            c.v[0] = new double[0][0]; double[][] val2 = get2();
 449 
 450                 assertTrue((isStableEnabled ? (val1 == val2) : (val1 != val2)));
 451             }
 452 
 453             {
 454                 c.v = new double[0][0][0]; Object[][] val1 = get3();
 455                 c.v = new double[0][0][0]; Object[][] val2 = get3();
 456 
 457                 assertTrue((isStableEnabled ? (val1 == val2) : (val1 != val2)));
 458             }
 459         }
 460     }
 461 
 462     /* ==================================================== */
 463 
 464     static class NestedStableField {
 465         static class A {
 466             public @Stable double a;
 467 
 468         }
 469         public @Stable A v;
 470 
 471         public static final NestedStableField c = new NestedStableField();
 472         public static A get() { return c.v; }
 473         public static double get1() { return get().a; }
 474 
 475         public static void test() throws Exception {
 476             {
 477                 c.v = new A(); c.v.a = 1.0; A val1 = get();
 478                                c.v.a = 2.0; A val2 = get();
 479 
 480                 assertEquals(val1.a, 2.0);
 481                 assertEquals(val2.a, 2.0);
 482             }
 483 
 484             {
 485                 c.v = new A(); c.v.a = 1.0; double val1 = get1();
 486                                c.v.a = 2.0; double val2 = get1();
 487                 c.v = new A(); c.v.a = 3.0; double val3 = get1();
 488 
 489                 assertEquals(val1, 1.0);
 490                 assertEquals(val2, (isStableEnabled ? 1.0 : 2.0));
 491                 assertEquals(val3, (isStableEnabled ? 1.0 : 3.0));
 492             }
 493         }
 494     }
 495 
 496     /* ==================================================== */
 497 
 498     static class NestedStableField1 {
 499         static class A {
 500             public @Stable double a;
 501             public @Stable A next;
 502         }
 503         public @Stable A v;
 504 
 505         public static final NestedStableField1 c = new NestedStableField1();
 506         public static A get() { return c.v.next.next.next.next.next.next.next; }
 507         public static double get1() { return get().a; }
 508 
 509         public static void test() throws Exception {
 510             {
 511                 c.v = new A(); c.v.next = new A();   c.v.next.next  = c.v;
 512                                c.v.a = 1.0; c.v.next.a = 1.0; A val1 = get();
 513                                c.v.a = 2.0; c.v.next.a = 2.0; A val2 = get();
 514 
 515                 assertEquals(val1.a, 2.0);
 516                 assertEquals(val2.a, 2.0);
 517             }
 518 
 519             {
 520                 c.v = new A(); c.v.next = c.v;
 521                                c.v.a = 1.0; double val1 = get1();
 522                                c.v.a = 2.0; double val2 = get1();
 523                 c.v = new A(); c.v.next = c.v;
 524                                c.v.a = 3.0; double val3 = get1();
 525 
 526                 assertEquals(val1, 1.0);
 527                 assertEquals(val2, (isStableEnabled ? 1.0 : 2.0));
 528                 assertEquals(val3, (isStableEnabled ? 1.0 : 3.0));
 529             }
 530         }
 531     }
 532    /* ==================================================== */
 533 
 534     static class NestedStableField2 {
 535         static class A {
 536             public @Stable double a;
 537             public @Stable A left;
 538             public         A right;
 539         }
 540 
 541         public @Stable A v;
 542 
 543         public static final NestedStableField2 c = new NestedStableField2();
 544         public static double get() { return c.v.left.left.left.a; }
 545         public static double get1() { return c.v.left.left.right.left.a; }
 546 
 547         public static void test() throws Exception {
 548             {
 549                 c.v = new A(); c.v.left = c.v.right = c.v;
 550                                c.v.a = 1.0; double val1 = get(); double val2 = get1();
 551                                c.v.a = 2.0; double val3 = get(); double val4 = get1();
 552 
 553                 assertEquals(val1, 1.0);
 554                 assertEquals(val3, (isStableEnabled ? 1.0 : 2.0));
 555 
 556                 assertEquals(val2, 1.0);
 557                 assertEquals(val4, 2.0);
 558             }
 559         }
 560     }
 561 
 562     /* ==================================================== */
 563 
 564     static class NestedStableField3 {
 565         static class A {
 566             public @Stable double a;
 567             public @Stable A[] left;
 568             public         A[] right;
 569         }
 570 
 571         public @Stable A[] v;
 572 
 573         public static final NestedStableField3 c = new NestedStableField3();
 574         public static double get() { return c.v[0].left[1].left[0].left[1].a; }
 575         public static double get1() { return c.v[1].left[0].left[1].right[0].left[1].a; }
 576 
 577         public static void test() throws Exception {
 578             {
 579                 A elem = new A();
 580                 c.v = new A[] { elem, elem }; c.v[0].left = c.v[0].right = c.v;
 581                                elem.a = 1.0; double val1 = get(); double val2 = get1();
 582                                elem.a = 2.0; double val3 = get(); double val4 = get1();
 583 
 584                 assertEquals(val1, 1.0);
 585                 assertEquals(val3, (isStableEnabled ? 1.0 : 2.0));
 586 
 587                 assertEquals(val2, 1.0);
 588                 assertEquals(val4, 2.0);
 589             }
 590         }
 591     }
 592 
 593     /* ==================================================== */
 594     // Auxiliary methods
 595     static void assertEquals(double i, double j) { if (i != j)  throw new AssertionError(i + " != " + j); }
 596     static void assertTrue(boolean b) { if (!b)  throw new AssertionError(); }
 597 
 598     static boolean failed = false;
 599 
 600     public static void run(Class<?> test) {
 601         Throwable ex = null;
 602         System.out.print(test.getName()+": ");
 603         try {
 604             test.getMethod("test").invoke(null);
 605         } catch (InvocationTargetException e) {
 606             ex = e.getCause();
 607         } catch (Throwable e) {
 608             ex = e;
 609         } finally {
 610             if (ex == null) {
 611                 System.out.println("PASSED");
 612             } else {
 613                 failed = true;
 614                 System.out.println("FAILED");
 615                 ex.printStackTrace(System.out);
 616             }
 617         }
 618     }
 619 
 620     static final boolean isStableEnabled;
 621     static {
 622         HotSpotDiagnosticMXBean diagnostic
 623                 = ManagementFactoryHelper.getDiagnosticMXBean();
 624         VMOption tmp;
 625         try {
 626             tmp = diagnostic.getVMOption("FoldStableValues");
 627         } catch (IllegalArgumentException e) {
 628             tmp = null;
 629         }
 630         isStableEnabled = (tmp == null ? false : Boolean.parseBoolean(tmp.getValue()));
 631     }
 632 }