1 /*
   2  * Copyright (c) 2005, 2011, 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.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 /*
  25  * @test
  26  * @bug     6207984 6272521 6192552 6269713 6197726 6260652 5073546 4137464
  27  *          4155650 4216399 4294891 6282555 6318622 6355327 6383475 6420753
  28  *          6431845 4802633 6570566 6570575 6570631 6570924 6691185 6691215
  29  *          4802647 7123424
  30  * @summary Run many tests on many Collection and Map implementations
  31  * @author  Martin Buchholz
  32  * @run main MOAT
  33  * @run main/othervm -XX:+AggressiveOpts MOAT
  34  */
  35 
  36 /* Mother Of All (Collection) Tests
  37  *
  38  * Testing of collection classes is often spotty, because many tests
  39  * need to be performed on many implementations, but the onus on
  40  * writing the tests falls on the engineer introducing the new
  41  * implementation.
  42  *
  43  * The idea of this mega-test is that:
  44  *
  45  * An engineer adding a new collection implementation could simply add
  46  * their new implementation to a list of implementations in this
  47  * test's main method.  Any general purpose Collection<Integer> or
  48  * Map<Integer,Integer> class is appropriate.
  49  *
  50  * An engineer fixing a regression could add their regression test here and
  51  * simultaneously test all other implementations.
  52  */
  53 
  54 import java.io.*;
  55 import java.util.*;
  56 import java.util.concurrent.*;
  57 import static java.util.Collections.*;
  58 
  59 public class MOAT {
  60     public static void realMain(String[] args) {
  61 
  62         testCollection(new NewAbstractCollection<Integer>());
  63         testCollection(new NewAbstractSet<Integer>());
  64         testCollection(new LinkedHashSet<Integer>());
  65         testCollection(new HashSet<Integer>());
  66         testCollection(new Vector<Integer>());
  67         testCollection(new Vector<Integer>().subList(0,0));
  68         testCollection(new ArrayDeque<Integer>());
  69         testCollection(new ArrayList<Integer>());
  70         testCollection(new ArrayList<Integer>().subList(0,0));
  71         testCollection(new LinkedList<Integer>());
  72         testCollection(new LinkedList<Integer>().subList(0,0));
  73         testCollection(new TreeSet<Integer>());
  74         testCollection(Collections.checkedList(new ArrayList<Integer>(), Integer.class));
  75         testCollection(Collections.synchronizedList(new ArrayList<Integer>()));
  76         testCollection(Collections.checkedSet(new HashSet<Integer>(), Integer.class));
  77         testCollection(Collections.checkedSortedSet(new TreeSet<Integer>(), Integer.class));
  78         testCollection(Collections.checkedNavigableSet(new TreeSet<Integer>(), Integer.class));
  79         testCollection(Collections.synchronizedSet(new HashSet<Integer>()));
  80         testCollection(Collections.synchronizedSortedSet(new TreeSet<Integer>()));
  81         testCollection(Collections.synchronizedNavigableSet(new TreeSet<Integer>()));
  82 
  83         testCollection(new CopyOnWriteArrayList<Integer>());
  84         testCollection(new CopyOnWriteArrayList<Integer>().subList(0,0));
  85         testCollection(new CopyOnWriteArraySet<Integer>());
  86         testCollection(new PriorityQueue<Integer>());
  87         testCollection(new PriorityBlockingQueue<Integer>());
  88         testCollection(new ArrayBlockingQueue<Integer>(20));
  89         testCollection(new LinkedBlockingQueue<Integer>(20));
  90         testCollection(new LinkedBlockingDeque<Integer>(20));
  91         testCollection(new ConcurrentLinkedDeque<Integer>());
  92         testCollection(new ConcurrentLinkedQueue<Integer>());
  93         testCollection(new LinkedTransferQueue<Integer>());
  94         testCollection(new ConcurrentSkipListSet<Integer>());
  95         testCollection(Arrays.asList(new Integer(42)));
  96         testCollection(Arrays.asList(1,2,3));
  97         testCollection(nCopies(25,1));
  98         testImmutableList(nCopies(25,1));
  99         testImmutableList(unmodifiableList(Arrays.asList(1,2,3)));
 100 
 101         testMap(new HashMap<Integer,Integer>());
 102         testMap(new LinkedHashMap<Integer,Integer>());
 103         testMap(new WeakHashMap<Integer,Integer>());
 104         testMap(new IdentityHashMap<Integer,Integer>());
 105         testMap(new TreeMap<Integer,Integer>());
 106         testMap(new Hashtable<Integer,Integer>());
 107         testMap(new ConcurrentHashMap<Integer,Integer>(10, 0.5f));
 108         testMap(new ConcurrentSkipListMap<Integer,Integer>());
 109         testMap(Collections.checkedMap(new HashMap<Integer,Integer>(), Integer.class, Integer.class));
 110         testMap(Collections.checkedSortedMap(new TreeMap<Integer,Integer>(), Integer.class, Integer.class));
 111         testMap(Collections.checkedNavigableMap(new TreeMap<Integer,Integer>(), Integer.class, Integer.class));
 112         testMap(Collections.synchronizedMap(new HashMap<Integer,Integer>()));
 113         testMap(Collections.synchronizedSortedMap(new TreeMap<Integer,Integer>()));
 114         testMap(Collections.synchronizedNavigableMap(new TreeMap<Integer,Integer>()));
 115 
 116         // Empty collections
 117         final List<Integer> emptyArray = Arrays.asList(new Integer[]{});
 118         testCollection(emptyArray);
 119         testEmptyList(emptyArray);
 120         THROWS(IndexOutOfBoundsException.class,
 121                new Fun(){void f(){ emptyArray.set(0,1); }});
 122         THROWS(UnsupportedOperationException.class,
 123                new Fun(){void f(){ emptyArray.add(0,1); }});
 124 
 125         List<Integer> noOne = nCopies(0,1);
 126         testCollection(noOne);
 127         testEmptyList(noOne);
 128         testImmutableList(noOne);
 129 
 130         Set<Integer> emptySet = emptySet();
 131         testCollection(emptySet);
 132         testEmptySet(emptySet);
 133         testEmptySet(EMPTY_SET);
 134         testEmptySet(Collections.emptySet());
 135         testEmptySet(Collections.emptySortedSet());
 136         testEmptySet(Collections.emptyNavigableSet());
 137         testImmutableSet(emptySet);
 138 
 139         List<Integer> emptyList = emptyList();
 140         testCollection(emptyList);
 141         testEmptyList(emptyList);
 142         testEmptyList(EMPTY_LIST);
 143         testEmptyList(Collections.emptyList());
 144         testImmutableList(emptyList);
 145 
 146         Map<Integer,Integer> emptyMap = emptyMap();
 147         testMap(emptyMap);
 148         testEmptyMap(emptyMap);
 149         testEmptyMap(EMPTY_MAP);
 150         testEmptyMap(Collections.emptyMap());
 151         testEmptyMap(Collections.emptySortedMap());
 152         testEmptyMap(Collections.emptyNavigableMap());
 153         testImmutableMap(emptyMap);
 154         testImmutableMap(Collections.emptyMap());
 155         testImmutableMap(Collections.emptySortedMap());
 156         testImmutableMap(Collections.emptyNavigableMap());
 157 
 158         // Singleton collections
 159         Set<Integer> singletonSet = singleton(1);
 160         equal(singletonSet.size(), 1);
 161         testCollection(singletonSet);
 162         testImmutableSet(singletonSet);
 163 
 164         List<Integer> singletonList = singletonList(1);
 165         equal(singletonList.size(), 1);
 166         testCollection(singletonList);
 167         testImmutableList(singletonList);
 168         testImmutableList(singletonList.subList(0,1));
 169         testImmutableList(singletonList.subList(0,1).subList(0,1));
 170         testEmptyList(singletonList.subList(0,0));
 171         testEmptyList(singletonList.subList(0,0).subList(0,0));
 172 
 173         Map<Integer,Integer> singletonMap = singletonMap(1,2);
 174         equal(singletonMap.size(), 1);
 175         testMap(singletonMap);
 176         testImmutableMap(singletonMap);
 177     }
 178 
 179     private static void checkContainsSelf(Collection<Integer> c) {
 180         check(c.containsAll(c));
 181         check(c.containsAll(Arrays.asList(c.toArray())));
 182         check(c.containsAll(Arrays.asList(c.toArray(new Integer[0]))));
 183     }
 184 
 185     private static void checkContainsEmpty(Collection<Integer> c) {
 186         check(c.containsAll(new ArrayList<Integer>()));
 187     }
 188 
 189     private static <T> void testEmptyCollection(Collection<T> c) {
 190         check(c.isEmpty());
 191         equal(c.size(), 0);
 192         equal(c.toString(),"[]");
 193         equal(c.toArray().length, 0);
 194         equal(c.toArray(new Object[0]).length, 0);
 195         check(c.toArray(new Object[]{42})[0] == null);
 196 
 197         Object[] a = new Object[1]; a[0] = Boolean.TRUE;
 198         equal(c.toArray(a), a);
 199         equal(a[0], null);
 200         testEmptyIterator(c.iterator());
 201     }
 202 
 203     static <T> void testEmptyIterator(final Iterator<T> it) {
 204         if (rnd.nextBoolean())
 205             check(! it.hasNext());
 206 
 207         THROWS(NoSuchElementException.class,
 208                new Fun(){void f(){ it.next(); }});
 209 
 210         try { it.remove(); }
 211         catch (IllegalStateException _) { pass(); }
 212         catch (UnsupportedOperationException _) { pass(); }
 213         catch (Throwable t) { unexpected(t); }
 214 
 215         if (rnd.nextBoolean())
 216             check(! it.hasNext());
 217     }
 218 
 219     private static void testEmptyList(List<?> c) {
 220         testEmptyCollection(c);
 221         equal(c.hashCode(), 1);
 222         equal2(c, Collections.<Integer>emptyList());
 223     }
 224 
 225     private static <T> void testEmptySet(Set<T> c) {
 226         testEmptyCollection(c);
 227         equal(c.hashCode(), 0);
 228         equal2(c, Collections.<Integer>emptySet());
 229         if (c instanceof NavigableSet<?>)
 230             testEmptyIterator(((NavigableSet<T>)c).descendingIterator());
 231     }
 232 
 233     private static void testImmutableCollection(final Collection<Integer> c) {
 234         THROWS(UnsupportedOperationException.class,
 235                new Fun(){void f(){ c.add(99); }},
 236                new Fun(){void f(){ c.addAll(singleton(99)); }});
 237         if (! c.isEmpty()) {
 238             final Integer first = c.iterator().next();
 239             THROWS(UnsupportedOperationException.class,
 240                    new Fun(){void f(){ c.clear(); }},
 241                    new Fun(){void f(){ c.remove(first); }},
 242                    new Fun(){void f(){ c.removeAll(singleton(first)); }},
 243                    new Fun(){void f(){ c.retainAll(emptyList()); }}
 244                    );
 245         }
 246     }
 247 
 248     private static void testImmutableSet(final Set<Integer> c) {
 249         testImmutableCollection(c);
 250     }
 251 
 252     private static void testImmutableList(final List<Integer> c) {
 253         testList(c);
 254         testImmutableCollection(c);
 255         THROWS(UnsupportedOperationException.class,
 256                new Fun(){void f(){ c.set(0,42); }},
 257                new Fun(){void f(){ c.add(0,42); }},
 258                new Fun(){void f(){ c.addAll(0,singleton(86)); }});
 259         if (! c.isEmpty())
 260             THROWS(UnsupportedOperationException.class,
 261                    new Fun(){void f(){
 262                            Iterator<Integer> it = c.iterator();
 263                            it.next(); it.remove();}},
 264                    new Fun(){void f(){
 265                            ListIterator<Integer> it = c.listIterator();
 266                            it.next(); it.remove();}});
 267     }
 268 
 269     private static void clear(Collection<Integer> c) {
 270         try { c.clear(); }
 271         catch (Throwable t) { unexpected(t); }
 272         testEmptyCollection(c);
 273     }
 274 
 275     private static <K,V> void testEmptyMap(final Map<K,V> m) {
 276         check(m.isEmpty());
 277         equal(m.size(), 0);
 278         equal(m.toString(),"{}");
 279         testEmptySet(m.keySet());
 280         testEmptySet(m.entrySet());
 281         testEmptyCollection(m.values());
 282 
 283         try { check(! m.containsValue(null)); }
 284         catch (NullPointerException _) { /* OK */ }
 285         try { check(! m.containsKey(null)); }
 286         catch (NullPointerException _) { /* OK */ }
 287         check(! m.containsValue(1));
 288         check(! m.containsKey(1));
 289     }
 290 
 291     private static void testImmutableMap(final Map<Integer,Integer> m) {
 292         THROWS(UnsupportedOperationException.class,
 293                new Fun(){void f(){ m.put(1,1); }},
 294                new Fun(){void f(){ m.putAll(singletonMap(1,1)); }});
 295         if (! m.isEmpty()) {
 296             final Integer first = m.keySet().iterator().next();
 297             THROWS(UnsupportedOperationException.class,
 298                    new Fun(){void f(){ m.remove(first); }},
 299                    new Fun(){void f(){ m.clear(); }});
 300             final Map.Entry<Integer,Integer> me
 301                 = m.entrySet().iterator().next();
 302             Integer key = me.getKey();
 303             Integer val = me.getValue();
 304             THROWS(UnsupportedOperationException.class,
 305                    new Fun(){void f(){ me.setValue(3); }});
 306             equal(key, me.getKey());
 307             equal(val, me.getValue());
 308         }
 309         testImmutableSet(m.keySet());
 310         testImmutableCollection(m.values());
 311         //testImmutableSet(m.entrySet());
 312     }
 313 
 314     private static void clear(Map<?,?> m) {
 315         try { m.clear(); }
 316         catch (Throwable t) { unexpected(t); }
 317         testEmptyMap(m);
 318     }
 319 
 320     private static void oneElement(Collection<Integer> c) {
 321         clear(c);
 322         try {
 323             check(c.add(-42));
 324             equal(c.toString(), "[-42]");
 325             if (c instanceof Set) check(! c.add(-42));
 326         } catch (Throwable t) { unexpected(t); }
 327         check(! c.isEmpty()); check(c.size() == 1);
 328     }
 329 
 330     private static boolean supportsAdd(Collection<Integer> c) {
 331         try { check(c.add(778347983)); }
 332         catch (UnsupportedOperationException t) { return false; }
 333         catch (Throwable t) { unexpected(t); }
 334 
 335         try {
 336             check(c.contains(778347983));
 337             check(c.remove(778347983));
 338         } catch (Throwable t) { unexpected(t); }
 339         return true;
 340     }
 341 
 342     private static boolean supportsRemove(Collection<Integer> c) {
 343         try { check(! c.remove(19134032)); }
 344         catch (UnsupportedOperationException t) { return false; }
 345         catch (Throwable t) { unexpected(t); }
 346         return true;
 347     }
 348 
 349     private static void checkFunctionalInvariants(Collection<Integer> c) {
 350         try {
 351             checkContainsSelf(c);
 352             checkContainsEmpty(c);
 353             check(c.size() != 0 ^ c.isEmpty());
 354 
 355             {
 356                 int size = 0;
 357                 for (Integer i : c) size++;
 358                 check(c.size() == size);
 359             }
 360 
 361             check(c.toArray().length == c.size());
 362             check(c.toArray().getClass() == Object[].class
 363                   ||
 364                   // !!!!
 365                   // 6260652: (coll) Arrays.asList(x).toArray().getClass()
 366                   // should be Object[].class
 367                   (c.getClass().getName().equals("java.util.Arrays$ArrayList"))
 368                   );
 369             for (int size : new int[]{0,1,c.size(), c.size()+1}) {
 370                 Integer[] a = c.toArray(new Integer[size]);
 371                 check((size > c.size()) || a.length == c.size());
 372                 int i = 0; for (Integer j : c) check(a[i++] == j);
 373                 check((size <= c.size()) || (a[c.size()] == null));
 374                 check(a.getClass() == Integer[].class);
 375             }
 376 
 377             check(c.equals(c));
 378             if (c instanceof Serializable) {
 379                 //System.out.printf("Serializing %s%n", c.getClass().getName());
 380                 try {
 381                     Object clone = serialClone(c);
 382                     equal(c instanceof Serializable,
 383                           clone instanceof Serializable);
 384                     equal(c instanceof RandomAccess,
 385                           clone instanceof RandomAccess);
 386                     if ((c instanceof List) || (c instanceof Set))
 387                         equal(c, clone);
 388                     else
 389                         equal(new HashSet<Integer>(c),
 390                               new HashSet<Integer>(serialClone(c)));
 391                 } catch (Error xxx) {
 392                     if (! (xxx.getCause() instanceof NotSerializableException))
 393                         throw xxx;
 394                 }
 395             }
 396         }
 397         catch (Throwable t) { unexpected(t); }
 398     }
 399 
 400     //----------------------------------------------------------------
 401     // If add(null) succeeds, contains(null) & remove(null) should succeed
 402     //----------------------------------------------------------------
 403     private static void testNullElement(Collection<Integer> c) {
 404         // !!!! 5018849: (coll) TreeSet.contains(null) does not agree with Javadoc
 405         if (c instanceof TreeSet) return;
 406 
 407         try {
 408             check(c.add(null));
 409             if (c.size() == 1)
 410                 equal(c.toString(), "[null]");
 411             try {
 412                 checkFunctionalInvariants(c);
 413                 check(c.contains(null));
 414                 check(c.remove(null));
 415             }
 416             catch (Throwable t) { unexpected(t); }
 417         }
 418         catch (NullPointerException e) { /* OK */ }
 419         catch (Throwable t) { unexpected(t); }
 420     }
 421 
 422 
 423     //----------------------------------------------------------------
 424     // If add("x") succeeds, contains("x") & remove("x") should succeed
 425     //----------------------------------------------------------------
 426     @SuppressWarnings("unchecked")
 427     private static void testStringElement(Collection<Integer> c) {
 428         Collection x = (Collection)c; // Make type-unsafe
 429         try {
 430             check(x.add("x"));
 431             try {
 432                 check(x.contains("x"));
 433                 check(x.remove("x"));
 434             } catch (Throwable t) { unexpected(t); }
 435         }
 436         catch (ClassCastException e) { /* OK */ }
 437         catch (Throwable t) { unexpected(t); }
 438     }
 439 
 440     private static void testConcurrentCollection(Collection<Integer> c) {
 441         try {
 442             c.add(1);
 443             Iterator<Integer> it = c.iterator();
 444             check(it.hasNext());
 445             clear(c);
 446             check(it.next() instanceof Integer); // No CME
 447             check(c.isEmpty());
 448         }
 449         catch (Throwable t) { unexpected(t); }
 450     }
 451 
 452     private static void testQueue(Queue<Integer> q) {
 453         q.clear();
 454         for (int i = 0; i < 5; i++) {
 455             testQueueAddRemove(q, null);
 456             testQueueAddRemove(q, 537);
 457             q.add(i);
 458         }
 459         equal(q.size(), 5);
 460         checkFunctionalInvariants(q);
 461         q.poll();
 462         equal(q.size(), 4);
 463         checkFunctionalInvariants(q);
 464         if ((q instanceof LinkedBlockingQueue)   ||
 465             (q instanceof LinkedBlockingDeque)   ||
 466             (q instanceof ConcurrentLinkedDeque) ||
 467             (q instanceof ConcurrentLinkedQueue)) {
 468             testQueueIteratorRemove(q);
 469         }
 470     }
 471 
 472     private static void testQueueAddRemove(final Queue<Integer> q,
 473                                            final Integer e) {
 474         final List<Integer> originalContents = new ArrayList<Integer>(q);
 475         final boolean isEmpty = q.isEmpty();
 476         final boolean isList = (q instanceof List);
 477         final List asList = isList ? (List) q : null;
 478         check(!q.contains(e));
 479         try {
 480             q.add(e);
 481         } catch (NullPointerException npe) {
 482             check(e == null);
 483             return;                     // Null elements not supported
 484         }
 485         check(q.contains(e));
 486         check(q.remove(e));
 487         check(!q.contains(e));
 488         equal(new ArrayList<Integer>(q), originalContents);
 489 
 490         if (q instanceof Deque<?>) {
 491             final Deque<Integer> deq = (Deque<Integer>) q;
 492             final List<Integer> singleton = Collections.singletonList(e);
 493 
 494             // insert, query, remove element at head
 495             if (isEmpty) {
 496                 THROWS(NoSuchElementException.class,
 497                        new Fun(){void f(){ deq.getFirst(); }},
 498                        new Fun(){void f(){ deq.element(); }},
 499                        new Fun(){void f(){ deq.iterator().next(); }});
 500                 check(deq.peekFirst() == null);
 501                 check(deq.peek() == null);
 502             } else {
 503                 check(deq.getFirst() != e);
 504                 check(deq.element() != e);
 505                 check(deq.iterator().next() != e);
 506                 check(deq.peekFirst() != e);
 507                 check(deq.peek() != e);
 508             }
 509             check(!deq.contains(e));
 510             check(!deq.removeFirstOccurrence(e));
 511             check(!deq.removeLastOccurrence(e));
 512             if (isList) {
 513                 check(asList.indexOf(e) == -1);
 514                 check(asList.lastIndexOf(e) == -1);
 515             }
 516             switch (rnd.nextInt(isList ? 4 : 3)) {
 517             case 0: deq.addFirst(e); break;
 518             case 1: check(deq.offerFirst(e)); break;
 519             case 2: deq.push(e); break;
 520             case 3: asList.add(0, e); break;
 521             default: throw new AssertionError();
 522             }
 523             check(deq.peekFirst() == e);
 524             check(deq.getFirst() == e);
 525             check(deq.element() == e);
 526             check(deq.peek() == e);
 527             check(deq.iterator().next() == e);
 528             check(deq.contains(e));
 529             if (isList) {
 530                 check(asList.get(0) == e);
 531                 check(asList.indexOf(e) == 0);
 532                 check(asList.lastIndexOf(e) == 0);
 533                 check(asList.subList(0, 1).equals(singleton));
 534             }
 535             switch (rnd.nextInt(isList ? 11 : 9)) {
 536             case 0: check(deq.pollFirst() == e); break;
 537             case 1: check(deq.removeFirst() == e); break;
 538             case 2: check(deq.remove() == e); break;
 539             case 3: check(deq.pop() == e); break;
 540             case 4: check(deq.removeFirstOccurrence(e)); break;
 541             case 5: check(deq.removeLastOccurrence(e)); break;
 542             case 6: check(deq.remove(e)); break;
 543             case 7: check(deq.removeAll(singleton)); break;
 544             case 8: Iterator it = deq.iterator(); it.next(); it.remove(); break;
 545             case 9: asList.remove(0); break;
 546             case 10: asList.subList(0, 1).clear(); break;
 547             default: throw new AssertionError();
 548             }
 549             if (isEmpty) {
 550                 THROWS(NoSuchElementException.class,
 551                        new Fun(){void f(){ deq.getFirst(); }},
 552                        new Fun(){void f(){ deq.element(); }},
 553                        new Fun(){void f(){ deq.iterator().next(); }});
 554                 check(deq.peekFirst() == null);
 555                 check(deq.peek() == null);
 556             } else {
 557                 check(deq.getFirst() != e);
 558                 check(deq.element() != e);
 559                 check(deq.iterator().next() != e);
 560                 check(deq.peekFirst() != e);
 561                 check(deq.peek() != e);
 562             }
 563             check(!deq.contains(e));
 564             check(!deq.removeFirstOccurrence(e));
 565             check(!deq.removeLastOccurrence(e));
 566             if (isList) {
 567                 check(isEmpty || asList.get(0) != e);
 568                 check(asList.indexOf(e) == -1);
 569                 check(asList.lastIndexOf(e) == -1);
 570             }
 571             equal(new ArrayList<Integer>(deq), originalContents);
 572 
 573             // insert, query, remove element at tail
 574             if (isEmpty) {
 575                 check(deq.peekLast() == null);
 576                 THROWS(NoSuchElementException.class,
 577                        new Fun(){void f(){ deq.getLast(); }});
 578             } else {
 579                 check(deq.peekLast() != e);
 580                 check(deq.getLast() != e);
 581             }
 582             switch (rnd.nextInt(isList ? 6 : 4)) {
 583             case 0: deq.addLast(e); break;
 584             case 1: check(deq.offerLast(e)); break;
 585             case 2: check(deq.add(e)); break;
 586             case 3: deq.addAll(singleton); break;
 587             case 4: asList.addAll(deq.size(), singleton); break;
 588             case 5: asList.add(deq.size(), e); break;
 589             default: throw new AssertionError();
 590             }
 591             check(deq.peekLast() == e);
 592             check(deq.getLast() == e);
 593             check(deq.contains(e));
 594             if (isList) {
 595                 ListIterator it = asList.listIterator(asList.size());
 596                 check(it.previous() == e);
 597                 check(asList.get(asList.size() - 1) == e);
 598                 check(asList.indexOf(e) == asList.size() - 1);
 599                 check(asList.lastIndexOf(e) == asList.size() - 1);
 600                 int size = asList.size();
 601                 check(asList.subList(size - 1, size).equals(singleton));
 602             }
 603             switch (rnd.nextInt(isList ? 8 : 6)) {
 604             case 0: check(deq.pollLast() == e); break;
 605             case 1: check(deq.removeLast() == e); break;
 606             case 2: check(deq.removeFirstOccurrence(e)); break;
 607             case 3: check(deq.removeLastOccurrence(e)); break;
 608             case 4: check(deq.remove(e)); break;
 609             case 5: check(deq.removeAll(singleton)); break;
 610             case 6: asList.remove(asList.size() - 1); break;
 611             case 7:
 612                 ListIterator it = asList.listIterator(asList.size());
 613                 it.previous();
 614                 it.remove();
 615                 break;
 616             default: throw new AssertionError();
 617             }
 618             if (isEmpty) {
 619                 check(deq.peekLast() == null);
 620                 THROWS(NoSuchElementException.class,
 621                        new Fun(){void f(){ deq.getLast(); }});
 622             } else {
 623                 check(deq.peekLast() != e);
 624                 check(deq.getLast() != e);
 625             }
 626             check(!deq.contains(e));
 627             equal(new ArrayList<Integer>(deq), originalContents);
 628 
 629             // Test operations on empty deque
 630             switch (rnd.nextInt(isList ? 4 : 2)) {
 631             case 0: deq.clear(); break;
 632             case 1:
 633                 Iterator it = deq.iterator();
 634                 while (it.hasNext()) {
 635                     it.next();
 636                     it.remove();
 637                 }
 638                 break;
 639             case 2: asList.subList(0, asList.size()).clear(); break;
 640             case 3:
 641                 ListIterator lit = asList.listIterator(asList.size());
 642                 while (lit.hasPrevious()) {
 643                     lit.previous();
 644                     lit.remove();
 645                 }
 646                 break;
 647             default: throw new AssertionError();
 648             }
 649             testEmptyCollection(deq);
 650             check(!deq.iterator().hasNext());
 651             if (isList) {
 652                 check(!asList.listIterator().hasPrevious());
 653                 THROWS(NoSuchElementException.class,
 654                        new Fun(){void f(){ asList.listIterator().previous(); }});
 655             }
 656             THROWS(NoSuchElementException.class,
 657                    new Fun(){void f(){ deq.iterator().next(); }},
 658                    new Fun(){void f(){ deq.element(); }},
 659                    new Fun(){void f(){ deq.getFirst(); }},
 660                    new Fun(){void f(){ deq.getLast(); }},
 661                    new Fun(){void f(){ deq.pop(); }},
 662                    new Fun(){void f(){ deq.remove(); }},
 663                    new Fun(){void f(){ deq.removeFirst(); }},
 664                    new Fun(){void f(){ deq.removeLast(); }});
 665 
 666             check(deq.poll() == null);
 667             check(deq.pollFirst() == null);
 668             check(deq.pollLast() == null);
 669             check(deq.peek() == null);
 670             check(deq.peekFirst() == null);
 671             check(deq.peekLast() == null);
 672             check(!deq.removeFirstOccurrence(e));
 673             check(!deq.removeLastOccurrence(e));
 674 
 675             check(deq.addAll(originalContents) == !isEmpty);
 676             equal(new ArrayList<Integer>(deq), originalContents);
 677             check(!deq.addAll(Collections.<Integer>emptyList()));
 678             equal(new ArrayList<Integer>(deq), originalContents);
 679         }
 680     }
 681 
 682     private static void testQueueIteratorRemove(Queue<Integer> q) {
 683         System.err.printf("testQueueIteratorRemove %s%n",
 684                           q.getClass().getSimpleName());
 685         q.clear();
 686         for (int i = 0; i < 5; i++)
 687             q.add(i);
 688         Iterator<Integer> it = q.iterator();
 689         check(it.hasNext());
 690         for (int i = 3; i >= 0; i--)
 691             q.remove(i);
 692         equal(it.next(), 0);
 693         equal(it.next(), 4);
 694 
 695         q.clear();
 696         for (int i = 0; i < 5; i++)
 697             q.add(i);
 698         it = q.iterator();
 699         equal(it.next(), 0);
 700         check(it.hasNext());
 701         for (int i = 1; i < 4; i++)
 702             q.remove(i);
 703         equal(it.next(), 1);
 704         equal(it.next(), 4);
 705     }
 706 
 707     private static void testList(final List<Integer> l) {
 708         //----------------------------------------------------------------
 709         // 4802633: (coll) AbstractList.addAll(-1,emptyCollection)
 710         // doesn't throw IndexOutOfBoundsException
 711         //----------------------------------------------------------------
 712         try {
 713             l.addAll(-1, Collections.<Integer>emptyList());
 714             fail("Expected IndexOutOfBoundsException not thrown");
 715         }
 716         catch (UnsupportedOperationException _) {/* OK */}
 717         catch (IndexOutOfBoundsException _) {/* OK */}
 718         catch (Throwable t) { unexpected(t); }
 719 
 720 //      equal(l instanceof Serializable,
 721 //            l.subList(0,0) instanceof Serializable);
 722         if (l.subList(0,0) instanceof Serializable)
 723             check(l instanceof Serializable);
 724 
 725         equal(l instanceof RandomAccess,
 726               l.subList(0,0) instanceof RandomAccess);
 727     }
 728 
 729     private static void testCollection(Collection<Integer> c) {
 730         try { testCollection1(c); }
 731         catch (Throwable t) { unexpected(t); }
 732     }
 733 
 734     private static void testCollection1(Collection<Integer> c) {
 735 
 736         System.out.println("\n==> " + c.getClass().getName());
 737 
 738         checkFunctionalInvariants(c);
 739 
 740         if (! supportsAdd(c)) return;
 741         //System.out.println("add() supported");
 742 
 743         if (c instanceof NavigableSet) {
 744             System.out.println("NavigableSet tests...");
 745 
 746             NavigableSet<Integer> ns = (NavigableSet<Integer>)c;
 747             testNavigableSet(ns);
 748             testNavigableSet(ns.headSet(6, false));
 749             testNavigableSet(ns.headSet(5, true));
 750             testNavigableSet(ns.tailSet(0, false));
 751             testNavigableSet(ns.tailSet(1, true));
 752             testNavigableSet(ns.subSet(0, false, 5, true));
 753             testNavigableSet(ns.subSet(1, true, 6, false));
 754         }
 755 
 756         if (c instanceof Queue)
 757             testQueue((Queue<Integer>)c);
 758 
 759         if (c instanceof List)
 760             testList((List<Integer>)c);
 761 
 762         check(supportsRemove(c));
 763 
 764         try {
 765             oneElement(c);
 766             checkFunctionalInvariants(c);
 767         }
 768         catch (Throwable t) { unexpected(t); }
 769 
 770         clear(c);      testNullElement(c);
 771         oneElement(c); testNullElement(c);
 772 
 773         clear(c);      testStringElement(c);
 774         oneElement(c); testStringElement(c);
 775 
 776         if (c.getClass().getName().matches(".*concurrent.*"))
 777             testConcurrentCollection(c);
 778 
 779         //----------------------------------------------------------------
 780         // The "all" operations should throw NPE when passed null
 781         //----------------------------------------------------------------
 782         {
 783             clear(c);
 784             try {
 785                 c.removeAll(null);
 786                 fail("Expected NullPointerException");
 787             }
 788             catch (NullPointerException e) { pass(); }
 789             catch (Throwable t) { unexpected(t); }
 790 
 791             oneElement(c);
 792             try {
 793                 c.removeAll(null);
 794                 fail("Expected NullPointerException");
 795             }
 796             catch (NullPointerException e) { pass(); }
 797             catch (Throwable t) { unexpected(t); }
 798 
 799             clear(c);
 800             try {
 801                 c.retainAll(null);
 802                 fail("Expected NullPointerException");
 803             }
 804             catch (NullPointerException e) { pass(); }
 805             catch (Throwable t) { unexpected(t); }
 806 
 807             oneElement(c);
 808             try {
 809                 c.retainAll(null);
 810                 fail("Expected NullPointerException");
 811             }
 812             catch (NullPointerException e) { pass(); }
 813             catch (Throwable t) { unexpected(t); }
 814 
 815             oneElement(c);
 816             try {
 817                 c.addAll(null);
 818                 fail("Expected NullPointerException");
 819             }
 820             catch (NullPointerException e) { pass(); }
 821             catch (Throwable t) { unexpected(t); }
 822 
 823             oneElement(c);
 824             try {
 825                 c.containsAll(null);
 826                 fail("Expected NullPointerException");
 827             }
 828             catch (NullPointerException e) { pass(); }
 829             catch (Throwable t) { unexpected(t); }
 830         }
 831     }
 832 
 833     //----------------------------------------------------------------
 834     // Map
 835     //----------------------------------------------------------------
 836     private static void checkFunctionalInvariants(Map<Integer,Integer> m) {
 837         check(m.keySet().size() == m.entrySet().size());
 838         check(m.keySet().size() == m.size());
 839         checkFunctionalInvariants(m.keySet());
 840         checkFunctionalInvariants(m.values());
 841         check(m.size() != 0 ^ m.isEmpty());
 842     }
 843 
 844     private static void testMap(Map<Integer,Integer> m) {
 845         System.out.println("\n==> " + m.getClass().getName());
 846 
 847         if (m instanceof ConcurrentMap)
 848             testConcurrentMap((ConcurrentMap<Integer,Integer>) m);
 849 
 850         if (m instanceof NavigableMap) {
 851             System.out.println("NavigableMap tests...");
 852 
 853             NavigableMap<Integer,Integer> nm =
 854                 (NavigableMap<Integer,Integer>) m;
 855             testNavigableMapRemovers(nm);
 856             testNavigableMap(nm);
 857             testNavigableMap(nm.headMap(6, false));
 858             testNavigableMap(nm.headMap(5, true));
 859             testNavigableMap(nm.tailMap(0, false));
 860             testNavigableMap(nm.tailMap(1, true));
 861             testNavigableMap(nm.subMap(1, true, 6, false));
 862             testNavigableMap(nm.subMap(0, false, 5, true));
 863         }
 864 
 865         checkFunctionalInvariants(m);
 866 
 867         if (supportsClear(m)) {
 868             try { clear(m); }
 869             catch (Throwable t) { unexpected(t); }
 870         }
 871 
 872         if (supportsPut(m)) {
 873             try {
 874                 check(m.put(3333, 77777) == null);
 875                 check(m.put(9134, 74982) == null);
 876                 check(m.get(9134) == 74982);
 877                 check(m.put(9134, 1382) == 74982);
 878                 check(m.get(9134) == 1382);
 879                 check(m.size() == 2);
 880                 checkFunctionalInvariants(m);
 881                 checkNPEConsistency(m);
 882             }
 883             catch (Throwable t) { unexpected(t); }
 884         }
 885     }
 886 
 887     private static boolean supportsPut(Map<Integer,Integer> m) {
 888         // We're asking for .equals(...) semantics
 889         if (m instanceof IdentityHashMap) return false;
 890 
 891         try { check(m.put(778347983,12735) == null); }
 892         catch (UnsupportedOperationException t) { return false; }
 893         catch (Throwable t) { unexpected(t); }
 894 
 895         try {
 896             check(m.containsKey(778347983));
 897             check(m.remove(778347983) != null);
 898         } catch (Throwable t) { unexpected(t); }
 899         return true;
 900     }
 901 
 902     private static boolean supportsClear(Map<?,?> m) {
 903         try { m.clear(); }
 904         catch (UnsupportedOperationException t) { return false; }
 905         catch (Throwable t) { unexpected(t); }
 906         return true;
 907     }
 908 
 909     //----------------------------------------------------------------
 910     // ConcurrentMap
 911     //----------------------------------------------------------------
 912     private static void testConcurrentMap(ConcurrentMap<Integer,Integer> m) {
 913         System.out.println("ConcurrentMap tests...");
 914 
 915         try {
 916             clear(m);
 917 
 918             check(m.putIfAbsent(18357,7346) == null);
 919             check(m.containsKey(18357));
 920             check(m.putIfAbsent(18357,8263) == 7346);
 921             try { m.putIfAbsent(18357,null); fail("NPE"); }
 922             catch (NullPointerException t) { }
 923             check(m.containsKey(18357));
 924 
 925             check(! m.replace(18357,8888,7777));
 926             check(m.containsKey(18357));
 927             try { m.replace(18357,null,7777); fail("NPE"); }
 928             catch (NullPointerException t) { }
 929             check(m.containsKey(18357));
 930             check(m.get(18357) == 7346);
 931             check(m.replace(18357,7346,5555));
 932             check(m.replace(18357,5555,7346));
 933             check(m.get(18357) == 7346);
 934 
 935             check(m.replace(92347,7834) == null);
 936             try { m.replace(18357,null); fail("NPE"); }
 937             catch (NullPointerException t) { }
 938             check(m.replace(18357,7346) == 7346);
 939             check(m.replace(18357,5555) == 7346);
 940             check(m.get(18357) == 5555);
 941             check(m.replace(18357,7346) == 5555);
 942             check(m.get(18357) == 7346);
 943 
 944             check(! m.remove(18357,9999));
 945             check(m.get(18357) == 7346);
 946             check(m.containsKey(18357));
 947             check(! m.remove(18357,null)); // 6272521
 948             check(m.get(18357) == 7346);
 949             check(m.remove(18357,7346));
 950             check(m.get(18357) == null);
 951             check(! m.containsKey(18357));
 952             check(m.isEmpty());
 953 
 954             m.putIfAbsent(1,2);
 955             check(m.size() == 1);
 956             check(! m.remove(1,null));
 957             check(! m.remove(1,null));
 958             check(! m.remove(1,1));
 959             check(m.remove(1,2));
 960             check(m.isEmpty());
 961 
 962             testEmptyMap(m);
 963         }
 964         catch (Throwable t) { unexpected(t); }
 965     }
 966 
 967     private static void throwsConsistently(Class<? extends Throwable> k,
 968                                            Iterable<Fun> fs) {
 969         List<Class<? extends Throwable>> threw
 970             = new ArrayList<Class<? extends Throwable>>();
 971         for (Fun f : fs)
 972             try { f.f(); threw.add(null); }
 973             catch (Throwable t) {
 974                 check(k.isAssignableFrom(t.getClass()));
 975                 threw.add(t.getClass());
 976             }
 977         if (new HashSet<Object>(threw).size() != 1)
 978             fail(threw.toString());
 979     }
 980 
 981     private static <T> void checkNPEConsistency(final Map<T,Integer> m) {
 982         m.clear();
 983         final ConcurrentMap<T,Integer> cm = (m instanceof ConcurrentMap)
 984             ? (ConcurrentMap<T,Integer>) m
 985             : null;
 986         List<Fun> fs = new ArrayList<Fun>();
 987         fs.add(new Fun(){void f(){ check(! m.containsKey(null));}});
 988         fs.add(new Fun(){void f(){ equal(m.remove(null), null);}});
 989         fs.add(new Fun(){void f(){ equal(m.get(null), null);}});
 990         if (cm != null) {
 991             fs.add(new Fun(){void f(){ check(! cm.remove(null,null));}});}
 992         throwsConsistently(NullPointerException.class, fs);
 993 
 994         fs.clear();
 995         final Map<T,Integer> sm = singletonMap(null,1);
 996         fs.add(new Fun(){void f(){ equal(m.put(null,1), null); m.clear();}});
 997         fs.add(new Fun(){void f(){ m.putAll(sm); m.clear();}});
 998         if (cm != null) {
 999             fs.add(new Fun(){void f(){ check(! cm.remove(null,null));}});
1000             fs.add(new Fun(){void f(){ equal(cm.putIfAbsent(null,1), 1);}});
1001             fs.add(new Fun(){void f(){ equal(cm.replace(null,1), null);}});
1002             fs.add(new Fun(){void f(){ equal(cm.replace(null,1, 1), 1);}});
1003         }
1004         throwsConsistently(NullPointerException.class, fs);
1005     }
1006 
1007     //----------------------------------------------------------------
1008     // NavigableMap
1009     //----------------------------------------------------------------
1010     private static void
1011         checkNavigableMapKeys(NavigableMap<Integer,Integer> m,
1012                               Integer i,
1013                               Integer lower,
1014                               Integer floor,
1015                               Integer ceiling,
1016                               Integer higher) {
1017         equal(m.lowerKey(i),   lower);
1018         equal(m.floorKey(i),   floor);
1019         equal(m.ceilingKey(i), ceiling);
1020         equal(m.higherKey(i),  higher);
1021     }
1022 
1023     private static void
1024         checkNavigableSetKeys(NavigableSet<Integer> m,
1025                               Integer i,
1026                               Integer lower,
1027                               Integer floor,
1028                               Integer ceiling,
1029                               Integer higher) {
1030         equal(m.lower(i),   lower);
1031         equal(m.floor(i),   floor);
1032         equal(m.ceiling(i), ceiling);
1033         equal(m.higher(i),  higher);
1034     }
1035 
1036     static final Random rnd = new Random();
1037     static void equalNext(final Iterator<?> it, Object expected) {
1038         if (rnd.nextBoolean())
1039             check(it.hasNext());
1040         equal(it.next(), expected);
1041     }
1042 
1043     static void equalMaps(Map m1, Map m2) {
1044         equal(m1, m2);
1045         equal(m2, m1);
1046         equal(m1.size(), m2.size());
1047         equal(m1.isEmpty(), m2.isEmpty());
1048         equal(m1.toString(), m2.toString());
1049         check(Arrays.equals(m1.entrySet().toArray(), m2.entrySet().toArray()));
1050     }
1051 
1052     @SuppressWarnings({"unchecked", "rawtypes"})
1053     static void testNavigableMapRemovers(NavigableMap m)
1054     {
1055         final Map emptyMap = new HashMap();
1056 
1057         final Map singletonMap = new HashMap();
1058         singletonMap.put(1, 2);
1059 
1060         abstract class NavigableMapView {
1061             abstract NavigableMap view(NavigableMap m);
1062         }
1063 
1064         NavigableMapView[] views = {
1065             new NavigableMapView() { NavigableMap view(NavigableMap m) {
1066                 return m; }},
1067             new NavigableMapView() { NavigableMap view(NavigableMap m) {
1068                 return m.headMap(99, true); }},
1069             new NavigableMapView() { NavigableMap view(NavigableMap m) {
1070                 return m.tailMap(-99, false); }},
1071             new NavigableMapView() { NavigableMap view(NavigableMap m) {
1072                 return m.subMap(-99, true, 99, false); }},
1073         };
1074 
1075         abstract class Remover {
1076             abstract void remove(NavigableMap m, Object k, Object v);
1077         }
1078 
1079         Remover[] removers = {
1080             new Remover() { void remove(NavigableMap m, Object k, Object v) {
1081                 equal(m.remove(k), v); }},
1082 
1083             new Remover() { void remove(NavigableMap m, Object k, Object v) {
1084                 equal(m.descendingMap().remove(k), v); }},
1085             new Remover() { void remove(NavigableMap m, Object k, Object v) {
1086                 equal(m.descendingMap().headMap(-86, false).remove(k), v); }},
1087             new Remover() { void remove(NavigableMap m, Object k, Object v) {
1088                 equal(m.descendingMap().tailMap(86, true).remove(k), v); }},
1089 
1090             new Remover() { void remove(NavigableMap m, Object k, Object v) {
1091                 equal(m.headMap(86, true).remove(k), v); }},
1092             new Remover() { void remove(NavigableMap m, Object k, Object v) {
1093                 equal(m.tailMap(-86, true).remove(k), v); }},
1094             new Remover() { void remove(NavigableMap m, Object k, Object v) {
1095                 equal(m.subMap(-86, false, 86, true).remove(k), v); }},
1096 
1097             new Remover() { void remove(NavigableMap m, Object k, Object v) {
1098                 check(m.keySet().remove(k)); }},
1099             new Remover() { void remove(NavigableMap m, Object k, Object v) {
1100                 check(m.navigableKeySet().remove(k)); }},
1101 
1102             new Remover() { void remove(NavigableMap m, Object k, Object v) {
1103                 check(m.navigableKeySet().headSet(86, true).remove(k)); }},
1104             new Remover() { void remove(NavigableMap m, Object k, Object v) {
1105                 check(m.navigableKeySet().tailSet(-86, false).remove(k)); }},
1106             new Remover() { void remove(NavigableMap m, Object k, Object v) {
1107                 check(m.navigableKeySet().subSet(-86, true, 86, false)
1108                       .remove(k)); }},
1109 
1110             new Remover() { void remove(NavigableMap m, Object k, Object v) {
1111                 check(m.descendingKeySet().headSet(-86, false).remove(k)); }},
1112             new Remover() { void remove(NavigableMap m, Object k, Object v) {
1113                 check(m.descendingKeySet().tailSet(86, true).remove(k)); }},
1114             new Remover() { void remove(NavigableMap m, Object k, Object v) {
1115                 check(m.descendingKeySet().subSet(86, true, -86, false)
1116                       .remove(k)); }},
1117         };
1118 
1119         for (NavigableMapView view : views) {
1120             for (Remover remover : removers) {
1121                 try {
1122                     m.clear();
1123                     equalMaps(m, emptyMap);
1124                     equal(m.put(1, 2), null);
1125                     equalMaps(m, singletonMap);
1126                     NavigableMap v = view.view(m);
1127                     remover.remove(v, 1, 2);
1128                     equalMaps(m, emptyMap);
1129                 } catch (Throwable t) { unexpected(t); }
1130             }
1131         }
1132     }
1133 
1134     private static void testNavigableMap(NavigableMap<Integer,Integer> m)
1135     {
1136         clear(m);
1137         checkNavigableMapKeys(m, 1, null, null, null, null);
1138 
1139         equal(m.put(1, 2), null);
1140         equal(m.put(3, 4), null);
1141         equal(m.put(5, 9), null);
1142 
1143         equal(m.put(1, 2), 2);
1144         equal(m.put(3, 4), 4);
1145         equal(m.put(5, 6), 9);
1146 
1147         checkNavigableMapKeys(m, 0, null, null,    1,    1);
1148         checkNavigableMapKeys(m, 1, null,    1,    1,    3);
1149         checkNavigableMapKeys(m, 2,    1,    1,    3,    3);
1150         checkNavigableMapKeys(m, 3,    1,    3,    3,    5);
1151         checkNavigableMapKeys(m, 5,    3,    5,    5, null);
1152         checkNavigableMapKeys(m, 6,    5,    5, null, null);
1153 
1154         for (final Iterator<Integer> it :
1155                  (Iterator<Integer>[])
1156                  new Iterator<?>[] {
1157                      m.descendingKeySet().iterator(),
1158                      m.navigableKeySet().descendingIterator()}) {
1159             equalNext(it, 5);
1160             equalNext(it, 3);
1161             equalNext(it, 1);
1162             check(! it.hasNext());
1163             THROWS(NoSuchElementException.class,
1164                    new Fun(){void f(){it.next();}});
1165         }
1166 
1167         {
1168             final Iterator<Map.Entry<Integer,Integer>> it
1169                 = m.descendingMap().entrySet().iterator();
1170             check(it.hasNext()); equal(it.next().getKey(), 5);
1171             check(it.hasNext()); equal(it.next().getKey(), 3);
1172             check(it.hasNext()); equal(it.next().getKey(), 1);
1173             check(! it.hasNext());
1174             THROWS(NoSuchElementException.class,
1175                    new Fun(){void f(){it.next();}});
1176         }
1177     }
1178 
1179 
1180     private static void testNavigableSet(NavigableSet<Integer> s) {
1181         clear(s);
1182         checkNavigableSetKeys(s, 1, null, null, null, null);
1183 
1184         check(s.add(1));
1185         check(s.add(3));
1186         check(s.add(5));
1187 
1188         check(! s.add(1));
1189         check(! s.add(3));
1190         check(! s.add(5));
1191 
1192         checkNavigableSetKeys(s, 0, null, null,    1,    1);
1193         checkNavigableSetKeys(s, 1, null,    1,    1,    3);
1194         checkNavigableSetKeys(s, 2,    1,    1,    3,    3);
1195         checkNavigableSetKeys(s, 3,    1,    3,    3,    5);
1196         checkNavigableSetKeys(s, 5,    3,    5,    5, null);
1197         checkNavigableSetKeys(s, 6,    5,    5, null, null);
1198 
1199         for (final Iterator<Integer> it :
1200                  (Iterator<Integer>[])
1201                  new Iterator<?>[] {
1202                      s.descendingIterator(),
1203                      s.descendingSet().iterator()}) {
1204             equalNext(it, 5);
1205             equalNext(it, 3);
1206             equalNext(it, 1);
1207             check(! it.hasNext());
1208             THROWS(NoSuchElementException.class,
1209                    new Fun(){void f(){it.next();}});
1210         }
1211     }
1212 
1213     //--------------------- Infrastructure ---------------------------
1214     static volatile int passed = 0, failed = 0;
1215     static void pass() { passed++; }
1216     static void fail() { failed++; Thread.dumpStack(); }
1217     static void fail(String msg) { System.out.println(msg); fail(); }
1218     static void unexpected(Throwable t) { failed++; t.printStackTrace(); }
1219     static void check(boolean cond) { if (cond) pass(); else fail(); }
1220     static void equal(Object x, Object y) {
1221         if (x == null ? y == null : x.equals(y)) pass();
1222         else {System.out.println(x + " not equal to " + y); fail();}}
1223     static void equal2(Object x, Object y) {equal(x, y); equal(y, x);}
1224     public static void main(String[] args) throws Throwable {
1225         try { realMain(args); } catch (Throwable t) { unexpected(t); }
1226 
1227         System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
1228         if (failed > 0) throw new Exception("Some tests failed");
1229     }
1230     private static abstract class Fun {abstract void f() throws Throwable;}
1231     private static void THROWS(Class<? extends Throwable> k, Fun... fs) {
1232           for (Fun f : fs)
1233               try { f.f(); fail("Expected " + k.getName() + " not thrown"); }
1234               catch (Throwable t) {
1235                   if (k.isAssignableFrom(t.getClass())) pass();
1236                   else unexpected(t);}}
1237     static byte[] serializedForm(Object obj) {
1238         try {
1239             ByteArrayOutputStream baos = new ByteArrayOutputStream();
1240             new ObjectOutputStream(baos).writeObject(obj);
1241             return baos.toByteArray();
1242         } catch (IOException e) { throw new Error(e); }}
1243     static Object readObject(byte[] bytes)
1244         throws IOException, ClassNotFoundException {
1245         InputStream is = new ByteArrayInputStream(bytes);
1246         return new ObjectInputStream(is).readObject();}
1247     @SuppressWarnings("unchecked")
1248     static <T> T serialClone(T obj) {
1249         try { return (T) readObject(serializedForm(obj)); }
1250         catch (Exception e) { throw new Error(e); }}
1251     private static class NewAbstractCollection<E> extends AbstractCollection<E> {
1252         ArrayList<E> list = new ArrayList<>();
1253         public boolean remove(Object obj) {
1254             return list.remove(obj);
1255         }
1256         public boolean add(E e) {
1257             return list.add(e);
1258         }
1259         public Iterator<E> iterator() {
1260             return list.iterator();
1261         }
1262         public int size() {
1263             return list.size();
1264         }
1265     }
1266     private static class NewAbstractSet<E> extends AbstractSet<E> {
1267         HashSet<E> set = new HashSet<>();
1268         public boolean remove(Object obj) {
1269             return set.remove(obj);
1270         }
1271         public boolean add(E e) {
1272             return set.add(e);
1273         }
1274         public Iterator<E> iterator() {
1275             return set.iterator();
1276         }
1277         public int size() {
1278             return set.size();
1279         }
1280     }
1281 
1282 }