RFR: jsr166 jdk9 integration wave 12 (original) (raw)

Fri Nov 18 03:17:33 UTC 2016

* nested loops for all traversals over the elements.
* nested loops for all traversals over the elements.  Having only
* one hot inner loop body instead of two or three eases human
* maintenance and encourages VM loop inlining into the caller.
*/
* We guarantee that all array cells not holding deque elements
* are always null.
* All array cells not holding deque elements are always null.
* The array always has at least one null slot (at tail).
*/
 /**
  * The index at which the next element would be added to the tail
* of the deque (via addLast(E), add(E), or push(E)).
* of the deque (via addLast(E), add(E), or push(E));
* elements[tail] is always null.
*/
   elements = new Object[Math.max(1, numElements + 1)];
   elements =
       new Object[(numElements < 1) ? 1 :
                  (numElements == Integer.MAX_VALUE) ?
                  numElements + 1];
   elements = new Object[c.size() + 1];
   this(c.size());
   addAll(c);
 /**
* Adds i and j, mod modulus.
* Precondition and postcondition: 0 <= i < modulus, 0 <= j <= modulus.
* Circularly adds the given distance to index i, mod modulus.
* Precondition: 0 <= i < modulus, 0 <= distance <= modulus.
* @return index 0 <= i < modulus
*/
   if ((i += j) - modulus >= 0) i -= modulus;
   if ((i += distance) - modulus >= 0) distance -= modulus;
   return i;
* Index i must be logically ahead of j.
* Returns the "circular distance" from j to i.
* Precondition and postcondition: 0 <= i < modulus, 0 <= j < modulus.
* Index i must be logically ahead of index j.
* Precondition: 0 <= i < modulus, 0 <= j < modulus.
* @return the "circular distance" from j to i; corner case i == j
* is diambiguated to "empty", returning 0.
*/
       final Object[] es;
       action.accept(nonNullElementAt(es = elements, i));
       final Object[] es = elements;
       cursor = inc(i, es.length);
       action.accept(nonNullElementAt(es, i));
       return true;
   }
 /** debugging */
 void checkInvariants() {
   // Use head and tail fields with empty slot at tail strategy.
   // head == tail disambiguates to "empty".
   try {
       int capacity = elements.length;
       // assert head >= 0 && head < capacity;
* Much of the implementation mechanics, especially the unusual
* nested loops, are shared and co-maintained with ArrayDeque.
*/
/**
 * Serialization ID. This class relies on default serialization
 * even for the items array, which is default-serialized, even if
 /**
  * Handle capacities near Integer.MAX_VALUE.
* ant -Dvmoptions='-Xms28g -Xmx28g'
* ant -Dvmoptions='-Xms28g -Xmx28g' -Djsr166.expensiveTests=true
   ArrayDeque q;
   Integer e = 42;
   final int maxSize = Integer.MAX_VALUE - 8;
   final Integer e = 42;
   final int maxArraySize = Integer.MAX_VALUE - 8;

   assertThrows(OutOfMemoryError.class,
                () -> new ArrayDeque<>(Integer.MAX_VALUE));
                () -> new ArrayDeque(Integer.MAX_VALUE));

   {
       q = new ArrayDeque<>(maxSize);
       ArrayDeque q = new ArrayDeque(maxArraySize - 1);
       assertEquals(0, q.size());
       assertTrue(q.isEmpty());
       q = null;
   }

   {
       q = new ArrayDeque();
       assertTrue(q.addAll(Collections.nCopies(maxSize - 2, e)));
       ArrayDeque q = new ArrayDeque();
       assertTrue(q.addAll(Collections.nCopies(maxArraySize - 3, e)));
       assertEquals(e, q.peekFirst());
       assertEquals(e, q.peekLast());
       assertEquals(maxSize - 2, q.size());
       assertEquals(maxArraySize - 3, q.size());
       q.addFirst((Integer) 0);
       q.addLast((Integer) 1);
       assertEquals((Integer) 0, q.peekFirst());
       assertEquals((Integer) 1, q.peekLast());
       assertEquals(maxSize, q.size());
       assertEquals(maxArraySize - 1, q.size());

       ArrayDeque qq = q;
       ArrayDeque smallish = new ArrayDeque(
           Collections.nCopies(Integer.MAX_VALUE - maxSize + 1, e));
           Collections.nCopies(Integer.MAX_VALUE - q.size() + 1, e));
       assertThrows(
           IllegalStateException.class,
           () -> qq.addAll(qq),

RFR: jsr166 jdk9 integration wave 12 (original) (raw)

Index: src/main/java/util/ArrayDeque.java

Index: src/main/java/util/concurrent/ArrayBlockingQueue.java