SynchronizedArrayList - saves space over synchroList() [1012179]

// Modified from java.util.ArrayList
 
sclass SynchronizedArrayList<A> extends SynchronizedArrayList_Base<A> implements RandomAccess, Cloneable {
  private static final int DEFAULT_CAPACITY = 10;
  private static final Object[] EMPTY_ELEMENTDATA = {};
  private static final Object[] DEFAULTCAPACITY_EMPTY_ELEMENTDATA = {};
  transient Object[] elementData; // non-private to simplify nested class access
  private int size;

  *(int initialCapacity) {
      if (initialCapacity > 0) {
          this.elementData = new Object[initialCapacity];
      } else if (initialCapacity == 0) {
          this.elementData = EMPTY_ELEMENTDATA;
      } else {
          throw new IllegalArgumentException("Illegal Capacity: "+
                                             initialCapacity);
      }
  }

  *() {
      this.elementData = DEFAULTCAPACITY_EMPTY_ELEMENTDATA;
  }

  *(Collection<? extends A> c) {
      elementData = c.toArray();
      if ((size = elementData.length) != 0) {
          // c.toArray might (incorrectly) not return Object[] (see 6260652)
          if (elementData.getClass() != Object[].class)
              elementData = Arrays.copyOf(elementData, size, Object[].class);
      } else {
          // replace with empty array.
          this.elementData = EMPTY_ELEMENTDATA;
      }
  }

  public synchronized void trimToSize() {
      modCount++;
      if (size < elementData.length) {
          elementData = (size == 0)
            ? EMPTY_ELEMENTDATA
            : Arrays.copyOf(elementData, size);
      }
  }

  public synchronized void ensureCapacity(int minCapacity) {
      int minExpand = (elementData != DEFAULTCAPACITY_EMPTY_ELEMENTDATA)
          // any size if not default element table
          ? 0
          // larger than default for default empty table. It's already
          // supposed to be at default size.
          : DEFAULT_CAPACITY;

      if (minCapacity > minExpand) {
          ensureExplicitCapacity(minCapacity);
      }
  }

  private void ensureCapacityInternal(int minCapacity) {
      if (elementData == DEFAULTCAPACITY_EMPTY_ELEMENTDATA) {
          minCapacity = Math.max(DEFAULT_CAPACITY, minCapacity);
      }

      ensureExplicitCapacity(minCapacity);
  }

  private void ensureExplicitCapacity(int minCapacity) {
      modCount++;

      // overflow-conscious code
      if (minCapacity - elementData.length > 0)
          grow(minCapacity);
  }

  private static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8;

  private void grow(int minCapacity) {
      // overflow-conscious code
      int oldCapacity = elementData.length;
      int newCapacity = oldCapacity + (oldCapacity >> 1);
      if (newCapacity - minCapacity < 0)
          newCapacity = minCapacity;
      if (newCapacity - MAX_ARRAY_SIZE > 0)
          newCapacity = hugeCapacity(minCapacity);
      // minCapacity is usually close to size, so this is a win:
      elementData = Arrays.copyOf(elementData, newCapacity);
  }

  private static int hugeCapacity(int minCapacity) {
      if (minCapacity < 0) // overflow
          throw new OutOfMemoryError();
      return (minCapacity > MAX_ARRAY_SIZE) ?
          Integer.MAX_VALUE :
          MAX_ARRAY_SIZE;
  }

  public synchronized int size() {
      return size;
  }

  public synchronized boolean isEmpty() {
      return size == 0;
  }

  public boolean contains(Object o) {
      return indexOf(o) >= 0;
  }

  public synchronized int indexOf(Object o) {
      if (o == null) {
          for (int i = 0; i < size; i++)
              if (elementData[i]==null)
                  return i;
      } else {
          for (int i = 0; i < size; i++)
              if (o.equals(elementData[i]))
                  return i;
      }
      return -1;
  }

  public synchronized int lastIndexOf(Object o) {
      if (o == null) {
          for (int i = size-1; i >= 0; i--)
              if (elementData[i]==null)
                  return i;
      } else {
          for (int i = size-1; i >= 0; i--)
              if (o.equals(elementData[i]))
                  return i;
      }
      return -1;
  }

  public synchronized Object clone() {
    ret new SynchronizedArrayList(this);
  }

  public synchronized Object[] toArray() {
      return Arrays.copyOf(elementData, size);
  }

  @SuppressWarnings("unchecked")
  public synchronized  <T> T[] toArray(T[] a) {
      if (a.length < size)
          // Make a new array of a's runtime type, but my contents:
          return (T[]) Arrays.copyOf(elementData, size, a.getClass());
      System.arraycopy(elementData, 0, a, 0, size);
      if (a.length > size)
          a[size] = null;
      return a;
  }

  // Positional Access Operations

  @SuppressWarnings("unchecked")
  A elementData(int index) {
      return (A) elementData[index];
  }

  public synchronized A get(int index) {
      rangeCheck(index);

      return elementData(index);
  }

  public synchronized A set(int index, A element) {
      rangeCheck(index);

      A oldValue = elementData(index);
      elementData[index] = element;
      return oldValue;
  }

  public synchronized boolean add(A e) {
      ensureCapacityInternal(size + 1);  // Increments modCount!!
      elementData[size++] = e;
      return true;
  }

  public synchronized void add(int index, A element) {
      rangeCheckForAdd(index);

      ensureCapacityInternal(size + 1);  // Increments modCount!!
      System.arraycopy(elementData, index, elementData, index + 1,
                       size - index);
      elementData[index] = element;
      size++;
  }

  public synchronized A remove(int index) {
      rangeCheck(index);

      modCount++;
      A oldValue = elementData(index);

      int numMoved = size - index - 1;
      if (numMoved > 0)
          System.arraycopy(elementData, index+1, elementData, index,
                           numMoved);
      elementData[--size] = null; // clear to let GC do its work

      return oldValue;
  }

  public synchronized boolean remove(Object o) {
      if (o == null) {
          for (int index = 0; index < size; index++)
              if (elementData[index] == null) {
                  fastRemove(index);
                  return true;
              }
      } else {
          for (int index = 0; index < size; index++)
              if (o.equals(elementData[index])) {
                  fastRemove(index);
                  return true;
              }
      }
      return false;
  }

  private void fastRemove(int index) {
      modCount++;
      int numMoved = size - index - 1;
      if (numMoved > 0)
          System.arraycopy(elementData, index+1, elementData, index,
                           numMoved);
      elementData[--size] = null; // clear to let GC do its work
  }

  public synchronized void clear() {
      modCount++;

      // clear to let GC do its work
      for (int i = 0; i < size; i++)
          elementData[i] = null;

      size = 0;
  }

  public synchronized boolean addAll(Collection<? extends A> c) {
      Object[] a = c.toArray();
      int numNew = a.length;
      ensureCapacityInternal(size + numNew);  // Increments modCount
      System.arraycopy(a, 0, elementData, size, numNew);
      size += numNew;
      return numNew != 0;
  }

  public synchronized boolean addAll(int index, Collection<? extends A> c) {
      rangeCheckForAdd(index);

      Object[] a = c.toArray();
      int numNew = a.length;
      ensureCapacityInternal(size + numNew);  // Increments modCount

      int numMoved = size - index;
      if (numMoved > 0)
          System.arraycopy(elementData, index, elementData, index + numNew,
                           numMoved);

      System.arraycopy(a, 0, elementData, index, numNew);
      size += numNew;
      return numNew != 0;
  }

  public synchronized void removeRange(int fromIndex, int toIndex) {
      modCount++;
      int numMoved = size - toIndex;
      System.arraycopy(elementData, toIndex, elementData, fromIndex,
                       numMoved);

      // clear to let GC do its work
      int newSize = size - (toIndex-fromIndex);
      for (int i = newSize; i < size; i++) {
          elementData[i] = null;
      }
      size = newSize;
  }

  private void rangeCheck(int index) {
      if (index >= size)
          throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
  }

  private void rangeCheckForAdd(int index) {
      if (index > size || index < 0)
          throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
  }

  /**
   * Constructs an IndexOutOfBoundsException detail message.
   * Of the many possible refactorings of the error handling code,
   * this "outlining" performs best with both server and client VMs.
   */
  private String outOfBoundsMsg(int index) {
      return "Index: "+index+", Size: "+size;
  }

  public synchronized boolean removeAll(Collection<?> c) {
      Objects.requireNonNull(c);
      return batchRemove(c, false);
  }

  public synchronized boolean retainAll(Collection<?> c) {
      Objects.requireNonNull(c);
      return batchRemove(c, true);
  }

  private boolean batchRemove(Collection<?> c, boolean complement) {
      final Object[] elementData = this.elementData;
      int r = 0, w = 0;
      boolean modified = false;
      try {
          for (; r < size; r++)
              if (c.contains(elementData[r]) == complement)
                  elementData[w++] = elementData[r];
      } finally {
          // Preserve behavioral compatibility with AbstractCollection,
          // even if c.contains() throws.
          if (r != size) {
              System.arraycopy(elementData, r,
                               elementData, w,
                               size - r);
              w += size - r;
          }
          if (w != size) {
              // clear to let GC do its work
              for (int i = w; i < size; i++)
                  elementData[i] = null;
              modCount += size - w;
              size = w;
              modified = true;
          }
      }
      return modified;
  }

  /**
   * Save the state of the <tt>ArrayList</tt> instance to a stream (that
   * is, serialize it).
   *
   * @serialData The length of the array backing the <tt>ArrayList</tt>
   *             instance is emitted (int), followed by all of its elements
   *             (each an <tt>Object</tt>) in the proper order.
   */
  private void writeObject(java.io.ObjectOutputStream s)
      throws java.io.IOException{
      // Write out element count, and any hidden stuff
      int expectedModCount = modCount;
      s.defaultWriteObject();

      // Write out size as capacity for behavioural compatibility with clone()
      s.writeInt(size);

      // Write out all elements in the proper order.
      for (int i=0; i<size; i++) {
          s.writeObject(elementData[i]);
      }

      if (modCount != expectedModCount) {
          throw new ConcurrentModificationException();
      }
  }

  private void readObject(java.io.ObjectInputStream s)
      throws java.io.IOException, ClassNotFoundException {
      elementData = EMPTY_ELEMENTDATA;

      // Read in size, and any hidden stuff
      s.defaultReadObject();

      // Read in capacity
      s.readInt(); // ignored

      if (size > 0) {
          // be like clone(), allocate array based upon size not capacity
          ensureCapacityInternal(size);

          Object[] a = elementData;
          // Read in all elements in the proper order.
          for (int i=0; i<size; i++) {
              a[i] = s.readObject();
          }
      }
  }

  /**
   * Returns a list iterator over the elements in this list (in proper
   * sequence), starting at the specified position in the list.
   * The specified index indicates the first element that would be
   * returned by an initial call to {@link ListIterator#next next}.
   * An initial call to {@link ListIterator#previous previous} would
   * return the element with the specified index minus one.
   *
   * <p>The returned list iterator is <a href="#fail-fast"><i>fail-fast</i></a>.
   *
   * @throws IndexOutOfBoundsException {@inheritDoc}
   */
  public synchronized ListIterator<A> listIterator(int index) {
      if (index < 0 || index > size)
          throw new IndexOutOfBoundsException("Index: "+index);
      return new ListItr(index);
  }

  /**
   * Returns a list iterator over the elements in this list (in proper
   * sequence).
   *
   * <p>The returned list iterator is <a href="#fail-fast"><i>fail-fast</i></a>.
   *
   * @see #listIterator(int)
   */
  public ListIterator<A> listIterator() {
      return new ListItr(0);
  }

  /**
   * Returns an iterator over the elements in this list in proper sequence.
   *
   * <p>The returned iterator is <a href="#fail-fast"><i>fail-fast</i></a>.
   *
   * @return an iterator over the elements in this list in proper sequence
   */
  public Iterator<A> iterator() {
      return concurrentlyIterateList(this);
  }

  /**
   * An optimized version of AbstractList.Itr
   */
  private class Itr implements Iterator<A> {
      int cursor;       // index of next element to return
      int lastRet = -1; // index of last element returned; -1 if no such
      int expectedModCount = modCount;

      public boolean hasNext() {
          return cursor != size;
      }

      @SuppressWarnings("unchecked")
      public A next() {
          checkForComodification();
          int i = cursor;
          if (i >= size)
              throw new NoSuchElementException();
          Object[] elementData = SynchronizedArrayList.this.elementData;
          if (i >= elementData.length)
              throw new ConcurrentModificationException();
          cursor = i + 1;
          return (A) elementData[lastRet = i];
      }

      public void remove() {
          if (lastRet < 0)
              throw new IllegalStateException();
          checkForComodification();

          try {
              SynchronizedArrayList.this.remove(lastRet);
              cursor = lastRet;
              lastRet = -1;
              expectedModCount = modCount;
          } catch (IndexOutOfBoundsException ex) {
              throw new ConcurrentModificationException();
          }
      }

      final void checkForComodification() {
          if (modCount != expectedModCount)
              throw new ConcurrentModificationException();
      }
  }

  /**
   * An optimized version of AbstractList.ListItr - TODO: replace with concurrent iterator or synchronize
   */
  private class ListItr extends Itr implements ListIterator<A> {
      ListItr(int index) {
          super();
          cursor = index;
      }

      public boolean hasPrevious() {
          return cursor != 0;
      }

      public int nextIndex() {
          return cursor;
      }

      public int previousIndex() {
          return cursor - 1;
      }

      @SuppressWarnings("unchecked")
      public A previous() {
          checkForComodification();
          int i = cursor - 1;
          if (i < 0)
              throw new NoSuchElementException();
          Object[] elementData = SynchronizedArrayList.this.elementData;
          if (i >= elementData.length)
              throw new ConcurrentModificationException();
          cursor = i;
          return (A) elementData[lastRet = i];
      }

      public void set(A e) {
          if (lastRet < 0)
              throw new IllegalStateException();
          checkForComodification();

          try {
              SynchronizedArrayList.this.set(lastRet, e);
          } catch (IndexOutOfBoundsException ex) {
              throw new ConcurrentModificationException();
          }
      }

      public void add(A e) {
          checkForComodification();

          try {
              int i = cursor;
              SynchronizedArrayList.this.add(i, e);
              cursor = i + 1;
              lastRet = -1;
              expectedModCount = modCount;
          } catch (IndexOutOfBoundsException ex) {
              throw new ConcurrentModificationException();
          }
      }
  }

  public List<A> subList(int fromIndex, int toIndex) {
      _subListRangeCheck(fromIndex, toIndex, size);
      return new SubList(this, 0, fromIndex, toIndex);
  }

  private class SubList extends SynchronizedArrayList_Base<A> implements RandomAccess {
      private final SynchronizedArrayList_Base<A> parent;
      private final int parentOffset;
      private final int offset;
      int size;

      SubList(SynchronizedArrayList_Base<A> parent,
              int offset, int fromIndex, int toIndex) {
          this.parent = parent;
          this.parentOffset = fromIndex;
          this.offset = offset + fromIndex;
          this.size = toIndex - fromIndex;
          this.modCount = SynchronizedArrayList.this.modCount;
      }

      public A set(int index, A e) { synchronized(SynchronizedArrayList.this) {
          rangeCheck(index);
          checkForComodification();
          A oldValue = SynchronizedArrayList.this.elementData(offset + index);
          SynchronizedArrayList.this.elementData[offset + index] = e;
          return oldValue;
      }}

      public A get(int index) { synchronized(SynchronizedArrayList.this) {
          rangeCheck(index);
          checkForComodification();
          return SynchronizedArrayList.this.elementData(offset + index);
      }}

      public int size() { synchronized(SynchronizedArrayList.this) {
          checkForComodification();
          return this.size;
      }}

      public void add(int index, A e) { synchronized(SynchronizedArrayList.this) {
          rangeCheckForAdd(index);
          checkForComodification();
          parent.add(parentOffset + index, e);
          this.modCount = parent.modCount();
          this.size++;
      }}

      public A remove(int index) { synchronized(SynchronizedArrayList.this) {
          rangeCheck(index);
          checkForComodification();
          A result = parent.remove(parentOffset + index);
          this.modCount = parent.modCount();
          this.size--;
          return result;
      }}

      public void removeRange(int fromIndex, int toIndex) { synchronized(SynchronizedArrayList.this) {
          checkForComodification();
          parent.removeRange(parentOffset + fromIndex,
                             parentOffset + toIndex);
          this.modCount = parent.modCount();
          this.size -= toIndex - fromIndex;
      }}

      public boolean addAll(Collection<? extends A> c) {
          return addAll(this.size, c);
      }

      public boolean addAll(int index, Collection<? extends A> c) { synchronized(SynchronizedArrayList.this) {
          rangeCheckForAdd(index);
          int cSize = c.size();
          if (cSize==0)
              return false;

          checkForComodification();
          parent.addAll(parentOffset + index, c);
          this.modCount = parent.modCount();
          this.size += cSize;
          return true;
      }}

      public Iterator<A> iterator() {
          return listIterator();
      }

      public ListIterator<A> listIterator(final int index) { synchronized(SynchronizedArrayList.this) {
          checkForComodification();
          rangeCheckForAdd(index);
          final int offset = this.offset;

          return new ListIterator<A>() {
              int cursor = index;
              int lastRet = -1;
              int expectedModCount = SynchronizedArrayList.this.modCount;

              public boolean hasNext() {
                  return cursor != SubList.this.size;
              }

              @SuppressWarnings("unchecked")
              public A next() {
                  checkForComodification();
                  int i = cursor;
                  if (i >= SubList.this.size)
                      throw new NoSuchElementException();
                  Object[] elementData = SynchronizedArrayList.this.elementData;
                  if (offset + i >= elementData.length)
                      throw new ConcurrentModificationException();
                  cursor = i + 1;
                  return (A) elementData[offset + (lastRet = i)];
              }

              public boolean hasPrevious() {
                  return cursor != 0;
              }

              @SuppressWarnings("unchecked")
              public A previous() {
                  checkForComodification();
                  int i = cursor - 1;
                  if (i < 0)
                      throw new NoSuchElementException();
                  Object[] elementData = SynchronizedArrayList.this.elementData;
                  if (offset + i >= elementData.length)
                      throw new ConcurrentModificationException();
                  cursor = i;
                  return (A) elementData[offset + (lastRet = i)];
              }

              public int nextIndex() {
                  return cursor;
              }

              public int previousIndex() {
                  return cursor - 1;
              }

              public void remove() {
                  if (lastRet < 0)
                      throw new IllegalStateException();
                  checkForComodification();

                  try {
                      SubList.this.remove(lastRet);
                      cursor = lastRet;
                      lastRet = -1;
                      expectedModCount = SynchronizedArrayList.this.modCount;
                  } catch (IndexOutOfBoundsException ex) {
                      throw new ConcurrentModificationException();
                  }
              }

              public void set(A e) {
                  if (lastRet < 0)
                      throw new IllegalStateException();
                  checkForComodification();

                  try {
                      SynchronizedArrayList.this.set(offset + lastRet, e);
                  } catch (IndexOutOfBoundsException ex) {
                      throw new ConcurrentModificationException();
                  }
              }

              public void add(A e) {
                  checkForComodification();

                  try {
                      int i = cursor;
                      SubList.this.add(i, e);
                      cursor = i + 1;
                      lastRet = -1;
                      expectedModCount = SynchronizedArrayList.this.modCount;
                  } catch (IndexOutOfBoundsException ex) {
                      throw new ConcurrentModificationException();
                  }
              }

              final void checkForComodification() {
                  if (expectedModCount != SynchronizedArrayList.this.modCount)
                      throw new ConcurrentModificationException();
              }
          };
      }}

      public List<A> subList(int fromIndex, int toIndex) { synchronized(SynchronizedArrayList.this) {
          _subListRangeCheck(fromIndex, toIndex, size);
          return new SubList(parent, offset, fromIndex, toIndex);
      }}

      private void rangeCheck(int index) {
          if (index < 0 || index >= this.size)
              throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
      }

      private void rangeCheckForAdd(int index) {
          if (index < 0 || index > this.size)
              throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
      }

      private String outOfBoundsMsg(int index) {
          return "Index: "+index+", Size: "+this.size;
      }

      private void checkForComodification() {
          if (SynchronizedArrayList.this.modCount != this.modCount)
              throw new ConcurrentModificationException();
      }
  }

  @Override
  @SuppressWarnings("unchecked")
  public synchronized void sort(Comparator<? super A> c) {
      final int expectedModCount = modCount;
      Arrays.sort((A[]) elementData, 0, size, c);
      if (modCount != expectedModCount) {
          throw new ConcurrentModificationException();
      }
      modCount++;
  }
}

Travelled to 15 computer(s): aoiabmzegqzx, bhatertpkbcr, cbybwowwnfue, cfunsshuasjs, gwrvuhgaqvyk, ishqpsrjomds, lpdgvwnxivlt, mqqgnosmbjvj, onxytkatvevr, pyentgdyhuwx, pzhvpgtvlbxg, tslmcundralx, tvejysmllsmz, vouqrxazstgt, ydilcnlqtmvn

Snippet ID:	#1012179
Snippet name:	SynchronizedArrayList - saves space over synchroList()
Eternal ID of this version:	#1012179/15
Text MD5:	e53e5aa7bc42f942f2782236603360d6
Transpilation MD5:	490abd71d95c9860471b0dd9ba03d3c7
Author:	stefan
Category:	javax / collections
Type:	JavaX fragment (include)
Public (visible to everyone):	Yes
Archived (hidden from active list):	No
Created/modified:	2021-07-24 02:34:45
Source code size:	24601 bytes / 757 lines
Pitched / IR pitched:	No / No
Views / Downloads:	604 / 2057
Version history:	14 change(s)
Referenced in:	[show references]

< > BotCompany Repo | #1012179 // SynchronizedArrayList - saves space over synchroList()

JavaX fragment (include) [tags: use-pretranspiled]

1	// Modified from java.util.ArrayList
2
3	sclass SynchronizedArrayList<A> extends SynchronizedArrayList_Base<A> implements RandomAccess, Cloneable {
4	private static final int DEFAULT_CAPACITY = 10;
5	private static final Object[] EMPTY_ELEMENTDATA = {};
6	private static final Object[] DEFAULTCAPACITY_EMPTY_ELEMENTDATA = {};
7	transient Object[] elementData; // non-private to simplify nested class access
8	private int size;
9
10	*(int initialCapacity) {
11	if (initialCapacity > 0) {
12	this.elementData = new Object[initialCapacity];
13	} else if (initialCapacity == 0) {
14	this.elementData = EMPTY_ELEMENTDATA;
15	} else {
16	throw new IllegalArgumentException("Illegal Capacity: "+
17	initialCapacity);
18	}
19	}
20
21	*() {
22	this.elementData = DEFAULTCAPACITY_EMPTY_ELEMENTDATA;
23	}
24
25	*(Collection<? extends A> c) {
26	elementData = c.toArray();
27	if ((size = elementData.length) != 0) {
28	// c.toArray might (incorrectly) not return Object[] (see 6260652)
29	if (elementData.getClass() != Object[].class)
30	elementData = Arrays.copyOf(elementData, size, Object[].class);
31	} else {
32	// replace with empty array.
33	this.elementData = EMPTY_ELEMENTDATA;
34	}
35	}
36
37	public synchronized void trimToSize() {
38	modCount++;
39	if (size < elementData.length) {
40	elementData = (size == 0)
41	? EMPTY_ELEMENTDATA
42	: Arrays.copyOf(elementData, size);
43	}
44	}
45
46	public synchronized void ensureCapacity(int minCapacity) {
47	int minExpand = (elementData != DEFAULTCAPACITY_EMPTY_ELEMENTDATA)
48	// any size if not default element table
49	? 0
50	// larger than default for default empty table. It's already
51	// supposed to be at default size.
52	: DEFAULT_CAPACITY;
53
54	if (minCapacity > minExpand) {
55	ensureExplicitCapacity(minCapacity);
56	}
57	}
58
59	private void ensureCapacityInternal(int minCapacity) {
60	if (elementData == DEFAULTCAPACITY_EMPTY_ELEMENTDATA) {
61	minCapacity = Math.max(DEFAULT_CAPACITY, minCapacity);
62	}
63
64	ensureExplicitCapacity(minCapacity);
65	}
66
67	private void ensureExplicitCapacity(int minCapacity) {
68	modCount++;
69
70	// overflow-conscious code
71	if (minCapacity - elementData.length > 0)
72	grow(minCapacity);
73	}
74
75	private static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8;
76
77	private void grow(int minCapacity) {
78	// overflow-conscious code
79	int oldCapacity = elementData.length;
80	int newCapacity = oldCapacity + (oldCapacity >> 1);
81	if (newCapacity - minCapacity < 0)
82	newCapacity = minCapacity;
83	if (newCapacity - MAX_ARRAY_SIZE > 0)
84	newCapacity = hugeCapacity(minCapacity);
85	// minCapacity is usually close to size, so this is a win:
86	elementData = Arrays.copyOf(elementData, newCapacity);
87	}
88
89	private static int hugeCapacity(int minCapacity) {
90	if (minCapacity < 0) // overflow
91	throw new OutOfMemoryError();
92	return (minCapacity > MAX_ARRAY_SIZE) ?
93	Integer.MAX_VALUE :
94	MAX_ARRAY_SIZE;
95	}
96
97	public synchronized int size() {
98	return size;
99	}
100
101	public synchronized boolean isEmpty() {
102	return size == 0;
103	}
104
105	public boolean contains(Object o) {
106	return indexOf(o) >= 0;
107	}
108
109	public synchronized int indexOf(Object o) {
110	if (o == null) {
111	for (int i = 0; i < size; i++)
112	if (elementData[i]==null)
113	return i;
114	} else {
115	for (int i = 0; i < size; i++)
116	if (o.equals(elementData[i]))
117	return i;
118	}
119	return -1;
120	}
121
122	public synchronized int lastIndexOf(Object o) {
123	if (o == null) {
124	for (int i = size-1; i >= 0; i--)
125	if (elementData[i]==null)
126	return i;
127	} else {
128	for (int i = size-1; i >= 0; i--)
129	if (o.equals(elementData[i]))
130	return i;
131	}
132	return -1;
133	}
134
135	public synchronized Object clone() {
136	ret new SynchronizedArrayList(this);
137	}
138
139	public synchronized Object[] toArray() {
140	return Arrays.copyOf(elementData, size);
141	}
142
143	@SuppressWarnings("unchecked")
144	public synchronized <T> T[] toArray(T[] a) {
145	if (a.length < size)
146	// Make a new array of a's runtime type, but my contents:
147	return (T[]) Arrays.copyOf(elementData, size, a.getClass());
148	System.arraycopy(elementData, 0, a, 0, size);
149	if (a.length > size)
150	a[size] = null;
151	return a;
152	}
153
154	// Positional Access Operations
155
156	@SuppressWarnings("unchecked")
157	A elementData(int index) {
158	return (A) elementData[index];
159	}
160
161	public synchronized A get(int index) {
162	rangeCheck(index);
163
164	return elementData(index);
165	}
166
167	public synchronized A set(int index, A element) {
168	rangeCheck(index);
169
170	A oldValue = elementData(index);
171	elementData[index] = element;
172	return oldValue;
173	}
174
175	public synchronized boolean add(A e) {
176	ensureCapacityInternal(size + 1); // Increments modCount!!
177	elementData[size++] = e;
178	return true;
179	}
180
181	public synchronized void add(int index, A element) {
182	rangeCheckForAdd(index);
183
184	ensureCapacityInternal(size + 1); // Increments modCount!!
185	System.arraycopy(elementData, index, elementData, index + 1,
186	size - index);
187	elementData[index] = element;
188	size++;
189	}
190
191	public synchronized A remove(int index) {
192	rangeCheck(index);
193
194	modCount++;
195	A oldValue = elementData(index);
196
197	int numMoved = size - index - 1;
198	if (numMoved > 0)
199	System.arraycopy(elementData, index+1, elementData, index,
200	numMoved);
201	elementData[--size] = null; // clear to let GC do its work
202
203	return oldValue;
204	}
205
206	public synchronized boolean remove(Object o) {
207	if (o == null) {
208	for (int index = 0; index < size; index++)
209	if (elementData[index] == null) {
210	fastRemove(index);
211	return true;
212	}
213	} else {
214	for (int index = 0; index < size; index++)
215	if (o.equals(elementData[index])) {
216	fastRemove(index);
217	return true;
218	}
219	}
220	return false;
221	}
222
223	private void fastRemove(int index) {
224	modCount++;
225	int numMoved = size - index - 1;
226	if (numMoved > 0)
227	System.arraycopy(elementData, index+1, elementData, index,
228	numMoved);
229	elementData[--size] = null; // clear to let GC do its work
230	}
231
232	public synchronized void clear() {
233	modCount++;
234
235	// clear to let GC do its work
236	for (int i = 0; i < size; i++)
237	elementData[i] = null;
238
239	size = 0;
240	}
241
242	public synchronized boolean addAll(Collection<? extends A> c) {
243	Object[] a = c.toArray();
244	int numNew = a.length;
245	ensureCapacityInternal(size + numNew); // Increments modCount
246	System.arraycopy(a, 0, elementData, size, numNew);
247	size += numNew;
248	return numNew != 0;
249	}
250
251	public synchronized boolean addAll(int index, Collection<? extends A> c) {
252	rangeCheckForAdd(index);
253
254	Object[] a = c.toArray();
255	int numNew = a.length;
256	ensureCapacityInternal(size + numNew); // Increments modCount
257
258	int numMoved = size - index;
259	if (numMoved > 0)
260	System.arraycopy(elementData, index, elementData, index + numNew,
261	numMoved);
262
263	System.arraycopy(a, 0, elementData, index, numNew);
264	size += numNew;
265	return numNew != 0;
266	}
267
268	public synchronized void removeRange(int fromIndex, int toIndex) {
269	modCount++;
270	int numMoved = size - toIndex;
271	System.arraycopy(elementData, toIndex, elementData, fromIndex,
272	numMoved);
273
274	// clear to let GC do its work
275	int newSize = size - (toIndex-fromIndex);
276	for (int i = newSize; i < size; i++) {
277	elementData[i] = null;
278	}
279	size = newSize;
280	}
281
282	private void rangeCheck(int index) {
283	if (index >= size)
284	throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
285	}
286
287	private void rangeCheckForAdd(int index) {
288	if (index > size \|\| index < 0)
289	throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
290	}
291
292	/**
293	* Constructs an IndexOutOfBoundsException detail message.
294	* Of the many possible refactorings of the error handling code,
295	* this "outlining" performs best with both server and client VMs.
296	*/
297	private String outOfBoundsMsg(int index) {
298	return "Index: "+index+", Size: "+size;
299	}
300
301	public synchronized boolean removeAll(Collection<?> c) {
302	Objects.requireNonNull(c);
303	return batchRemove(c, false);
304	}
305
306	public synchronized boolean retainAll(Collection<?> c) {
307	Objects.requireNonNull(c);
308	return batchRemove(c, true);
309	}
310
311	private boolean batchRemove(Collection<?> c, boolean complement) {
312	final Object[] elementData = this.elementData;
313	int r = 0, w = 0;
314	boolean modified = false;
315	try {
316	for (; r < size; r++)
317	if (c.contains(elementData[r]) == complement)
318	elementData[w++] = elementData[r];
319	} finally {
320	// Preserve behavioral compatibility with AbstractCollection,
321	// even if c.contains() throws.
322	if (r != size) {
323	System.arraycopy(elementData, r,
324	elementData, w,
325	size - r);
326	w += size - r;
327	}
328	if (w != size) {
329	// clear to let GC do its work
330	for (int i = w; i < size; i++)
331	elementData[i] = null;
332	modCount += size - w;
333	size = w;
334	modified = true;
335	}
336	}
337	return modified;
338	}
339
340	/**
341	* Save the state of the <tt>ArrayList</tt> instance to a stream (that
342	* is, serialize it).
343	*
344	* @serialData The length of the array backing the <tt>ArrayList</tt>
345	* instance is emitted (int), followed by all of its elements
346	* (each an <tt>Object</tt>) in the proper order.
347	*/
348	private void writeObject(java.io.ObjectOutputStream s)
349	throws java.io.IOException{
350	// Write out element count, and any hidden stuff
351	int expectedModCount = modCount;
352	s.defaultWriteObject();
353
354	// Write out size as capacity for behavioural compatibility with clone()
355	s.writeInt(size);
356
357	// Write out all elements in the proper order.
358	for (int i=0; i<size; i++) {
359	s.writeObject(elementData[i]);
360	}
361
362	if (modCount != expectedModCount) {
363	throw new ConcurrentModificationException();
364	}
365	}
366
367	private void readObject(java.io.ObjectInputStream s)
368	throws java.io.IOException, ClassNotFoundException {
369	elementData = EMPTY_ELEMENTDATA;
370
371	// Read in size, and any hidden stuff
372	s.defaultReadObject();
373
374	// Read in capacity
375	s.readInt(); // ignored
376
377	if (size > 0) {
378	// be like clone(), allocate array based upon size not capacity
379	ensureCapacityInternal(size);
380
381	Object[] a = elementData;
382	// Read in all elements in the proper order.
383	for (int i=0; i<size; i++) {
384	a[i] = s.readObject();
385	}
386	}
387	}
388
389	/**
390	* Returns a list iterator over the elements in this list (in proper
391	* sequence), starting at the specified position in the list.
392	* The specified index indicates the first element that would be
393	* returned by an initial call to {@link ListIterator#next next}.
394	* An initial call to {@link ListIterator#previous previous} would
395	* return the element with the specified index minus one.
396	*
397	* <p>The returned list iterator is <a href="#fail-fast"><i>fail-fast</i></a>.
398	*
399	* @throws IndexOutOfBoundsException {@inheritDoc}
400	*/
401	public synchronized ListIterator<A> listIterator(int index) {
402	if (index < 0 \|\| index > size)
403	throw new IndexOutOfBoundsException("Index: "+index);
404	return new ListItr(index);
405	}
406
407	/**
408	* Returns a list iterator over the elements in this list (in proper
409	* sequence).
410	*
411	* <p>The returned list iterator is <a href="#fail-fast"><i>fail-fast</i></a>.
412	*
413	* @see #listIterator(int)
414	*/
415	public ListIterator<A> listIterator() {
416	return new ListItr(0);
417	}
418
419	/**
420	* Returns an iterator over the elements in this list in proper sequence.
421	*
422	* <p>The returned iterator is <a href="#fail-fast"><i>fail-fast</i></a>.
423	*
424	* @return an iterator over the elements in this list in proper sequence
425	*/
426	public Iterator<A> iterator() {
427	return concurrentlyIterateList(this);
428	}
429
430	/**
431	* An optimized version of AbstractList.Itr
432	*/
433	private class Itr implements Iterator<A> {
434	int cursor; // index of next element to return
435	int lastRet = -1; // index of last element returned; -1 if no such
436	int expectedModCount = modCount;
437
438	public boolean hasNext() {
439	return cursor != size;
440	}
441
442	@SuppressWarnings("unchecked")
443	public A next() {
444	checkForComodification();
445	int i = cursor;
446	if (i >= size)
447	throw new NoSuchElementException();
448	Object[] elementData = SynchronizedArrayList.this.elementData;
449	if (i >= elementData.length)
450	throw new ConcurrentModificationException();
451	cursor = i + 1;
452	return (A) elementData[lastRet = i];
453	}
454
455	public void remove() {
456	if (lastRet < 0)
457	throw new IllegalStateException();
458	checkForComodification();
459
460	try {
461	SynchronizedArrayList.this.remove(lastRet);
462	cursor = lastRet;
463	lastRet = -1;
464	expectedModCount = modCount;
465	} catch (IndexOutOfBoundsException ex) {
466	throw new ConcurrentModificationException();
467	}
468	}
469
470	final void checkForComodification() {
471	if (modCount != expectedModCount)
472	throw new ConcurrentModificationException();
473	}
474	}
475
476	/**
477	* An optimized version of AbstractList.ListItr - TODO: replace with concurrent iterator or synchronize
478	*/
479	private class ListItr extends Itr implements ListIterator<A> {
480	ListItr(int index) {
481	super();
482	cursor = index;
483	}
484
485	public boolean hasPrevious() {
486	return cursor != 0;
487	}
488
489	public int nextIndex() {
490	return cursor;
491	}
492
493	public int previousIndex() {
494	return cursor - 1;
495	}
496
497	@SuppressWarnings("unchecked")
498	public A previous() {
499	checkForComodification();
500	int i = cursor - 1;
501	if (i < 0)
502	throw new NoSuchElementException();
503	Object[] elementData = SynchronizedArrayList.this.elementData;
504	if (i >= elementData.length)
505	throw new ConcurrentModificationException();
506	cursor = i;
507	return (A) elementData[lastRet = i];
508	}
509
510	public void set(A e) {
511	if (lastRet < 0)
512	throw new IllegalStateException();
513	checkForComodification();
514
515	try {
516	SynchronizedArrayList.this.set(lastRet, e);
517	} catch (IndexOutOfBoundsException ex) {
518	throw new ConcurrentModificationException();
519	}
520	}
521
522	public void add(A e) {
523	checkForComodification();
524
525	try {
526	int i = cursor;
527	SynchronizedArrayList.this.add(i, e);
528	cursor = i + 1;
529	lastRet = -1;
530	expectedModCount = modCount;
531	} catch (IndexOutOfBoundsException ex) {
532	throw new ConcurrentModificationException();
533	}
534	}
535	}
536
537	public List<A> subList(int fromIndex, int toIndex) {
538	_subListRangeCheck(fromIndex, toIndex, size);
539	return new SubList(this, 0, fromIndex, toIndex);
540	}
541
542	private class SubList extends SynchronizedArrayList_Base<A> implements RandomAccess {
543	private final SynchronizedArrayList_Base<A> parent;
544	private final int parentOffset;
545	private final int offset;
546	int size;
547
548	SubList(SynchronizedArrayList_Base<A> parent,
549	int offset, int fromIndex, int toIndex) {
550	this.parent = parent;
551	this.parentOffset = fromIndex;
552	this.offset = offset + fromIndex;
553	this.size = toIndex - fromIndex;
554	this.modCount = SynchronizedArrayList.this.modCount;
555	}
556
557	public A set(int index, A e) { synchronized(SynchronizedArrayList.this) {
558	rangeCheck(index);
559	checkForComodification();
560	A oldValue = SynchronizedArrayList.this.elementData(offset + index);
561	SynchronizedArrayList.this.elementData[offset + index] = e;
562	return oldValue;
563	}}
564
565	public A get(int index) { synchronized(SynchronizedArrayList.this) {
566	rangeCheck(index);
567	checkForComodification();
568	return SynchronizedArrayList.this.elementData(offset + index);
569	}}
570
571	public int size() { synchronized(SynchronizedArrayList.this) {
572	checkForComodification();
573	return this.size;
574	}}
575
576	public void add(int index, A e) { synchronized(SynchronizedArrayList.this) {
577	rangeCheckForAdd(index);
578	checkForComodification();
579	parent.add(parentOffset + index, e);
580	this.modCount = parent.modCount();
581	this.size++;
582	}}
583
584	public A remove(int index) { synchronized(SynchronizedArrayList.this) {
585	rangeCheck(index);
586	checkForComodification();
587	A result = parent.remove(parentOffset + index);
588	this.modCount = parent.modCount();
589	this.size--;
590	return result;
591	}}
592
593	public void removeRange(int fromIndex, int toIndex) { synchronized(SynchronizedArrayList.this) {
594	checkForComodification();
595	parent.removeRange(parentOffset + fromIndex,
596	parentOffset + toIndex);
597	this.modCount = parent.modCount();
598	this.size -= toIndex - fromIndex;
599	}}
600
601	public boolean addAll(Collection<? extends A> c) {
602	return addAll(this.size, c);
603	}
604
605	public boolean addAll(int index, Collection<? extends A> c) { synchronized(SynchronizedArrayList.this) {
606	rangeCheckForAdd(index);
607	int cSize = c.size();
608	if (cSize==0)
609	return false;
610
611	checkForComodification();
612	parent.addAll(parentOffset + index, c);
613	this.modCount = parent.modCount();
614	this.size += cSize;
615	return true;
616	}}
617
618	public Iterator<A> iterator() {
619	return listIterator();
620	}
621
622	public ListIterator<A> listIterator(final int index) { synchronized(SynchronizedArrayList.this) {
623	checkForComodification();
624	rangeCheckForAdd(index);
625	final int offset = this.offset;
626
627	return new ListIterator<A>() {
628	int cursor = index;
629	int lastRet = -1;
630	int expectedModCount = SynchronizedArrayList.this.modCount;
631
632	public boolean hasNext() {
633	return cursor != SubList.this.size;
634	}
635
636	@SuppressWarnings("unchecked")
637	public A next() {
638	checkForComodification();
639	int i = cursor;
640	if (i >= SubList.this.size)
641	throw new NoSuchElementException();
642	Object[] elementData = SynchronizedArrayList.this.elementData;
643	if (offset + i >= elementData.length)
644	throw new ConcurrentModificationException();
645	cursor = i + 1;
646	return (A) elementData[offset + (lastRet = i)];
647	}
648
649	public boolean hasPrevious() {
650	return cursor != 0;
651	}
652
653	@SuppressWarnings("unchecked")
654	public A previous() {
655	checkForComodification();
656	int i = cursor - 1;
657	if (i < 0)
658	throw new NoSuchElementException();
659	Object[] elementData = SynchronizedArrayList.this.elementData;
660	if (offset + i >= elementData.length)
661	throw new ConcurrentModificationException();
662	cursor = i;
663	return (A) elementData[offset + (lastRet = i)];
664	}
665
666	public int nextIndex() {
667	return cursor;
668	}
669
670	public int previousIndex() {
671	return cursor - 1;
672	}
673
674	public void remove() {
675	if (lastRet < 0)
676	throw new IllegalStateException();
677	checkForComodification();
678
679	try {
680	SubList.this.remove(lastRet);
681	cursor = lastRet;
682	lastRet = -1;
683	expectedModCount = SynchronizedArrayList.this.modCount;
684	} catch (IndexOutOfBoundsException ex) {
685	throw new ConcurrentModificationException();
686	}
687	}
688
689	public void set(A e) {
690	if (lastRet < 0)
691	throw new IllegalStateException();
692	checkForComodification();
693
694	try {
695	SynchronizedArrayList.this.set(offset + lastRet, e);
696	} catch (IndexOutOfBoundsException ex) {
697	throw new ConcurrentModificationException();
698	}
699	}
700
701	public void add(A e) {
702	checkForComodification();
703
704	try {
705	int i = cursor;
706	SubList.this.add(i, e);
707	cursor = i + 1;
708	lastRet = -1;
709	expectedModCount = SynchronizedArrayList.this.modCount;
710	} catch (IndexOutOfBoundsException ex) {
711	throw new ConcurrentModificationException();
712	}
713	}
714
715	final void checkForComodification() {
716	if (expectedModCount != SynchronizedArrayList.this.modCount)
717	throw new ConcurrentModificationException();
718	}
719	};
720	}}
721
722	public List<A> subList(int fromIndex, int toIndex) { synchronized(SynchronizedArrayList.this) {
723	_subListRangeCheck(fromIndex, toIndex, size);
724	return new SubList(parent, offset, fromIndex, toIndex);
725	}}
726
727	private void rangeCheck(int index) {
728	if (index < 0 \|\| index >= this.size)
729	throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
730	}
731
732	private void rangeCheckForAdd(int index) {
733	if (index < 0 \|\| index > this.size)
734	throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
735	}
736
737	private String outOfBoundsMsg(int index) {
738	return "Index: "+index+", Size: "+this.size;
739	}
740
741	private void checkForComodification() {
742	if (SynchronizedArrayList.this.modCount != this.modCount)
743	throw new ConcurrentModificationException();
744	}
745	}
746
747	@Override
748	@SuppressWarnings("unchecked")
749	public synchronized void sort(Comparator<? super A> c) {
750	final int expectedModCount = modCount;
751	Arrays.sort((A[]) elementData, 0, size, c);
752	if (modCount != expectedModCount) {
753	throw new ConcurrentModificationException();
754	}
755	modCount++;
756	}
757	}