java.util.concurrent.atomic.AtomicLongArray#get()源码实例Demo

long changeWord(int bitIndex, @Nonnull TLongFunction change) {
  if (bitIndex < 0) {
    throw new IndexOutOfBoundsException("bitIndex < 0: " + bitIndex);
  }

  AtomicLongArray array = getOrCreateArray(bitIndex);

  int wordIndexInArray = wordIndexInArray(bitIndex);
  long word;
  long newWord;
  do {
    word = array.get(wordIndexInArray);
    newWord = change.execute(word);
  }
  while (!array.compareAndSet(wordIndexInArray, word, newWord));
  return word;
}
 

public void set(int position) {
    int segmentPosition = position >>> log2SegmentSize; /// which segment -- div by num bits per segment
    int longPosition = (position >>> 6) & segmentMask; /// which long in the segment -- remainder of div by num bits per segment
    int bitPosition = position & 0x3F; /// which bit in the long -- remainder of div by num bits in long (64)

    AtomicLongArray segment = getSegment(segmentPosition);

    long mask = 1L << bitPosition;

    // Thread safety: we need to loop until we win the race to set the long value.
    while(true) {
        // determine what the new long value will be after we set the appropriate bit.
        long currentLongValue = segment.get(longPosition);
        long newLongValue = currentLongValue | mask;

        // if no other thread has modified the value since we read it, we won the race and we are done.
        if(segment.compareAndSet(longPosition, currentLongValue, newLongValue))
            break;
    }
}
 

public void clear(int position) {
    int segmentPosition = position >>> log2SegmentSize; /// which segment -- div by num bits per segment
    int longPosition = (position >>> 6) & segmentMask; /// which long in the segment -- remainder of div by num bits per segment
    int bitPosition = position & 0x3F; /// which bit in the long -- remainder of div by num bits in long (64)

    AtomicLongArray segment = getSegment(segmentPosition);

    long mask = ~(1L << bitPosition);

    // Thread safety: we need to loop until we win the race to set the long value.
    while(true) {
        // determine what the new long value will be after we set the appropriate bit.
        long currentLongValue = segment.get(longPosition);
        long newLongValue = currentLongValue & mask;

        // if no other thread has modified the value since we read it, we won the race and we are done.
        if(segment.compareAndSet(longPosition, currentLongValue, newLongValue))
            break;
    }
}
 

public long maxSetBit() {
    ThreadSafeBitSetSegments segments = this.segments.get();

    int segmentIdx = segments.numSegments() - 1;

    for(;segmentIdx >= 0; segmentIdx--) {
        AtomicLongArray segment = segments.getSegment(segmentIdx);
        for(int longIdx=segment.length() - 1; longIdx >= 0; longIdx--) {
            long l = segment.get(longIdx);
            if(l != 0)
                return (segmentIdx << log2SegmentSize) + (longIdx * 64) + (63 - Long.numberOfLeadingZeros(l));
        }
    }

    return -1;
}
 

@Override
public void request(long n) {
	if (Operators.validate(n)) {
		AtomicLongArray ra = parent.requests;
		for (;;) {
			long r = ra.get(index);
			if (r == Long.MAX_VALUE) {
				return;
			}
			long u = Operators.addCap(r, n);
			if (ra.compareAndSet(index, r, u)) {
				break;
			}
		}
		if (parent.subscriberCount == length) {
			parent.drain();
		}
	}
}
 

public long poll(boolean[] hasValue) {
    final AtomicLongArray a = buffer;
    final int m = mask;
    final long ci = a.get(1);

    int offset = calcOffset(ci, m);
    int offset1 = offset + 1;

    long v = a.get(offset1);
    if (v == 0L) {
        hasValue[0] = false;
        return 0L;
    }
    hasValue[0] = true;
    v = a.get(offset);
    a.lazySet(offset1, 0L);
    a.lazySet(1, ci + 2);

    return v;
}
 

public long poll() {
    final AtomicLongArray a = buffer;
    final int m = mask;
    final long ci = a.get(1);

    int offset = calcOffset(ci, m);

    long v = a.get(offset + 1);
    if (v == 0L) {
        return 0L;
    }
    v = a.get(offset);
    a.lazySet(offset + 1, 0L);
    a.lazySet(1, ci + 2);
    return v;
}
 

private List<CountAtBucket> nonZeroBuckets() {
    List<CountAtBucket> buckets = new ArrayList<>();

    long zeroSnap = zeros.get();
    if (zeroSnap > 0) {
        buckets.add(new CountAtBucket(UPPER_BOUNDS[getRangeIndex(ZERO.bucketIdx, ZERO.offset)], zeroSnap));
    }

    long lowerSnap = lower.get();
    if (lowerSnap > 0) {
        buckets.add(new CountAtBucket(UPPER_BOUNDS[getRangeIndex(LOWER.bucketIdx, LOWER.offset)], lowerSnap));
    }

    long upperSnap = upper.get();
    if (upperSnap > 0) {
        buckets.add(new CountAtBucket(UPPER_BOUNDS[getRangeIndex(UPPER.bucketIdx, UPPER.offset)], upperSnap));
    }

    for (int i = 0; i < values.length(); i++) {
        AtomicLongArray bucket = values.get(i);
        if (bucket != null) {
            for (int j = 0; j < bucket.length(); j++) {
                long cnt = bucket.get(j);
                if (cnt > 0) {
                    buckets.add(new CountAtBucket(UPPER_BOUNDS[getRangeIndex(i, j)], cnt));
                }
            }
        }
    }

    return buckets;
}
 

/** Returns an {@link AtomicLongArray} array as a string, but does not print trailing zeroes.
 *
 * @param a an atomic array.
 * @return {@link Arrays#toString(long[])} of {@code a}, but without trailing zeroes.
 */
public static String toString(final AtomicLongArray a) {
	int i;
	for(i = a.length(); i-- != 0;) if (a.get(i) != 0) break;
	final long[] b = new long[i + 1];
	for(++i; i-- != 0;) b[i] = a.get(i);
	return Arrays.toString(b);
}
 

public boolean get(int position) {
    int segmentPosition = position >>> log2SegmentSize; /// which segment -- div by num bits per segment
    int longPosition = (position >>> 6) & segmentMask; /// which long in the segment -- remainder of div by num bits per segment
    int bitPosition = position & 0x3F; /// which bit in the long -- remainder of div by num bits in long (64)

    AtomicLongArray segment = getSegment(segmentPosition);

    long mask = 1L << bitPosition;

    return ((segment.get(longPosition) & mask) != 0);
}
 

public int nextSetBit(int fromIndex) {
    if (fromIndex < 0)
        throw new IndexOutOfBoundsException("fromIndex < 0: " + fromIndex);

    int segmentPosition = fromIndex >>> log2SegmentSize; /// which segment -- div by num bits per segment

    ThreadSafeBitSetSegments segments = this.segments.get();

    if(segmentPosition >= segments.numSegments())
        return -1;

    int longPosition = (fromIndex >>> 6) & segmentMask; /// which long in the segment -- remainder of div by num bits per segment
    int bitPosition = fromIndex & 0x3F; /// which bit in the long -- remainder of div by num bits in long (64)
    AtomicLongArray segment = segments.getSegment(segmentPosition);

    long word = segment.get(longPosition) & (0xffffffffffffffffL << bitPosition);

    while (true) {
        if (word != 0)
            return (segmentPosition << (log2SegmentSize)) + (longPosition << 6) + Long.numberOfTrailingZeros(word);
        if (++longPosition > segmentMask) {
            segmentPosition++;
            if(segmentPosition >= segments.numSegments())
                return -1;
            segment = segments.getSegment(segmentPosition);
            longPosition = 0;
        }

        word = segment.get(longPosition);
    }
}
 

private static long[] toArray(AtomicLongArray a)
{
    final long[] r = new long[a.length()];
    for (int i = 0 ; i < r.length ; i++)
        r[i] = a.get(i);
    return r;
}
 

long getWord(int bitIndex) {
  if (bitIndex < 0) {
    throw new IndexOutOfBoundsException("bitIndex < 0: " + bitIndex);
  }

  int arrayIndex = arrayIndex(bitIndex);
  AtomicLongArray array = arrays.get(arrayIndex);
  if (array == null) {
    return 0;
  }

  int wordIndexInArray = wordIndexInArray(bitIndex);
  return array.get(wordIndexInArray);
}
 

@Override
protected final void _incDouble(int offset, double delta) {
  final AtomicLongArray doubleStorage = this.doubleStorage;
  while (true) {
    final long longValue = doubleStorage.get(offset);
    final long newValue = Double.doubleToLongBits(Double
        .longBitsToDouble(longValue) + delta);
    if (doubleStorage.compareAndSet(offset, longValue, newValue)) {
      return;
    }
  }
}
 

/**
 * Returns the index of the first bit that is set to {@code false}
 * that occurs on or after the specified starting index.
 *
 * @param fromIndex the index to start checking from (inclusive)
 * @return the index of the next clear bit
 * @throws IndexOutOfBoundsException if the specified index is negative
 */
public int nextClearBit(int fromIndex) {
  if (fromIndex < 0) {
    throw new IndexOutOfBoundsException("fromIndex < 0: " + fromIndex);
  }

  int arrayIndex = arrayIndex(fromIndex);
  AtomicLongArray array = arrays.get(arrayIndex);
  int wordIndexInArray = wordIndexInArray(fromIndex);
  if (array == null) {
    return ((1<<arrayIndex)-1+wordIndexInArray) * BITS_PER_WORD+(fromIndex%BITS_PER_WORD);
  }

  long word = ~array.get(wordIndexInArray) & (WORD_MASK << fromIndex);

  while (true) {
    if (word != 0) {
      return ((1<<arrayIndex)-1 + wordIndexInArray) * BITS_PER_WORD + Long.numberOfTrailingZeros(word);
    }
    if (++wordIndexInArray == array.length()) {
      wordIndexInArray = 0;
      if (++arrayIndex == arrays.length()) return -1;
      array = arrays.get(arrayIndex);
      if (array == null) {
        return ((1<<arrayIndex)-1+wordIndexInArray) * BITS_PER_WORD;
      }
    }

    word = ~array.get(wordIndexInArray);
  }
}
 

/**
 * Returns the index of the first bit that is set to {@code true}
 * that occurs on or after the specified starting index. If no such
 * bit exists then {@code -1} is returned.
 * <p/>
 * <p>To iterate over the {@code true} bits,
 * use the following loop:
 * <p/>
 * <pre> {@code
 * for (int i = bs.nextSetBit(0); i >= 0; i = bs.nextSetBit(i+1)) {
 *     // operate on index i here
 * }}</pre>
 *
 * @param fromIndex the index to start checking from (inclusive)
 * @return the index of the next set bit, or {@code -1} if there
 * is no such bit
 * @throws IndexOutOfBoundsException if the specified index is negative
 */
public int nextSetBit(int fromIndex) {
  if (fromIndex < 0) {
    throw new IndexOutOfBoundsException("bitIndex < 0: " + fromIndex);
  }

  int arrayIndex;
  AtomicLongArray array = null;
  for (arrayIndex = arrayIndex(fromIndex); arrayIndex < arrays.length() && (array = arrays.get(arrayIndex)) == null; arrayIndex++);
  if (array == null) {
    return -1;
  }

  int wordIndexInArray = wordIndexInArray(fromIndex);

  long word = array.get(wordIndexInArray) & (WORD_MASK << fromIndex);

  while (true) {
    if (word != 0) {
      return ((1<<arrayIndex)-1 + wordIndexInArray) * BITS_PER_WORD + Long.numberOfTrailingZeros(word);
    }
    if (++wordIndexInArray == array.length()) {
      wordIndexInArray = 0;
      for (++arrayIndex; arrayIndex != arrays.length() && (array = arrays.get(arrayIndex)) == null; arrayIndex++);
      if (array == null) {
        return -1;
      }
    }

    word = array.get(wordIndexInArray);
  }
}
 

@Override
protected final void _incDouble(int offset, double delta) {
  final AtomicLongArray doubleStorage = this.doubleStorage;
  while (true) {
    final long longValue = doubleStorage.get(offset);
    final long newValue = Double.doubleToLongBits(Double
        .longBitsToDouble(longValue) + delta);
    if (doubleStorage.compareAndSet(offset, longValue, newValue)) {
      return;
    }
  }
}
 

@Nonnull
public long[] toLongArray() {
  int bits = size();
  long[] result = new long[bits/BITS_PER_WORD];
  int i = 0;
  for (int b=0; b<bits;b += BITS_PER_WORD){
    AtomicLongArray array = arrays.get(arrayIndex(b));
    long word = array == null ? 0 : array.get(wordIndexInArray(b));
    result[i++] = word;
  }
  return result;
}
 

protected static long lvValue(AtomicLongArray elements, int index)
{
    return elements.get(calcValueOffset(index));
}
 

protected final long lvSequence(AtomicLongArray buffer, int offset)
{
    return buffer.get(offset);
}