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root/jsr166/jsr166/src/jsr166e/LongAdder.java
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Comparing jsr166/src/jsr166e/LongAdder.java (file contents):
Revision 1.5 by dl, Tue Aug 2 18:04:12 2011 UTC vs.
Revision 1.12 by jsr166, Sun Jan 6 18:50:00 2013 UTC

# Line 19 | Line 19 | import java.io.ObjectOutputStream;
19   * #longValue}) returns the current total combined across the
20   * variables maintaining the sum.
21   *
22 < * <p> This class is usually preferable to {@link AtomicLong} when
22 > * <p>This class is usually preferable to {@link AtomicLong} when
23   * multiple threads update a common sum that is used for purposes such
24   * as collecting statistics, not for fine-grained synchronization
25   * control.  Under low update contention, the two classes have similar
# Line 28 | Line 28 | import java.io.ObjectOutputStream;
28   * consumption.
29   *
30   * <p>This class extends {@link Number}, but does <em>not</em> define
31 < * methods such as {@code hashCode} and {@code compareTo} because
32 < * instances are expected to be mutated, and so are not useful as
33 < * collection keys.
31 > * methods such as {@code equals}, {@code hashCode} and {@code
32 > * compareTo} because instances are expected to be mutated, and so are
33 > * not useful as collection keys.
34   *
35   * <p><em>jsr166e note: This class is targeted to be placed in
36 < * java.util.concurrent.atomic<em>
36 > * java.util.concurrent.atomic.</em>
37   *
38 + * @since 1.8
39   * @author Doug Lea
40   */
41   public class LongAdder extends Striped64 implements Serializable {
# Line 84 | Line 85 | public class LongAdder extends Striped64
85  
86      /**
87       * Returns the current sum.  The returned value is <em>NOT</em> an
88 <     * atomic snapshot: Invocation in the absence of concurrent
88 >     * atomic snapshot: invocation in the absence of concurrent
89       * updates returns an accurate result, but concurrent updates that
90       * occur while the sum is being calculated might not be
91       * incorporated.
# Line 92 | Line 93 | public class LongAdder extends Striped64
93       * @return the sum
94       */
95      public long sum() {
95 –        Cell[] as = cells;
96          long sum = base;
97 +        Cell[] as = cells;
98          if (as != null) {
99              int n = as.length;
100              for (int i = 0; i < n; ++i) {
# Line 127 | Line 128 | public class LongAdder extends Striped64
128       * @return the sum
129       */
130      public long sumThenReset() {
130 –        Cell[] as = cells;
131          long sum = base;
132 +        Cell[] as = cells;
133          base = 0L;
134          if (as != null) {
135              int n = as.length;
136              for (int i = 0; i < n; ++i) {
137                  Cell a = as[i];
138                  if (a != null) {
139 <                    long v = a.value;
139 >                    sum += a.value;
140                      a.value = 0L;
140 –                    sum += v;
141                  }
142              }
143          }
# Line 146 | Line 146 | public class LongAdder extends Striped64
146  
147      /**
148       * Returns the String representation of the {@link #sum}.
149 <     * @return the String representation of the {@link #sum}.
149 >     * @return the String representation of the {@link #sum}
150       */
151      public String toString() {
152          return Long.toString(sum());

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