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Diffstat (limited to 'kamon-core/src/legacy-main/java/kamon/jsr166/LongAdder.java')
-rw-r--r-- | kamon-core/src/legacy-main/java/kamon/jsr166/LongAdder.java | 224 |
1 files changed, 0 insertions, 224 deletions
diff --git a/kamon-core/src/legacy-main/java/kamon/jsr166/LongAdder.java b/kamon-core/src/legacy-main/java/kamon/jsr166/LongAdder.java deleted file mode 100644 index 7e47ae63..00000000 --- a/kamon-core/src/legacy-main/java/kamon/jsr166/LongAdder.java +++ /dev/null @@ -1,224 +0,0 @@ -/* - -Note: this was copied from Doug Lea's CVS repository - http://gee.cs.oswego.edu/cgi-bin/viewcvs.cgi/jsr166/src/jsr166e/ - -LongAdder.java version 1.14 - -*/ - - -/* - * Written by Doug Lea with assistance from members of JCP JSR-166 - * Expert Group and released to the public domain, as explained at - * http://creativecommons.org/publicdomain/zero/1.0/ - */ - -package kamon.jsr166; - -import java.io.Serializable; - -/** - * One or more variables that together maintain an initially zero - * {@code long} sum. When updates (method {@link #add}) are contended - * across threads, the set of variables may grow dynamically to reduce - * contention. Method {@link #sum} (or, equivalently, {@link - * #longValue}) returns the current total combined across the - * variables maintaining the sum. - * - * <p>This class is usually preferable to {@link java.util.concurrent.atomic.AtomicLong} when - * multiple threads update a common sum that is used for purposes such - * as collecting statistics, not for fine-grained synchronization - * control. Under low update contention, the two classes have similar - * characteristics. But under high contention, expected throughput of - * this class is significantly higher, at the expense of higher space - * consumption. - * - * <p>This class extends {@link Number}, but does <em>not</em> define - * methods such as {@code equals}, {@code hashCode} and {@code - * compareTo} because instances are expected to be mutated, and so are - * not useful as collection keys. - * - * <p><em>jsr166e note: This class is targeted to be placed in - * java.util.concurrent.atomic.</em> - * - * @since 1.8 - * @author Doug Lea - */ -public class LongAdder extends Striped64 implements Serializable { - private static final long serialVersionUID = 7249069246863182397L; - - /** - * Version of plus for use in retryUpdate - */ - final long fn(long v, long x) { return v + x; } - - /** - * Creates a new adder with initial sum of zero. - */ - public LongAdder() { - } - - /** - * Adds the given value. - * - * @param x the value to add - */ - public void add(long x) { - Cell[] as; long b, v; HashCode hc; Cell a; int n; - if ((as = cells) != null || !casBase(b = base, b + x)) { - boolean uncontended = true; - int h = (hc = threadHashCode.get()).code; - if (as == null || (n = as.length) < 1 || - (a = as[(n - 1) & h]) == null || - !(uncontended = a.cas(v = a.value, v + x))) - retryUpdate(x, hc, uncontended); - } - } - - /** - * Equivalent to {@code add(1)}. - */ - public void increment() { - add(1L); - } - - /** - * Equivalent to {@code add(-1)}. - */ - public void decrement() { - add(-1L); - } - - /** - * Returns the current sum. The returned value is <em>NOT</em> an - * atomic snapshot; invocation in the absence of concurrent - * updates returns an accurate result, but concurrent updates that - * occur while the sum is being calculated might not be - * incorporated. - * - * @return the sum - */ - public long sum() { - long sum = base; - Cell[] as = cells; - if (as != null) { - int n = as.length; - for (int i = 0; i < n; ++i) { - Cell a = as[i]; - if (a != null) - sum += a.value; - } - } - return sum; - } - - /** - * Resets variables maintaining the sum to zero. This method may - * be a useful alternative to creating a new adder, but is only - * effective if there are no concurrent updates. Because this - * method is intrinsically racy, it should only be used when it is - * known that no threads are concurrently updating. - */ - public void reset() { - internalReset(0L); - } - - /** - * Equivalent in effect to {@link #sum} followed by {@link - * #reset}. This method may apply for example during quiescent - * points between multithreaded computations. If there are - * updates concurrent with this method, the returned value is - * <em>not</em> guaranteed to be the final value occurring before - * the reset. - * - * @return the sum - */ - public long sumThenReset() { - long sum = base; - Cell[] as = cells; - base = 0L; - if (as != null) { - int n = as.length; - for (int i = 0; i < n; ++i) { - Cell a = as[i]; - if (a != null) { - sum += a.value; - a.value = 0L; - } - } - } - return sum; - } - - public long sumAndReset() { - long sum = getAndSetBase(0L); - Cell[] as = cells; - if (as != null) { - int n = as.length; - for (int i = 0; i < n; ++i) { - Cell a = as[i]; - if (a != null) { - sum += a.getAndSet(0L); - } - } - } - return sum; - } - - /** - * Returns the String representation of the {@link #sum}. - * @return the String representation of the {@link #sum} - */ - public String toString() { - return Long.toString(sum()); - } - - /** - * Equivalent to {@link #sum}. - * - * @return the sum - */ - public long longValue() { - return sum(); - } - - /** - * Returns the {@link #sum} as an {@code int} after a narrowing - * primitive conversion. - */ - public int intValue() { - return (int)sum(); - } - - /** - * Returns the {@link #sum} as a {@code float} - * after a widening primitive conversion. - */ - public float floatValue() { - return (float)sum(); - } - - /** - * Returns the {@link #sum} as a {@code double} after a widening - * primitive conversion. - */ - public double doubleValue() { - return (double)sum(); - } - - private void writeObject(java.io.ObjectOutputStream s) - throws java.io.IOException { - s.defaultWriteObject(); - s.writeLong(sum()); - } - - private void readObject(java.io.ObjectInputStream s) - throws java.io.IOException, ClassNotFoundException { - s.defaultReadObject(); - busy = 0; - cells = null; - base = s.readLong(); - } - -} |