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/* |
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* Written by Doug Lea with assistance from members of JCP JSR-166 |
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* Expert Group and released to the public domain, as explained at |
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* http://creativecommons.org/publicdomain/zero/1.0/ |
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*/ |
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|
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package java.util; |
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|
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import java.util.concurrent.CountedCompleter; |
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import java.util.concurrent.ForkJoinPool; |
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import java.util.function.BinaryOperator; |
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import java.util.function.DoubleBinaryOperator; |
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import java.util.function.IntBinaryOperator; |
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import java.util.function.LongBinaryOperator; |
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|
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/** |
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* ForkJoin tasks to perform Arrays.parallelPrefix operations. |
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* |
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* @author Doug Lea |
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* @since 1.8 |
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*/ |
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class ArrayPrefixHelpers { |
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private ArrayPrefixHelpers() {} // non-instantiable |
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|
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/* |
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* Parallel prefix (aka cumulate, scan) task classes |
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* are based loosely on Guy Blelloch's original |
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* algorithm (http://www.cs.cmu.edu/~scandal/alg/scan.html): |
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* Keep dividing by two to threshold segment size, and then: |
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* Pass 1: Create tree of partial sums for each segment |
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* Pass 2: For each segment, cumulate with offset of left sibling |
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* |
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* This version improves performance within FJ framework mainly by |
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* allowing the second pass of ready left-hand sides to proceed |
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* even if some right-hand side first passes are still executing. |
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* It also combines first and second pass for leftmost segment, |
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* and skips the first pass for rightmost segment (whose result is |
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* not needed for second pass). It similarly manages to avoid |
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* requiring that users supply an identity basis for accumulations |
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* by tracking those segments/subtasks for which the first |
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* existing element is used as base. |
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* |
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* Managing this relies on ORing some bits in the pendingCount for |
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* phases/states: CUMULATE, SUMMED, and FINISHED. CUMULATE is the |
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* main phase bit. When false, segments compute only their sum. |
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* When true, they cumulate array elements. CUMULATE is set at |
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* root at beginning of second pass and then propagated down. But |
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* it may also be set earlier for subtrees with lo==0 (the left |
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* spine of tree). SUMMED is a one bit join count. For leafs, it |
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* is set when summed. For internal nodes, it becomes true when |
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* one child is summed. When the second child finishes summing, |
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* we then moves up tree to trigger the cumulate phase. FINISHED |
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* is also a one bit join count. For leafs, it is set when |
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* cumulated. For internal nodes, it becomes true when one child |
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* is cumulated. When the second child finishes cumulating, it |
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* then moves up tree, completing at the root. |
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* |
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* To better exploit locality and reduce overhead, the compute |
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* method loops starting with the current task, moving if possible |
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* to one of its subtasks rather than forking. |
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* |
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* As usual for this sort of utility, there are 4 versions, that |
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* are simple copy/paste/adapt variants of each other. (The |
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* double and int versions differ from long version solely by |
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* replacing "long" (with case-matching)). |
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*/ |
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|
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// see above |
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static final int CUMULATE = 1; |
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static final int SUMMED = 2; |
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static final int FINISHED = 4; |
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|
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/** The smallest subtask array partition size to use as threshold */ |
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static final int MIN_PARTITION = 16; |
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|
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static final class CumulateTask<T> extends CountedCompleter<Void> { |
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@SuppressWarnings("serial") // Not statically typed as Serializable |
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final T[] array; |
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@SuppressWarnings("serial") // Not statically typed as Serializable |
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final BinaryOperator<T> function; |
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CumulateTask<T> left, right; |
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@SuppressWarnings("serial") // Not statically typed as Serializable |
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T in; |
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@SuppressWarnings("serial") // Not statically typed as Serializable |
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T out; |
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final int lo, hi, origin, fence, threshold; |
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|
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/** Root task constructor */ |
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public CumulateTask(CumulateTask<T> parent, |
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BinaryOperator<T> function, |
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T[] array, int lo, int hi) { |
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super(parent); |
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this.function = function; this.array = array; |
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this.lo = this.origin = lo; this.hi = this.fence = hi; |
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int p; |
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this.threshold = |
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(p = (hi - lo) / (ForkJoinPool.getCommonPoolParallelism() << 3)) |
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<= MIN_PARTITION ? MIN_PARTITION : p; |
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} |
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|
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/** Subtask constructor */ |
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CumulateTask(CumulateTask<T> parent, BinaryOperator<T> function, |
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T[] array, int origin, int fence, int threshold, |
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int lo, int hi) { |
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super(parent); |
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this.function = function; this.array = array; |
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this.origin = origin; this.fence = fence; |
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this.threshold = threshold; |
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this.lo = lo; this.hi = hi; |
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} |
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|
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public final void compute() { |
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final BinaryOperator<T> fn; |
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final T[] a; |
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if ((fn = this.function) == null || (a = this.array) == null) |
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throw new NullPointerException(); // hoist checks |
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int th = threshold, org = origin, fnc = fence, l, h; |
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CumulateTask<T> t = this; |
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outer: while ((l = t.lo) >= 0 && (h = t.hi) <= a.length) { |
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if (h - l > th) { |
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CumulateTask<T> lt = t.left, rt = t.right, f; |
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if (lt == null) { // first pass |
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int mid = (l + h) >>> 1; |
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f = rt = t.right = |
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new CumulateTask<T>(t, fn, a, org, fnc, th, mid, h); |
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t = lt = t.left = |
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new CumulateTask<T>(t, fn, a, org, fnc, th, l, mid); |
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} |
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else { // possibly refork |
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T pin = t.in; |
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lt.in = pin; |
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f = t = null; |
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if (rt != null) { |
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T lout = lt.out; |
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rt.in = (l == org ? lout : |
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fn.apply(pin, lout)); |
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for (int c;;) { |
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if (((c = rt.getPendingCount()) & CUMULATE) != 0) |
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break; |
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if (rt.compareAndSetPendingCount(c, c|CUMULATE)){ |
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t = rt; |
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break; |
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} |
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} |
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} |
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for (int c;;) { |
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if (((c = lt.getPendingCount()) & CUMULATE) != 0) |
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break; |
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if (lt.compareAndSetPendingCount(c, c|CUMULATE)) { |
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if (t != null) |
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f = t; |
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t = lt; |
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break; |
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} |
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} |
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if (t == null) |
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break; |
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} |
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if (f != null) |
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f.fork(); |
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} |
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else { |
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int state; // Transition to sum, cumulate, or both |
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for (int b;;) { |
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if (((b = t.getPendingCount()) & FINISHED) != 0) |
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break outer; // already done |
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state = ((b & CUMULATE) != 0 ? FINISHED : |
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(l > org) ? SUMMED : (SUMMED|FINISHED)); |
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if (t.compareAndSetPendingCount(b, b|state)) |
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break; |
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} |
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|
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T sum; |
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if (state != SUMMED) { |
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int first; |
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if (l == org) { // leftmost; no in |
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sum = a[org]; |
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first = org + 1; |
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} |
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else { |
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sum = t.in; |
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first = l; |
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} |
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for (int i = first; i < h; ++i) // cumulate |
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a[i] = sum = fn.apply(sum, a[i]); |
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} |
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else if (h < fnc) { // skip rightmost |
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sum = a[l]; |
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for (int i = l + 1; i < h; ++i) // sum only |
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sum = fn.apply(sum, a[i]); |
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} |
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else |
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sum = t.in; |
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t.out = sum; |
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for (CumulateTask<T> par;;) { // propagate |
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@SuppressWarnings("unchecked") CumulateTask<T> partmp |
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= (CumulateTask<T>)t.getCompleter(); |
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if ((par = partmp) == null) { |
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if ((state & FINISHED) != 0) // enable join |
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t.quietlyComplete(); |
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break outer; |
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} |
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int b = par.getPendingCount(); |
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if ((b & state & FINISHED) != 0) |
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t = par; // both done |
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else if ((b & state & SUMMED) != 0) { // both summed |
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int nextState; CumulateTask<T> lt, rt; |
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if ((lt = par.left) != null && |
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(rt = par.right) != null) { |
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T lout = lt.out; |
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par.out = (rt.hi == fnc ? lout : |
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fn.apply(lout, rt.out)); |
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} |
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int refork = (((b & CUMULATE) == 0 && |
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par.lo == org) ? CUMULATE : 0); |
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if ((nextState = b|state|refork) == b || |
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par.compareAndSetPendingCount(b, nextState)) { |
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state = SUMMED; // drop finished |
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t = par; |
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if (refork != 0) |
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par.fork(); |
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} |
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} |
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else if (par.compareAndSetPendingCount(b, b|state)) |
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break outer; // sib not ready |
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} |
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} |
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} |
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} |
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// OPENJDK @java.io.Serial |
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private static final long serialVersionUID = 5293554502939613543L; |
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} |
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|
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static final class LongCumulateTask extends CountedCompleter<Void> { |
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final long[] array; |
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@SuppressWarnings("serial") // Not statically typed as Serializable |
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final LongBinaryOperator function; |
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LongCumulateTask left, right; |
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long in, out; |
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final int lo, hi, origin, fence, threshold; |
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|
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/** Root task constructor */ |
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public LongCumulateTask(LongCumulateTask parent, |
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LongBinaryOperator function, |
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long[] array, int lo, int hi) { |
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super(parent); |
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this.function = function; this.array = array; |
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this.lo = this.origin = lo; this.hi = this.fence = hi; |
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int p; |
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this.threshold = |
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(p = (hi - lo) / (ForkJoinPool.getCommonPoolParallelism() << 3)) |
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<= MIN_PARTITION ? MIN_PARTITION : p; |
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} |
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|
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/** Subtask constructor */ |
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LongCumulateTask(LongCumulateTask parent, LongBinaryOperator function, |
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long[] array, int origin, int fence, int threshold, |
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int lo, int hi) { |
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super(parent); |
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this.function = function; this.array = array; |
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this.origin = origin; this.fence = fence; |
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this.threshold = threshold; |
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this.lo = lo; this.hi = hi; |
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} |
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|
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public final void compute() { |
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final LongBinaryOperator fn; |
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final long[] a; |
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if ((fn = this.function) == null || (a = this.array) == null) |
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throw new NullPointerException(); // hoist checks |
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int th = threshold, org = origin, fnc = fence, l, h; |
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LongCumulateTask t = this; |
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outer: while ((l = t.lo) >= 0 && (h = t.hi) <= a.length) { |
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if (h - l > th) { |
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LongCumulateTask lt = t.left, rt = t.right, f; |
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if (lt == null) { // first pass |
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int mid = (l + h) >>> 1; |
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f = rt = t.right = |
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new LongCumulateTask(t, fn, a, org, fnc, th, mid, h); |
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t = lt = t.left = |
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new LongCumulateTask(t, fn, a, org, fnc, th, l, mid); |
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} |
283 |
else { // possibly refork |
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long pin = t.in; |
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lt.in = pin; |
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f = t = null; |
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if (rt != null) { |
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long lout = lt.out; |
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rt.in = (l == org ? lout : |
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fn.applyAsLong(pin, lout)); |
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for (int c;;) { |
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if (((c = rt.getPendingCount()) & CUMULATE) != 0) |
293 |
break; |
294 |
if (rt.compareAndSetPendingCount(c, c|CUMULATE)){ |
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t = rt; |
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break; |
297 |
} |
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} |
299 |
} |
300 |
for (int c;;) { |
301 |
if (((c = lt.getPendingCount()) & CUMULATE) != 0) |
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break; |
303 |
if (lt.compareAndSetPendingCount(c, c|CUMULATE)) { |
304 |
if (t != null) |
305 |
f = t; |
306 |
t = lt; |
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break; |
308 |
} |
309 |
} |
310 |
if (t == null) |
311 |
break; |
312 |
} |
313 |
if (f != null) |
314 |
f.fork(); |
315 |
} |
316 |
else { |
317 |
int state; // Transition to sum, cumulate, or both |
318 |
for (int b;;) { |
319 |
if (((b = t.getPendingCount()) & FINISHED) != 0) |
320 |
break outer; // already done |
321 |
state = ((b & CUMULATE) != 0 ? FINISHED : |
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(l > org) ? SUMMED : (SUMMED|FINISHED)); |
323 |
if (t.compareAndSetPendingCount(b, b|state)) |
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break; |
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} |
326 |
|
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long sum; |
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if (state != SUMMED) { |
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int first; |
330 |
if (l == org) { // leftmost; no in |
331 |
sum = a[org]; |
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first = org + 1; |
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} |
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else { |
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sum = t.in; |
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first = l; |
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} |
338 |
for (int i = first; i < h; ++i) // cumulate |
339 |
a[i] = sum = fn.applyAsLong(sum, a[i]); |
340 |
} |
341 |
else if (h < fnc) { // skip rightmost |
342 |
sum = a[l]; |
343 |
for (int i = l + 1; i < h; ++i) // sum only |
344 |
sum = fn.applyAsLong(sum, a[i]); |
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} |
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else |
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sum = t.in; |
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t.out = sum; |
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for (LongCumulateTask par;;) { // propagate |
350 |
if ((par = (LongCumulateTask)t.getCompleter()) == null) { |
351 |
if ((state & FINISHED) != 0) // enable join |
352 |
t.quietlyComplete(); |
353 |
break outer; |
354 |
} |
355 |
int b = par.getPendingCount(); |
356 |
if ((b & state & FINISHED) != 0) |
357 |
t = par; // both done |
358 |
else if ((b & state & SUMMED) != 0) { // both summed |
359 |
int nextState; LongCumulateTask lt, rt; |
360 |
if ((lt = par.left) != null && |
361 |
(rt = par.right) != null) { |
362 |
long lout = lt.out; |
363 |
par.out = (rt.hi == fnc ? lout : |
364 |
fn.applyAsLong(lout, rt.out)); |
365 |
} |
366 |
int refork = (((b & CUMULATE) == 0 && |
367 |
par.lo == org) ? CUMULATE : 0); |
368 |
if ((nextState = b|state|refork) == b || |
369 |
par.compareAndSetPendingCount(b, nextState)) { |
370 |
state = SUMMED; // drop finished |
371 |
t = par; |
372 |
if (refork != 0) |
373 |
par.fork(); |
374 |
} |
375 |
} |
376 |
else if (par.compareAndSetPendingCount(b, b|state)) |
377 |
break outer; // sib not ready |
378 |
} |
379 |
} |
380 |
} |
381 |
} |
382 |
// OPENJDK @java.io.Serial |
383 |
private static final long serialVersionUID = -5074099945909284273L; |
384 |
} |
385 |
|
386 |
static final class DoubleCumulateTask extends CountedCompleter<Void> { |
387 |
final double[] array; |
388 |
@SuppressWarnings("serial") // Not statically typed as Serializable |
389 |
final DoubleBinaryOperator function; |
390 |
DoubleCumulateTask left, right; |
391 |
double in, out; |
392 |
final int lo, hi, origin, fence, threshold; |
393 |
|
394 |
/** Root task constructor */ |
395 |
public DoubleCumulateTask(DoubleCumulateTask parent, |
396 |
DoubleBinaryOperator function, |
397 |
double[] array, int lo, int hi) { |
398 |
super(parent); |
399 |
this.function = function; this.array = array; |
400 |
this.lo = this.origin = lo; this.hi = this.fence = hi; |
401 |
int p; |
402 |
this.threshold = |
403 |
(p = (hi - lo) / (ForkJoinPool.getCommonPoolParallelism() << 3)) |
404 |
<= MIN_PARTITION ? MIN_PARTITION : p; |
405 |
} |
406 |
|
407 |
/** Subtask constructor */ |
408 |
DoubleCumulateTask(DoubleCumulateTask parent, DoubleBinaryOperator function, |
409 |
double[] array, int origin, int fence, int threshold, |
410 |
int lo, int hi) { |
411 |
super(parent); |
412 |
this.function = function; this.array = array; |
413 |
this.origin = origin; this.fence = fence; |
414 |
this.threshold = threshold; |
415 |
this.lo = lo; this.hi = hi; |
416 |
} |
417 |
|
418 |
public final void compute() { |
419 |
final DoubleBinaryOperator fn; |
420 |
final double[] a; |
421 |
if ((fn = this.function) == null || (a = this.array) == null) |
422 |
throw new NullPointerException(); // hoist checks |
423 |
int th = threshold, org = origin, fnc = fence, l, h; |
424 |
DoubleCumulateTask t = this; |
425 |
outer: while ((l = t.lo) >= 0 && (h = t.hi) <= a.length) { |
426 |
if (h - l > th) { |
427 |
DoubleCumulateTask lt = t.left, rt = t.right, f; |
428 |
if (lt == null) { // first pass |
429 |
int mid = (l + h) >>> 1; |
430 |
f = rt = t.right = |
431 |
new DoubleCumulateTask(t, fn, a, org, fnc, th, mid, h); |
432 |
t = lt = t.left = |
433 |
new DoubleCumulateTask(t, fn, a, org, fnc, th, l, mid); |
434 |
} |
435 |
else { // possibly refork |
436 |
double pin = t.in; |
437 |
lt.in = pin; |
438 |
f = t = null; |
439 |
if (rt != null) { |
440 |
double lout = lt.out; |
441 |
rt.in = (l == org ? lout : |
442 |
fn.applyAsDouble(pin, lout)); |
443 |
for (int c;;) { |
444 |
if (((c = rt.getPendingCount()) & CUMULATE) != 0) |
445 |
break; |
446 |
if (rt.compareAndSetPendingCount(c, c|CUMULATE)){ |
447 |
t = rt; |
448 |
break; |
449 |
} |
450 |
} |
451 |
} |
452 |
for (int c;;) { |
453 |
if (((c = lt.getPendingCount()) & CUMULATE) != 0) |
454 |
break; |
455 |
if (lt.compareAndSetPendingCount(c, c|CUMULATE)) { |
456 |
if (t != null) |
457 |
f = t; |
458 |
t = lt; |
459 |
break; |
460 |
} |
461 |
} |
462 |
if (t == null) |
463 |
break; |
464 |
} |
465 |
if (f != null) |
466 |
f.fork(); |
467 |
} |
468 |
else { |
469 |
int state; // Transition to sum, cumulate, or both |
470 |
for (int b;;) { |
471 |
if (((b = t.getPendingCount()) & FINISHED) != 0) |
472 |
break outer; // already done |
473 |
state = ((b & CUMULATE) != 0 ? FINISHED : |
474 |
(l > org) ? SUMMED : (SUMMED|FINISHED)); |
475 |
if (t.compareAndSetPendingCount(b, b|state)) |
476 |
break; |
477 |
} |
478 |
|
479 |
double sum; |
480 |
if (state != SUMMED) { |
481 |
int first; |
482 |
if (l == org) { // leftmost; no in |
483 |
sum = a[org]; |
484 |
first = org + 1; |
485 |
} |
486 |
else { |
487 |
sum = t.in; |
488 |
first = l; |
489 |
} |
490 |
for (int i = first; i < h; ++i) // cumulate |
491 |
a[i] = sum = fn.applyAsDouble(sum, a[i]); |
492 |
} |
493 |
else if (h < fnc) { // skip rightmost |
494 |
sum = a[l]; |
495 |
for (int i = l + 1; i < h; ++i) // sum only |
496 |
sum = fn.applyAsDouble(sum, a[i]); |
497 |
} |
498 |
else |
499 |
sum = t.in; |
500 |
t.out = sum; |
501 |
for (DoubleCumulateTask par;;) { // propagate |
502 |
if ((par = (DoubleCumulateTask)t.getCompleter()) == null) { |
503 |
if ((state & FINISHED) != 0) // enable join |
504 |
t.quietlyComplete(); |
505 |
break outer; |
506 |
} |
507 |
int b = par.getPendingCount(); |
508 |
if ((b & state & FINISHED) != 0) |
509 |
t = par; // both done |
510 |
else if ((b & state & SUMMED) != 0) { // both summed |
511 |
int nextState; DoubleCumulateTask lt, rt; |
512 |
if ((lt = par.left) != null && |
513 |
(rt = par.right) != null) { |
514 |
double lout = lt.out; |
515 |
par.out = (rt.hi == fnc ? lout : |
516 |
fn.applyAsDouble(lout, rt.out)); |
517 |
} |
518 |
int refork = (((b & CUMULATE) == 0 && |
519 |
par.lo == org) ? CUMULATE : 0); |
520 |
if ((nextState = b|state|refork) == b || |
521 |
par.compareAndSetPendingCount(b, nextState)) { |
522 |
state = SUMMED; // drop finished |
523 |
t = par; |
524 |
if (refork != 0) |
525 |
par.fork(); |
526 |
} |
527 |
} |
528 |
else if (par.compareAndSetPendingCount(b, b|state)) |
529 |
break outer; // sib not ready |
530 |
} |
531 |
} |
532 |
} |
533 |
} |
534 |
// OPENJDK @java.io.Serial |
535 |
private static final long serialVersionUID = -586947823794232033L; |
536 |
} |
537 |
|
538 |
static final class IntCumulateTask extends CountedCompleter<Void> { |
539 |
final int[] array; |
540 |
@SuppressWarnings("serial") // Not statically typed as Serializable |
541 |
final IntBinaryOperator function; |
542 |
IntCumulateTask left, right; |
543 |
int in, out; |
544 |
final int lo, hi, origin, fence, threshold; |
545 |
|
546 |
/** Root task constructor */ |
547 |
public IntCumulateTask(IntCumulateTask parent, |
548 |
IntBinaryOperator function, |
549 |
int[] array, int lo, int hi) { |
550 |
super(parent); |
551 |
this.function = function; this.array = array; |
552 |
this.lo = this.origin = lo; this.hi = this.fence = hi; |
553 |
int p; |
554 |
this.threshold = |
555 |
(p = (hi - lo) / (ForkJoinPool.getCommonPoolParallelism() << 3)) |
556 |
<= MIN_PARTITION ? MIN_PARTITION : p; |
557 |
} |
558 |
|
559 |
/** Subtask constructor */ |
560 |
IntCumulateTask(IntCumulateTask parent, IntBinaryOperator function, |
561 |
int[] array, int origin, int fence, int threshold, |
562 |
int lo, int hi) { |
563 |
super(parent); |
564 |
this.function = function; this.array = array; |
565 |
this.origin = origin; this.fence = fence; |
566 |
this.threshold = threshold; |
567 |
this.lo = lo; this.hi = hi; |
568 |
} |
569 |
|
570 |
public final void compute() { |
571 |
final IntBinaryOperator fn; |
572 |
final int[] a; |
573 |
if ((fn = this.function) == null || (a = this.array) == null) |
574 |
throw new NullPointerException(); // hoist checks |
575 |
int th = threshold, org = origin, fnc = fence, l, h; |
576 |
IntCumulateTask t = this; |
577 |
outer: while ((l = t.lo) >= 0 && (h = t.hi) <= a.length) { |
578 |
if (h - l > th) { |
579 |
IntCumulateTask lt = t.left, rt = t.right, f; |
580 |
if (lt == null) { // first pass |
581 |
int mid = (l + h) >>> 1; |
582 |
f = rt = t.right = |
583 |
new IntCumulateTask(t, fn, a, org, fnc, th, mid, h); |
584 |
t = lt = t.left = |
585 |
new IntCumulateTask(t, fn, a, org, fnc, th, l, mid); |
586 |
} |
587 |
else { // possibly refork |
588 |
int pin = t.in; |
589 |
lt.in = pin; |
590 |
f = t = null; |
591 |
if (rt != null) { |
592 |
int lout = lt.out; |
593 |
rt.in = (l == org ? lout : |
594 |
fn.applyAsInt(pin, lout)); |
595 |
for (int c;;) { |
596 |
if (((c = rt.getPendingCount()) & CUMULATE) != 0) |
597 |
break; |
598 |
if (rt.compareAndSetPendingCount(c, c|CUMULATE)){ |
599 |
t = rt; |
600 |
break; |
601 |
} |
602 |
} |
603 |
} |
604 |
for (int c;;) { |
605 |
if (((c = lt.getPendingCount()) & CUMULATE) != 0) |
606 |
break; |
607 |
if (lt.compareAndSetPendingCount(c, c|CUMULATE)) { |
608 |
if (t != null) |
609 |
f = t; |
610 |
t = lt; |
611 |
break; |
612 |
} |
613 |
} |
614 |
if (t == null) |
615 |
break; |
616 |
} |
617 |
if (f != null) |
618 |
f.fork(); |
619 |
} |
620 |
else { |
621 |
int state; // Transition to sum, cumulate, or both |
622 |
for (int b;;) { |
623 |
if (((b = t.getPendingCount()) & FINISHED) != 0) |
624 |
break outer; // already done |
625 |
state = ((b & CUMULATE) != 0 ? FINISHED : |
626 |
(l > org) ? SUMMED : (SUMMED|FINISHED)); |
627 |
if (t.compareAndSetPendingCount(b, b|state)) |
628 |
break; |
629 |
} |
630 |
|
631 |
int sum; |
632 |
if (state != SUMMED) { |
633 |
int first; |
634 |
if (l == org) { // leftmost; no in |
635 |
sum = a[org]; |
636 |
first = org + 1; |
637 |
} |
638 |
else { |
639 |
sum = t.in; |
640 |
first = l; |
641 |
} |
642 |
for (int i = first; i < h; ++i) // cumulate |
643 |
a[i] = sum = fn.applyAsInt(sum, a[i]); |
644 |
} |
645 |
else if (h < fnc) { // skip rightmost |
646 |
sum = a[l]; |
647 |
for (int i = l + 1; i < h; ++i) // sum only |
648 |
sum = fn.applyAsInt(sum, a[i]); |
649 |
} |
650 |
else |
651 |
sum = t.in; |
652 |
t.out = sum; |
653 |
for (IntCumulateTask par;;) { // propagate |
654 |
if ((par = (IntCumulateTask)t.getCompleter()) == null) { |
655 |
if ((state & FINISHED) != 0) // enable join |
656 |
t.quietlyComplete(); |
657 |
break outer; |
658 |
} |
659 |
int b = par.getPendingCount(); |
660 |
if ((b & state & FINISHED) != 0) |
661 |
t = par; // both done |
662 |
else if ((b & state & SUMMED) != 0) { // both summed |
663 |
int nextState; IntCumulateTask lt, rt; |
664 |
if ((lt = par.left) != null && |
665 |
(rt = par.right) != null) { |
666 |
int lout = lt.out; |
667 |
par.out = (rt.hi == fnc ? lout : |
668 |
fn.applyAsInt(lout, rt.out)); |
669 |
} |
670 |
int refork = (((b & CUMULATE) == 0 && |
671 |
par.lo == org) ? CUMULATE : 0); |
672 |
if ((nextState = b|state|refork) == b || |
673 |
par.compareAndSetPendingCount(b, nextState)) { |
674 |
state = SUMMED; // drop finished |
675 |
t = par; |
676 |
if (refork != 0) |
677 |
par.fork(); |
678 |
} |
679 |
} |
680 |
else if (par.compareAndSetPendingCount(b, b|state)) |
681 |
break outer; // sib not ready |
682 |
} |
683 |
} |
684 |
} |
685 |
} |
686 |
// OPENJDK @java.io.Serial |
687 |
private static final long serialVersionUID = 3731755594596840961L; |
688 |
} |
689 |
} |