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dl |
1.1 |
/* |
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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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package java.util; |
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jsr166 |
1.4 |
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import java.util.concurrent.CountedCompleter; |
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dl |
1.1 |
import java.util.function.BinaryOperator; |
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jsr166 |
1.4 |
import java.util.function.DoubleBinaryOperator; |
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dl |
1.1 |
import java.util.function.IntBinaryOperator; |
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import java.util.function.LongBinaryOperator; |
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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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jsr166 |
1.3 |
private ArrayPrefixHelpers() {} // non-instantiable |
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dl |
1.1 |
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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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// 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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/** 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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jsr166 |
1.8 |
static final class CumulateTask<T> extends CountedCompleter<Void> { |
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dl |
1.1 |
final T[] array; |
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final BinaryOperator<T> function; |
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CumulateTask<T> left, right; |
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T in, out; |
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final int lo, hi, origin, fence, threshold; |
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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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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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} |
135 |
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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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153 |
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T sum; |
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if (state != SUMMED) { |
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int first; |
156 |
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if (l == org) { // leftmost; no in |
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sum = a[org]; |
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first = org + 1; |
159 |
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} |
160 |
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else { |
161 |
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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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jsr166 |
1.2 |
@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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dl |
1.1 |
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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} |
194 |
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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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} |
203 |
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} |
204 |
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else if (par.compareAndSetPendingCount(b, b|state)) |
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break outer; // sib not ready |
206 |
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} |
207 |
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} |
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} |
209 |
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} |
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private static final long serialVersionUID = 5293554502939613543L; |
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} |
212 |
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213 |
jsr166 |
1.8 |
static final class LongCumulateTask extends CountedCompleter<Void> { |
214 |
dl |
1.1 |
final long[] array; |
215 |
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final LongBinaryOperator function; |
216 |
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LongCumulateTask left, right; |
217 |
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long in, out; |
218 |
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final int lo, hi, origin, fence, threshold; |
219 |
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220 |
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LongCumulateTask(LongCumulateTask parent, LongBinaryOperator function, |
221 |
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long[] array, int origin, int fence, int threshold, |
222 |
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int lo, int hi) { |
223 |
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super(parent); |
224 |
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this.function = function; this.array = array; |
225 |
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this.origin = origin; this.fence = fence; |
226 |
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this.threshold = threshold; |
227 |
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this.lo = lo; this.hi = hi; |
228 |
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} |
229 |
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230 |
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public final void compute() { |
231 |
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final LongBinaryOperator fn; |
232 |
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final long[] a; |
233 |
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if ((fn = this.function) == null || (a = this.array) == null) |
234 |
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throw new NullPointerException(); // hoist checks |
235 |
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int th = threshold, org = origin, fnc = fence, l, h; |
236 |
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LongCumulateTask t = this; |
237 |
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outer: while ((l = t.lo) >= 0 && (h = t.hi) <= a.length) { |
238 |
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if (h - l > th) { |
239 |
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LongCumulateTask lt = t.left, rt = t.right, f; |
240 |
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if (lt == null) { // first pass |
241 |
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int mid = (l + h) >>> 1; |
242 |
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f = rt = t.right = |
243 |
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new LongCumulateTask(t, fn, a, org, fnc, th, mid, h); |
244 |
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t = lt = t.left = |
245 |
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new LongCumulateTask(t, fn, a, org, fnc, th, l, mid); |
246 |
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} |
247 |
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else { // possibly refork |
248 |
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long pin = t.in; |
249 |
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lt.in = pin; |
250 |
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f = t = null; |
251 |
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if (rt != null) { |
252 |
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long lout = lt.out; |
253 |
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rt.in = (l == org ? lout : |
254 |
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fn.applyAsLong(pin, lout)); |
255 |
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for (int c;;) { |
256 |
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if (((c = rt.getPendingCount()) & CUMULATE) != 0) |
257 |
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break; |
258 |
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if (rt.compareAndSetPendingCount(c, c|CUMULATE)){ |
259 |
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t = rt; |
260 |
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break; |
261 |
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} |
262 |
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} |
263 |
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} |
264 |
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for (int c;;) { |
265 |
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if (((c = lt.getPendingCount()) & CUMULATE) != 0) |
266 |
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break; |
267 |
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if (lt.compareAndSetPendingCount(c, c|CUMULATE)) { |
268 |
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if (t != null) |
269 |
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f = t; |
270 |
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t = lt; |
271 |
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break; |
272 |
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} |
273 |
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} |
274 |
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if (t == null) |
275 |
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break; |
276 |
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} |
277 |
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if (f != null) |
278 |
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f.fork(); |
279 |
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} |
280 |
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else { |
281 |
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int state; // Transition to sum, cumulate, or both |
282 |
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for (int b;;) { |
283 |
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if (((b = t.getPendingCount()) & FINISHED) != 0) |
284 |
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break outer; // already done |
285 |
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state = ((b & CUMULATE) != 0 ? FINISHED : |
286 |
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(l > org) ? SUMMED : (SUMMED|FINISHED)); |
287 |
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if (t.compareAndSetPendingCount(b, b|state)) |
288 |
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break; |
289 |
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} |
290 |
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291 |
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long sum; |
292 |
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if (state != SUMMED) { |
293 |
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int first; |
294 |
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if (l == org) { // leftmost; no in |
295 |
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sum = a[org]; |
296 |
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first = org + 1; |
297 |
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} |
298 |
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else { |
299 |
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sum = t.in; |
300 |
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first = l; |
301 |
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} |
302 |
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for (int i = first; i < h; ++i) // cumulate |
303 |
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a[i] = sum = fn.applyAsLong(sum, a[i]); |
304 |
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} |
305 |
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else if (h < fnc) { // skip rightmost |
306 |
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sum = a[l]; |
307 |
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for (int i = l + 1; i < h; ++i) // sum only |
308 |
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sum = fn.applyAsLong(sum, a[i]); |
309 |
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} |
310 |
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else |
311 |
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sum = t.in; |
312 |
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t.out = sum; |
313 |
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for (LongCumulateTask par;;) { // propagate |
314 |
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if ((par = (LongCumulateTask)t.getCompleter()) == null) { |
315 |
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if ((state & FINISHED) != 0) // enable join |
316 |
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t.quietlyComplete(); |
317 |
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break outer; |
318 |
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} |
319 |
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int b = par.getPendingCount(); |
320 |
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if ((b & state & FINISHED) != 0) |
321 |
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t = par; // both done |
322 |
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else if ((b & state & SUMMED) != 0) { // both summed |
323 |
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int nextState; LongCumulateTask lt, rt; |
324 |
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if ((lt = par.left) != null && |
325 |
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(rt = par.right) != null) { |
326 |
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long lout = lt.out; |
327 |
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par.out = (rt.hi == fnc ? lout : |
328 |
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fn.applyAsLong(lout, rt.out)); |
329 |
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} |
330 |
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int refork = (((b & CUMULATE) == 0 && |
331 |
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par.lo == org) ? CUMULATE : 0); |
332 |
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if ((nextState = b|state|refork) == b || |
333 |
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par.compareAndSetPendingCount(b, nextState)) { |
334 |
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state = SUMMED; // drop finished |
335 |
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t = par; |
336 |
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if (refork != 0) |
337 |
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par.fork(); |
338 |
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} |
339 |
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} |
340 |
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else if (par.compareAndSetPendingCount(b, b|state)) |
341 |
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break outer; // sib not ready |
342 |
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} |
343 |
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} |
344 |
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} |
345 |
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} |
346 |
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private static final long serialVersionUID = -5074099945909284273L; |
347 |
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} |
348 |
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|
349 |
jsr166 |
1.8 |
static final class DoubleCumulateTask extends CountedCompleter<Void> { |
350 |
dl |
1.1 |
final double[] array; |
351 |
|
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final DoubleBinaryOperator function; |
352 |
|
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DoubleCumulateTask left, right; |
353 |
|
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double in, out; |
354 |
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final int lo, hi, origin, fence, threshold; |
355 |
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|
356 |
|
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DoubleCumulateTask(DoubleCumulateTask parent, DoubleBinaryOperator function, |
357 |
jsr166 |
1.5 |
double[] array, int origin, int fence, int threshold, |
358 |
|
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int lo, int hi) { |
359 |
dl |
1.1 |
super(parent); |
360 |
|
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this.function = function; this.array = array; |
361 |
|
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this.origin = origin; this.fence = fence; |
362 |
|
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this.threshold = threshold; |
363 |
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this.lo = lo; this.hi = hi; |
364 |
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} |
365 |
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|
366 |
|
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public final void compute() { |
367 |
|
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final DoubleBinaryOperator fn; |
368 |
|
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final double[] a; |
369 |
|
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if ((fn = this.function) == null || (a = this.array) == null) |
370 |
|
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throw new NullPointerException(); // hoist checks |
371 |
|
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int th = threshold, org = origin, fnc = fence, l, h; |
372 |
|
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DoubleCumulateTask t = this; |
373 |
|
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outer: while ((l = t.lo) >= 0 && (h = t.hi) <= a.length) { |
374 |
|
|
if (h - l > th) { |
375 |
|
|
DoubleCumulateTask lt = t.left, rt = t.right, f; |
376 |
|
|
if (lt == null) { // first pass |
377 |
|
|
int mid = (l + h) >>> 1; |
378 |
|
|
f = rt = t.right = |
379 |
|
|
new DoubleCumulateTask(t, fn, a, org, fnc, th, mid, h); |
380 |
|
|
t = lt = t.left = |
381 |
|
|
new DoubleCumulateTask(t, fn, a, org, fnc, th, l, mid); |
382 |
|
|
} |
383 |
|
|
else { // possibly refork |
384 |
|
|
double pin = t.in; |
385 |
|
|
lt.in = pin; |
386 |
|
|
f = t = null; |
387 |
|
|
if (rt != null) { |
388 |
|
|
double lout = lt.out; |
389 |
|
|
rt.in = (l == org ? lout : |
390 |
|
|
fn.applyAsDouble(pin, lout)); |
391 |
|
|
for (int c;;) { |
392 |
|
|
if (((c = rt.getPendingCount()) & CUMULATE) != 0) |
393 |
|
|
break; |
394 |
|
|
if (rt.compareAndSetPendingCount(c, c|CUMULATE)){ |
395 |
|
|
t = rt; |
396 |
|
|
break; |
397 |
|
|
} |
398 |
|
|
} |
399 |
|
|
} |
400 |
|
|
for (int c;;) { |
401 |
|
|
if (((c = lt.getPendingCount()) & CUMULATE) != 0) |
402 |
|
|
break; |
403 |
|
|
if (lt.compareAndSetPendingCount(c, c|CUMULATE)) { |
404 |
|
|
if (t != null) |
405 |
|
|
f = t; |
406 |
|
|
t = lt; |
407 |
|
|
break; |
408 |
|
|
} |
409 |
|
|
} |
410 |
|
|
if (t == null) |
411 |
|
|
break; |
412 |
|
|
} |
413 |
|
|
if (f != null) |
414 |
|
|
f.fork(); |
415 |
|
|
} |
416 |
|
|
else { |
417 |
|
|
int state; // Transition to sum, cumulate, or both |
418 |
|
|
for (int b;;) { |
419 |
|
|
if (((b = t.getPendingCount()) & FINISHED) != 0) |
420 |
|
|
break outer; // already done |
421 |
|
|
state = ((b & CUMULATE) != 0 ? FINISHED : |
422 |
|
|
(l > org) ? SUMMED : (SUMMED|FINISHED)); |
423 |
|
|
if (t.compareAndSetPendingCount(b, b|state)) |
424 |
|
|
break; |
425 |
|
|
} |
426 |
|
|
|
427 |
|
|
double sum; |
428 |
|
|
if (state != SUMMED) { |
429 |
|
|
int first; |
430 |
|
|
if (l == org) { // leftmost; no in |
431 |
|
|
sum = a[org]; |
432 |
|
|
first = org + 1; |
433 |
|
|
} |
434 |
|
|
else { |
435 |
|
|
sum = t.in; |
436 |
|
|
first = l; |
437 |
|
|
} |
438 |
|
|
for (int i = first; i < h; ++i) // cumulate |
439 |
|
|
a[i] = sum = fn.applyAsDouble(sum, a[i]); |
440 |
|
|
} |
441 |
|
|
else if (h < fnc) { // skip rightmost |
442 |
|
|
sum = a[l]; |
443 |
|
|
for (int i = l + 1; i < h; ++i) // sum only |
444 |
|
|
sum = fn.applyAsDouble(sum, a[i]); |
445 |
|
|
} |
446 |
|
|
else |
447 |
|
|
sum = t.in; |
448 |
|
|
t.out = sum; |
449 |
|
|
for (DoubleCumulateTask par;;) { // propagate |
450 |
|
|
if ((par = (DoubleCumulateTask)t.getCompleter()) == null) { |
451 |
|
|
if ((state & FINISHED) != 0) // enable join |
452 |
|
|
t.quietlyComplete(); |
453 |
|
|
break outer; |
454 |
|
|
} |
455 |
|
|
int b = par.getPendingCount(); |
456 |
|
|
if ((b & state & FINISHED) != 0) |
457 |
|
|
t = par; // both done |
458 |
|
|
else if ((b & state & SUMMED) != 0) { // both summed |
459 |
|
|
int nextState; DoubleCumulateTask lt, rt; |
460 |
|
|
if ((lt = par.left) != null && |
461 |
|
|
(rt = par.right) != null) { |
462 |
|
|
double lout = lt.out; |
463 |
|
|
par.out = (rt.hi == fnc ? lout : |
464 |
|
|
fn.applyAsDouble(lout, rt.out)); |
465 |
|
|
} |
466 |
|
|
int refork = (((b & CUMULATE) == 0 && |
467 |
|
|
par.lo == org) ? CUMULATE : 0); |
468 |
|
|
if ((nextState = b|state|refork) == b || |
469 |
|
|
par.compareAndSetPendingCount(b, nextState)) { |
470 |
|
|
state = SUMMED; // drop finished |
471 |
|
|
t = par; |
472 |
|
|
if (refork != 0) |
473 |
|
|
par.fork(); |
474 |
|
|
} |
475 |
|
|
} |
476 |
|
|
else if (par.compareAndSetPendingCount(b, b|state)) |
477 |
|
|
break outer; // sib not ready |
478 |
|
|
} |
479 |
|
|
} |
480 |
|
|
} |
481 |
|
|
} |
482 |
|
|
private static final long serialVersionUID = -586947823794232033L; |
483 |
|
|
} |
484 |
|
|
|
485 |
jsr166 |
1.8 |
static final class IntCumulateTask extends CountedCompleter<Void> { |
486 |
dl |
1.1 |
final int[] array; |
487 |
|
|
final IntBinaryOperator function; |
488 |
|
|
IntCumulateTask left, right; |
489 |
|
|
int in, out; |
490 |
|
|
final int lo, hi, origin, fence, threshold; |
491 |
|
|
|
492 |
|
|
IntCumulateTask(IntCumulateTask parent, IntBinaryOperator function, |
493 |
jsr166 |
1.5 |
int[] array, int origin, int fence, int threshold, |
494 |
|
|
int lo, int hi) { |
495 |
dl |
1.1 |
super(parent); |
496 |
|
|
this.function = function; this.array = array; |
497 |
|
|
this.origin = origin; this.fence = fence; |
498 |
|
|
this.threshold = threshold; |
499 |
|
|
this.lo = lo; this.hi = hi; |
500 |
|
|
} |
501 |
|
|
|
502 |
|
|
public final void compute() { |
503 |
|
|
final IntBinaryOperator fn; |
504 |
|
|
final int[] a; |
505 |
|
|
if ((fn = this.function) == null || (a = this.array) == null) |
506 |
|
|
throw new NullPointerException(); // hoist checks |
507 |
|
|
int th = threshold, org = origin, fnc = fence, l, h; |
508 |
|
|
IntCumulateTask t = this; |
509 |
|
|
outer: while ((l = t.lo) >= 0 && (h = t.hi) <= a.length) { |
510 |
|
|
if (h - l > th) { |
511 |
|
|
IntCumulateTask lt = t.left, rt = t.right, f; |
512 |
|
|
if (lt == null) { // first pass |
513 |
|
|
int mid = (l + h) >>> 1; |
514 |
|
|
f = rt = t.right = |
515 |
|
|
new IntCumulateTask(t, fn, a, org, fnc, th, mid, h); |
516 |
|
|
t = lt = t.left = |
517 |
|
|
new IntCumulateTask(t, fn, a, org, fnc, th, l, mid); |
518 |
|
|
} |
519 |
|
|
else { // possibly refork |
520 |
|
|
int pin = t.in; |
521 |
|
|
lt.in = pin; |
522 |
|
|
f = t = null; |
523 |
|
|
if (rt != null) { |
524 |
|
|
int lout = lt.out; |
525 |
|
|
rt.in = (l == org ? lout : |
526 |
|
|
fn.applyAsInt(pin, lout)); |
527 |
|
|
for (int c;;) { |
528 |
|
|
if (((c = rt.getPendingCount()) & CUMULATE) != 0) |
529 |
|
|
break; |
530 |
|
|
if (rt.compareAndSetPendingCount(c, c|CUMULATE)){ |
531 |
|
|
t = rt; |
532 |
|
|
break; |
533 |
|
|
} |
534 |
|
|
} |
535 |
|
|
} |
536 |
|
|
for (int c;;) { |
537 |
|
|
if (((c = lt.getPendingCount()) & CUMULATE) != 0) |
538 |
|
|
break; |
539 |
|
|
if (lt.compareAndSetPendingCount(c, c|CUMULATE)) { |
540 |
|
|
if (t != null) |
541 |
|
|
f = t; |
542 |
|
|
t = lt; |
543 |
|
|
break; |
544 |
|
|
} |
545 |
|
|
} |
546 |
|
|
if (t == null) |
547 |
|
|
break; |
548 |
|
|
} |
549 |
|
|
if (f != null) |
550 |
|
|
f.fork(); |
551 |
|
|
} |
552 |
|
|
else { |
553 |
|
|
int state; // Transition to sum, cumulate, or both |
554 |
|
|
for (int b;;) { |
555 |
|
|
if (((b = t.getPendingCount()) & FINISHED) != 0) |
556 |
|
|
break outer; // already done |
557 |
|
|
state = ((b & CUMULATE) != 0 ? FINISHED : |
558 |
|
|
(l > org) ? SUMMED : (SUMMED|FINISHED)); |
559 |
|
|
if (t.compareAndSetPendingCount(b, b|state)) |
560 |
|
|
break; |
561 |
|
|
} |
562 |
|
|
|
563 |
|
|
int sum; |
564 |
|
|
if (state != SUMMED) { |
565 |
|
|
int first; |
566 |
|
|
if (l == org) { // leftmost; no in |
567 |
|
|
sum = a[org]; |
568 |
|
|
first = org + 1; |
569 |
|
|
} |
570 |
|
|
else { |
571 |
|
|
sum = t.in; |
572 |
|
|
first = l; |
573 |
|
|
} |
574 |
|
|
for (int i = first; i < h; ++i) // cumulate |
575 |
|
|
a[i] = sum = fn.applyAsInt(sum, a[i]); |
576 |
|
|
} |
577 |
|
|
else if (h < fnc) { // skip rightmost |
578 |
|
|
sum = a[l]; |
579 |
|
|
for (int i = l + 1; i < h; ++i) // sum only |
580 |
|
|
sum = fn.applyAsInt(sum, a[i]); |
581 |
|
|
} |
582 |
|
|
else |
583 |
|
|
sum = t.in; |
584 |
|
|
t.out = sum; |
585 |
|
|
for (IntCumulateTask par;;) { // propagate |
586 |
|
|
if ((par = (IntCumulateTask)t.getCompleter()) == null) { |
587 |
|
|
if ((state & FINISHED) != 0) // enable join |
588 |
|
|
t.quietlyComplete(); |
589 |
|
|
break outer; |
590 |
|
|
} |
591 |
|
|
int b = par.getPendingCount(); |
592 |
|
|
if ((b & state & FINISHED) != 0) |
593 |
|
|
t = par; // both done |
594 |
|
|
else if ((b & state & SUMMED) != 0) { // both summed |
595 |
|
|
int nextState; IntCumulateTask lt, rt; |
596 |
|
|
if ((lt = par.left) != null && |
597 |
|
|
(rt = par.right) != null) { |
598 |
|
|
int lout = lt.out; |
599 |
|
|
par.out = (rt.hi == fnc ? lout : |
600 |
|
|
fn.applyAsInt(lout, rt.out)); |
601 |
|
|
} |
602 |
|
|
int refork = (((b & CUMULATE) == 0 && |
603 |
|
|
par.lo == org) ? CUMULATE : 0); |
604 |
|
|
if ((nextState = b|state|refork) == b || |
605 |
|
|
par.compareAndSetPendingCount(b, nextState)) { |
606 |
|
|
state = SUMMED; // drop finished |
607 |
|
|
t = par; |
608 |
|
|
if (refork != 0) |
609 |
|
|
par.fork(); |
610 |
|
|
} |
611 |
|
|
} |
612 |
|
|
else if (par.compareAndSetPendingCount(b, b|state)) |
613 |
|
|
break outer; // sib not ready |
614 |
|
|
} |
615 |
|
|
} |
616 |
|
|
} |
617 |
|
|
} |
618 |
|
|
private static final long serialVersionUID = 3731755594596840961L; |
619 |
|
|
} |
620 |
|
|
|
621 |
|
|
} |