719 lines
33 KiB
Java
719 lines
33 KiB
Java
/*
|
|
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
|
|
*
|
|
* This code is free software; you can redistribute it and/or modify it
|
|
* under the terms of the GNU General Public License version 2 only, as
|
|
* published by the Free Software Foundation. Oracle designates this
|
|
* particular file as subject to the "Classpath" exception as provided
|
|
* by Oracle in the LICENSE file that accompanied this code.
|
|
*
|
|
* This code is distributed in the hope that it will be useful, but WITHOUT
|
|
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
|
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
|
* version 2 for more details (a copy is included in the LICENSE file that
|
|
* accompanied this code).
|
|
*
|
|
* You should have received a copy of the GNU General Public License version
|
|
* 2 along with this work; if not, write to the Free Software Foundation,
|
|
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
|
|
*
|
|
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
|
|
* or visit www.oracle.com if you need additional information or have any
|
|
* questions.
|
|
*/
|
|
|
|
/*
|
|
* This file is available under and governed by the GNU General Public
|
|
* License version 2 only, as published by the Free Software Foundation.
|
|
* However, the following notice accompanied the original version of this
|
|
* file:
|
|
*
|
|
* 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 java.util;
|
|
|
|
import java.util.concurrent.CountedCompleter;
|
|
import java.util.concurrent.ForkJoinPool;
|
|
import java.util.function.BinaryOperator;
|
|
import java.util.function.DoubleBinaryOperator;
|
|
import java.util.function.IntBinaryOperator;
|
|
import java.util.function.LongBinaryOperator;
|
|
|
|
/**
|
|
* ForkJoin tasks to perform Arrays.parallelPrefix operations.
|
|
*
|
|
* @author Doug Lea
|
|
* @since 1.8
|
|
*/
|
|
class ArrayPrefixHelpers {
|
|
private ArrayPrefixHelpers() {} // non-instantiable
|
|
|
|
/*
|
|
* Parallel prefix (aka cumulate, scan) task classes
|
|
* are based loosely on Guy Blelloch's original
|
|
* algorithm (http://www.cs.cmu.edu/~scandal/alg/scan.html):
|
|
* Keep dividing by two to threshold segment size, and then:
|
|
* Pass 1: Create tree of partial sums for each segment
|
|
* Pass 2: For each segment, cumulate with offset of left sibling
|
|
*
|
|
* This version improves performance within FJ framework mainly by
|
|
* allowing the second pass of ready left-hand sides to proceed
|
|
* even if some right-hand side first passes are still executing.
|
|
* It also combines first and second pass for leftmost segment,
|
|
* and skips the first pass for rightmost segment (whose result is
|
|
* not needed for second pass). It similarly manages to avoid
|
|
* requiring that users supply an identity basis for accumulations
|
|
* by tracking those segments/subtasks for which the first
|
|
* existing element is used as base.
|
|
*
|
|
* Managing this relies on ORing some bits in the pendingCount for
|
|
* phases/states: CUMULATE, SUMMED, and FINISHED. CUMULATE is the
|
|
* main phase bit. When false, segments compute only their sum.
|
|
* When true, they cumulate array elements. CUMULATE is set at
|
|
* root at beginning of second pass and then propagated down. But
|
|
* it may also be set earlier for subtrees with lo==0 (the left
|
|
* spine of tree). SUMMED is a one bit join count. For leafs, it
|
|
* is set when summed. For internal nodes, it becomes true when
|
|
* one child is summed. When the second child finishes summing,
|
|
* we then moves up tree to trigger the cumulate phase. FINISHED
|
|
* is also a one bit join count. For leafs, it is set when
|
|
* cumulated. For internal nodes, it becomes true when one child
|
|
* is cumulated. When the second child finishes cumulating, it
|
|
* then moves up tree, completing at the root.
|
|
*
|
|
* To better exploit locality and reduce overhead, the compute
|
|
* method loops starting with the current task, moving if possible
|
|
* to one of its subtasks rather than forking.
|
|
*
|
|
* As usual for this sort of utility, there are 4 versions, that
|
|
* are simple copy/paste/adapt variants of each other. (The
|
|
* double and int versions differ from long version solely by
|
|
* replacing "long" (with case-matching)).
|
|
*/
|
|
|
|
// see above
|
|
static final int CUMULATE = 1;
|
|
static final int SUMMED = 2;
|
|
static final int FINISHED = 4;
|
|
|
|
/** The smallest subtask array partition size to use as threshold */
|
|
static final int MIN_PARTITION = 16;
|
|
|
|
static final class CumulateTask<T> extends CountedCompleter<Void> {
|
|
@SuppressWarnings("serial") // Not statically typed as Serializable
|
|
final T[] array;
|
|
@SuppressWarnings("serial") // Not statically typed as Serializable
|
|
final BinaryOperator<T> function;
|
|
CumulateTask<T> left, right;
|
|
@SuppressWarnings("serial") // Not statically typed as Serializable
|
|
T in;
|
|
@SuppressWarnings("serial") // Not statically typed as Serializable
|
|
T out;
|
|
final int lo, hi, origin, fence, threshold;
|
|
|
|
/** Root task constructor */
|
|
public CumulateTask(CumulateTask<T> parent,
|
|
BinaryOperator<T> function,
|
|
T[] array, int lo, int hi) {
|
|
super(parent);
|
|
this.function = function; this.array = array;
|
|
this.lo = this.origin = lo; this.hi = this.fence = hi;
|
|
int p;
|
|
this.threshold =
|
|
(p = (hi - lo) / (ForkJoinPool.getCommonPoolParallelism() << 3))
|
|
<= MIN_PARTITION ? MIN_PARTITION : p;
|
|
}
|
|
|
|
/** Subtask constructor */
|
|
CumulateTask(CumulateTask<T> parent, BinaryOperator<T> function,
|
|
T[] array, int origin, int fence, int threshold,
|
|
int lo, int hi) {
|
|
super(parent);
|
|
this.function = function; this.array = array;
|
|
this.origin = origin; this.fence = fence;
|
|
this.threshold = threshold;
|
|
this.lo = lo; this.hi = hi;
|
|
}
|
|
|
|
public final void compute() {
|
|
final BinaryOperator<T> fn;
|
|
final T[] a;
|
|
if ((fn = this.function) == null || (a = this.array) == null)
|
|
throw new NullPointerException(); // hoist checks
|
|
int th = threshold, org = origin, fnc = fence, l, h;
|
|
CumulateTask<T> t = this;
|
|
outer: while ((l = t.lo) >= 0 && (h = t.hi) <= a.length) {
|
|
if (h - l > th) {
|
|
CumulateTask<T> lt = t.left, rt = t.right, f;
|
|
if (lt == null) { // first pass
|
|
int mid = (l + h) >>> 1;
|
|
f = rt = t.right =
|
|
new CumulateTask<T>(t, fn, a, org, fnc, th, mid, h);
|
|
t = lt = t.left =
|
|
new CumulateTask<T>(t, fn, a, org, fnc, th, l, mid);
|
|
}
|
|
else { // possibly refork
|
|
T pin = t.in;
|
|
lt.in = pin;
|
|
f = t = null;
|
|
if (rt != null) {
|
|
T lout = lt.out;
|
|
rt.in = (l == org ? lout :
|
|
fn.apply(pin, lout));
|
|
for (int c;;) {
|
|
if (((c = rt.getPendingCount()) & CUMULATE) != 0)
|
|
break;
|
|
if (rt.compareAndSetPendingCount(c, c|CUMULATE)){
|
|
t = rt;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
for (int c;;) {
|
|
if (((c = lt.getPendingCount()) & CUMULATE) != 0)
|
|
break;
|
|
if (lt.compareAndSetPendingCount(c, c|CUMULATE)) {
|
|
if (t != null)
|
|
f = t;
|
|
t = lt;
|
|
break;
|
|
}
|
|
}
|
|
if (t == null)
|
|
break;
|
|
}
|
|
if (f != null)
|
|
f.fork();
|
|
}
|
|
else {
|
|
int state; // Transition to sum, cumulate, or both
|
|
for (int b;;) {
|
|
if (((b = t.getPendingCount()) & FINISHED) != 0)
|
|
break outer; // already done
|
|
state = ((b & CUMULATE) != 0 ? FINISHED :
|
|
(l > org) ? SUMMED : (SUMMED|FINISHED));
|
|
if (t.compareAndSetPendingCount(b, b|state))
|
|
break;
|
|
}
|
|
|
|
T sum;
|
|
if (state != SUMMED) {
|
|
int first;
|
|
if (l == org) { // leftmost; no in
|
|
sum = a[org];
|
|
first = org + 1;
|
|
}
|
|
else {
|
|
sum = t.in;
|
|
first = l;
|
|
}
|
|
for (int i = first; i < h; ++i) // cumulate
|
|
a[i] = sum = fn.apply(sum, a[i]);
|
|
}
|
|
else if (h < fnc) { // skip rightmost
|
|
sum = a[l];
|
|
for (int i = l + 1; i < h; ++i) // sum only
|
|
sum = fn.apply(sum, a[i]);
|
|
}
|
|
else
|
|
sum = t.in;
|
|
t.out = sum;
|
|
for (CumulateTask<T> par;;) { // propagate
|
|
@SuppressWarnings("unchecked") CumulateTask<T> partmp
|
|
= (CumulateTask<T>)t.getCompleter();
|
|
if ((par = partmp) == null) {
|
|
if ((state & FINISHED) != 0) // enable join
|
|
t.quietlyComplete();
|
|
break outer;
|
|
}
|
|
int b = par.getPendingCount();
|
|
if ((b & state & FINISHED) != 0)
|
|
t = par; // both done
|
|
else if ((b & state & SUMMED) != 0) { // both summed
|
|
int nextState; CumulateTask<T> lt, rt;
|
|
if ((lt = par.left) != null &&
|
|
(rt = par.right) != null) {
|
|
T lout = lt.out;
|
|
par.out = (rt.hi == fnc ? lout :
|
|
fn.apply(lout, rt.out));
|
|
}
|
|
int refork = (((b & CUMULATE) == 0 &&
|
|
par.lo == org) ? CUMULATE : 0);
|
|
if ((nextState = b|state|refork) == b ||
|
|
par.compareAndSetPendingCount(b, nextState)) {
|
|
state = SUMMED; // drop finished
|
|
t = par;
|
|
if (refork != 0)
|
|
par.fork();
|
|
}
|
|
}
|
|
else if (par.compareAndSetPendingCount(b, b|state))
|
|
break outer; // sib not ready
|
|
}
|
|
}
|
|
}
|
|
}
|
|
@java.io.Serial
|
|
private static final long serialVersionUID = 5293554502939613543L;
|
|
}
|
|
|
|
static final class LongCumulateTask extends CountedCompleter<Void> {
|
|
final long[] array;
|
|
@SuppressWarnings("serial") // Not statically typed as Serializable
|
|
final LongBinaryOperator function;
|
|
LongCumulateTask left, right;
|
|
long in, out;
|
|
final int lo, hi, origin, fence, threshold;
|
|
|
|
/** Root task constructor */
|
|
public LongCumulateTask(LongCumulateTask parent,
|
|
LongBinaryOperator function,
|
|
long[] array, int lo, int hi) {
|
|
super(parent);
|
|
this.function = function; this.array = array;
|
|
this.lo = this.origin = lo; this.hi = this.fence = hi;
|
|
int p;
|
|
this.threshold =
|
|
(p = (hi - lo) / (ForkJoinPool.getCommonPoolParallelism() << 3))
|
|
<= MIN_PARTITION ? MIN_PARTITION : p;
|
|
}
|
|
|
|
/** Subtask constructor */
|
|
LongCumulateTask(LongCumulateTask parent, LongBinaryOperator function,
|
|
long[] array, int origin, int fence, int threshold,
|
|
int lo, int hi) {
|
|
super(parent);
|
|
this.function = function; this.array = array;
|
|
this.origin = origin; this.fence = fence;
|
|
this.threshold = threshold;
|
|
this.lo = lo; this.hi = hi;
|
|
}
|
|
|
|
public final void compute() {
|
|
final LongBinaryOperator fn;
|
|
final long[] a;
|
|
if ((fn = this.function) == null || (a = this.array) == null)
|
|
throw new NullPointerException(); // hoist checks
|
|
int th = threshold, org = origin, fnc = fence, l, h;
|
|
LongCumulateTask t = this;
|
|
outer: while ((l = t.lo) >= 0 && (h = t.hi) <= a.length) {
|
|
if (h - l > th) {
|
|
LongCumulateTask lt = t.left, rt = t.right, f;
|
|
if (lt == null) { // first pass
|
|
int mid = (l + h) >>> 1;
|
|
f = rt = t.right =
|
|
new LongCumulateTask(t, fn, a, org, fnc, th, mid, h);
|
|
t = lt = t.left =
|
|
new LongCumulateTask(t, fn, a, org, fnc, th, l, mid);
|
|
}
|
|
else { // possibly refork
|
|
long pin = t.in;
|
|
lt.in = pin;
|
|
f = t = null;
|
|
if (rt != null) {
|
|
long lout = lt.out;
|
|
rt.in = (l == org ? lout :
|
|
fn.applyAsLong(pin, lout));
|
|
for (int c;;) {
|
|
if (((c = rt.getPendingCount()) & CUMULATE) != 0)
|
|
break;
|
|
if (rt.compareAndSetPendingCount(c, c|CUMULATE)){
|
|
t = rt;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
for (int c;;) {
|
|
if (((c = lt.getPendingCount()) & CUMULATE) != 0)
|
|
break;
|
|
if (lt.compareAndSetPendingCount(c, c|CUMULATE)) {
|
|
if (t != null)
|
|
f = t;
|
|
t = lt;
|
|
break;
|
|
}
|
|
}
|
|
if (t == null)
|
|
break;
|
|
}
|
|
if (f != null)
|
|
f.fork();
|
|
}
|
|
else {
|
|
int state; // Transition to sum, cumulate, or both
|
|
for (int b;;) {
|
|
if (((b = t.getPendingCount()) & FINISHED) != 0)
|
|
break outer; // already done
|
|
state = ((b & CUMULATE) != 0 ? FINISHED :
|
|
(l > org) ? SUMMED : (SUMMED|FINISHED));
|
|
if (t.compareAndSetPendingCount(b, b|state))
|
|
break;
|
|
}
|
|
|
|
long sum;
|
|
if (state != SUMMED) {
|
|
int first;
|
|
if (l == org) { // leftmost; no in
|
|
sum = a[org];
|
|
first = org + 1;
|
|
}
|
|
else {
|
|
sum = t.in;
|
|
first = l;
|
|
}
|
|
for (int i = first; i < h; ++i) // cumulate
|
|
a[i] = sum = fn.applyAsLong(sum, a[i]);
|
|
}
|
|
else if (h < fnc) { // skip rightmost
|
|
sum = a[l];
|
|
for (int i = l + 1; i < h; ++i) // sum only
|
|
sum = fn.applyAsLong(sum, a[i]);
|
|
}
|
|
else
|
|
sum = t.in;
|
|
t.out = sum;
|
|
for (LongCumulateTask par;;) { // propagate
|
|
if ((par = (LongCumulateTask)t.getCompleter()) == null) {
|
|
if ((state & FINISHED) != 0) // enable join
|
|
t.quietlyComplete();
|
|
break outer;
|
|
}
|
|
int b = par.getPendingCount();
|
|
if ((b & state & FINISHED) != 0)
|
|
t = par; // both done
|
|
else if ((b & state & SUMMED) != 0) { // both summed
|
|
int nextState; LongCumulateTask lt, rt;
|
|
if ((lt = par.left) != null &&
|
|
(rt = par.right) != null) {
|
|
long lout = lt.out;
|
|
par.out = (rt.hi == fnc ? lout :
|
|
fn.applyAsLong(lout, rt.out));
|
|
}
|
|
int refork = (((b & CUMULATE) == 0 &&
|
|
par.lo == org) ? CUMULATE : 0);
|
|
if ((nextState = b|state|refork) == b ||
|
|
par.compareAndSetPendingCount(b, nextState)) {
|
|
state = SUMMED; // drop finished
|
|
t = par;
|
|
if (refork != 0)
|
|
par.fork();
|
|
}
|
|
}
|
|
else if (par.compareAndSetPendingCount(b, b|state))
|
|
break outer; // sib not ready
|
|
}
|
|
}
|
|
}
|
|
}
|
|
@java.io.Serial
|
|
private static final long serialVersionUID = -5074099945909284273L;
|
|
}
|
|
|
|
static final class DoubleCumulateTask extends CountedCompleter<Void> {
|
|
final double[] array;
|
|
@SuppressWarnings("serial") // Not statically typed as Serializable
|
|
final DoubleBinaryOperator function;
|
|
DoubleCumulateTask left, right;
|
|
double in, out;
|
|
final int lo, hi, origin, fence, threshold;
|
|
|
|
/** Root task constructor */
|
|
public DoubleCumulateTask(DoubleCumulateTask parent,
|
|
DoubleBinaryOperator function,
|
|
double[] array, int lo, int hi) {
|
|
super(parent);
|
|
this.function = function; this.array = array;
|
|
this.lo = this.origin = lo; this.hi = this.fence = hi;
|
|
int p;
|
|
this.threshold =
|
|
(p = (hi - lo) / (ForkJoinPool.getCommonPoolParallelism() << 3))
|
|
<= MIN_PARTITION ? MIN_PARTITION : p;
|
|
}
|
|
|
|
/** Subtask constructor */
|
|
DoubleCumulateTask(DoubleCumulateTask parent, DoubleBinaryOperator function,
|
|
double[] array, int origin, int fence, int threshold,
|
|
int lo, int hi) {
|
|
super(parent);
|
|
this.function = function; this.array = array;
|
|
this.origin = origin; this.fence = fence;
|
|
this.threshold = threshold;
|
|
this.lo = lo; this.hi = hi;
|
|
}
|
|
|
|
public final void compute() {
|
|
final DoubleBinaryOperator fn;
|
|
final double[] a;
|
|
if ((fn = this.function) == null || (a = this.array) == null)
|
|
throw new NullPointerException(); // hoist checks
|
|
int th = threshold, org = origin, fnc = fence, l, h;
|
|
DoubleCumulateTask t = this;
|
|
outer: while ((l = t.lo) >= 0 && (h = t.hi) <= a.length) {
|
|
if (h - l > th) {
|
|
DoubleCumulateTask lt = t.left, rt = t.right, f;
|
|
if (lt == null) { // first pass
|
|
int mid = (l + h) >>> 1;
|
|
f = rt = t.right =
|
|
new DoubleCumulateTask(t, fn, a, org, fnc, th, mid, h);
|
|
t = lt = t.left =
|
|
new DoubleCumulateTask(t, fn, a, org, fnc, th, l, mid);
|
|
}
|
|
else { // possibly refork
|
|
double pin = t.in;
|
|
lt.in = pin;
|
|
f = t = null;
|
|
if (rt != null) {
|
|
double lout = lt.out;
|
|
rt.in = (l == org ? lout :
|
|
fn.applyAsDouble(pin, lout));
|
|
for (int c;;) {
|
|
if (((c = rt.getPendingCount()) & CUMULATE) != 0)
|
|
break;
|
|
if (rt.compareAndSetPendingCount(c, c|CUMULATE)){
|
|
t = rt;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
for (int c;;) {
|
|
if (((c = lt.getPendingCount()) & CUMULATE) != 0)
|
|
break;
|
|
if (lt.compareAndSetPendingCount(c, c|CUMULATE)) {
|
|
if (t != null)
|
|
f = t;
|
|
t = lt;
|
|
break;
|
|
}
|
|
}
|
|
if (t == null)
|
|
break;
|
|
}
|
|
if (f != null)
|
|
f.fork();
|
|
}
|
|
else {
|
|
int state; // Transition to sum, cumulate, or both
|
|
for (int b;;) {
|
|
if (((b = t.getPendingCount()) & FINISHED) != 0)
|
|
break outer; // already done
|
|
state = ((b & CUMULATE) != 0 ? FINISHED :
|
|
(l > org) ? SUMMED : (SUMMED|FINISHED));
|
|
if (t.compareAndSetPendingCount(b, b|state))
|
|
break;
|
|
}
|
|
|
|
double sum;
|
|
if (state != SUMMED) {
|
|
int first;
|
|
if (l == org) { // leftmost; no in
|
|
sum = a[org];
|
|
first = org + 1;
|
|
}
|
|
else {
|
|
sum = t.in;
|
|
first = l;
|
|
}
|
|
for (int i = first; i < h; ++i) // cumulate
|
|
a[i] = sum = fn.applyAsDouble(sum, a[i]);
|
|
}
|
|
else if (h < fnc) { // skip rightmost
|
|
sum = a[l];
|
|
for (int i = l + 1; i < h; ++i) // sum only
|
|
sum = fn.applyAsDouble(sum, a[i]);
|
|
}
|
|
else
|
|
sum = t.in;
|
|
t.out = sum;
|
|
for (DoubleCumulateTask par;;) { // propagate
|
|
if ((par = (DoubleCumulateTask)t.getCompleter()) == null) {
|
|
if ((state & FINISHED) != 0) // enable join
|
|
t.quietlyComplete();
|
|
break outer;
|
|
}
|
|
int b = par.getPendingCount();
|
|
if ((b & state & FINISHED) != 0)
|
|
t = par; // both done
|
|
else if ((b & state & SUMMED) != 0) { // both summed
|
|
int nextState; DoubleCumulateTask lt, rt;
|
|
if ((lt = par.left) != null &&
|
|
(rt = par.right) != null) {
|
|
double lout = lt.out;
|
|
par.out = (rt.hi == fnc ? lout :
|
|
fn.applyAsDouble(lout, rt.out));
|
|
}
|
|
int refork = (((b & CUMULATE) == 0 &&
|
|
par.lo == org) ? CUMULATE : 0);
|
|
if ((nextState = b|state|refork) == b ||
|
|
par.compareAndSetPendingCount(b, nextState)) {
|
|
state = SUMMED; // drop finished
|
|
t = par;
|
|
if (refork != 0)
|
|
par.fork();
|
|
}
|
|
}
|
|
else if (par.compareAndSetPendingCount(b, b|state))
|
|
break outer; // sib not ready
|
|
}
|
|
}
|
|
}
|
|
}
|
|
@java.io.Serial
|
|
private static final long serialVersionUID = -586947823794232033L;
|
|
}
|
|
|
|
static final class IntCumulateTask extends CountedCompleter<Void> {
|
|
final int[] array;
|
|
@SuppressWarnings("serial") // Not statically typed as Serializable
|
|
final IntBinaryOperator function;
|
|
IntCumulateTask left, right;
|
|
int in, out;
|
|
final int lo, hi, origin, fence, threshold;
|
|
|
|
/** Root task constructor */
|
|
public IntCumulateTask(IntCumulateTask parent,
|
|
IntBinaryOperator function,
|
|
int[] array, int lo, int hi) {
|
|
super(parent);
|
|
this.function = function; this.array = array;
|
|
this.lo = this.origin = lo; this.hi = this.fence = hi;
|
|
int p;
|
|
this.threshold =
|
|
(p = (hi - lo) / (ForkJoinPool.getCommonPoolParallelism() << 3))
|
|
<= MIN_PARTITION ? MIN_PARTITION : p;
|
|
}
|
|
|
|
/** Subtask constructor */
|
|
IntCumulateTask(IntCumulateTask parent, IntBinaryOperator function,
|
|
int[] array, int origin, int fence, int threshold,
|
|
int lo, int hi) {
|
|
super(parent);
|
|
this.function = function; this.array = array;
|
|
this.origin = origin; this.fence = fence;
|
|
this.threshold = threshold;
|
|
this.lo = lo; this.hi = hi;
|
|
}
|
|
|
|
public final void compute() {
|
|
final IntBinaryOperator fn;
|
|
final int[] a;
|
|
if ((fn = this.function) == null || (a = this.array) == null)
|
|
throw new NullPointerException(); // hoist checks
|
|
int th = threshold, org = origin, fnc = fence, l, h;
|
|
IntCumulateTask t = this;
|
|
outer: while ((l = t.lo) >= 0 && (h = t.hi) <= a.length) {
|
|
if (h - l > th) {
|
|
IntCumulateTask lt = t.left, rt = t.right, f;
|
|
if (lt == null) { // first pass
|
|
int mid = (l + h) >>> 1;
|
|
f = rt = t.right =
|
|
new IntCumulateTask(t, fn, a, org, fnc, th, mid, h);
|
|
t = lt = t.left =
|
|
new IntCumulateTask(t, fn, a, org, fnc, th, l, mid);
|
|
}
|
|
else { // possibly refork
|
|
int pin = t.in;
|
|
lt.in = pin;
|
|
f = t = null;
|
|
if (rt != null) {
|
|
int lout = lt.out;
|
|
rt.in = (l == org ? lout :
|
|
fn.applyAsInt(pin, lout));
|
|
for (int c;;) {
|
|
if (((c = rt.getPendingCount()) & CUMULATE) != 0)
|
|
break;
|
|
if (rt.compareAndSetPendingCount(c, c|CUMULATE)){
|
|
t = rt;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
for (int c;;) {
|
|
if (((c = lt.getPendingCount()) & CUMULATE) != 0)
|
|
break;
|
|
if (lt.compareAndSetPendingCount(c, c|CUMULATE)) {
|
|
if (t != null)
|
|
f = t;
|
|
t = lt;
|
|
break;
|
|
}
|
|
}
|
|
if (t == null)
|
|
break;
|
|
}
|
|
if (f != null)
|
|
f.fork();
|
|
}
|
|
else {
|
|
int state; // Transition to sum, cumulate, or both
|
|
for (int b;;) {
|
|
if (((b = t.getPendingCount()) & FINISHED) != 0)
|
|
break outer; // already done
|
|
state = ((b & CUMULATE) != 0 ? FINISHED :
|
|
(l > org) ? SUMMED : (SUMMED|FINISHED));
|
|
if (t.compareAndSetPendingCount(b, b|state))
|
|
break;
|
|
}
|
|
|
|
int sum;
|
|
if (state != SUMMED) {
|
|
int first;
|
|
if (l == org) { // leftmost; no in
|
|
sum = a[org];
|
|
first = org + 1;
|
|
}
|
|
else {
|
|
sum = t.in;
|
|
first = l;
|
|
}
|
|
for (int i = first; i < h; ++i) // cumulate
|
|
a[i] = sum = fn.applyAsInt(sum, a[i]);
|
|
}
|
|
else if (h < fnc) { // skip rightmost
|
|
sum = a[l];
|
|
for (int i = l + 1; i < h; ++i) // sum only
|
|
sum = fn.applyAsInt(sum, a[i]);
|
|
}
|
|
else
|
|
sum = t.in;
|
|
t.out = sum;
|
|
for (IntCumulateTask par;;) { // propagate
|
|
if ((par = (IntCumulateTask)t.getCompleter()) == null) {
|
|
if ((state & FINISHED) != 0) // enable join
|
|
t.quietlyComplete();
|
|
break outer;
|
|
}
|
|
int b = par.getPendingCount();
|
|
if ((b & state & FINISHED) != 0)
|
|
t = par; // both done
|
|
else if ((b & state & SUMMED) != 0) { // both summed
|
|
int nextState; IntCumulateTask lt, rt;
|
|
if ((lt = par.left) != null &&
|
|
(rt = par.right) != null) {
|
|
int lout = lt.out;
|
|
par.out = (rt.hi == fnc ? lout :
|
|
fn.applyAsInt(lout, rt.out));
|
|
}
|
|
int refork = (((b & CUMULATE) == 0 &&
|
|
par.lo == org) ? CUMULATE : 0);
|
|
if ((nextState = b|state|refork) == b ||
|
|
par.compareAndSetPendingCount(b, nextState)) {
|
|
state = SUMMED; // drop finished
|
|
t = par;
|
|
if (refork != 0)
|
|
par.fork();
|
|
}
|
|
}
|
|
else if (par.compareAndSetPendingCount(b, b|state))
|
|
break outer; // sib not ready
|
|
}
|
|
}
|
|
}
|
|
}
|
|
@java.io.Serial
|
|
private static final long serialVersionUID = 3731755594596840961L;
|
|
}
|
|
}
|