test/loops/ScalarLongSort.java

/*
 * 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/
 */

import java.util.*;
import java.util.concurrent.*;

class ScalarLongSort {
    static final long NPS = (1000L * 1000 * 1000);

    static int THRESHOLD = -1;
    static final boolean warmup = true;

    public static void main(String[] args) throws Exception {
        int procs = 0;
        int n = 1 << 22;
        int reps = 20;
        int sreps = 2;
        int st = -1;
        try {
            if (args.length > 0)
                procs = Integer.parseInt(args[0]);
            if (args.length > 1)
                n = Integer.parseInt(args[1]);
            if (args.length > 2)
                reps = Integer.parseInt(args[2]);
            if (args.length > 3)
                st = Integer.parseInt(args[3]);
        }
        catch (Exception e) {
            System.out.println("Usage: java ScalarLongSort threads n reps sequential-threshold");
            return;
        }
        ForkJoinPool pool = (procs == 0) ? new ForkJoinPool() :
            new ForkJoinPool(procs);

        long[] a = new long[n];
        seqRandomFill(a, 0, n);

        if (warmup) {
            System.out.printf("Sorting %d longs, %d replications\n", n, 1);
            seqRandomFill(a, 0, n);
            long last = System.nanoTime();
            java.util.Arrays.sort(a);
            double elapsed = (double)(System.nanoTime() - last) / NPS;
            System.out.printf("Arrays.sort   time:  %7.3f\n", elapsed);
            checkSorted(a);
        }

        if (st <= 0) // for now hardwire 8 * #CPUs leaf tasks
            THRESHOLD = 1 + ((n + 7) >>> 3) / pool.getParallelism();
        else
            THRESHOLD = st;

        System.out.printf("Sorting %d longs, %d replications\n", n, reps);
        for (int i = 0; i < reps; ++i) {
            pool.invoke(new RandomFiller(a, 0, n));
            long last = System.nanoTime();
            pool.invoke(new Sorter(a, new long[n], 0, n));
            double elapsed = (double)(System.nanoTime() - last) / NPS;
            System.out.printf("Parallel sort time: %7.3f\n", elapsed);
            if (i == 0)
                checkSorted(a);
        }
        System.out.println(pool);

        System.out.printf("Sorting %d longs, %d replications\n", n, sreps);
        for (int i = 0; i < sreps; ++i) {
            pool.invoke(new RandomFiller(a, 0, n));
            long last = System.nanoTime();
            java.util.Arrays.sort(a);
            double elapsed = (double)(System.nanoTime() - last) / NPS;
            System.out.printf("Arrays.sort   time:  %7.3f\n", elapsed);
            if (i == 0)
                checkSorted(a);
        }
        System.out.println(pool);

        pool.shutdown();
    }

    static final class Sorter extends RecursiveAction {
        final long[] a;
        final long[] w;
        final int origin;
        final int n;
        Sorter(long[] a, long[] w, int origin, int n) {
            this.a = a; this.w = w; this.origin = origin; this.n = n;
        }

        public void compute() {
            int l = origin;
            if (n <= THRESHOLD)
                Arrays.sort(a, l, l+n);
            else { // divide in quarters to ensure sorted array in a not w
                int h = n >>> 1;
                int q = n >>> 2;
                int u = h + q;
                SubSorter rs = new SubSorter
                    (new Sorter(a, w, l+h, q),
                     new Sorter(a, w, l+u, n-u),
                     new Merger(a, w, l+h, q, l+u, n-u, l+h, null));
                rs.fork();
                Sorter rl = new Sorter(a, w, l+q, h-q);
                rl.fork();
                (new Sorter(a, w, l,   q)).compute();
                rl.join();
                (new Merger(a, w, l,   q, l+q, h-q, l, null)).compute();
                rs.join();
                new Merger(w, a, l, h, l+h, n-h, l, null).compute();
            }
        }
    }

    static final class SubSorter extends RecursiveAction {
        final Sorter left;
        final Sorter right;
        final Merger merger;
        SubSorter(Sorter left, Sorter right, Merger merger) {
            this.left = left; this.right = right; this.merger = merger;
        }
        public void compute() {
            right.fork();
            left.compute();
            right.join();
            merger.compute();
        }
    }

    static final class Merger extends RecursiveAction {
        final long[] a; final long[] w;
        final int lo; final int ln; final int ro; final int rn; final int wo;
        Merger next;
        Merger(long[] a, long[] w, int lo, int ln, int ro, int rn, int wo,
               Merger next) {
            this.a = a;    this.w = w;
            this.lo = lo;  this.ln = ln;
            this.ro = ro;  this.rn = rn;
            this.wo = wo;
            this.next = next;
        }

        /**
         * Merge left and right by splitting left in half,
         * and finding index of right closest to split point.
         * Uses left-spine decomposition to generate all
         * merge tasks before bottomming out at base case.
         */
        public final void compute() {
            Merger rights = null;
            int nleft = ln;
            int nright = rn;
            while (nleft > THRESHOLD) { //  && nright > (THRESHOLD >>> 3)) {
                int lh = nleft >>> 1;
                int splitIndex = lo + lh;
                long split = a[splitIndex];
                int rl = 0;
                int rh = nright;
                while (rl < rh) {
                    int mid = (rl + rh) >>> 1;
                    if (split <= a[ro + mid])
                        rh = mid;
                    else
                        rl = mid + 1;
                }
                (rights = new Merger(a, w, splitIndex, nleft-lh, ro+rh,
                                     nright-rh, wo+lh+rh, rights)).fork();
                nleft = lh;
                nright = rh;
            }

            merge(nleft, nright);
            if (rights != null)
                collectRights(rights);
        }

        final void merge(int nleft, int nright) {
            int l = lo;
            int lFence = lo + nleft;
            int r = ro;
            int rFence = ro + nright;
            int k = wo;
            while (l < lFence && r < rFence) {
                long al = a[l];
                long ar = a[r];
                long t;
                if (al <= ar) { ++l; t = al; } else { ++r; t = ar; }
                w[k++] = t;
            }
            while (l < lFence)
                w[k++] = a[l++];
            while (r < rFence)
                w[k++] = a[r++];
        }

        static void collectRights(Merger rt) {
            while (rt != null) {
                Merger next = rt.next;
                rt.next = null;
                if (rt.tryUnfork()) rt.compute(); else rt.join();
                rt = next;
            }
        }

    }

    static void checkSorted(long[] a) {
        int n = a.length;
        for (int i = 0; i < n - 1; i++) {
            if (a[i] > a[i+1]) {
                throw new Error("Unsorted at " + i + ": " +
                                a[i] + " / " + a[i+1]);
            }
        }
    }

    static void seqRandomFill(long[] array, int lo, int hi) {
        ThreadLocalRandom rng = ThreadLocalRandom.current();
        for (int i = lo; i < hi; ++i)
            array[i] = rng.nextLong();
    }

    static final class RandomFiller extends RecursiveAction {
        final long[] array;
        final int lo, hi;
        RandomFiller(long[] array, int lo, int hi) {
            this.array = array; this.lo = lo; this.hi = hi;
        }
        public void compute() {
            if (hi - lo <= THRESHOLD) {
                long[] a = array;
                ThreadLocalRandom rng = ThreadLocalRandom.current();
                for (int i = lo; i < hi; ++i)
                    a[i] = rng.nextLong();
            }
            else {
                int mid = (lo + hi) >>> 1;
                RandomFiller r = new RandomFiller(array, mid, hi);
                r.fork();
                (new RandomFiller(array, lo, mid)).compute();
                r.join();
            }
        }
    }
}
Revision:	1.14
Committed:	Mon Aug 10 03:13:33 2015 UTC (8 years, 8 months ago) by jsr166
Branch:	MAIN
CVS Tags:	HEAD
Changes since 1.13:	+0 -1 lines
Log Message:	delete unwanted blank lines
#	Content
1	/*
2	* Written by Doug Lea with assistance from members of JCP JSR-166
3	* Expert Group and released to the public domain, as explained at
4	* http://creativecommons.org/publicdomain/zero/1.0/
5	*/
6
7	import java.util.*;
8	import java.util.concurrent.*;
9
10	class ScalarLongSort {
11	static final long NPS = (1000L * 1000 * 1000);
12
13	static int THRESHOLD = -1;
14	static final boolean warmup = true;
15
16	public static void main(String[] args) throws Exception {
17	int procs = 0;
18	int n = 1 << 22;
19	int reps = 20;
20	int sreps = 2;
21	int st = -1;
22	try {
23	if (args.length > 0)
24	procs = Integer.parseInt(args[0]);
25	if (args.length > 1)
26	n = Integer.parseInt(args[1]);
27	if (args.length > 2)
28	reps = Integer.parseInt(args[2]);
29	if (args.length > 3)
30	st = Integer.parseInt(args[3]);
31	}
32	catch (Exception e) {
33	System.out.println("Usage: java ScalarLongSort threads n reps sequential-threshold");
34	return;
35	}
36	ForkJoinPool pool = (procs == 0) ? new ForkJoinPool() :
37	new ForkJoinPool(procs);
38
39	long[] a = new long[n];
40	seqRandomFill(a, 0, n);
41
42	if (warmup) {
43	System.out.printf("Sorting %d longs, %d replications\n", n, 1);
44	seqRandomFill(a, 0, n);
45	long last = System.nanoTime();
46	java.util.Arrays.sort(a);
47	double elapsed = (double)(System.nanoTime() - last) / NPS;
48	System.out.printf("Arrays.sort time: %7.3f\n", elapsed);
49	checkSorted(a);
50	}
51
52	if (st <= 0) // for now hardwire 8 * #CPUs leaf tasks
53	THRESHOLD = 1 + ((n + 7) >>> 3) / pool.getParallelism();
54	else
55	THRESHOLD = st;
56
57	System.out.printf("Sorting %d longs, %d replications\n", n, reps);
58	for (int i = 0; i < reps; ++i) {
59	pool.invoke(new RandomFiller(a, 0, n));
60	long last = System.nanoTime();
61	pool.invoke(new Sorter(a, new long[n], 0, n));
62	double elapsed = (double)(System.nanoTime() - last) / NPS;
63	System.out.printf("Parallel sort time: %7.3f\n", elapsed);
64	if (i == 0)
65	checkSorted(a);
66	}
67	System.out.println(pool);
68
69	System.out.printf("Sorting %d longs, %d replications\n", n, sreps);
70	for (int i = 0; i < sreps; ++i) {
71	pool.invoke(new RandomFiller(a, 0, n));
72	long last = System.nanoTime();
73	java.util.Arrays.sort(a);
74	double elapsed = (double)(System.nanoTime() - last) / NPS;
75	System.out.printf("Arrays.sort time: %7.3f\n", elapsed);
76	if (i == 0)
77	checkSorted(a);
78	}
79	System.out.println(pool);
80
81	pool.shutdown();
82	}
83
84	static final class Sorter extends RecursiveAction {
85	final long[] a;
86	final long[] w;
87	final int origin;
88	final int n;
89	Sorter(long[] a, long[] w, int origin, int n) {
90	this.a = a; this.w = w; this.origin = origin; this.n = n;
91	}
92
93	public void compute() {
94	int l = origin;
95	if (n <= THRESHOLD)
96	Arrays.sort(a, l, l+n);
97	else { // divide in quarters to ensure sorted array in a not w
98	int h = n >>> 1;
99	int q = n >>> 2;
100	int u = h + q;
101	SubSorter rs = new SubSorter
102	(new Sorter(a, w, l+h, q),
103	new Sorter(a, w, l+u, n-u),
104	new Merger(a, w, l+h, q, l+u, n-u, l+h, null));
105	rs.fork();
106	Sorter rl = new Sorter(a, w, l+q, h-q);
107	rl.fork();
108	(new Sorter(a, w, l, q)).compute();
109	rl.join();
110	(new Merger(a, w, l, q, l+q, h-q, l, null)).compute();
111	rs.join();
112	new Merger(w, a, l, h, l+h, n-h, l, null).compute();
113	}
114	}
115	}
116
117	static final class SubSorter extends RecursiveAction {
118	final Sorter left;
119	final Sorter right;
120	final Merger merger;
121	SubSorter(Sorter left, Sorter right, Merger merger) {
122	this.left = left; this.right = right; this.merger = merger;
123	}
124	public void compute() {
125	right.fork();
126	left.compute();
127	right.join();
128	merger.compute();
129	}
130	}
131
132	static final class Merger extends RecursiveAction {
133	final long[] a; final long[] w;
134	final int lo; final int ln; final int ro; final int rn; final int wo;
135	Merger next;
136	Merger(long[] a, long[] w, int lo, int ln, int ro, int rn, int wo,
137	Merger next) {
138	this.a = a; this.w = w;
139	this.lo = lo; this.ln = ln;
140	this.ro = ro; this.rn = rn;
141	this.wo = wo;
142	this.next = next;
143	}
144
145	/**
146	* Merge left and right by splitting left in half,
147	* and finding index of right closest to split point.
148	* Uses left-spine decomposition to generate all
149	* merge tasks before bottomming out at base case.
150	*/
151	public final void compute() {
152	Merger rights = null;
153	int nleft = ln;
154	int nright = rn;
155	while (nleft > THRESHOLD) { // && nright > (THRESHOLD >>> 3)) {
156	int lh = nleft >>> 1;
157	int splitIndex = lo + lh;
158	long split = a[splitIndex];
159	int rl = 0;
160	int rh = nright;
161	while (rl < rh) {
162	int mid = (rl + rh) >>> 1;
163	if (split <= a[ro + mid])
164	rh = mid;
165	else
166	rl = mid + 1;
167	}
168	(rights = new Merger(a, w, splitIndex, nleft-lh, ro+rh,
169	nright-rh, wo+lh+rh, rights)).fork();
170	nleft = lh;
171	nright = rh;
172	}
173
174	merge(nleft, nright);
175	if (rights != null)
176	collectRights(rights);
177	}
178
179	final void merge(int nleft, int nright) {
180	int l = lo;
181	int lFence = lo + nleft;
182	int r = ro;
183	int rFence = ro + nright;
184	int k = wo;
185	while (l < lFence && r < rFence) {
186	long al = a[l];
187	long ar = a[r];
188	long t;
189	if (al <= ar) { ++l; t = al; } else { ++r; t = ar; }
190	w[k++] = t;
191	}
192	while (l < lFence)
193	w[k++] = a[l++];
194	while (r < rFence)
195	w[k++] = a[r++];
196	}
197
198	static void collectRights(Merger rt) {
199	while (rt != null) {
200	Merger next = rt.next;
201	rt.next = null;
202	if (rt.tryUnfork()) rt.compute(); else rt.join();
203	rt = next;
204	}
205	}
206
207	}
208
209	static void checkSorted(long[] a) {
210	int n = a.length;
211	for (int i = 0; i < n - 1; i++) {
212	if (a[i] > a[i+1]) {
213	throw new Error("Unsorted at " + i + ": " +
214	a[i] + " / " + a[i+1]);
215	}
216	}
217	}
218
219	static void seqRandomFill(long[] array, int lo, int hi) {
220	ThreadLocalRandom rng = ThreadLocalRandom.current();
221	for (int i = lo; i < hi; ++i)
222	array[i] = rng.nextLong();
223	}
224
225	static final class RandomFiller extends RecursiveAction {
226	final long[] array;
227	final int lo, hi;
228	RandomFiller(long[] array, int lo, int hi) {
229	this.array = array; this.lo = lo; this.hi = hi;
230	}
231	public void compute() {
232	if (hi - lo <= THRESHOLD) {
233	long[] a = array;
234	ThreadLocalRandom rng = ThreadLocalRandom.current();
235	for (int i = lo; i < hi; ++i)
236	a[i] = rng.nextLong();
237	}
238	else {
239	int mid = (lo + hi) >>> 1;
240	RandomFiller r = new RandomFiller(array, mid, hi);
241	r.fork();
242	(new RandomFiller(array, lo, mid)).compute();
243	r.join();
244	}
245	}
246	}
247	}