test/loops/BoxedLongSort.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.concurrent.*;
import java.util.*;

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

    static int THRESHOLD;
    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;
        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[1]);
        }
        catch (Exception e) {
            System.out.println("Usage: java BoxedLongSort threads n reps");
            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);
            Collections.shuffle(Arrays.asList(a));
            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);
        }

        // for now hardwire 8 * #CPUs leaf tasks
        THRESHOLD = 1 + ((n + 7) >>> 3) / pool.getParallelism();
        //        THRESHOLD = 1 + ((n + 15) >>> 4) / pool.getParallelism();
        //        THRESHOLD = 1 + ((n + 31) >>> 5) / pool.getParallelism();

        System.out.printf("Sorting %d longs, %d replications\n", n, reps);
        for (int i = 0; i < reps; ++i) {
            Collections.shuffle(Arrays.asList(a));
            //            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) {
            Collections.shuffle(Arrays.asList(a));
            //            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:	1.6
Committed:	Mon Oct 10 16:59:04 2011 UTC (12 years, 7 months ago) by jsr166
Branch:	MAIN
Changes since 1.5:	+2 -2 lines
Log Message:	whitespace
#	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.concurrent.*;
8	import java.util.*;
9
10	class BoxedLongSort {
11	static final long NPS = (1000L * 1000 * 1000);
12
13	static int THRESHOLD;
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	try {
22	if (args.length > 0)
23	procs = Integer.parseInt(args[0]);
24	if (args.length > 1)
25	n = Integer.parseInt(args[1]);
26	if (args.length > 2)
27	reps = Integer.parseInt(args[1]);
28	}
29	catch (Exception e) {
30	System.out.println("Usage: java BoxedLongSort threads n reps");
31	return;
32	}
33	ForkJoinPool pool = (procs == 0) ? new ForkJoinPool() :
34	new ForkJoinPool(procs);
35
36	Long[] a = new Long[n];
37	seqRandomFill(a, 0, n);
38
39	if (warmup) {
40	System.out.printf("Sorting %d longs, %d replications\n", n, 1);
41	Collections.shuffle(Arrays.asList(a));
42	long last = System.nanoTime();
43	java.util.Arrays.sort(a);
44	double elapsed = (double)(System.nanoTime() - last) / NPS;
45	System.out.printf("Arrays.sort time: %7.3f\n", elapsed);
46	checkSorted(a);
47	}
48
49	// for now hardwire 8 * #CPUs leaf tasks
50	THRESHOLD = 1 + ((n + 7) >>> 3) / pool.getParallelism();
51	// THRESHOLD = 1 + ((n + 15) >>> 4) / pool.getParallelism();
52	// THRESHOLD = 1 + ((n + 31) >>> 5) / pool.getParallelism();
53
54	System.out.printf("Sorting %d longs, %d replications\n", n, reps);
55	for (int i = 0; i < reps; ++i) {
56	Collections.shuffle(Arrays.asList(a));
57	// pool.invoke(new RandomFiller(a, 0, n));
58	long last = System.nanoTime();
59	pool.invoke(new Sorter(a, new Long[n], 0, n));
60	double elapsed = (double)(System.nanoTime() - last) / NPS;
61	System.out.printf("Parallel sort time: %7.3f\n", elapsed);
62	if (i == 0)
63	checkSorted(a);
64	}
65	System.out.println(pool);
66
67	System.out.printf("Sorting %d longs, %d replications\n", n, sreps);
68	for (int i = 0; i < sreps; ++i) {
69	Collections.shuffle(Arrays.asList(a));
70	// pool.invoke(new RandomFiller(a, 0, n));
71	long last = System.nanoTime();
72	java.util.Arrays.sort(a);
73	double elapsed = (double)(System.nanoTime() - last) / NPS;
74	System.out.printf("Arrays.sort time: %7.3f\n", elapsed);
75	if (i == 0)
76	checkSorted(a);
77	}
78	System.out.println(pool);
79	pool.shutdown();
80	}
81
82	static final class Sorter extends RecursiveAction {
83	final Long[] a;
84	final Long[] w;
85	final int origin;
86	final int n;
87	Sorter(Long[] a, Long[] w, int origin, int n) {
88	this.a = a; this.w = w; this.origin = origin; this.n = n;
89	}
90
91	public void compute() {
92	int l = origin;
93	if (n <= THRESHOLD)
94	Arrays.sort(a, l, l+n);
95	else { // divide in quarters to ensure sorted array in a not w
96	int h = n >>> 1;
97	int q = n >>> 2;
98	int u = h + q;
99	SubSorter rs = new SubSorter
100	(new Sorter(a, w, l+h, q),
101	new Sorter(a, w, l+u, n-u),
102	new Merger(a, w, l+h, q, l+u, n-u, l+h, null));
103	rs.fork();
104	Sorter rl = new Sorter(a, w, l+q, h-q);
105	rl.fork();
106	(new Sorter(a, w, l, q)).compute();
107	rl.join();
108	(new Merger(a, w, l, q, l+q, h-q, l, null)).compute();
109	rs.join();
110	new Merger(w, a, l, h, l+h, n-h, l, null).compute();
111	}
112	}
113	}
114
115	static final class SubSorter extends RecursiveAction {
116	final Sorter left;
117	final Sorter right;
118	final Merger merger;
119	SubSorter(Sorter left, Sorter right, Merger merger) {
120	this.left = left; this.right = right; this.merger = merger;
121	}
122	public void compute() {
123	right.fork();
124	left.compute();
125	right.join();
126	merger.compute();
127	}
128	}
129
130	static final class Merger extends RecursiveAction {
131	final Long[] a; final Long[] w;
132	final int lo; final int ln; final int ro; final int rn; final int wo;
133	Merger next;
134	Merger(Long[] a, Long[] w, int lo, int ln, int ro, int rn, int wo,
135	Merger next) {
136	this.a = a; this.w = w;
137	this.lo = lo; this.ln = ln;
138	this.ro = ro; this.rn = rn;
139	this.wo = wo;
140	this.next = next;
141	}
142
143	/**
144	* Merge left and right by splitting left in half,
145	* and finding index of right closest to split point.
146	* Uses left-spine decomposition to generate all
147	* merge tasks before bottomming out at base case.
148	*
149	*/
150	public final void compute() {
151	Merger rights = null;
152	int nleft = ln;
153	int nright = rn;
154	while (nleft > THRESHOLD) { // && nright > (THRESHOLD >>> 3)) {
155	int lh = nleft >>> 1;
156	int splitIndex = lo + lh;
157	Long split = a[splitIndex];
158	int rl = 0;
159	int rh = nright;
160	while (rl < rh) {
161	int mid = (rl + rh) >>> 1;
162	if (split <= a[ro + mid])
163	rh = mid;
164	else
165	rl = mid + 1;
166	}
167	(rights = new Merger(a, w, splitIndex, nleft-lh, ro+rh,
168	nright-rh, wo+lh+rh, rights)).fork();
169	nleft = lh;
170	nright = rh;
171	}
172
173	merge(nleft, nright);
174	if (rights != null)
175	collectRights(rights);
176
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
248
249	}