test/loops/Integrate.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.*;

/**
 * Sample program using Guassian Quadrature for numerical integration.
 * This version uses a simplified hardwired function.  Inspired by a
 * <A href="http://www.cs.uga.edu/~dkl/filaments/dist.html">
 * Filaments</A> demo program.
 *
 */
public final class Integrate {

    static final double errorTolerance = 1.0e-12;
    /** for time conversion */
    static final long NPS = (1000L * 1000 * 1000);

    static final int SERIAL = -1;
    static final int DYNAMIC = 0;
    static final int FORK = 1;
    static int forkPolicy = DYNAMIC;
    static String forkArg = "dynamic";

    // the function to integrate
    static double computeFunction(double x) {
        return (x * x + 1.0) * x;
    }

    static final double start = 0.0;
    static final double end = 1536.0;
    /*
     * The number of recursive calls for
     * integrate from start to end.
     * (Empirically determined)
     */
    static final int calls = 263479047;

    public static void main(String[] args) throws Exception {
        int procs = 0;

        try {
            if (args.length > 0)
                procs = Integer.parseInt(args[0]);
            if (args.length > 1) {
                forkArg = args[1];
                if (forkArg.startsWith("s"))
                    forkPolicy = SERIAL;
                else if (forkArg.startsWith("f"))
                    forkPolicy = FORK;
            }
        }
        catch (Exception e) {
            System.out.println("Usage: java Integrate3 threads <s[erial] | d[ynamic] | f[ork] - default d>");
            return;
        }
        oneTest(procs);
        oneTest(procs);
        oneTest(procs);
    }

    static void oneTest(int procs) {
        ForkJoinPool g = (procs == 0) ? new ForkJoinPool() :
            new ForkJoinPool(procs);
        System.out.println("Number of procs=" + g.getParallelism());
        System.out.println("Integrating from " + start + " to " + end +
                           " forkPolicy = " + forkArg);
        long lastTime = System.nanoTime();
        for (int i = 0; i < 20; ++i) {
            double a;
            if (forkPolicy == SERIAL)
                a = SQuad.computeArea(g, start, end);
            else if (forkPolicy == FORK)
                a = FQuad.computeArea(g, start, end);
            else
                a = DQuad.computeArea(g, start, end);
            long now = System.nanoTime();
            double s = ((double)(now - lastTime))/NPS;
            lastTime = now;
            System.out.printf("Calls/sec: %12d", (long) (calls / s));
            System.out.printf(" Time: %7.3f", s);
            System.out.printf(" Threads: %5d", g.getPoolSize());
            //            System.out.printf(" Area: %12.1f", a);
            System.out.println();
        }
        System.out.println(g);
        g.shutdown();
    }


    // Sequential version
    static final class SQuad extends RecursiveAction {
        static double computeArea(ForkJoinPool pool, double l, double r) {
            SQuad q = new SQuad(l, r, 0);
            pool.invoke(q);
            return q.area;
        }

        final double left;       // lower bound
        final double right;      // upper bound
        double area;

        SQuad(double l, double r, double a) {
            this.left = l; this.right = r; this.area = a;
        }

        public final void compute() {
            double l = left;
            double r = right;
            area = recEval(l, r, (l * l + 1.0) * l, (r * r + 1.0) * r, area);
        }

        static final double recEval(double l, double r, double fl,
                                    double fr, double a) {
            double h = (r - l) * 0.5;
            double c = l + h;
            double fc = (c * c + 1.0) * c;
            double hh = h * 0.5;
            double al = (fl + fc) * hh;
            double ar = (fr + fc) * hh;
            double alr = al + ar;
            if (Math.abs(alr - a) <= errorTolerance)
                return alr;
            else
                return recEval(c, r, fc, fr, ar) + recEval(l, c, fl, fc, al);
        }

    }

    //....................................

    // ForkJoin version
    static final class FQuad extends RecursiveAction {
        static double computeArea(ForkJoinPool pool, double l, double r) {
            FQuad q = new FQuad(l, r, 0);
            pool.invoke(q);
            return q.area;
        }

        final double left;       // lower bound
        final double right;      // upper bound
        double area;

        FQuad(double l, double r, double a) {
            this.left = l; this.right = r; this.area = a;
        }

        public final void compute() {
            double l = left;
            double r = right;
            area = recEval(l, r, (l * l + 1.0) * l, (r * r + 1.0) * r, area);
        }

        static final double recEval(double l, double r, double fl,
                                    double fr, double a) {
            double h = (r - l) * 0.5;
            double c = l + h;
            double fc = (c * c + 1.0) * c;
            double hh = h * 0.5;
            double al = (fl + fc) * hh;
            double ar = (fr + fc) * hh;
            double alr = al + ar;
            if (Math.abs(alr - a) <= errorTolerance)
                return alr;
            FQuad q = new FQuad(l, c, al);
            q.fork();
            ar = recEval(c, r, fc, fr, ar);
            if (!q.tryUnfork()) {
                q.quietlyJoin();
                return ar + q.area;
            }
            return ar + recEval(l, c, fl, fc, al);
        }

    }

    // ...........................

    // Version using on-demand Fork
    static final class DQuad extends RecursiveAction {
        static double computeArea(ForkJoinPool pool, double l, double r) {
            DQuad q = new DQuad(l, r, 0);
            pool.invoke(q);
            return q.area;
        }

        final double left;       // lower bound
        final double right;      // upper bound
        double area;

        DQuad(double l, double r, double a) {
            this.left = l; this.right = r; this.area = a;
        }

        public final void compute() {
            double l = left;
            double r = right;
            area = recEval(l, r, (l * l + 1.0) * l, (r * r + 1.0) * r, area);
        }

        static final double recEval(double l, double r, double fl,
                                    double fr, double a) {
            double h = (r - l) * 0.5;
            double c = l + h;
            double fc = (c * c + 1.0) * c;
            double hh = h * 0.5;
            double al = (fl + fc) * hh;
            double ar = (fr + fc) * hh;
            double alr = al + ar;
            if (Math.abs(alr - a) <= errorTolerance)
                return alr;
            DQuad q = null;
            if (getSurplusQueuedTaskCount() <= 3)
                (q = new DQuad(l, c, al)).fork();
            ar = recEval(c, r, fc, fr, ar);
            if (q != null && !q.tryUnfork()) {
                q.quietlyJoin();
                return ar + q.area;
            }
            return ar + recEval(l, c, fl, fc, al);
        }

    }

}


Revision:	1.13
Committed:	Tue Mar 15 19:47:05 2011 UTC (13 years, 2 months ago) by jsr166
Branch:	MAIN
CVS Tags:	release-1_7_0
Changes since 1.12:	+1 -1 lines
Log Message:	Update Creative Commons license URL in legal notices
#	User	Rev	Content
1	dl	1.1	/*
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	jsr166	1.13	* http://creativecommons.org/publicdomain/zero/1.0/
5	dl	1.1	*/
6
7			import java.util.concurrent.*;
8
9			/**
10	dl	1.8	* Sample program using Guassian Quadrature for numerical integration.
11	dl	1.1	* This version uses a simplified hardwired function. Inspired by a
12			* <A href="http://www.cs.uga.edu/~dkl/filaments/dist.html">
13			* Filaments</A> demo program.
14	jsr166	1.9	*
15	dl	1.1	*/
16			public final class Integrate {
17
18			static final double errorTolerance = 1.0e-12;
19			/** for time conversion */
20			static final long NPS = (1000L * 1000 * 1000);
21
22			static final int SERIAL = -1;
23			static final int DYNAMIC = 0;
24			static final int FORK = 1;
25			static int forkPolicy = DYNAMIC;
26			static String forkArg = "dynamic";
27
28			// the function to integrate
29	jsr166	1.10	static double computeFunction(double x) {
30	dl	1.1	return (x * x + 1.0) * x;
31			}
32
33			static final double start = 0.0;
34			static final double end = 1536.0;
35	jsr166	1.9	/*
36			* The number of recursive calls for
37	dl	1.1	* integrate from start to end.
38			* (Empirically determined)
39			*/
40			static final int calls = 263479047;
41
42			public static void main(String[] args) throws Exception {
43	dl	1.8	int procs = 0;
44	dl	1.1
45			try {
46			if (args.length > 0)
47			procs = Integer.parseInt(args[0]);
48			if (args.length > 1) {
49			forkArg = args[1];
50			if (forkArg.startsWith("s"))
51			forkPolicy = SERIAL;
52			else if (forkArg.startsWith("f"))
53			forkPolicy = FORK;
54			}
55			}
56			catch (Exception e) {
57	dl	1.8	System.out.println("Usage: java Integrate3 threads <s[erial] \| d[ynamic] \| f[ork] - default d>");
58	dl	1.1	return;
59			}
60	dl	1.8	oneTest(procs);
61			oneTest(procs);
62			oneTest(procs);
63			}
64	dl	1.1
65	dl	1.8	static void oneTest(int procs) {
66	jsr166	1.12	ForkJoinPool g = (procs == 0) ? new ForkJoinPool() :
67	dl	1.8	new ForkJoinPool(procs);
68			System.out.println("Number of procs=" + g.getParallelism());
69	jsr166	1.9	System.out.println("Integrating from " + start + " to " + end +
70	dl	1.1	" forkPolicy = " + forkArg);
71			long lastTime = System.nanoTime();
72	dl	1.8	for (int i = 0; i < 20; ++i) {
73	dl	1.1	double a;
74			if (forkPolicy == SERIAL)
75			a = SQuad.computeArea(g, start, end);
76	jsr166	1.9	else if (forkPolicy == FORK)
77	dl	1.1	a = FQuad.computeArea(g, start, end);
78			else
79			a = DQuad.computeArea(g, start, end);
80			long now = System.nanoTime();
81	dl	1.8	double s = ((double)(now - lastTime))/NPS;
82	dl	1.1	lastTime = now;
83			System.out.printf("Calls/sec: %12d", (long) (calls / s));
84			System.out.printf(" Time: %7.3f", s);
85	dl	1.8	System.out.printf(" Threads: %5d", g.getPoolSize());
86			// System.out.printf(" Area: %12.1f", a);
87	dl	1.1	System.out.println();
88			}
89			System.out.println(g);
90			g.shutdown();
91			}
92
93
94			// Sequential version
95			static final class SQuad extends RecursiveAction {
96			static double computeArea(ForkJoinPool pool, double l, double r) {
97			SQuad q = new SQuad(l, r, 0);
98			pool.invoke(q);
99			return q.area;
100			}
101
102			final double left; // lower bound
103			final double right; // upper bound
104			double area;
105	jsr166	1.9
106	dl	1.1	SQuad(double l, double r, double a) {
107			this.left = l; this.right = r; this.area = a;
108			}
109	jsr166	1.9
110	dl	1.1	public final void compute() {
111			double l = left;
112			double r = right;
113			area = recEval(l, r, (l * l + 1.0) * l, (r * r + 1.0) * r, area);
114			}
115	jsr166	1.9
116	dl	1.1	static final double recEval(double l, double r, double fl,
117			double fr, double a) {
118			double h = (r - l) * 0.5;
119			double c = l + h;
120	jsr166	1.9	double fc = (c * c + 1.0) * c;
121	dl	1.1	double hh = h * 0.5;
122	jsr166	1.9	double al = (fl + fc) * hh;
123	dl	1.1	double ar = (fr + fc) * hh;
124			double alr = al + ar;
125			if (Math.abs(alr - a) <= errorTolerance)
126			return alr;
127			else
128			return recEval(c, r, fc, fr, ar) + recEval(l, c, fl, fc, al);
129			}
130
131			}
132
133			//....................................
134
135			// ForkJoin version
136			static final class FQuad extends RecursiveAction {
137			static double computeArea(ForkJoinPool pool, double l, double r) {
138			FQuad q = new FQuad(l, r, 0);
139			pool.invoke(q);
140			return q.area;
141			}
142
143			final double left; // lower bound
144			final double right; // upper bound
145			double area;
146	jsr166	1.9
147	dl	1.1	FQuad(double l, double r, double a) {
148			this.left = l; this.right = r; this.area = a;
149			}
150	jsr166	1.9
151	dl	1.1	public final void compute() {
152			double l = left;
153			double r = right;
154			area = recEval(l, r, (l * l + 1.0) * l, (r * r + 1.0) * r, area);
155			}
156	jsr166	1.9
157	dl	1.1	static final double recEval(double l, double r, double fl,
158			double fr, double a) {
159			double h = (r - l) * 0.5;
160			double c = l + h;
161	jsr166	1.9	double fc = (c * c + 1.0) * c;
162	dl	1.1	double hh = h * 0.5;
163	jsr166	1.9	double al = (fl + fc) * hh;
164	dl	1.1	double ar = (fr + fc) * hh;
165			double alr = al + ar;
166			if (Math.abs(alr - a) <= errorTolerance)
167			return alr;
168			FQuad q = new FQuad(l, c, al);
169			q.fork();
170			ar = recEval(c, r, fc, fr, ar);
171			if (!q.tryUnfork()) {
172	dl	1.7	q.quietlyJoin();
173	dl	1.1	return ar + q.area;
174			}
175			return ar + recEval(l, c, fl, fc, al);
176			}
177
178			}
179
180			// ...........................
181
182	jsr166	1.9	// Version using on-demand Fork
183	dl	1.1	static final class DQuad extends RecursiveAction {
184			static double computeArea(ForkJoinPool pool, double l, double r) {
185			DQuad q = new DQuad(l, r, 0);
186			pool.invoke(q);
187			return q.area;
188			}
189
190			final double left; // lower bound
191			final double right; // upper bound
192			double area;
193	jsr166	1.9
194	dl	1.1	DQuad(double l, double r, double a) {
195			this.left = l; this.right = r; this.area = a;
196			}
197	jsr166	1.9
198	dl	1.1	public final void compute() {
199			double l = left;
200			double r = right;
201			area = recEval(l, r, (l * l + 1.0) * l, (r * r + 1.0) * r, area);
202			}
203	jsr166	1.9
204	dl	1.1	static final double recEval(double l, double r, double fl,
205			double fr, double a) {
206			double h = (r - l) * 0.5;
207			double c = l + h;
208	jsr166	1.9	double fc = (c * c + 1.0) * c;
209	dl	1.1	double hh = h * 0.5;
210	jsr166	1.9	double al = (fl + fc) * hh;
211	dl	1.1	double ar = (fr + fc) * hh;
212			double alr = al + ar;
213			if (Math.abs(alr - a) <= errorTolerance)
214			return alr;
215			DQuad q = null;
216			if (getSurplusQueuedTaskCount() <= 3)
217			(q = new DQuad(l, c, al)).fork();
218			ar = recEval(c, r, fc, fr, ar);
219			if (q != null && !q.tryUnfork()) {
220	dl	1.7	q.quietlyJoin();
221	dl	1.1	return ar + q.area;
222			}
223			return ar + recEval(l, c, fl, fc, al);
224			}
225
226			}
227
228			}
229	dl	1.8
230	jsr166	1.9