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/licenses/publicdomain
 */

//import jsr166y.*;
import java.util.concurrent.*;

/**
 * Sample program using Gaussian 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 = Runtime.getRuntime().availableProcessors();

        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 Integrate threads <s[erial] | d[ynamic] | f[ork] - default d>");
            return;
        }

        ForkJoinPool g = new ForkJoinPool(procs);
        System.out.println("Integrating from " + start + " to " + end +
                           " forkPolicy = " + forkArg);
        long lastTime = System.nanoTime();
        for (int i = 0; i < 10; ++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(" 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.quietlyHelpJoin();
                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.quietlyHelpJoin();
                return ar + q.area;
            }
            return ar + recEval(l, c, fl, fc, al);
        }

    }

}
Revision:	1.5
Committed:	Tue Nov 3 00:02:00 2009 UTC (14 years, 6 months ago) by jsr166
Branch:	MAIN
Changes since 1.4:	+0 -1 lines
Log Message:	whitespace
#	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			* http://creativecommons.org/licenses/publicdomain
5			*/
6
7			//import jsr166y.*;
8			import java.util.concurrent.*;
9
10			/**
11	jsr166	1.3	* Sample program using Gaussian Quadrature for numerical integration.
12	dl	1.1	* This version uses a simplified hardwired function. Inspired by a
13			* <A href="http://www.cs.uga.edu/~dkl/filaments/dist.html">
14			* Filaments</A> demo program.
15			*/
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			static double computeFunction(double x) {
30			return (x * x + 1.0) * x;
31			}
32
33			static final double start = 0.0;
34			static final double end = 1536.0;
35	jsr166	1.2	/*
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			int procs = Runtime.getRuntime().availableProcessors();
44
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	jsr166	1.4	System.out.println("Usage: java Integrate threads <s[erial] \| d[ynamic] \| f[ork] - default d>");
58	dl	1.1	return;
59			}
60
61			ForkJoinPool g = new ForkJoinPool(procs);
62	jsr166	1.2	System.out.println("Integrating from " + start + " to " + end +
63	dl	1.1	" forkPolicy = " + forkArg);
64			long lastTime = System.nanoTime();
65			for (int i = 0; i < 10; ++i) {
66			double a;
67			if (forkPolicy == SERIAL)
68			a = SQuad.computeArea(g, start, end);
69	jsr166	1.2	else if (forkPolicy == FORK)
70	dl	1.1	a = FQuad.computeArea(g, start, end);
71			else
72			a = DQuad.computeArea(g, start, end);
73			long now = System.nanoTime();
74			double s = ((double)(now - lastTime))/NPS;
75			lastTime = now;
76			System.out.printf("Calls/sec: %12d", (long) (calls / s));
77			System.out.printf(" Time: %7.3f", s);
78			System.out.printf(" Area: %12.1f", a);
79			System.out.println();
80			}
81			System.out.println(g);
82			g.shutdown();
83			}
84
85
86			// Sequential version
87			static final class SQuad extends RecursiveAction {
88			static double computeArea(ForkJoinPool pool, double l, double r) {
89			SQuad q = new SQuad(l, r, 0);
90			pool.invoke(q);
91			return q.area;
92			}
93
94			final double left; // lower bound
95			final double right; // upper bound
96			double area;
97	jsr166	1.2
98	dl	1.1	SQuad(double l, double r, double a) {
99			this.left = l; this.right = r; this.area = a;
100			}
101	jsr166	1.2
102	dl	1.1	public final void compute() {
103			double l = left;
104			double r = right;
105			area = recEval(l, r, (l * l + 1.0) * l, (r * r + 1.0) * r, area);
106			}
107	jsr166	1.2
108	dl	1.1	static final double recEval(double l, double r, double fl,
109			double fr, double a) {
110			double h = (r - l) * 0.5;
111			double c = l + h;
112	jsr166	1.2	double fc = (c * c + 1.0) * c;
113	dl	1.1	double hh = h * 0.5;
114	jsr166	1.2	double al = (fl + fc) * hh;
115	dl	1.1	double ar = (fr + fc) * hh;
116			double alr = al + ar;
117			if (Math.abs(alr - a) <= errorTolerance)
118			return alr;
119			else
120			return recEval(c, r, fc, fr, ar) + recEval(l, c, fl, fc, al);
121			}
122
123			}
124
125			//....................................
126
127			// ForkJoin version
128			static final class FQuad extends RecursiveAction {
129			static double computeArea(ForkJoinPool pool, double l, double r) {
130			FQuad q = new FQuad(l, r, 0);
131			pool.invoke(q);
132			return q.area;
133			}
134
135			final double left; // lower bound
136			final double right; // upper bound
137			double area;
138	jsr166	1.2
139	dl	1.1	FQuad(double l, double r, double a) {
140			this.left = l; this.right = r; this.area = a;
141			}
142	jsr166	1.2
143	dl	1.1	public final void compute() {
144			double l = left;
145			double r = right;
146			area = recEval(l, r, (l * l + 1.0) * l, (r * r + 1.0) * r, area);
147			}
148	jsr166	1.2
149	dl	1.1	static final double recEval(double l, double r, double fl,
150			double fr, double a) {
151			double h = (r - l) * 0.5;
152			double c = l + h;
153	jsr166	1.2	double fc = (c * c + 1.0) * c;
154	dl	1.1	double hh = h * 0.5;
155	jsr166	1.2	double al = (fl + fc) * hh;
156	dl	1.1	double ar = (fr + fc) * hh;
157			double alr = al + ar;
158			if (Math.abs(alr - a) <= errorTolerance)
159			return alr;
160			FQuad q = new FQuad(l, c, al);
161			q.fork();
162			ar = recEval(c, r, fc, fr, ar);
163			if (!q.tryUnfork()) {
164			q.quietlyHelpJoin();
165			return ar + q.area;
166			}
167			return ar + recEval(l, c, fl, fc, al);
168			}
169
170			}
171
172			// ...........................
173
174	jsr166	1.2	// Version using on-demand Fork
175	dl	1.1	static final class DQuad extends RecursiveAction {
176			static double computeArea(ForkJoinPool pool, double l, double r) {
177			DQuad q = new DQuad(l, r, 0);
178			pool.invoke(q);
179			return q.area;
180			}
181
182			final double left; // lower bound
183			final double right; // upper bound
184			double area;
185	jsr166	1.2
186	dl	1.1	DQuad(double l, double r, double a) {
187			this.left = l; this.right = r; this.area = a;
188			}
189	jsr166	1.2
190	dl	1.1	public final void compute() {
191			double l = left;
192			double r = right;
193			area = recEval(l, r, (l * l + 1.0) * l, (r * r + 1.0) * r, area);
194			}
195	jsr166	1.2
196	dl	1.1	static final double recEval(double l, double r, double fl,
197			double fr, double a) {
198			double h = (r - l) * 0.5;
199			double c = l + h;
200	jsr166	1.2	double fc = (c * c + 1.0) * c;
201	dl	1.1	double hh = h * 0.5;
202	jsr166	1.2	double al = (fl + fc) * hh;
203	dl	1.1	double ar = (fr + fc) * hh;
204			double alr = al + ar;
205			if (Math.abs(alr - a) <= errorTolerance)
206			return alr;
207			DQuad q = null;
208			if (getSurplusQueuedTaskCount() <= 3)
209			(q = new DQuad(l, c, al)).fork();
210			ar = recEval(c, r, fc, fr, ar);
211			if (q != null && !q.tryUnfork()) {
212			q.quietlyHelpJoin();
213			return ar + q.area;
214			}
215			return ar + recEval(l, c, fl, fc, al);
216			}
217
218			}
219
220			}