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 Integrate3 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:	1.3
Committed:	Thu Oct 29 23:11:03 2009 UTC (14 years, 6 months ago) by jsr166
Branch:	MAIN
Changes since 1.2:	+1 -1 lines
Log Message:	typos
#	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/licenses/publicdomain
5	*/
6
7	//import jsr166y.*;
8	import java.util.concurrent.*;
9
10	/**
11	* Sample program using Gaussian Quadrature for numerical integration.
12	* 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	*/
17	public final class Integrate {
18
19	static final double errorTolerance = 1.0e-12;
20	/** for time conversion */
21	static final long NPS = (1000L * 1000 * 1000);
22
23	static final int SERIAL = -1;
24	static final int DYNAMIC = 0;
25	static final int FORK = 1;
26	static int forkPolicy = DYNAMIC;
27	static String forkArg = "dynamic";
28
29	// the function to integrate
30	static double computeFunction(double x) {
31	return (x * x + 1.0) * x;
32	}
33
34	static final double start = 0.0;
35	static final double end = 1536.0;
36	/*
37	* The number of recursive calls for
38	* integrate from start to end.
39	* (Empirically determined)
40	*/
41	static final int calls = 263479047;
42
43	public static void main(String[] args) throws Exception {
44	int procs = Runtime.getRuntime().availableProcessors();
45
46	try {
47	if (args.length > 0)
48	procs = Integer.parseInt(args[0]);
49	if (args.length > 1) {
50	forkArg = args[1];
51	if (forkArg.startsWith("s"))
52	forkPolicy = SERIAL;
53	else if (forkArg.startsWith("f"))
54	forkPolicy = FORK;
55	}
56	}
57	catch (Exception e) {
58	System.out.println("Usage: java Integrate3 threads <s[erial] \| d[ynamic] \| f[ork] - default d>");
59	return;
60	}
61
62	ForkJoinPool g = new ForkJoinPool(procs);
63	System.out.println("Integrating from " + start + " to " + end +
64	" forkPolicy = " + forkArg);
65	long lastTime = System.nanoTime();
66	for (int i = 0; i < 10; ++i) {
67	double a;
68	if (forkPolicy == SERIAL)
69	a = SQuad.computeArea(g, start, end);
70	else if (forkPolicy == FORK)
71	a = FQuad.computeArea(g, start, end);
72	else
73	a = DQuad.computeArea(g, start, end);
74	long now = System.nanoTime();
75	double s = ((double)(now - lastTime))/NPS;
76	lastTime = now;
77	System.out.printf("Calls/sec: %12d", (long) (calls / s));
78	System.out.printf(" Time: %7.3f", s);
79	System.out.printf(" Area: %12.1f", a);
80	System.out.println();
81	}
82	System.out.println(g);
83	g.shutdown();
84	}
85
86
87	// Sequential version
88	static final class SQuad extends RecursiveAction {
89	static double computeArea(ForkJoinPool pool, double l, double r) {
90	SQuad q = new SQuad(l, r, 0);
91	pool.invoke(q);
92	return q.area;
93	}
94
95	final double left; // lower bound
96	final double right; // upper bound
97	double area;
98
99	SQuad(double l, double r, double a) {
100	this.left = l; this.right = r; this.area = a;
101	}
102
103	public final void compute() {
104	double l = left;
105	double r = right;
106	area = recEval(l, r, (l * l + 1.0) * l, (r * r + 1.0) * r, area);
107	}
108
109	static final double recEval(double l, double r, double fl,
110	double fr, double a) {
111	double h = (r - l) * 0.5;
112	double c = l + h;
113	double fc = (c * c + 1.0) * c;
114	double hh = h * 0.5;
115	double al = (fl + fc) * hh;
116	double ar = (fr + fc) * hh;
117	double alr = al + ar;
118	if (Math.abs(alr - a) <= errorTolerance)
119	return alr;
120	else
121	return recEval(c, r, fc, fr, ar) + recEval(l, c, fl, fc, al);
122	}
123
124	}
125
126	//....................................
127
128	// ForkJoin version
129	static final class FQuad extends RecursiveAction {
130	static double computeArea(ForkJoinPool pool, double l, double r) {
131	FQuad q = new FQuad(l, r, 0);
132	pool.invoke(q);
133	return q.area;
134	}
135
136	final double left; // lower bound
137	final double right; // upper bound
138	double area;
139
140	FQuad(double l, double r, double a) {
141	this.left = l; this.right = r; this.area = a;
142	}
143
144	public final void compute() {
145	double l = left;
146	double r = right;
147	area = recEval(l, r, (l * l + 1.0) * l, (r * r + 1.0) * r, area);
148	}
149
150	static final double recEval(double l, double r, double fl,
151	double fr, double a) {
152	double h = (r - l) * 0.5;
153	double c = l + h;
154	double fc = (c * c + 1.0) * c;
155	double hh = h * 0.5;
156	double al = (fl + fc) * hh;
157	double ar = (fr + fc) * hh;
158	double alr = al + ar;
159	if (Math.abs(alr - a) <= errorTolerance)
160	return alr;
161	FQuad q = new FQuad(l, c, al);
162	q.fork();
163	ar = recEval(c, r, fc, fr, ar);
164	if (!q.tryUnfork()) {
165	q.quietlyHelpJoin();
166	return ar + q.area;
167	}
168	return ar + recEval(l, c, fl, fc, al);
169	}
170
171	}
172
173	// ...........................
174
175	// Version using on-demand Fork
176	static final class DQuad extends RecursiveAction {
177	static double computeArea(ForkJoinPool pool, double l, double r) {
178	DQuad q = new DQuad(l, r, 0);
179	pool.invoke(q);
180	return q.area;
181	}
182
183	final double left; // lower bound
184	final double right; // upper bound
185	double area;
186
187	DQuad(double l, double r, double a) {
188	this.left = l; this.right = r; this.area = a;
189	}
190
191	public final void compute() {
192	double l = left;
193	double r = right;
194	area = recEval(l, r, (l * l + 1.0) * l, (r * r + 1.0) * r, area);
195	}
196
197	static final double recEval(double l, double r, double fl,
198	double fr, double a) {
199	double h = (r - l) * 0.5;
200	double c = l + h;
201	double fc = (c * c + 1.0) * c;
202	double hh = h * 0.5;
203	double al = (fl + fc) * hh;
204	double ar = (fr + fc) * hh;
205	double alr = al + ar;
206	if (Math.abs(alr - a) <= errorTolerance)
207	return alr;
208	DQuad q = null;
209	if (getSurplusQueuedTaskCount() <= 3)
210	(q = new DQuad(l, c, al)).fork();
211	ar = recEval(c, r, fc, fr, ar);
212	if (q != null && !q.tryUnfork()) {
213	q.quietlyHelpJoin();
214	return ar + q.area;
215	}
216	return ar + recEval(l, c, fl, fc, al);
217	}
218
219	}
220
221	}