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
#	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	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	/*
36	* The number of recursive calls for
37	* 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	System.out.println("Usage: java Integrate threads <s[erial] \| d[ynamic] \| f[ork] - default d>");
58	return;
59	}
60
61	ForkJoinPool g = new ForkJoinPool(procs);
62	System.out.println("Integrating from " + start + " to " + end +
63	" 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	else if (forkPolicy == FORK)
70	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
98	SQuad(double l, double r, double a) {
99	this.left = l; this.right = r; this.area = a;
100	}
101
102	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
108	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	double fc = (c * c + 1.0) * c;
113	double hh = h * 0.5;
114	double al = (fl + fc) * hh;
115	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
139	FQuad(double l, double r, double a) {
140	this.left = l; this.right = r; this.area = a;
141	}
142
143	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
149	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	double fc = (c * c + 1.0) * c;
154	double hh = h * 0.5;
155	double al = (fl + fc) * hh;
156	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	// Version using on-demand Fork
175	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
186	DQuad(double l, double r, double a) {
187	this.left = l; this.right = r; this.area = a;
188	}
189
190	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
196	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	double fc = (c * c + 1.0) * c;
201	double hh = h * 0.5;
202	double al = (fl + fc) * hh;
203	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	}