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 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 = 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:	1.18
Committed:	Thu Jan 15 18:42:39 2015 UTC (9 years, 3 months ago) by jsr166
Branch:	MAIN
CVS Tags:	HEAD
Changes since 1.17:	+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/publicdomain/zero/1.0/
5	*/
6
7	import java.util.concurrent.*;
8
9	/**
10	* Sample program using Gaussian Quadrature for numerical integration.
11	* 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	*/
15	public final class Integrate {
16
17	static final double errorTolerance = 1.0e-12;
18	/** for time conversion */
19	static final long NPS = (1000L * 1000 * 1000);
20
21	static final int SERIAL = -1;
22	static final int DYNAMIC = 0;
23	static final int FORK = 1;
24	static int forkPolicy = DYNAMIC;
25	static String forkArg = "dynamic";
26
27	/** the function to integrate */
28	static double computeFunction(double x) {
29	return (x * x + 1.0) * x;
30	}
31
32	static final double start = 0.0;
33	static final double end = 1536.0;
34
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 = 0;
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 Integrate3 threads <s[erial] \| d[ynamic] \| f[ork] - default d>");
58	return;
59	}
60	oneTest(procs);
61	oneTest(procs);
62	oneTest(procs);
63	}
64
65	static void oneTest(int procs) {
66	ForkJoinPool g = (procs == 0) ? new ForkJoinPool() :
67	new ForkJoinPool(procs);
68	System.out.println("Number of procs=" + g.getParallelism());
69	System.out.println("Integrating from " + start + " to " + end +
70	" forkPolicy = " + forkArg);
71	long lastTime = System.nanoTime();
72	for (int i = 0; i < 20; ++i) {
73	double a;
74	if (forkPolicy == SERIAL)
75	a = SQuad.computeArea(g, start, end);
76	else if (forkPolicy == FORK)
77	a = FQuad.computeArea(g, start, end);
78	else
79	a = DQuad.computeArea(g, start, end);
80	long now = System.nanoTime();
81	double s = ((double)(now - lastTime))/NPS;
82	lastTime = now;
83	System.out.printf("Calls/sec: %12d", (long) (calls / s));
84	System.out.printf(" Time: %7.3f", s);
85	System.out.printf(" Threads: %5d", g.getPoolSize());
86	// System.out.printf(" Area: %12.1f", a);
87	System.out.println();
88	}
89	System.out.println(g);
90	g.shutdown();
91	}
92
93	// Sequential version
94	static final class SQuad extends RecursiveAction {
95	static double computeArea(ForkJoinPool pool, double l, double r) {
96	SQuad q = new SQuad(l, r, 0);
97	pool.invoke(q);
98	return q.area;
99	}
100
101	final double left; // lower bound
102	final double right; // upper bound
103	double area;
104
105	SQuad(double l, double r, double a) {
106	this.left = l; this.right = r; this.area = a;
107	}
108
109	public final void compute() {
110	double l = left;
111	double r = right;
112	area = recEval(l, r, (l * l + 1.0) * l, (r * r + 1.0) * r, area);
113	}
114
115	static final double recEval(double l, double r, double fl,
116	double fr, double a) {
117	double h = (r - l) * 0.5;
118	double c = l + h;
119	double fc = (c * c + 1.0) * c;
120	double hh = h * 0.5;
121	double al = (fl + fc) * hh;
122	double ar = (fr + fc) * hh;
123	double alr = al + ar;
124	if (Math.abs(alr - a) <= errorTolerance)
125	return alr;
126	else
127	return recEval(c, r, fc, fr, ar) + recEval(l, c, fl, fc, al);
128	}
129
130	}
131
132	//....................................
133
134	// ForkJoin version
135	static final class FQuad extends RecursiveAction {
136	static double computeArea(ForkJoinPool pool, double l, double r) {
137	FQuad q = new FQuad(l, r, 0);
138	pool.invoke(q);
139	return q.area;
140	}
141
142	final double left; // lower bound
143	final double right; // upper bound
144	double area;
145
146	FQuad(double l, double r, double a) {
147	this.left = l; this.right = r; this.area = a;
148	}
149
150	public final void compute() {
151	double l = left;
152	double r = right;
153	area = recEval(l, r, (l * l + 1.0) * l, (r * r + 1.0) * r, area);
154	}
155
156	static final double recEval(double l, double r, double fl,
157	double fr, double a) {
158	double h = (r - l) * 0.5;
159	double c = l + h;
160	double fc = (c * c + 1.0) * c;
161	double hh = h * 0.5;
162	double al = (fl + fc) * hh;
163	double ar = (fr + fc) * hh;
164	double alr = al + ar;
165	if (Math.abs(alr - a) <= errorTolerance)
166	return alr;
167	FQuad q = new FQuad(l, c, al);
168	q.fork();
169	ar = recEval(c, r, fc, fr, ar);
170	if (!q.tryUnfork()) {
171	q.quietlyJoin();
172	return ar + q.area;
173	}
174	return ar + recEval(l, c, fl, fc, al);
175	}
176
177	}
178
179	// ...........................
180
181	// Version using on-demand Fork
182	static final class DQuad extends RecursiveAction {
183	static double computeArea(ForkJoinPool pool, double l, double r) {
184	DQuad q = new DQuad(l, r, 0);
185	pool.invoke(q);
186	return q.area;
187	}
188
189	final double left; // lower bound
190	final double right; // upper bound
191	double area;
192
193	DQuad(double l, double r, double a) {
194	this.left = l; this.right = r; this.area = a;
195	}
196
197	public final void compute() {
198	double l = left;
199	double r = right;
200	area = recEval(l, r, (l * l + 1.0) * l, (r * r + 1.0) * r, area);
201	}
202
203	static final double recEval(double l, double r, double fl,
204	double fr, double a) {
205	double h = (r - l) * 0.5;
206	double c = l + h;
207	double fc = (c * c + 1.0) * c;
208	double hh = h * 0.5;
209	double al = (fl + fc) * hh;
210	double ar = (fr + fc) * hh;
211	double alr = al + ar;
212	if (Math.abs(alr - a) <= errorTolerance)
213	return alr;
214	DQuad q = null;
215	if (getSurplusQueuedTaskCount() <= 3)
216	(q = new DQuad(l, c, al)).fork();
217	ar = recEval(c, r, fc, fr, ar);
218	if (q != null && !q.tryUnfork()) {
219	q.quietlyJoin();
220	return ar + q.area;
221	}
222	return ar + recEval(l, c, fl, fc, al);
223	}
224
225	}
226
227	}