1 /*
2  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
3  *
4  * This code is free software; you can redistribute it and/or modify it
5  * under the terms of the GNU General Public License version 2 only, as
6  * published by the Free Software Foundation.
7  *
8  * This code is distributed in the hope that it will be useful, but WITHOUT
9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
11  * version 2 for more details (a copy is included in the LICENSE file that
12  * accompanied this code).
13  *
14  * You should have received a copy of the GNU General Public License version
15  * 2 along with this work; if not, write to the Free Software Foundation,
16  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
17  *
18  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
19  * or visit www.oracle.com if you need additional information or have any
20  * questions.
21  */
22 
23 /*
24  * This file is available under and governed by the GNU General Public
25  * License version 2 only, as published by the Free Software Foundation.
26  * However, the following notice accompanied the original version of this
27  * file:
28  *
29  * Written by Doug Lea with assistance from members of JCP JSR-166
30  * Expert Group and released to the public domain, as explained at
31  * http://creativecommons.org/publicdomain/zero/1.0/
32  */
33 
34 /*
35  * @test
36  * @bug 4965960
37  * @summary  Exercise ExecutorCompletionService
38  * @library /test/lib
39  */
40 
41 import static java.util.concurrent.TimeUnit.MILLISECONDS;
42 
43 import java.util.concurrent.Callable;
44 import java.util.concurrent.ExecutorCompletionService;
45 import java.util.concurrent.ExecutorService;
46 import java.util.concurrent.Executors;
47 import jdk.test.lib.Utils;
48 
49 public class ExecutorCompletionServiceLoops {
50     static final long LONG_DELAY_MS = Utils.adjustTimeout(10_000);
51     static final int POOLSIZE = 10;
52     static final ExecutorService pool =
53         Executors.newFixedThreadPool(POOLSIZE);
54     static final ExecutorCompletionService<Integer> ecs =
55         new ExecutorCompletionService<>(pool);
56     static boolean print = false;
57 
main(String[] args)58     public static void main(String[] args) throws Exception {
59         int max = 8;
60         int base = 2000;
61 
62         if (args.length > 0)
63             max = Integer.parseInt(args[0]);
64 
65         System.out.println("Warmup...");
66         oneTest(base);
67         print = true;
68 
69         for (int i = 1; i <= max; i += (i+1) >>> 1) {
70             System.out.print("n: " + i * base);
71             oneTest(i * base);
72         }
73         pool.shutdown();
74         if (! pool.awaitTermination(LONG_DELAY_MS, MILLISECONDS))
75             throw new Error();
76    }
77 
78     static class Task implements Callable<Integer> {
call()79         public Integer call() {
80             int s = 0;
81             int l = System.identityHashCode(this);
82             for (int i = 0; i < 5; ++i) {
83                 l = LoopHelpers.compute2(l);
84                 s += LoopHelpers.compute1(l);
85             }
86             return new Integer(s);
87         }
88     }
89 
90     static class Producer implements Runnable {
91         final ExecutorCompletionService cs;
92         final int iters;
Producer(ExecutorCompletionService ecs, int i)93         Producer(ExecutorCompletionService ecs, int i) {
94             cs = ecs;
95             iters = i;
96         }
run()97         public void run() {
98             for (int i = 0; i < iters; ++i)
99                 ecs.submit(new Task());
100         }
101     }
102 
oneTest(int iters)103     static void oneTest(int iters) throws Exception {
104         long startTime = System.nanoTime();
105         new Thread(new Producer(ecs, iters)).start();
106 
107         int r = 0;
108         for (int i = 0; i < iters; ++i)
109             r += ecs.take().get().intValue();
110 
111         long elapsed = System.nanoTime() - startTime;
112         long tpi = elapsed/ iters;
113 
114         if (print)
115             System.out.println("\t: " + LoopHelpers.rightJustify(tpi) + " ns per task");
116 
117         if (r == 0) // avoid overoptimization
118             System.out.println("useless result: " + r);
119     }
120 
121 }
122