1 |
/* |
2 |
* @test |
3 |
* @synopsis multiple producers and single consumer using blocking queues |
4 |
*/ |
5 |
/* |
6 |
* Written by Doug Lea with assistance from members of JCP JSR-166 |
7 |
* Expert Group and released to the public domain. Use, modify, and |
8 |
* redistribute this code in any way without acknowledgement. |
9 |
*/ |
10 |
|
11 |
import java.util.concurrent.*; |
12 |
|
13 |
public class MultipleProducersSingleConsumerLoops { |
14 |
static final int CAPACITY = 100; |
15 |
static final ExecutorService pool = Executors.newCachedThreadPool(); |
16 |
static boolean print = false; |
17 |
static int producerSum; |
18 |
static int consumerSum; |
19 |
|
20 |
static synchronized void addProducerSum(int x) { |
21 |
producerSum += x; |
22 |
} |
23 |
|
24 |
static synchronized void addConsumerSum(int x) { |
25 |
consumerSum += x; |
26 |
} |
27 |
|
28 |
static synchronized void checkSum() { |
29 |
if (producerSum != consumerSum) |
30 |
throw new Error("CheckSum mismatch"); |
31 |
} |
32 |
|
33 |
public static void main(String[] args) throws Exception { |
34 |
int maxProducers = 100; |
35 |
int iters = 100000; |
36 |
|
37 |
if (args.length > 0) |
38 |
maxProducers = Integer.parseInt(args[0]); |
39 |
|
40 |
print = false; |
41 |
System.out.println("Warmup..."); |
42 |
oneTest(1, 10000); |
43 |
Thread.sleep(100); |
44 |
oneTest(2, 10000); |
45 |
Thread.sleep(100); |
46 |
print = true; |
47 |
|
48 |
for (int i = 1; i <= maxProducers; i += (i+1) >>> 1) { |
49 |
System.out.println("Producers:" + i); |
50 |
oneTest(i, iters); |
51 |
Thread.sleep(100); |
52 |
} |
53 |
pool.shutdown(); |
54 |
} |
55 |
|
56 |
static void oneTest(int producers, int iters) throws Exception { |
57 |
if (print) |
58 |
System.out.print("ArrayBlockingQueue "); |
59 |
oneRun(new ArrayBlockingQueue<Integer>(CAPACITY), producers, iters); |
60 |
|
61 |
if (print) |
62 |
System.out.print("LinkedBlockingQueue "); |
63 |
oneRun(new LinkedBlockingQueue<Integer>(CAPACITY), producers, iters); |
64 |
|
65 |
// Don't run PBQ since can legitimately run out of memory |
66 |
// if (print) |
67 |
// System.out.print("PriorityBlockingQueue "); |
68 |
// oneRun(new PriorityBlockingQueue<Integer>(), producers, iters); |
69 |
|
70 |
if (print) |
71 |
System.out.print("SynchronousQueue "); |
72 |
oneRun(new SynchronousQueue<Integer>(), producers, iters); |
73 |
|
74 |
if (print) |
75 |
System.out.print("SynchronousQueue(fair) "); |
76 |
oneRun(new SynchronousQueue<Integer>(true), producers, iters); |
77 |
|
78 |
if (print) |
79 |
System.out.print("ArrayBlockingQueue(fair)"); |
80 |
oneRun(new ArrayBlockingQueue<Integer>(CAPACITY, true), producers, iters/10); |
81 |
} |
82 |
|
83 |
static abstract class Stage implements Runnable { |
84 |
final int iters; |
85 |
final BlockingQueue<Integer> queue; |
86 |
final CyclicBarrier barrier; |
87 |
Stage (BlockingQueue<Integer> q, CyclicBarrier b, int iters) { |
88 |
queue = q; |
89 |
barrier = b; |
90 |
this.iters = iters; |
91 |
} |
92 |
} |
93 |
|
94 |
static class Producer extends Stage { |
95 |
Producer(BlockingQueue<Integer> q, CyclicBarrier b, int iters) { |
96 |
super(q, b, iters); |
97 |
} |
98 |
|
99 |
public void run() { |
100 |
try { |
101 |
barrier.await(); |
102 |
int s = 0; |
103 |
int l = hashCode(); |
104 |
for (int i = 0; i < iters; ++i) { |
105 |
l = LoopHelpers.compute1(l); |
106 |
l = LoopHelpers.compute2(l); |
107 |
queue.put(new Integer(l)); |
108 |
s += l; |
109 |
} |
110 |
addProducerSum(s); |
111 |
barrier.await(); |
112 |
} |
113 |
catch (Exception ie) { |
114 |
ie.printStackTrace(); |
115 |
return; |
116 |
} |
117 |
} |
118 |
} |
119 |
|
120 |
static class Consumer extends Stage { |
121 |
Consumer(BlockingQueue<Integer> q, CyclicBarrier b, int iters) { |
122 |
super(q, b, iters); |
123 |
} |
124 |
|
125 |
public void run() { |
126 |
try { |
127 |
barrier.await(); |
128 |
int s = 0; |
129 |
for (int i = 0; i < iters; ++i) { |
130 |
s += queue.take().intValue(); |
131 |
} |
132 |
addConsumerSum(s); |
133 |
barrier.await(); |
134 |
} |
135 |
catch (Exception ie) { |
136 |
ie.printStackTrace(); |
137 |
return; |
138 |
} |
139 |
} |
140 |
|
141 |
} |
142 |
|
143 |
static void oneRun(BlockingQueue<Integer> q, int nproducers, int iters) throws Exception { |
144 |
LoopHelpers.BarrierTimer timer = new LoopHelpers.BarrierTimer(); |
145 |
CyclicBarrier barrier = new CyclicBarrier(nproducers + 2, timer); |
146 |
for (int i = 0; i < nproducers; ++i) { |
147 |
pool.execute(new Producer(q, barrier, iters)); |
148 |
} |
149 |
pool.execute(new Consumer(q, barrier, iters * nproducers)); |
150 |
barrier.await(); |
151 |
barrier.await(); |
152 |
long time = timer.getTime(); |
153 |
checkSum(); |
154 |
if (print) |
155 |
System.out.println("\t: " + LoopHelpers.rightJustify(time / (iters * nproducers)) + " ns per transfer"); |
156 |
} |
157 |
|
158 |
} |