1 |
/* |
2 |
* Written by Bill Scherer and Doug Lea with assistance from members |
3 |
* of JCP JSR-166 Expert Group and released to the public domain, as |
4 |
* explained at http://creativecommons.org/publicdomain/zero/1.0/ |
5 |
*/ |
6 |
|
7 |
import java.util.concurrent.*; |
8 |
import java.util.concurrent.atomic.*; |
9 |
import java.util.concurrent.locks.*; |
10 |
|
11 |
public class TimeoutExchangerLoops { |
12 |
static final int NCPUS = Runtime.getRuntime().availableProcessors(); |
13 |
|
14 |
static final int DEFAULT_THREADS = NCPUS + 2; |
15 |
static final long DEFAULT_PATIENCE_NANOS = 100000; |
16 |
static final long DEFAULT_TRIAL_MILLIS = 10000; |
17 |
|
18 |
public static void main(String[] args) throws Exception { |
19 |
int maxThreads = DEFAULT_THREADS; |
20 |
long trialMillis = DEFAULT_TRIAL_MILLIS; |
21 |
long patienceNanos = DEFAULT_PATIENCE_NANOS; |
22 |
int nReps = 3; |
23 |
|
24 |
// Parse and check args |
25 |
int argc = 0; |
26 |
while (argc < args.length) { |
27 |
String option = args[argc++]; |
28 |
if (option.equals("-t")) |
29 |
trialMillis = Integer.parseInt(args[argc]); |
30 |
else if (option.equals("-p")) |
31 |
patienceNanos = Long.parseLong(args[argc]); |
32 |
else if (option.equals("-r")) |
33 |
nReps = Integer.parseInt(args[argc]); |
34 |
else |
35 |
maxThreads = Integer.parseInt(option); |
36 |
argc++; |
37 |
} |
38 |
|
39 |
// Display runtime parameters |
40 |
System.out.print("TimeoutExchangerTest"); |
41 |
System.out.print(" -t " + trialMillis); |
42 |
System.out.print(" -p " + patienceNanos); |
43 |
System.out.print(" -r " + nReps); |
44 |
System.out.print(" max threads " + maxThreads); |
45 |
System.out.println(); |
46 |
|
47 |
System.out.println("Warmups.."); |
48 |
long warmupTime = 1000; |
49 |
long sleepTime = 500; |
50 |
if (false) { |
51 |
for (int k = 0; k < 10; ++k) { |
52 |
for (int j = 0; j < 10; ++j) { |
53 |
oneRun(2, (j + 1) * 1000, patienceNanos); |
54 |
Thread.sleep(sleepTime); |
55 |
} |
56 |
} |
57 |
} |
58 |
|
59 |
oneRun(3, warmupTime, patienceNanos); |
60 |
Thread.sleep(sleepTime); |
61 |
|
62 |
for (int i = maxThreads; i >= 2; i -= 1) { |
63 |
oneRun(i, warmupTime, patienceNanos); |
64 |
Thread.sleep(sleepTime); |
65 |
} |
66 |
|
67 |
for (int j = 0; j < nReps; ++j) { |
68 |
System.out.println("Replication " + j); |
69 |
for (int i = 2; i <= maxThreads; i += 2) { |
70 |
oneRun(i, trialMillis, patienceNanos); |
71 |
Thread.sleep(sleepTime); |
72 |
} |
73 |
} |
74 |
} |
75 |
|
76 |
static void oneRun(int nThreads, long trialMillis, long patienceNanos) |
77 |
throws Exception { |
78 |
System.out.printf("%4d threads", nThreads); |
79 |
System.out.printf("%9dms", trialMillis); |
80 |
final CountDownLatch start = new CountDownLatch(1); |
81 |
Exchanger x = new Exchanger(); |
82 |
Runner[] runners = new Runner[nThreads]; |
83 |
Thread[] threads = new Thread[nThreads]; |
84 |
for (int i = 0; i < nThreads; ++i) { |
85 |
runners[i] = new Runner(x, patienceNanos, start); |
86 |
threads[i] = new Thread(runners[i]); |
87 |
threads[i].start(); |
88 |
} |
89 |
long startTime = System.nanoTime(); |
90 |
start.countDown(); |
91 |
Thread.sleep(trialMillis); |
92 |
for (int i = 0; i < nThreads; ++i) |
93 |
threads[i].interrupt(); |
94 |
long elapsed = System.nanoTime() - startTime; |
95 |
for (int i = 0; i < nThreads; ++i) |
96 |
threads[i].join(); |
97 |
int iters = 0; |
98 |
long fails = 0; |
99 |
for (int i = 0; i < nThreads; ++i) { |
100 |
iters += runners[i].iters; |
101 |
fails += runners[i].failures; |
102 |
} |
103 |
if (iters <= 0) iters = 1; |
104 |
long rate = iters * 1000L * 1000L * 1000L / elapsed; |
105 |
long npt = elapsed / iters; |
106 |
double failRate = (fails * 100.0) / (double) iters; |
107 |
System.out.printf("%9d it/s ", rate); |
108 |
System.out.printf("%9d ns/it", npt); |
109 |
System.out.printf("%9.5f%% fails ", failRate); |
110 |
System.out.print(fails); |
111 |
System.out.println(); |
112 |
// x.printStats(); |
113 |
} |
114 |
|
115 |
static final class Runner implements Runnable { |
116 |
final Exchanger exchanger; |
117 |
final CountDownLatch start; |
118 |
final long patience; |
119 |
volatile int iters; |
120 |
volatile int failures; |
121 |
Runner(Exchanger x, long patience, CountDownLatch start) { |
122 |
this.exchanger = x; |
123 |
this.patience = patience; |
124 |
this.start = start; |
125 |
} |
126 |
|
127 |
public void run() { |
128 |
int i = 0; |
129 |
try { |
130 |
Exchanger x = exchanger; |
131 |
Object m = new Integer(17); |
132 |
long p = patience; |
133 |
start.await(); |
134 |
for (;;) { |
135 |
try { |
136 |
Object e = x.exchange(m, p, TimeUnit.NANOSECONDS); |
137 |
if (e == null || e == m) |
138 |
throw new Error(); |
139 |
m = e; |
140 |
++i; |
141 |
} catch (TimeoutException to) { |
142 |
if (Thread.interrupted()) { |
143 |
iters = i; |
144 |
return; |
145 |
} |
146 |
++i; |
147 |
++failures; |
148 |
} |
149 |
} |
150 |
} catch (InterruptedException ie) { |
151 |
iters = i; |
152 |
} |
153 |
} |
154 |
} |
155 |
} |