1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
|
<?xml version="1.0" encoding="ISO-8859-1"?>
<document>
<head>
<name>Using Multi-Threaded Tests</name>
<doc-version>$Date: 2003/10/03 14:26:45 $</doc-version>
<author>Matt Albrecht</author>
</head>
<body>
<!--
The code in this document were generated with the jEdit "Code2HTML" plugin.
-->
<P>
The GroboUtils class <tt>MultiThreadedTestRunner</tt> was based on the
article "JUnit Best Practices" by Andy Schneider
(andrew.schneider@javaworld.com), published online at
<a href="http://www.javaworld.com/javaworld/jw-12-2000/jw-1221-junit_p.html">
http://www.javaworld.com/javaworld/jw-12-2000/jw-1221-junit_p.html</a>.
Since GroboUtils first started using that implementation, many changes have
occured in the code to make a more robust and stable testing environment.
Due to these changes, the use of the class will be fully described in this
document.
</P>
<P>
Let's start by testing a sample application:
<!--
import java.io.*;
public class WriterCache
{
public static interface IWriterFactory
{
public Writer createWriter( String location )
throws IOException;
}
private String openLocation;
private Writer w;
private IWriterFactory factory;
private volatile int openCount = 0;
public WriterCache( IWriterFactory wf )
{
if (wf == null)
{
throw new IllegalArgumentException( "factory cannot be null" );
}
this.factory = wf;
}
public void writeToFile( String location, String text )
throws IOException
{
if (location == null) return;
if (!location.equals( this.openLocation ))
{
if (this.w != null)
{
this.openCount = this.openCount - 1;
this.w.close();
}
++this.openCount;
this.w = this.factory.createWriter( location );
}
this.w.write( text );
}
public int getNumberWritersOpen()
{
return this.openCount;
}
}
-->
<PRE CLASS="JavaCode"><SPAN CLASS="gutter"> 1:</SPAN><SPAN CLASS="syntax7">import</SPAN><SPAN CLASS="syntax125"> </SPAN>java.io.*;
<SPAN CLASS="gutter"> 2:</SPAN><SPAN CLASS="syntax6">public</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax8">class</SPAN><SPAN CLASS="syntax125"> </SPAN>WriterCache
<SPAN CLASS="gutter"> 3:</SPAN><SPAN CLASS="syntax11">{</SPAN>
<SPAN CLASS="gutter"> 4:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">public</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">static</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax8">interface</SPAN><SPAN CLASS="syntax125"> </SPAN>IWriterFactory
<SPAN CLASS="gutterH"> 5:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">{</SPAN>
<SPAN CLASS="gutter"> 6:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">public</SPAN><SPAN CLASS="syntax125"> </SPAN>Writer<SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax9">createWriter</SPAN>(<SPAN CLASS="syntax125"> </SPAN>String<SPAN CLASS="syntax125"> </SPAN>location<SPAN CLASS="syntax125"> </SPAN>)
<SPAN CLASS="gutter"> 7:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">throws</SPAN><SPAN CLASS="syntax125"> </SPAN>IOException;
<SPAN CLASS="gutter"> 8:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">}</SPAN>
<SPAN CLASS="gutter"> 9:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN>
<SPAN CLASS="gutterH"> 10:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">private</SPAN><SPAN CLASS="syntax125"> </SPAN>String<SPAN CLASS="syntax125"> </SPAN>openLocation;
<SPAN CLASS="gutter"> 11:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">private</SPAN><SPAN CLASS="syntax125"> </SPAN>Writer<SPAN CLASS="syntax125"> </SPAN>w;
<SPAN CLASS="gutter"> 12:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">private</SPAN><SPAN CLASS="syntax125"> </SPAN>IWriterFactory<SPAN CLASS="syntax125"> </SPAN>factory;
<SPAN CLASS="gutter"> 13:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">private volatile</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax8">int</SPAN><SPAN CLASS="syntax125"> </SPAN>openCount<SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">=</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax12">0</SPAN>;
<SPAN CLASS="gutter"> 14:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN>
<SPAN CLASS="gutterH"> 15:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">public</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax9">WriterCache</SPAN>(<SPAN CLASS="syntax125"> </SPAN>IWriterFactory<SPAN CLASS="syntax125"> </SPAN>wf<SPAN CLASS="syntax125"> </SPAN>)
<SPAN CLASS="gutter"> 16:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">{</SPAN>
<SPAN CLASS="gutter"> 17:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">if</SPAN><SPAN CLASS="syntax125"> </SPAN>(wf<SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">=</SPAN><SPAN CLASS="syntax11">=</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax4">null</SPAN>)
<SPAN CLASS="gutter"> 18:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">{</SPAN>
<SPAN CLASS="gutter"> 19:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">throw</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">new</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax9">IllegalArgumentException</SPAN>(<SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax3">"</SPAN><SPAN CLASS="syntax3">factory</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax3">cannot</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax3">be</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax3">null</SPAN><SPAN CLASS="syntax3">"</SPAN><SPAN CLASS="syntax125"> </SPAN>);
<SPAN CLASS="gutterH"> 20:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">}</SPAN>
<SPAN CLASS="gutter"> 21:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax4">this</SPAN>.factory<SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">=</SPAN><SPAN CLASS="syntax125"> </SPAN>wf;
<SPAN CLASS="gutter"> 22:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">}</SPAN>
<SPAN CLASS="gutter"> 23:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN>
<SPAN CLASS="gutter"> 24:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">public</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax8">void</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax9">writeToFile</SPAN>(<SPAN CLASS="syntax125"> </SPAN>String<SPAN CLASS="syntax125"> </SPAN>location,<SPAN CLASS="syntax125"> </SPAN>String<SPAN CLASS="syntax125"> </SPAN>text<SPAN CLASS="syntax125"> </SPAN>)
<SPAN CLASS="gutterH"> 25:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">throws</SPAN><SPAN CLASS="syntax125"> </SPAN>IOException
<SPAN CLASS="gutter"> 26:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">{</SPAN>
<SPAN CLASS="gutter"> 27:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">if</SPAN><SPAN CLASS="syntax125"> </SPAN>(location<SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">=</SPAN><SPAN CLASS="syntax11">=</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax4">null</SPAN>)<SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">return</SPAN>;
<SPAN CLASS="gutter"> 28:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">if</SPAN><SPAN CLASS="syntax125"> </SPAN>(<SPAN CLASS="syntax11">!</SPAN>location.<SPAN CLASS="syntax9">equals</SPAN>(<SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax4">this</SPAN>.openLocation<SPAN CLASS="syntax125"> </SPAN>))
<SPAN CLASS="gutter"> 29:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">{</SPAN>
<SPAN CLASS="gutterH"> 30:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">if</SPAN><SPAN CLASS="syntax125"> </SPAN>(<SPAN CLASS="syntax4">this</SPAN>.w<SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">!</SPAN><SPAN CLASS="syntax11">=</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax4">null</SPAN>)
<SPAN CLASS="gutter"> 31:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">{</SPAN>
<SPAN CLASS="gutter"> 32:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">-</SPAN><SPAN CLASS="syntax11">-</SPAN><SPAN CLASS="syntax4">this</SPAN>.openCount;
<SPAN CLASS="gutter"> 33:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax4">this</SPAN>.w.<SPAN CLASS="syntax9">close</SPAN>();
<SPAN CLASS="gutter"> 34:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">}</SPAN>
<SPAN CLASS="gutterH"> 35:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">+</SPAN><SPAN CLASS="syntax11">+</SPAN><SPAN CLASS="syntax4">this</SPAN>.openCount;
<SPAN CLASS="gutter"> 36:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax4">this</SPAN>.w<SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">=</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax4">this</SPAN>.factory.<SPAN CLASS="syntax9">createWriter</SPAN>(<SPAN CLASS="syntax125"> </SPAN>location<SPAN CLASS="syntax125"> </SPAN>);
<SPAN CLASS="gutter"> 37:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">}</SPAN>
<SPAN CLASS="gutter"> 38:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax4">this</SPAN>.w.<SPAN CLASS="syntax9">write</SPAN>(<SPAN CLASS="syntax125"> </SPAN>text<SPAN CLASS="syntax125"> </SPAN>);
<SPAN CLASS="gutter"> 39:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">}</SPAN>
<SPAN CLASS="gutterH"> 40:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN>
<SPAN CLASS="gutter"> 41:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">public</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax8">int</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax9">getNumberWritersOpen</SPAN>()
<SPAN CLASS="gutter"> 42:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">{</SPAN>
<SPAN CLASS="gutter"> 43:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">return</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax4">this</SPAN>.openCount;
<SPAN CLASS="gutter"> 44:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">}</SPAN>
<SPAN CLASS="gutterH"> 45:</SPAN><SPAN CLASS="syntax11">}</SPAN>
</PRE>
Obviously, this class isn't very thread safe - <tt>w</tt> could easily be
closed in one thread when a thread execution switch causes another thread
to run its write statement on the closed writer, or even writing to a
different writer than what was created (this is data corruption, which is
worse than a raised exception).
</P>
<P>
<I>Note that this class is designed for testing: we can easily create streams in
our tests and note what gets written and to which stream. This follows a
pattern of designing for mock objects.</I>
</P>
<section>Beginning the Unit Test Class</section>
<P>
The test class starts off with the standard naming conventions and constructor,
and all necessary imports:
<!--
import net.sourceforge.groboutils.junit.v1.MultiThreadedTestRunner;
import net.sourceforge.groboutils.junit.v1.TestRunnable;
import junit.framework.TestCase;
import junit.framework.TestSuite;
import java.io.*;
import java.util.*;
public class WriterCacheUTest extends TestCase
{
public WriterCacheUTest( String name )
{
super( name );
}
-->
<PRE CLASS="JavaCode"><SPAN CLASS="gutter"> 1:</SPAN><SPAN CLASS="syntax7">import</SPAN><SPAN CLASS="syntax125"> </SPAN>net.sourceforge.groboutils.junit.v1.MultiThreadedTestRunner;
<SPAN CLASS="gutter"> 2:</SPAN><SPAN CLASS="syntax7">import</SPAN><SPAN CLASS="syntax125"> </SPAN>net.sourceforge.groboutils.junit.v1.TestRunnable;
<SPAN CLASS="gutter"> 3:</SPAN><SPAN CLASS="syntax7">import</SPAN><SPAN CLASS="syntax125"> </SPAN>junit.framework.TestCase;
<SPAN CLASS="gutter"> 4:</SPAN><SPAN CLASS="syntax7">import</SPAN><SPAN CLASS="syntax125"> </SPAN>junit.framework.TestSuite;
<SPAN CLASS="gutterH"> 5:</SPAN><SPAN CLASS="syntax7">import</SPAN><SPAN CLASS="syntax125"> </SPAN>java.io.*;
<SPAN CLASS="gutter"> 6:</SPAN><SPAN CLASS="syntax7">import</SPAN><SPAN CLASS="syntax125"> </SPAN>java.util.*;
<SPAN CLASS="gutter"> 7:</SPAN>
<SPAN CLASS="gutter"> 8:</SPAN><SPAN CLASS="syntax6">public</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax8">class</SPAN><SPAN CLASS="syntax125"> </SPAN>WriterCacheUTest<SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">extends</SPAN><SPAN CLASS="syntax125"> </SPAN>TestCase
<SPAN CLASS="gutter"> 9:</SPAN><SPAN CLASS="syntax11">{</SPAN>
<SPAN CLASS="gutterH">10:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">public</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax9">WriterCacheUTest</SPAN>(<SPAN CLASS="syntax125"> </SPAN>String<SPAN CLASS="syntax125"> </SPAN>name<SPAN CLASS="syntax125"> </SPAN>)
<SPAN CLASS="gutter">11:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">{</SPAN>
<SPAN CLASS="gutter">12:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax4">super</SPAN>(<SPAN CLASS="syntax125"> </SPAN>name<SPAN CLASS="syntax125"> </SPAN>);
<SPAN CLASS="gutter">13:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">}</SPAN>
</PRE>
Next, we need a way to archive the <tt>WriterCache</tt> created streams in our
own <tt>IWriterFactory</tt>:
<!--
public static class MyWriterFactory implements WriterCache.IWriterFactory
{
Hashtable nameToStream = new Hashtable();
public Writer createWriter( String location )
throws IOException
{
StringWriter sw = (StringWriter)nameToStream.get( location );
if (sw == null)
{
sw = new StringWriter();
nameToStream.put( location, sw );
}
return sw;
}
}
-->
<PRE CLASS="JavaCode"><SPAN CLASS="gutterH">15:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">public</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">static</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax8">class</SPAN><SPAN CLASS="syntax125"> </SPAN>MyWriterFactory<SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">implements</SPAN><SPAN CLASS="syntax125"> </SPAN>WriterCache.IWriterFactory
<SPAN CLASS="gutter">16:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">{</SPAN>
<SPAN CLASS="gutter">17:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN>Hashtable<SPAN CLASS="syntax125"> </SPAN>nameToStream<SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">=</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">new</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax9">Hashtable</SPAN>();
<SPAN CLASS="gutter">18:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">public</SPAN><SPAN CLASS="syntax125"> </SPAN>Writer<SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax9">createWriter</SPAN>(<SPAN CLASS="syntax125"> </SPAN>String<SPAN CLASS="syntax125"> </SPAN>location<SPAN CLASS="syntax125"> </SPAN>)
<SPAN CLASS="gutter">19:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">throws</SPAN><SPAN CLASS="syntax125"> </SPAN>IOException
<SPAN CLASS="gutterH">20:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">{</SPAN>
<SPAN CLASS="gutter">21:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN>StringWriter<SPAN CLASS="syntax125"> </SPAN>sw<SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">=</SPAN><SPAN CLASS="syntax125"> </SPAN>(StringWriter)nameToStream.<SPAN CLASS="syntax9">get</SPAN>(<SPAN CLASS="syntax125"> </SPAN>location<SPAN CLASS="syntax125"> </SPAN>);
<SPAN CLASS="gutter">22:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">if</SPAN><SPAN CLASS="syntax125"> </SPAN>(sw<SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">=</SPAN><SPAN CLASS="syntax11">=</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax4">null</SPAN>)
<SPAN CLASS="gutter">23:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">{</SPAN>
<SPAN CLASS="gutter">24:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN>sw<SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">=</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">new</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax9">StringWriter</SPAN>();
<SPAN CLASS="gutterH">25:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN>nameToStream.<SPAN CLASS="syntax9">put</SPAN>(<SPAN CLASS="syntax125"> </SPAN>location,<SPAN CLASS="syntax125"> </SPAN>sw<SPAN CLASS="syntax125"> </SPAN>);
<SPAN CLASS="gutter">26:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">}</SPAN>
<SPAN CLASS="gutter">27:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">return</SPAN><SPAN CLASS="syntax125"> </SPAN>sw;
<SPAN CLASS="gutter">28:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">}</SPAN>
<SPAN CLASS="gutter">29:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">}</SPAN>
<SPAN CLASS="gutterH">30:</SPAN><SPAN CLASS="syntax11">}</SPAN>
</PRE>
It uses <tt>StringWriter</tt> instances so that the tests can examine what
what written to which stream.
</P>
<P>
Ignoring the standard non-threaded tests for such a class (for brevity's sake),
we move onto the threaded tests. But before we can write the tests, we need to
devise the different tests that we can perform.
<OL>
<LI>
One thread can write to one location with a known text pattern, while
another writes to a different location with a different text pattern.
The test would check to make sure that each location contains only
the expected text pattern, and exactly the number of text patterns
actually written. Let's call this test "TextPattern"
</LI>
<LI>
Use lots of writing threads (say 10), but this time we check for the
number of opened writers to ensure it never becomes negative, and
generate some kind of warning if it is not 0 or 1. Let's call this
test "OpenWriterCount".
</LI>
</OL>
</P>
<P>
<I>Note: since this class uses a <tt>StringWriter</tt> instance as the
returned <tt>Writer</tt>, the <tt>WriterCache</tt> calls to <tt>close()</tt>
on the instance will be ignored, as this is the documented behavior of the
<tt>StringWriter</tt> class. Thus, the same <tt>StringWriter</tt> instance
can be sent to the <tt>WriterCache</tt> over and over.</I>
</P>
<section>Creating a TestRunnable</section>
<P>
In order to support the above tests, we'll need a way to generate the text
pattern for a given location, a given number of times. This is where the
GroboUtil extension for multi-threaded testing comes into play. We create
another inner class to generate the <tt>WriterCache</tt> calls by extending
the <tt>TestRunnable</tt> class:
<!--
static class WriteText extends TestRunnable
{
private WriterCache wc;
private int count;
private String textPattern;
private String location;
private int sleepTime;
public WriteText( WriterCache wc, int count, String pattern,
String loc, int delay )
{
this.wc = wc;
this.count = count;
this.textPattern = pattern;
this.location = loc;
this.sleepTime = delay;
}
public void runTest() throws Throwable
{
for (int i = 0; i < this.count; ++i)
{
Thread.sleep( this.sleepTime );
this.wc.writeToFile( this.location, this.textPattern );
}
}
}
-->
<PRE CLASS="JavaCode"><SPAN CLASS="gutter">31:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">static</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax8">class</SPAN><SPAN CLASS="syntax125"> </SPAN>WriteText<SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">extends</SPAN><SPAN CLASS="syntax125"> </SPAN>TestRunnable
<SPAN CLASS="gutter">32:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">{</SPAN>
<SPAN CLASS="gutter">33:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">private</SPAN><SPAN CLASS="syntax125"> </SPAN>WriterCache<SPAN CLASS="syntax125"> </SPAN>wc;
<SPAN CLASS="gutter">34:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">private</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax8">int</SPAN><SPAN CLASS="syntax125"> </SPAN>count;
<SPAN CLASS="gutterH">35:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">private</SPAN><SPAN CLASS="syntax125"> </SPAN>String<SPAN CLASS="syntax125"> </SPAN>textPattern;
<SPAN CLASS="gutter">36:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">private</SPAN><SPAN CLASS="syntax125"> </SPAN>String<SPAN CLASS="syntax125"> </SPAN>location;
<SPAN CLASS="gutter">37:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">private</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax8">int</SPAN><SPAN CLASS="syntax125"> </SPAN>sleepTime;
<SPAN CLASS="gutter">38:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">public</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax9">WriteText</SPAN>(<SPAN CLASS="syntax125"> </SPAN>WriterCache<SPAN CLASS="syntax125"> </SPAN>wc,<SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax8">int</SPAN><SPAN CLASS="syntax125"> </SPAN>count,<SPAN CLASS="syntax125"> </SPAN>String<SPAN CLASS="syntax125"> </SPAN>pattern,
<SPAN CLASS="gutter">39:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN>String<SPAN CLASS="syntax125"> </SPAN>loc,<SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax8">int</SPAN><SPAN CLASS="syntax125"> </SPAN>delay<SPAN CLASS="syntax125"> </SPAN>)
<SPAN CLASS="gutterH">40:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">{</SPAN>
<SPAN CLASS="gutter">41:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax4">this</SPAN>.wc<SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">=</SPAN><SPAN CLASS="syntax125"> </SPAN>wc;
<SPAN CLASS="gutter">42:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax4">this</SPAN>.count<SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">=</SPAN><SPAN CLASS="syntax125"> </SPAN>count;
<SPAN CLASS="gutter">43:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax4">this</SPAN>.textPattern<SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">=</SPAN><SPAN CLASS="syntax125"> </SPAN>pattern;
<SPAN CLASS="gutter">44:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax4">this</SPAN>.location<SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">=</SPAN><SPAN CLASS="syntax125"> </SPAN>loc;
<SPAN CLASS="gutterH">45:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax4">this</SPAN>.sleepTime<SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">=</SPAN><SPAN CLASS="syntax125"> </SPAN>delay;
<SPAN CLASS="gutter">46:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">}</SPAN>
<SPAN CLASS="gutter">47:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN>
<SPAN CLASS="gutter">48:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">public</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax8">void</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax9">runTest</SPAN>()<SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">throws</SPAN><SPAN CLASS="syntax125"> </SPAN>Throwable
<SPAN CLASS="gutter">49:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">{</SPAN>
<SPAN CLASS="gutterH">50:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax6">for</SPAN><SPAN CLASS="syntax125"> </SPAN>(<SPAN CLASS="syntax8">int</SPAN><SPAN CLASS="syntax125"> </SPAN>i<SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">=</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax12">0</SPAN>;<SPAN CLASS="syntax125"> </SPAN>i<SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11"><</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax4">this</SPAN>.count;<SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">+</SPAN><SPAN CLASS="syntax11">+</SPAN>i)
<SPAN CLASS="gutter">51:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">{</SPAN>
<SPAN CLASS="gutter">52:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN>Thread.<SPAN CLASS="syntax9">sleep</SPAN>(<SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax4">this</SPAN>.sleepTime<SPAN CLASS="syntax125"> </SPAN>);
<SPAN CLASS="gutter">53:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax4">this</SPAN>.wc.<SPAN CLASS="syntax9">writeToFile</SPAN>(<SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax4">this</SPAN>.location,<SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax4">this</SPAN>.textPattern<SPAN CLASS="syntax125"> </SPAN>);
<SPAN CLASS="gutter">54:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">}</SPAN>
<SPAN CLASS="gutterH">55:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">}</SPAN>
<SPAN CLASS="gutter">56:</SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax125"> </SPAN><SPAN CLASS="syntax11">}</SPAN>
<SPAN CLASS="gutter">57:</SPAN><SPAN CLASS="syntax11">}</SPAN>
</PRE>
The <tt>void runTest()</tt> method must be implemented by concrete subclasses of
<tt>TestRunnable</tt>: this is the equivalent of the standard Java interface
<tt>Runnable</tt>'s <tt>void run()</tt> method, but properly wrapped for
testing.
</P>
<section>Running Several Tasks In Parallel</section>
<P>
This allows us to begin writing the test for "TextPattern". This test says that
we need to write to two different streams with different text in parallel.
Then, we need to ensure that the correct amount of data was written to each,
and that no inappropriate data was written. In this test, we'll have one
<tt>WriteText</tt> instance write to location "0" with text "0" (we'll call this
thread 0), and another write to location "1" with text "1" (we'll call this
thread 1). To vary things up, thread 0 will write 10 times with a 50
millisecond wait, and thread 1 will write 12 times with a 20 millisecond wait.
The test ends up looking like:
<!--
public void testTextPattern() throws Throwable
{
MyWriterFactor mwf = new MyWriterFactory();
WriterCache wc = new WriterCache( mwf );
TestRunnable tcs[] = {
new WriteText( wc, 10, "0", "0", 50 ),
new WriteText( wc, 12, "1", "1", 20 )
};
MultiThreadedTestRunner mttr =
new MultiThreadedTestRunner( tcs );
mttr.runTestRunnables( 2 * 60 * 1000 );
String s0 = mwf.nameToStream.get( "0" ).toString();
String s1 = mwf.nameToStream.get( "1" ).toString();
assertEquals( "Data corruption: stream 0", 10,
s0.length() );
assertEquals( "Data corruption: stream 1", 12,
s1.length() );
assertTrue( "Incorrect data written to stream 0.",
s0.indexOf( '1' ) < 0 );
assertTrue( "Incorrect data written to stream 1.",
s1.indexOf( '0' ) < 0 );
}
-->
<PRE CLASS="JavaCode"><SPAN CLASS="gutter">59:</SPAN> <SPAN CLASS="syntax6">public</SPAN> <SPAN CLASS="syntax10">void</SPAN> <SPAN CLASS="syntax6">testTextPattern</SPAN>() <SPAN CLASS="syntax8">throws</SPAN> Throwable
<SPAN CLASS="gutterH">60:</SPAN> <SPAN CLASS="syntax18">{</SPAN>
<SPAN CLASS="gutter">61:</SPAN> MyWriterFactor mwf <SPAN CLASS="syntax18">=</SPAN> <SPAN CLASS="syntax8">new</SPAN> <SPAN CLASS="syntax6">MyWriterFactory</SPAN>();
<SPAN CLASS="gutter">62:</SPAN> WriterCache wc <SPAN CLASS="syntax18">=</SPAN> <SPAN CLASS="syntax8">new</SPAN> <SPAN CLASS="syntax6">WriterCache</SPAN>( mwf );
<SPAN CLASS="gutter">63:</SPAN> TestRunnable tcs[] <SPAN CLASS="syntax18">=</SPAN> <SPAN CLASS="syntax18">{</SPAN>
<SPAN CLASS="gutter">64:</SPAN> <SPAN CLASS="syntax8">new</SPAN> <SPAN CLASS="syntax6">WriteText</SPAN>( wc, <SPAN CLASS="syntax5">10</SPAN>, <SPAN CLASS="syntax13">"</SPAN><SPAN CLASS="syntax13">0</SPAN><SPAN CLASS="syntax13">"</SPAN>, <SPAN CLASS="syntax13">"</SPAN><SPAN CLASS="syntax13">0</SPAN><SPAN CLASS="syntax13">"</SPAN>, <SPAN CLASS="syntax5">50</SPAN> ),
<SPAN CLASS="gutterH">65:</SPAN> <SPAN CLASS="syntax8">new</SPAN> <SPAN CLASS="syntax6">WriteText</SPAN>( wc, <SPAN CLASS="syntax5">12</SPAN>, <SPAN CLASS="syntax13">"</SPAN><SPAN CLASS="syntax13">1</SPAN><SPAN CLASS="syntax13">"</SPAN>, <SPAN CLASS="syntax13">"</SPAN><SPAN CLASS="syntax13">1</SPAN><SPAN CLASS="syntax13">"</SPAN>, <SPAN CLASS="syntax5">20</SPAN> )
<SPAN CLASS="gutter">66:</SPAN> <SPAN CLASS="syntax18">}</SPAN>;
<SPAN CLASS="gutter">67:</SPAN> MultiThreadedTestRunner mttr <SPAN CLASS="syntax18">=</SPAN>
<SPAN CLASS="gutter">68:</SPAN> <SPAN CLASS="syntax8">new</SPAN> <SPAN CLASS="syntax6">MultiThreadedTestRunner</SPAN>( tcs );
<SPAN CLASS="gutter">69:</SPAN> mttr.<SPAN CLASS="syntax6">runTestRunnables</SPAN>( <SPAN CLASS="syntax5">2</SPAN> <SPAN CLASS="syntax18">*</SPAN> <SPAN CLASS="syntax5">60</SPAN> <SPAN CLASS="syntax18">*</SPAN> <SPAN CLASS="syntax5">1000</SPAN> );
<SPAN CLASS="gutterH">70:</SPAN> String s0 <SPAN CLASS="syntax18">=</SPAN> mwf.nameToStream.<SPAN CLASS="syntax6">get</SPAN>( <SPAN CLASS="syntax13">"</SPAN><SPAN CLASS="syntax13">0</SPAN><SPAN CLASS="syntax13">"</SPAN> ).<SPAN CLASS="syntax6">toString</SPAN>();
<SPAN CLASS="gutter">71:</SPAN> String s1 <SPAN CLASS="syntax18">=</SPAN> mwf.nameToStream.<SPAN CLASS="syntax6">get</SPAN>( <SPAN CLASS="syntax13">"</SPAN><SPAN CLASS="syntax13">1</SPAN><SPAN CLASS="syntax13">"</SPAN> ).<SPAN CLASS="syntax6">toString</SPAN>();
<SPAN CLASS="gutter">72:</SPAN> <SPAN CLASS="syntax6">assertEquals</SPAN>( <SPAN CLASS="syntax13">"</SPAN><SPAN CLASS="syntax13">Data</SPAN><SPAN CLASS="syntax13"> </SPAN><SPAN CLASS="syntax13">corruption:</SPAN><SPAN CLASS="syntax13"> </SPAN><SPAN CLASS="syntax13">stream</SPAN><SPAN CLASS="syntax13"> </SPAN><SPAN CLASS="syntax13">0</SPAN><SPAN CLASS="syntax13">"</SPAN>, <SPAN CLASS="syntax5">10</SPAN>,
<SPAN CLASS="gutter">73:</SPAN> s0.<SPAN CLASS="syntax6">length</SPAN>() );
<SPAN CLASS="gutter">74:</SPAN> <SPAN CLASS="syntax6">assertEquals</SPAN>( <SPAN CLASS="syntax13">"</SPAN><SPAN CLASS="syntax13">Data</SPAN><SPAN CLASS="syntax13"> </SPAN><SPAN CLASS="syntax13">corruption:</SPAN><SPAN CLASS="syntax13"> </SPAN><SPAN CLASS="syntax13">stream</SPAN><SPAN CLASS="syntax13"> </SPAN><SPAN CLASS="syntax13">1</SPAN><SPAN CLASS="syntax13">"</SPAN>, <SPAN CLASS="syntax5">12</SPAN>,
<SPAN CLASS="gutterH">75:</SPAN> s1.<SPAN CLASS="syntax6">length</SPAN>() );
<SPAN CLASS="gutter">76:</SPAN> <SPAN CLASS="syntax6">assertTrue</SPAN>( <SPAN CLASS="syntax13">"</SPAN><SPAN CLASS="syntax13">Incorrect</SPAN><SPAN CLASS="syntax13"> </SPAN><SPAN CLASS="syntax13">data</SPAN><SPAN CLASS="syntax13"> </SPAN><SPAN CLASS="syntax13">written</SPAN><SPAN CLASS="syntax13"> </SPAN><SPAN CLASS="syntax13">to</SPAN><SPAN CLASS="syntax13"> </SPAN><SPAN CLASS="syntax13">stream</SPAN><SPAN CLASS="syntax13"> </SPAN><SPAN CLASS="syntax13">0.</SPAN><SPAN CLASS="syntax13">"</SPAN>,
<SPAN CLASS="gutter">77:</SPAN> s0.<SPAN CLASS="syntax6">indexOf</SPAN>( <SPAN CLASS="syntax13">'</SPAN><SPAN CLASS="syntax13">1</SPAN><SPAN CLASS="syntax13">'</SPAN> ) <SPAN CLASS="syntax18"><</SPAN> <SPAN CLASS="syntax5">0</SPAN> );
<SPAN CLASS="gutter">78:</SPAN> <SPAN CLASS="syntax6">assertTrue</SPAN>( <SPAN CLASS="syntax13">"</SPAN><SPAN CLASS="syntax13">Incorrect</SPAN><SPAN CLASS="syntax13"> </SPAN><SPAN CLASS="syntax13">data</SPAN><SPAN CLASS="syntax13"> </SPAN><SPAN CLASS="syntax13">written</SPAN><SPAN CLASS="syntax13"> </SPAN><SPAN CLASS="syntax13">to</SPAN><SPAN CLASS="syntax13"> </SPAN><SPAN CLASS="syntax13">stream</SPAN><SPAN CLASS="syntax13"> </SPAN><SPAN CLASS="syntax13">1.</SPAN><SPAN CLASS="syntax13">"</SPAN>,
<SPAN CLASS="gutter">79:</SPAN> s1.<SPAN CLASS="syntax6">indexOf</SPAN>( <SPAN CLASS="syntax13">'</SPAN><SPAN CLASS="syntax13">0</SPAN><SPAN CLASS="syntax13">'</SPAN> ) <SPAN CLASS="syntax18"><</SPAN> <SPAN CLASS="syntax5">0</SPAN> );
<SPAN CLASS="gutterH">80:</SPAN> <SPAN CLASS="syntax18">}</SPAN>
<SPAN CLASS="gutter">81:</SPAN>
</PRE>
Lines 61-62 initialize the <tt>WriterCache</tt> instance with our test factory.
Line 63 creates our list of parallel tasks to execute, which are instances of
our <tt>WriteText</tt> class above.
</P>
<P>
Line 64 creates an instance of the
<tt>MultiThreadedTestRunner</tt> class, a utility class which handles the
creation, execution, and termination of the threads which run the
<tt>TestRunnable</tt> instances. Line 65 invokes the utility method to run the
tasks. The argument to this method specifies the maximum amount
of time (in milliseconds) to let the threads run before killing them and marking
the execution as a failure (through <tt>junit.famework.Assert</tt>). If any
of the <tt>TestRunnable</tt> instances dies due to an exception (including an
Assert failure), then all of the running threads are terminated, and the
<tt>runTestRunnables</tt> method rethrows the underlying exception.
</P>
<P>
The remainder of the test ensures that only the correct data was placed where
it was intended to go.
</P>
<section>Parallel Monitoring of Threaded Access</section>
<P>
Now we can move on to the OpenWriterCount test. As of GroboTestingJUnit
version 1.2.0, there is a very simple way to add a thread that monitors the
status of the common object while other threads manipulate its state.
</P>
<P>
The monitors are in a separate group from the runners, as the monitors are
intended to loop over a set of checks until all the runners have completed.
Before this functionality was added, the monitor runners had to communicate
with the other runners to learn when the runners were finished. Now, the
<tt>MultiThreadedTestRunner</tt> class handles this communication.
</P>
<P>
We create another runnable class, but this time subclassing from
<tt>TestMonitorRunnable</tt>. This frees the new class from having to perform
the proper looping and detection of when the runners have completed.
In order to use this added functionality, the subclasses overload the
<tt>runMonitor()</tt> method instead of the <tt>runTest()</tt> method.
<!--
public static class WriterCountMonitor extends TestMonitorRunnable
{
private WriterCache wc;
public WriterCountMonitor( WriterCache wc )
{
this.wc = wc;
}
public void runMonitor() throws Throwable
{
int open = this.wc.getNumberWritersOpen();
assertTrue(
"Invalid number of open writers.",
open == 0 || open == 1 );
}
}
-->
<PRE CLASS="JavaCode"><SPAN CLASS="gutter">83:</SPAN> <SPAN CLASS="syntax8">public</SPAN> <SPAN CLASS="syntax8">static</SPAN> <SPAN CLASS="syntax10">class</SPAN> WriterCountMonitor <SPAN CLASS="syntax8">extends</SPAN> TestMonitorRunnable
<SPAN CLASS="gutter">84:</SPAN> <SPAN CLASS="syntax18">{</SPAN>
<SPAN CLASS="gutterH">85:</SPAN> <SPAN CLASS="syntax8">private</SPAN> WriterCache wc;
<SPAN CLASS="gutter">86:</SPAN> <SPAN CLASS="syntax8">public</SPAN> <SPAN CLASS="syntax6">WriterCountMonitor</SPAN>( WriterCache wc )
<SPAN CLASS="gutter">87:</SPAN> <SPAN CLASS="syntax18">{</SPAN>
<SPAN CLASS="gutter">88:</SPAN> <SPAN CLASS="syntax14">this</SPAN>.wc <SPAN CLASS="syntax18">=</SPAN> wc;
<SPAN CLASS="gutter">89:</SPAN> <SPAN CLASS="syntax18">}</SPAN>
<SPAN CLASS="gutterH">90:</SPAN>
<SPAN CLASS="gutter">91:</SPAN> <SPAN CLASS="syntax8">public</SPAN> <SPAN CLASS="syntax10">void</SPAN> <SPAN CLASS="syntax6">runMonitor</SPAN>() <SPAN CLASS="syntax8">throws</SPAN> Throwable
<SPAN CLASS="gutter">92:</SPAN> <SPAN CLASS="syntax18">{</SPAN>
<SPAN CLASS="gutter">93:</SPAN> <SPAN CLASS="syntax10">int</SPAN> open <SPAN CLASS="syntax18">=</SPAN> <SPAN CLASS="syntax14">this</SPAN>.wc.<SPAN CLASS="syntax6">getNumberWritersOpen</SPAN>();
<SPAN CLASS="gutter">94:</SPAN> <SPAN CLASS="syntax6">assertTrue</SPAN>(
<SPAN CLASS="gutterH">95:</SPAN> <SPAN CLASS="syntax13">"</SPAN><SPAN CLASS="syntax13">Invalid</SPAN><SPAN CLASS="syntax13"> </SPAN><SPAN CLASS="syntax13">number</SPAN><SPAN CLASS="syntax13"> </SPAN><SPAN CLASS="syntax13">of</SPAN><SPAN CLASS="syntax13"> </SPAN><SPAN CLASS="syntax13">open</SPAN><SPAN CLASS="syntax13"> </SPAN><SPAN CLASS="syntax13">writers.</SPAN><SPAN CLASS="syntax13">"</SPAN>,
<SPAN CLASS="gutter">96:</SPAN> open <SPAN CLASS="syntax18">=</SPAN><SPAN CLASS="syntax18">=</SPAN> <SPAN CLASS="syntax5">0</SPAN> <SPAN CLASS="syntax18">|</SPAN><SPAN CLASS="syntax18">|</SPAN> open <SPAN CLASS="syntax18">=</SPAN><SPAN CLASS="syntax18">=</SPAN> <SPAN CLASS="syntax5">1</SPAN> );
<SPAN CLASS="gutter">97:</SPAN> <SPAN CLASS="syntax18">}</SPAN>
<SPAN CLASS="gutter">98:</SPAN> <SPAN CLASS="syntax18">}</SPAN>
<SPAN CLASS="gutter">99:</SPAN>
</PRE>
</P>
<P>
The monitors are added to the <tt>MultiThreadedTestRunner</tt> through
a second argument in another constructor. For our test, in order to have
high confidence that threading errors causing the writer open count to
be invalid (not 1 or 0), we need to have a sufficient number of threaded
access on the object-under-test. So, we generate 30 runners to iterate
500 times each over the writer.
<!--
public void testOpenWriterCount() throws Throwable
{
int runnerCount = 30;
int iterations = 500;
MyWriterFactor mwf = new MyWriterFactory();
WriterCache wc = new WriterCache( mwf );
TestRunnable tcs[] = new TestRunnable[ runnerCount ];
for (int i = 0; i < runnerCount; ++i)
{
tcs[i] = new WriteText( wc, 500, ""+(char)i,
""+(char)i, 50 );
}
TestRunnable monitors[] = {
new WriterCountMonitor( wc );
};
MultiThreadedTestRunner mttr =
new MultiThreadedTestRunner( tcs, monitors );
mttr.runTestRunnables( 10 * 60 * 1000 );
// verify streams
for (int i = 0; i < runnerCount; ++i)
{
String s = mwf.nameToString.get( ""+(char)i ).toString();
assertEquals( "Data corruption: stream "+i,
500, s.length() );
}
}
-->
<PRE CLASS="JavaCode"><SPAN CLASS="gutter">101:</SPAN> <SPAN CLASS="syntax8">public</SPAN> <SPAN CLASS="syntax10">void</SPAN> <SPAN CLASS="syntax6">testOpenWriterCount</SPAN>() <SPAN CLASS="syntax8">throws</SPAN> Throwable
<SPAN CLASS="gutter">102:</SPAN> <SPAN CLASS="syntax18">{</SPAN>
<SPAN CLASS="gutter">103:</SPAN> <SPAN CLASS="syntax10">int</SPAN> runnerCount <SPAN CLASS="syntax18">=</SPAN> <SPAN CLASS="syntax5">30</SPAN>;
<SPAN CLASS="gutter">104:</SPAN> <SPAN CLASS="syntax10">int</SPAN> iterations <SPAN CLASS="syntax18">=</SPAN> <SPAN CLASS="syntax5">500</SPAN>;
<SPAN CLASS="gutterH">105:</SPAN> MyWriterFactor mwf <SPAN CLASS="syntax18">=</SPAN> <SPAN CLASS="syntax8">new</SPAN> <SPAN CLASS="syntax6">MyWriterFactory</SPAN>();
<SPAN CLASS="gutter">106:</SPAN> WriterCache wc <SPAN CLASS="syntax18">=</SPAN> <SPAN CLASS="syntax8">new</SPAN> <SPAN CLASS="syntax6">WriterCache</SPAN>( mwf );
<SPAN CLASS="gutter">107:</SPAN> TestRunnable tcs[] <SPAN CLASS="syntax18">=</SPAN> <SPAN CLASS="syntax8">new</SPAN> TestRunnable[ runnerCount ];
<SPAN CLASS="gutter">108:</SPAN> <SPAN CLASS="syntax8">for</SPAN> (<SPAN CLASS="syntax10">int</SPAN> i <SPAN CLASS="syntax18">=</SPAN> <SPAN CLASS="syntax5">0</SPAN>; i <SPAN CLASS="syntax18"><</SPAN> runnerCount; <SPAN CLASS="syntax18">+</SPAN><SPAN CLASS="syntax18">+</SPAN>i)
<SPAN CLASS="gutter">109:</SPAN> <SPAN CLASS="syntax18">{</SPAN>
<SPAN CLASS="gutterH">110:</SPAN> tcs[i] <SPAN CLASS="syntax18">=</SPAN> <SPAN CLASS="syntax8">new</SPAN> <SPAN CLASS="syntax6">WriteText</SPAN>( wc, <SPAN CLASS="syntax5">500</SPAN>, <SPAN CLASS="syntax13">"</SPAN><SPAN CLASS="syntax13">"</SPAN><SPAN CLASS="syntax18">+</SPAN>(<SPAN CLASS="syntax10">char</SPAN>)i,
<SPAN CLASS="gutter">111:</SPAN> <SPAN CLASS="syntax13">"</SPAN><SPAN CLASS="syntax13">"</SPAN><SPAN CLASS="syntax18">+</SPAN>(<SPAN CLASS="syntax10">char</SPAN>)i, <SPAN CLASS="syntax5">50</SPAN> );
<SPAN CLASS="gutter">112:</SPAN> <SPAN CLASS="syntax18">}</SPAN>
<SPAN CLASS="gutter">113:</SPAN> TestRunnable monitors[] <SPAN CLASS="syntax18">=</SPAN> <SPAN CLASS="syntax18">{</SPAN>
<SPAN CLASS="gutter">114:</SPAN> <SPAN CLASS="syntax8">new</SPAN> <SPAN CLASS="syntax6">WriterCountMonitor</SPAN>( wc );
<SPAN CLASS="gutterH">115:</SPAN> <SPAN CLASS="syntax18">}</SPAN>;
<SPAN CLASS="gutter">116:</SPAN> MultiThreadedTestRunner mttr <SPAN CLASS="syntax18">=</SPAN>
<SPAN CLASS="gutter">117:</SPAN> <SPAN CLASS="syntax8">new</SPAN> <SPAN CLASS="syntax6">MultiThreadedTestRunner</SPAN>( tcs, monitors );
<SPAN CLASS="gutter">118:</SPAN> mttr.<SPAN CLASS="syntax6">runTestRunnables</SPAN>( <SPAN CLASS="syntax5">10</SPAN> <SPAN CLASS="syntax18">*</SPAN> <SPAN CLASS="syntax5">60</SPAN> <SPAN CLASS="syntax18">*</SPAN> <SPAN CLASS="syntax5">1000</SPAN> );
<SPAN CLASS="gutter">119:</SPAN>
<SPAN CLASS="gutterH">120:</SPAN> <SPAN CLASS="syntax2">//</SPAN><SPAN CLASS="syntax2"> </SPAN><SPAN CLASS="syntax2">verify</SPAN><SPAN CLASS="syntax2"> </SPAN><SPAN CLASS="syntax2">streams</SPAN>
<SPAN CLASS="gutter">121:</SPAN> <SPAN CLASS="syntax8">for</SPAN> (<SPAN CLASS="syntax10">int</SPAN> i <SPAN CLASS="syntax18">=</SPAN> <SPAN CLASS="syntax5">0</SPAN>; i <SPAN CLASS="syntax18"><</SPAN> runnerCount; <SPAN CLASS="syntax18">+</SPAN><SPAN CLASS="syntax18">+</SPAN>i)
<SPAN CLASS="gutter">122:</SPAN> <SPAN CLASS="syntax18">{</SPAN>
<SPAN CLASS="gutter">123:</SPAN> String s <SPAN CLASS="syntax18">=</SPAN> mwf.nameToString.<SPAN CLASS="syntax6">get</SPAN>( <SPAN CLASS="syntax13">"</SPAN><SPAN CLASS="syntax13">"</SPAN><SPAN CLASS="syntax18">+</SPAN>(<SPAN CLASS="syntax10">char</SPAN>)i ).<SPAN CLASS="syntax6">toString</SPAN>();
<SPAN CLASS="gutter">124:</SPAN> <SPAN CLASS="syntax6">assertEquals</SPAN>( <SPAN CLASS="syntax13">"</SPAN><SPAN CLASS="syntax13">Data</SPAN><SPAN CLASS="syntax13"> </SPAN><SPAN CLASS="syntax13">corruption:</SPAN><SPAN CLASS="syntax13"> </SPAN><SPAN CLASS="syntax13">stream</SPAN><SPAN CLASS="syntax13"> </SPAN><SPAN CLASS="syntax13">"</SPAN><SPAN CLASS="syntax18">+</SPAN>i,
<SPAN CLASS="gutterH">125:</SPAN> <SPAN CLASS="syntax5">500</SPAN>, s.<SPAN CLASS="syntax6">length</SPAN>() );
<SPAN CLASS="gutter">126:</SPAN> <SPAN CLASS="syntax18">}</SPAN>
<SPAN CLASS="gutter">127:</SPAN> <SPAN CLASS="syntax18">}</SPAN>
<SPAN CLASS="gutter">128:</SPAN>
</PRE>
</P>
<P>
So, while this test runs the 30 runners, each writing 500 times, the
monitor runs concurrently, analyzing the status of the <tt>WriterCache</tt>
instance to ensure its integrety.
</P>
<P>
As one would expect, both of these tests expose serious synchronization
flaws in the <tt>WriterCache</tt> implementation.
</P>
<section>Things To Look Out For</section>
<P>
This package isn't without its pitfalls. Here's a checklist to review
to ensure that your tests comply with the MTTR caveats.
<OL>
<LI>
Never directly run <tt>TestRunnable</tt> instances. They are designed
to only be run in threads generated by the <tt>runTestRunnables()</tt>
method inside the <tt>MultiThreadedTestRunner</tt> class.
</LI>
<LI>
The <tt>TestRunnable</tt> subclasses need to have their
<tt>runTest()</tt> methods be watchful of <tt>InterruptedException</tt>
and <tt>Thread.currentThread().isInterrupted()</tt>. The
<tt>MultiThreadedTestRunner</tt> prematurely halts the runner threads
by calling <tt>Thread.interrupt()</tt> on them. If the threads don't
terminate themselves within a certain time limit, then
<tt>MultiThreadedTestRunner</tt> will perform the dangerous
<tt>Thread.stop()</tt> operation, in order to prevent threads from
going rogue. (Future versions may allow the <tt>Thread.stop()</tt>
call to be disabled.)
</LI>
</OL>
</P>
<section>Alternatives</section>
<P>
One alternative design to this approach is Greg Vaughn's <tt>TestDecorator</tt>
approach, which is located <a href=
"http://sourceforge.net/tracker/index.php?func=detail&aid=535058&group_id=15278&atid=315278"
>here</a>. However, it forces the decorated Test instance to create the
threads itself, and does nothing to manage runaway threads.
</P>
</body>
</document>
|
