File: ACE-guidelines.html

package info (click to toggle)
ace 6.4.5%2Bdfsg-1
  • links: PTS, VCS
  • area: main
  • in suites: buster
  • size: 48,640 kB
  • ctags: 41,204
  • sloc: cpp: 336,448; perl: 33,068; ansic: 20,676; sh: 3,735; exp: 787; python: 635; yacc: 511; xml: 330; lex: 158; lisp: 116; makefile: 80; csh: 20; tcl: 5
file content (1394 lines) | stat: -rw-r--r-- 51,266 bytes parent folder | download | duplicates (2)
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
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
<!--  -->

<html>
  <head>
    <title>ACE Software Development Guidelines</title>
    <link rev=made href="mailto:ace-users@list.isis.vanderbilt.edu">
  </head>

<body text = "#000000"
link="#000fff"
vlink="#ff0f0f"
bgcolor="#ffffff">

<hr>
<h3>ACE Software Development Guidelines</h3>

<ul>
  <li><strong>General</strong><p>
  <ul>
    <li>Every text file must end with a newline.<p>

    <li>Use spaces instead of tabs, except in Makefiles.  Emacs users
        can add this to their <strong>.emacs</strong>:

        <pre>(setq-default indent-tabs-mode nil)</pre></p>

        Microsoft Visual C++ users should do the following:

        <pre>
        Choose:  Tools -- Options -- Tabs
        Then Set:  "Tab size" to 8 and "Indent size" to 2, and
        indent using spaces.
        </pre><p>

    <li>Do not end text lines with spaces.  Emacs users can add this to
        their <strong>.emacs</strong>:

        <pre>(setq-default nuke-trailing-whitespace-p t)</pre>

        Newer versions of emacs will require the following instead:

        <pre>(add-hook 'before-save-hook 'delete-trailing-whitespace)</pre>

        <strong>Note for Microsoft Visual Studio .NET Users:</strong>
        <p>There is a macro project <code>(ace_guidelines.vsmacros)</code>
        located in <code>$ACE_ROOT/docs</code> that replaces tabs with spaces
        and removes trailing spaces each time you save a file.</p>

    <li>Try to limit the length of source code lines to less than 80
        characters.  Users with 14 inch monitors appreciate it when
        reading code.  And, it avoids mangling problems with email
        and net news.<p>

        <li>Try to avoid creating files with excessively long names (45 characters).
        Moreover, ensure that the names of generated files e.g. <code>MakeProjectCreator</code>,
        <code>tao_idl</code> do not also go beyond that limit. Some operating
        systems cannot handle very long file names correctly.<p>

    <li>If you add a comment to code that is directed to, or
        requires the attention of, a particular individual:
        <strong>SEND EMAIL TO THAT INDIVIDUAL!</strong>.<p>

    <li>Every program should have a "usage" message.  It should be
        printed out if erroneous command line arguments, or a
        <strong><code>-?</code></strong> command line argument, are
        provided to the program.<p>

    <li>An ACE-using program's entry point should use the portable form:
        <pre>
        int ACE_TMAIN (int argc, ACE_TCHAR *argv[])
        </pre>
        This form is portable to all ACE platforms whether using narrow
        or wide characters. The other two common forms:
        <pre>
        int main (int argc, char *argv[])
        int wmain (int argc, wchar_t *argv[])
        </pre>
        as well as any other main entrypoint form should only be used
        when there is some overarching reason to not use the portable form.
        One example would be a Windows GUI program that requires WinMain.
        <p>See <a href="wchar.txt"><code>$ACE_ROOT/docs/wchar.txt</code></a>
        for more information on ACE support on <code>wchar</code>.<p>

    <li>The program entry point function, in any form mentioned above, must
        always be declared with arguments, <em>e.g.</em>,
        <pre>
        int
        ACE_TMAIN (int argc, ACE_TCHAR *argv[])
        {
          [...]

          return 0;
        }
        </pre><p>

        If you don't use the <code>argc</code> and/or <code>argv</code>
        arguments, don't declare them, <em>e.g.</em>,
        <pre>
        int
        ACE_TMAIN (int, ACE_TCHAR *[])
        {
          [...]

          return 0;
        }
        </pre><p>

        Please declare the second argument as <code>ACE_TCHAR *[]</code>
        instead of <code>ACE_TCHAR **</code> or <code>char *[]</CODE>.
        Ancient versions of MSC++
        complained about <code>ACE_TCHAR **</code> and <code>char
        *[]</CODE> is not Unicode-compliant.<p>

        <code>main</code> must also return 0 on successful
        termination, and non-zero otherwise.<p>

    <li>Avoid use of floating point types (<code>float</code> and
            <code>double</code>) and operations
        unless absolutely necessary.  Not all ACE platforms support them.
        Therefore, wherever they are used, <code>ACE_LACKS_FLOATING_POINT</code>
        conditional code must be also be used.<p>

    <li>Avoid including the string "<code>Error</code>" in a source
            code filename. GNU Make's error messages start with
            "<code>Error</code>".  So, it's much easier to search for
            errors if filenames don't contain "<code>Error</code>".<p>


    <li>Narrow interfaces are better than wide interfaces.  If there
        isn't a need for an interface, leave it out.  This eases maintenance,
        minimizes footprint, and reduces the likelihood of interference
        when other interfaces need to be added later.  (See the
        <a href="#ACE_Time_Value example">ACE_Time_Value</a> example
        .<p>

     <li> Never use <CODE>assert()</CODE> macros or related constructs
         (such as abort()) calls in core ACE, TAO, and CIAO
         library/framework code.  These macros are a major problem for
         production software that uses this code since the
         error-handling strategy (i.e., abort the process) is
         excessive.  Instead, extract out the expressions from
         assert() macros and use them as
         precondition/postconditions/invariants in the
         software and return any violations of these
         conditions/invariants via exceptions or error return values.
         It's fine to use <CODE>assert()</CODE> macros et al. in test
         programs, but make sure these tests never find their way into
         the core ACE, TAO, and CIAO library/framework code base. <P>

  </ul>

  <li><strong>Coding Style</strong><p>
  <ul>
  <LI> When writing ACE, TAO, and CIAO class and method names make sure to use underscores ('_') to separate the parts of a name rather than intercaps.  For example, use

        <pre>
        class ACE_Monitor_Control
        {
        public:
          int read_monitor (void);
          // ...
        };
        </PRE>

rather than

        <pre>
        class ACEMonitorControl
        {
        public:
          int readMonitor (void);
          // ...
        };
        </PRE>

  </UL>

  <li><strong>Code Documentation</strong><p>
  <ul>
    <li>Use comments and whitespace (:-) liberally.  Comments
        should consist of complete sentences, <em>i.e.</em>, start
        with a capital letter and end with a period.<p>

    <li>Insert a svn keyword string at the top of every source file,
        Makefile, config file, <em>etc</em>.  For C++ files, it is:
        <pre>
        // $<!-- -->Id$
        </pre>
        It is not necessary to fill in the fields of the keyword string,
        or modify them when you edit a file that already has one. SVN
        does that automatically when you checkout or update the file.<p>

        To insert that string at the top of a file:
        <pre>
        perl -pi -e \
          'if (! $o) {printf "// \$<!-- -->Id\$\n\n";}; $o = 1;' <em>file</em>
        </pre><p>

    <li>Be sure to follow the guidelines and restrictions for use of the
        documentation tools for ACE
        header files, which must follow the
        <a href="http://www.doxygen.org/">Doxygen</a>
        format requirements.
        The complete documentation for Doxygen is available in the
        <a href="http://www.stack.nl/~dimitri/doxygen/download.html#latestman">
        Doxygen manual</a>.
        For an example header file using Doxygen-style comments,
        please refer to <a href="../ace/ACE.h">ACE.h</a>.<p>

    <li>The header file comment should at least contain the following
        entries:
        <pre>
        /**
         * @file Foo.h
         * @author Authors Name &lt;author@email.org&gt;
         *
         *  A few words describing the file.
         */
        </pre></p>

    <li>A class should be commented this way:
        <pre>
        /**
         * @class Foo_Impl
         * @brief A brief description of the class
         *
         * A more detailed description.
         */
        </pre></p>

     <li>The preferred way to document methods is:
         <pre>
         /// This function foos the bars
         /// another line of documentation if necessary
         /// @param bar The bar you want to foo
         void foo (int bar);
         </pre></p>

    <li>All binary options for ACE and TAO should be specified in
        terms of the integral values 0 and 1, rather than "true" and
        "false" or "yes" and "no".  All TAO options should be
        documented in the <A HREF="../TAO/docs/Options.html">online
        TAO options document</A>. <P>.

  </ul>

  <li><strong>Preprocessor</strong><p>
  <ul>
    <li>Never #include standard headers directly, except in a few
        specific ACE files, <em>e.g.</em>, OS.h and stdcpp.h.  Let
        those files #include the correct headers.  If you do not do
        this, your code will not compile with the Standard C++ Library.<p>

    <li>Always use <strong><code>#if defined (MACRONAME)</code></strong>
        to test if a macro is defined, rather than the simpler
        <strong><code>#if MACRONAME</code></strong>. Doxygen requires this.
        The one exception to this the macros used to prevent multiple
        inclusion of header files, as shown below.

    <li>Always follow a preprocessor <strong><code>#endif</code></strong>
        with a <strong><code>/*  */</code></strong> C-style comment. Using
        C-style comments with preprocessor code is required for some old
        compilers. It should correspond to the condition in the matching
        <strong><code>#if</code></strong> directive.  For example,
        <pre>
        #if defined (ACE_HAS_THREADS)
        # if defined (ACE_HAS_STHREADS)
        #   include /**/ &lt;synch.h&gt;
        #   include /**/ &lt;thread.h&gt;
        #   define ACE_SCOPE_PROCESS P_PID
        #   define ACE_SCOPE_LWP P_LWPID
        #   define ACE_SCOPE_THREAD (ACE_SCOPE_LWP + 1)
        # else
        #   define ACE_SCOPE_PROCESS 0
        #   define ACE_SCOPE_LWP 1
        #   define ACE_SCOPE_THREAD 2
        # endif /* ACE_HAS_STHREADS */
        #endif /* ACE_HAS_THREADS */
        </pre><p>

    <li>Be sure to put spaces around comment delimiters, e.g.,
        <strong><code>char * /* foo */</code></strong> instead of
        <strong><code>char */*foo*/</code></strong>.  MS VC++
        complains otherwise.<p>

    <li>Always insert a <strong><code>/**/</code></strong> between an
        <strong><code>#include</code></strong> and
        <strong><code>filename</code></strong>, for system headers and
        <strong><code>ace/pre.h</code></strong> and
        <strong><code>ace/post.h</code></strong> as
        shown in the above example.  This avoids dependency problems
        with Visual C++ and prevents Doxygen from including the
        headers in the file reference trees.  <p>

    <li>Be very careful with names of macros, <code>enum</code> values, and variables
        It's always best to prefix them with something like <code>ACE_</code>
        or <code>TAO_</code>.  There are too many system headers out
        there that <code>#define</code> <code>OK</code>, <code>SUCCESS</code>,
        <code>ERROR</code>, <code>index</code>, <code>s_type</code>,
        and so on.<p>

    <li>When using macros in an arithmetic expression, be sure to test
      that the macro is defined, using <code>defined(<em>macro</em>)</code> before specifying
      the expression.  For example:
<pre>
#if __FreeBSD__ &lt; 3
</pre>

will evaluate true on any platform where <code>__FreeBSD__</code> is
not defined.  The correct way to write that guard is:
<pre>
#if defined (__FreeBSD__)  &&  __FreeBSD__ &lt; 3
</pre>

If using g++, problems like this can be flagged as a warning by using the "<code>-Wundef</code>" command line option.

    <li>Try to centralize <code>#ifdef</code>s with <code>typedef</code>s
        and <code>#define</code>s.  For example, use this:
        <pre>
        #if defined(ACE_PSOS)
          typedef long ACE_NETIF_TYPE;
        # define ACE_DEFAULT_NETIF 0
        #else  /* ! ACE_PSOS */
          typedef const TCHAR* ACE_NETIF_TYPE;
        # define ACE_DEFAULT_NETIF ASYS_TEXT("le0")
        #endif /* ! ACE_PSOS */
        </pre><p>

        instead of:

        <pre><p>
        #if defined (ACE_PSOS)
          // pSOS supports numbers, not names for network interfaces
          long net_if,
        #else  /* ! ACE_PSOS */
          const TCHAR *net_if,
        #endif /* ! ACE_PSOS */
        </pre><p>

    <li>Protect header files against multiple inclusion with this
        construct:
        <pre>
        #ifndef FOO_H
        #define FOO_H

        [contents of header file]

        #endif /* FOO_H */
        </pre><p>

        This exact construct (note the <code>#ifndef</code>)
        is optimized by many compilers such they only open the
        file once per compilation unit.  Thanks to Eric C. Newton
        &lt;ecn@smart.net&gt; for pointing that out.<p>

        If the header <code>#include</code>s an ACE library header,
        then it's a good idea to include the <code>#pragma once</code>
        directive:
        <pre>
        #ifndef FOO_H
        #define FOO_H

        #include "ace/ACE.h"
        #if !defined (ACE_LACKS_PRAGMA_ONCE)
        # pragma once
        #endif /* ACE_LACKS_PRAGMA_ONCE */

        [contents of header file]

        #endif /* FOO_H */
        </pre><p>

        <code>#pragma once</code> must be protected, because some
        compilers complain about it.  The protection depends on
        <code>ACE_LACKS_PRAGMA_ONCE</code>, which is defined in
        some ACE config headers.  Therefore, the protected
        <code>#pragma once</code> construct should only be used after
        an <code>#include</code> of an ACE library header.  Note that
        many compilers enable the optimization if the <code>#ifndef</code>
        protection construct is used, so for them, <code>#pragma once</code>
        is superfluous.<p>

        <strong>No</strong> code can appear after the final
        <code>#endif</code> for the optimization to be effective and
        correct.<p>

    <li><p>Files that contain parametric classes should follow this style:
      <pre>
      #ifndef FOO_T_H
      #define FOO_T_H

      #include "ace/ACE.h"
      #if !defined (ACE_LACKS_PRAGMA_ONCE)
      # pragma once
      #endif /* ACE_LACKS_PRAGMA_ONCE */

      // Put your template declarations here...

      #if defined (__ACE_INLINE__)
      #include "Foo_T.inl"
      #endif /* __ACE_INLINE__ */

      #if defined (ACE_TEMPLATES_REQUIRE_SOURCE)
      #include "Foo_T.cpp"
      #endif /* ACE_TEMPLATES_REQUIRE_SOURCE */

      #if defined (ACE_TEMPLATES_REQUIRE_PRAGMA)
      #pragma implementation "Foo_T.cpp"
      #endif /* ACE_TEMPLATES_REQUIRE_PRAGMA */

      #endif /* FOO_T_H */
</pre></p>
      <p>
      Notice that some compilers need to see the code of the template,
      hence the <code>.cpp</code> file must be included from the
      header file.
      </p>
      <p>
      To avoid multiple inclusions of the <code>.cpp</code> file it
      should also be protected as in:
      <pre>
      #ifndef FOO_T_CPP
      #define FOO_T_CPP

      #include "Foo_T.h"
      #if !defined (ACE_LACKS_PRAGMA_ONCE)
      # pragma once
      #endif /* ACE_LACKS_PRAGMA_ONCE */

      #if !defined (__ACE_INLINE__)
      #include "ace/Foo_T.inl"
      #endif /* __ACE_INLINE__ */

      // put your template code here

      #endif /* FOO_T_H */
</pre></p>
      <p>Finally, you may want to include the template header file from a
      non-template header file (check
      <code>$ACE_ROOT/ace/Synch.h</code>); in such a case the template
      header should be included <strong>after</strong> the inline
      function definitions, as in:</p>
      <p><pre>
      #ifndef FOO_H
      #define FOO_H

      #include "ace/ACE.h"
      #if !defined (ACE_LACKS_PRAGMA_ONCE)
      # pragma once
      #endif /* ACE_LACKS_PRAGMA_ONCE */

      // Put your non-template declarations here...

      #if defined (__ACE_INLINE__)
      #include "Foo.inl"
      #endif /* __ACE_INLINE__ */

      #include "Foo_T.h"

      #endif /* FOO_H */
</pre></p></li>

    <li>Avoid <code>#include &lt;math.h&gt;</code> if at all possible.
      The <code>/usr/include/math.h</code> on SunOS 5.5.1 through 5.7
      defines a struct name <strong>exception</strong>, which complicates
      use of exceptions.<p>

    <li>On a <code>.cpp</code> file always include the corresponding
      header file <em>first</em>, like this:<p>
<pre>
        // This is Foo.cpp

        #include "Foo.h"
        #include "tao/Bar.h"
        #include "ace/Baz.h"

        // Here comes the Foo.cpp code....
</pre><p>

      In this way we are sure that the header file is self-contained
      and can be safely included from some place else.

    <li>In the TAO library <strong>never</strong> include
      <code>&lt;corba.h&gt</code>, this file should only be included
      by the user and introduces cyclic dependencies in the library
      that we must avoid.<p>

    <li>Never include a header file when a forward reference will do,
      remember that templates can be forward referenced too.
      Consult your favorite C++ book to find out when you must include
      the full class definition.<p>
  </ul>

  <li><strong>C++ Syntax and Constructs</strong><p>
  <ul>
    <li><strong><code>for</code></strong> loops should look like:
        <pre>
        for (unsigned int i = 0; i &lt; count; ++i)
          ++total;
        </pre>

        Similarly, <strong><code>if</code></strong> statements should have
        a space after the "<strong>if</strong>", and no spaces just after
        the opening parenthesis and just before the closing parenthesis.<p>

        If there's just one statement in the loop or if statement
        there's no need to use additional braces.

    <li>If a loop index is used after the body of the loop, it
        <strong>must</strong> be declared before the loop.  For example,

        <pre>
        size_t i = 0;
        for (size_t j = 0; file_name [j] != '\0'; ++i, ++j)
          {
            if (file_name [j] == '\\' && file_name [j + 1] == '\\')
              ++j;

            file_name [i] = file_name [j];
          }

        // Terminate this string.
        file_name [i] = '\0';
        </pre><p>

   <li>Prefix operators are generally more efficient than postfix
       operators.  Therefore, they are preferred over their postfix
       counterparts where the expression value is not used.<p>

       Therefore, use this idiom for iterators, with prefix operator
       on the loop index:
       <pre>
       ACE_Ordered_MultiSet&lt;int&gt; set;
       ACE_Ordered_MultiSet_Iterator&lt;int&gt; iter(set);

       for (i = -10; i &lt; 10; ++i)
         set.insert (2 * i + 1);

       </pre>
       rather than the postfix operator:
       <pre>
       for (i = -10; i &lt; 10; i++)
         set.insert (2 * i + 1);
       </pre><p>

    <li>Prefer using <strong> <code> if (...) else .... </code> </strong>
    instead of <strong> <code> ?: </code> </strong> operator. It is a lot
    less error prone, and will help you avoid bugs caused due to the
    precedence of <strong> <code> ?: </code> </strong>, compared with other
    operators in an expression.

    <li>When a class provides <code>operator==</code>, it must also provide
        <code>operator!=</code>.  Also, both these operators must be
        <code>const</code> and return <code>bool</code>.

    <li>Avoid unnecessary parenthesis.  We're not writing Lisp :-)<p>

    <li>Put inline member functions in a <strong><code>.inl</code></strong>
        file.  That file is conditionally included by both the
        <strong><code>.h</code></strong> file, for example:<p>

            <pre>
            class ACE_Export ACE_High_Res_Timer
            {
              [...]
            };

            #if defined (__ACE_INLINE__)
            #include "ace/High_Res_Timer.inl"
            #endif /* __ACE_INLINE__ */
            </pre><p>

        and <strong><code>.cpp</code></strong> file:<p>

            <pre>
            #define ACE_BUILD_DLL
            #include "ace/High_Res_Timer.h"

            #if !defined (__ACE_INLINE__)
            #include "ace/High_Res_Timer.inl"
            #endif /* __ACE_INLINE__ */

            ACE_ALLOC_HOOK_DEFINE(ACE_High_Res_Timer)
            </pre><p>

        <strong>NOTE:</strong> It is very important to ensure than an
        inline function will not be used before its definition is seen.
        Therefore, the inline functions in the .inl file should be arranged
        properly.  Some compilers, such as <code>g++</code> with the
        <code>-Wall</code> option, will issue warnings for violations.<p>

    <li>Some inlining heuristics:<p>
      <ul>
        <li>One liners should almost always be inline, as in:
<pre>
ACE_INLINE
Foo::bar ()
{
  this-&gt;baz ();
}
</pre><p>

        <li>The notable exception is virtual functions, which should
            generally not be inlined.<p>

        <li>Big (more than 10 lines) and complex function (more than one if ()
          statement, or a switch, or a loop) should not be inlined.<p>

        <li>Medium sized stuff depends on how performance critical it is.
          If you know that it's in the critical path, then make it
                inline.  When in doubt, profile the code.<p>
      </ul>

    <li><code>ACE_Export</code> must be inserted between the
        <code>class</code> keyword and class name for all classes that
        are exported from libraries, as shown in the example above.
        <strong>However</strong>, do <strong>not</strong> use
        <code>ACE_Export</code> for template classes or classes that
        are not used out of the ACE library, for example.!<p>

    <li>Mutators and accessors should be of this form:<p>

        <pre>
        /// Sets @c object_addr_ cache from @c host and @c port.
        void object_addr (const ACE_INET_Addr &);

        /// Returns the ACE_INET_Addr for this profile.
        const ACE_INET_Addr &object_addr const (void);
        </pre><p>

        instead of the "set_" and "get_" form.<p>

    <li>Never use <strong><code>delete</code></strong> to deallocate
        memory that was allocated with <strong><code>malloc</code></strong>.
        Similarly, never associate <strong><code>free</code></strong> with
        <strong><code>new</code></strong>.
        <strong><code>ACE_NEW</code></strong> or
        <strong><code>ACE_NEW_RETURN</code></strong> should be used to
        allocate memory, and <strong><code>delete</code></strong> should
        be used to deallocate it.  And be careful to use the correct form,
        <strong><code>delete</code></strong> or
        <strong><code>delete []</code></strong> to correspond to the
        allocation.<p>

    <li>Don't check for a pointer being 0 before deleting it.  It's
        always safe to delete a 0 pointer.  If the pointer is visible
        outside the local scope, it's often a good idea to 0 it
        _after_ deleting it.  Note, the same argument applies to
        free().<p>

    <li>Always use <strong><code>ACE_NEW</code></strong> or
        <strong><code>ACE_NEW_RETURN</code></strong> to allocate memory,
        because they check for successful allocation and set errno
        appropriately if it fails.<p>

    <li>Never compare or assign a pointer value with <strong>NULL</strong>;
        use <strong>0</strong> instead.  The language allows any pointer to
        be compared or assigned with <strong>0</strong>.  The definition
        of <strong>NULL</strong> is implementation dependent, so it is
        difficult to use portably without casting.<p>

    <li>Never cast a pointer to or from an <strong><code>int</code></strong>
        or a <strong><code>long</code></strong>.  On all currently supported
        ACE platforms, it is safe to cast a pointer to or from
        <strong><code>intptr_t</code></strong> or
        <strong><code>uintptr_t</code></strong> (include ace/Basic_Types.h).<p>

    <li>Be very careful when selecting an integer type that must be a
        certain size, <em>e.g.</em>, 4 bytes.  <strong>long</strong> is
        not 4 bytes on all platforms; it is 8 bytes on many 64-bit
        machines.  ACE_UINT32 is always 4 bytes, and ACE_UINT64 is
        always 8 bytes.<p>

    <li>If a class has any virtual functions, and its destructor is
        declared explicitly in the class, then the destructor should
        <strong>always</strong> be virtual as well.  And to support
        compiler activities such as generation of virtual tables and,
        in some cases, template instantiation, the virtual destructor
        should <strong>not be inline</strong>.  (Actually, any non-pure
        virtual function could be made non-inline for this purpose.  But,
        for convenience, if its performance is not critical, it is usually
        easiest just to make the virtual destructor non-inline.)<p>


    <li><a name="ACE_Time_Value example">Avoid default arguments</a>
        unless there's a good reason.  For an example of how they got
        us into a jam is:
        <pre>
        ACE_Time_Value (long sec, long usec = 0);
        </pre>

        So, <code>ACE_Time_Value (2.5)</code> has the unfortunate
        effect of coercing the 2.5 to a long with value 2.  That's
        probably not what the programmer intended, and many compilers
        don't warn about it.<p>

        A nice fix would be to add an <code>ACE_Time_Value (double)</code>
        constructor.  But, that would cause ambiguous overloading
        due to the default value for the second argument of
        <code>ACE_Time_Value (long sec, long usec = 0)</code>.
        We're stuck with <code>ACE_Time_Value</code>, but now we
        know that it's easy to avoid.<p>

    <li>Constructor initializers must appear in the same order as
        the data members are declared in the class header.  This avoids
        subtle errors, because initialization takes place in the order
        of member declaration.<p>

    <li>Initialization is usually cleaner than assignment, especially
        in a conditional.  So, instead of writing code like this:

        <pre>
        ssize_t n_bytes;

        // Send multicast of one byte, enough to wake up server.
        if ((n_bytes = multicast.send ((char *) &reply_port,
          sizeof reply_port)) == -1)
        </pre>

        Write it like this:

        <pre>
        ssize_t n_bytes = multicast.send ((char *) &reply_port,
          sizeof reply_port)

        // Send multicast of one byte, enough to wake up server.
        if (n_bytes == -1)
        </pre><p>

        But, beware if the initialization is of a static variable.
        A static variable is only initialized the first time its
        declaration is seen.  Of course, we should avoid using
        static (and non-constant) variables at all.<p>

    <li>It is usually clearer to write conditionals that have
        both branches without a negated condition.  For example,<p>

        <pre>
        if (test)
          {
            // true branch
          }
        else
          {
            // false branch
          }
        </pre><p>

        is preferred over:<p>

        <pre>
        if (! test)
          {
            // false test branch
          }
        else
          {
            // true test branch
          }
        </pre><p>

    <li>If a cast is necessary, avoid use of C-style "sledgehammer"
            casts.  Use standard C++ casts
            (e.g. <code>static_cast&lt;int&gt; (foo)</code>) instead.<p>

    <li>In general, if instances of a class should not be copied,
        then a private copy constructor and assignment operator should
        be declared for the class, but not implemented.  For example:

        <pre>
        // Disallow copying by not implementing the following . . .
        ACE_Object_Manager (const ACE_Object_Manager &);
        ACE_Object_Manager &operator= (const ACE_Object_Manager &);
        </pre><p>

        If the class is a template class, then the
        <code>ACE_UNIMPLEMENTED_FUNC</code> macro should be used:

        <pre>
        // = Disallow copying...
        ACE_UNIMPLEMENTED_FUNC (ACE_TSS (const ACE_TSS&lt;TYPE&gt; &))
        ACE_UNIMPLEMENTED_FUNC (void operator= (const ACE_TSS&lt;TYPE&gt; &))
        </pre><p>

        <code>ACE_UNIMPLEMENTED_FUNC</code> can be used with non-template
        classes as well.  Though for consistency and maximum safety, it
        should be avoided for non-template classes.<p>

    <li>Never use <code>BOOL</code>, or similar types.
            (<code>ACE_CDR::Boolean</code> and
            <code>CORBA::Boolean</code> are acceptable).  Use the
            standard C++ <code>bool</code> for boolean variables, instead.<p>

    <li>Functions should always return -1 to indicate failure, and
        0 or greater to indicate success.<p>

    <li>Separate the code of your templates from the code for
        non-parametric classes: some compilers get confused when
        template and non-template code is mixed in the same file.<p>

    <li>It's a good idea to specify the include path (with <code>-I</code>)
        to include any directory which contains files with template
        definitions.  The Compaq Tru64 cxx <code>-ptv</code> compiler option
        may help diagnose missing template instantiation problems.<p>

    <li>When referring to member variables and functions, use
        <code>this-&gt;</code><em>member</em>. This makes it clear to the
        reader that a class member is being used. It also makes it crystal
        clear to the compiler which variable/function you mean in cases
        where it might make a difference. <p>

    <li>Don't use template template arguments, this C++ construct is not
        supported by the HP aCC 3.70 compiler at this moment. For example the
  following template decleration is one that just doesn't work.
        <pre>
        template&lt;typename S_var, size_t BOUND, template &lt;typename&gt; class Insert_Policy&gt; class A {};
        </pre>
  </ul>
  <li><strong>I/O</strong><p>
  <ul>
     <li>Use <strong><code>ACE_DEBUG</code></strong> for printouts,
         and <strong><code>ACE_OS::fprintf ()</code></strong> for
         file I/O.  Avoid using iostreams because of implementation
         differences across platforms.<p>
     <li>After attempting to open an existing file, always check for success.
         Take appropriate action if the open failed.<p>
     <li>Notice that <strong><code>ACE_DEBUG</code></strong> and
         <strong><code>ACE_ERROR</code></strong> don't support
         <code>%ld</code> of any other multicharacter format.<p>
  </ul>

  <li><strong>WCHAR conformity</strong><p>

  <ul>
     <li>For ACE, use <code>ACE_TCHAR</code> instead of char for strings and <code>ACE_TEXT()</code>
         around string literals.  Exceptions are <code>char</code>
            arrays used for data  and strings that need to remain as 1
            byte characters.

     <li>If you have a char string that needs to be converted to <code>ACE_TCHAR</code>,
         use the <code>ACE_TEXT_CHAR_TO_TCHAR()</code> macro.  If you have a <code>ACE_TCHAR</code>
         string that needs to be converted to a <code>char</code> string, use the
         <code>ACE_TEXT_ALWAYS_CHAR()</code> macro

     <li>Do not use the Win32 <code>TCHAR</code> macros.  The wide character-ness of ACE
         is separate from UNICODE and _UNICODE.

     <li>For TAO, don't use <code>ACE_TCHAR</code> or <code>ACE_TEXT</code>.  The CORBA specification
         defines APIs as using char.  So most of the time there is no need
         to use wide characters.
  </ul><P>

  <li><strong>Exceptions</strong><p>

  <ul>
    <li>There are many ways of throwing and catching exceptions. The
        code below gives several examples.  Note that each method has
        different semantics and costs. Whenever possible, use the
        first approach.<p>

        <pre>
        #include "iostream.h"

        class exe_foo
        {
        public:
          exe_foo (int data) : data_ (data)
            { cerr &lt;&lt; "constructor of exception called" &lt;&lt; endl; }
          ~exe_foo ()
            { cerr &lt;&lt; "destructor of exception called" &lt;&lt; endl; }
          exe_foo (const exe_foo& foo) : data_ (foo.data_)
            { cerr &lt;&lt; "copy constructor of exception called"
                   &lt;&lt; endl; }
          int data_;
        };


        void
        good (int a)
        {
          throw exe_foo (a);
        };

        void
        bad (int a)
        {
          exe_foo foo (a);
          throw foo;
        };

        int main ()
        {
          cout &lt;&lt; endl &lt;&lt; "First exception" &lt;&lt; endl
               &lt;&lt; endl;
          try
            {
              good (0);
            }
          catch (exe_foo &foo)
            {
              cerr &lt;&lt; "exception caught: " &lt;&lt; foo.data_
                   &lt;&lt; endl;
            }

          cout &lt;&lt; endl &lt;&lt; "Second exception" &lt;&lt; endl
               &lt;&lt; endl;
          try
            {
              good (0);
            }
          catch (exe_foo foo)
            {
              cerr &lt;&lt; "exception caught: " &lt;&lt; foo.data_
                   &lt;&lt; endl;
            }

          cout &lt;&lt; endl &lt;&lt; "Third exception" &lt;&lt; endl
               &lt;&lt; endl;
          try
            {
              bad (1);
            }
          catch (exe_foo &foo)
            {
              cerr &lt;&lt; "exception caught: " &lt;&lt; foo.data_
                   &lt;&lt; endl;
            }

          cout &lt;&lt; endl &lt;&lt; "Fourth exception" &lt;&lt; endl
               &lt;&lt; endl;
          try
            {
              bad (1);
            }
          catch (exe_foo foo)
            {
              cerr &lt;&lt; "exception caught: " &lt;&lt; foo.data_
                   &lt;&lt; endl;
            }

          return 0;
        }
        </pre>

     Output is: <p>

        <pre>
        First exception

        constructor of exception called
        exception caught: 0
        destructor of exception called

        Second exception

        constructor of exception called
        copy constructor of exception called
        exception caught: 0
        destructor of exception called
        destructor of exception called

        Third exception

        constructor of exception called
        copy constructor of exception called
        destructor of exception called
        exception caught: 1
        destructor of exception called

        Fourth exception

        constructor of exception called
        copy constructor of exception called
        destructor of exception called
        copy constructor of exception called
        exception caught: 1
        destructor of exception called
        destructor of exception called

        </pre>

      </ul><p>

  <li><strong>Compilation</strong><p>
  <ul>
    <li>Whenever you add a new test or example to ACE or TAO, make
        sure that you modify the MPC file in the parent directory.
      This will make sure that your code gets compiled on a
      regular basis.<p>
  </ul><p>
</ul>

<hr>
<h3><a href="http://www.cs.wustl.edu/~schmidt/ACE-overview.html">ACE</a>
  Shared Libary Guidelines</h3>
    <ul>
      <li>
        <p>
          Create a separate export macro for each dynamic library.  A
          header file containing the export macro and additional
          support macros should be generated by using the <a
            href="../bin/generate_export_file.pl">ACE_wrappers/bin/generate_export_file.pl</a> Perl script.
          </p>
      </li>
      <li>
        <p>
          Make sure that your classes, structures and free functions
          are annotated with this export macro.  The only exceptions
          are pure template classes, structures and free functions.
        </p>
        <p>
          Only classes (and structures, free functions, etc) that are
          part of the library public interface must be exported
          (e.g. declared with an export macro).  Those that are only
          meant to be used internally need not be exported,
          particularly for g++ <code>&gt;=</code>4.0  since doing so
          defeats some neat optimizations.  Here's a common case in
          where an export macro is generally used unnecessarily:
        </p>
        <blockquote>
          <pre>
class FooExport Foo
{
public:
  virtual void kung_fu () = 0;
};

class FooExport Bar : public Foo
{
public:
  virtual void kung_fu ()  { ... }
};

class FooExport FooFactory
{
public:
  Foo * make_foo ()
    {
      // Assume that this implementation is hidden from
      // the application and is consequently out of line.
      return new Bar();
    }
};
          </pre>
        </blockquote>
        <p>
          Here the application is only meant to invoke operations
          through a pointer or reference to the abstract base class
          "<code>Foo</code>" created by the "<code>FooFactory</code>",
          not the "<code>Bar</code>" subclass.  In this case,
          exporting "<code>Bar</code>" is unnecessary.  If your
          concrete class is meant to be used outside of the shared
          library (e.g. as a template parameter, within a
          <code>dynamic_cast&lt;&gt;</code>, etc) you must then export
          it.  Otherwise, avoid doing so if you can.
        </p>
      </li>
      <li>
        <p>
          Make sure that you specify that you are creating a dynamic
          library in your <a href="../MPC/README">MPC</a> file by adding
          a <code>sharedname</code> tag.
        </p>
      </li>
      <li>
        <p>
          Make sure that you add the <code>FOO_BUILD_DLL</code>
          preprocessor symbol to the <code>dynamicflags</code> of the
          MPC project that is used to build a library.  Note that the
          export files are setup such that when this macro is defined,
          the symbols are exported, otherwise they are imported.  The
          default behaviour is to set up for import so that clients of
          your library don't need to worry about arcane build flags
          like <code>FOO_BUILD_DLL</code> in their build setup.  This
          ties back to the first item.
        </p>
      </li>
      <li>
        <p>
          When you specify the order of libraries to link to, make
          sure that the dependent libraries come after the libraries
          which depend on them, i.e., your link line should always
          contain <code>-lDependsOnFoo -lFoo</code>.  Note that this
          is not a requirement on GNU/Linux but linkers on other
          platforms are not as forgiving.
        </p>
      </li>
      <li>
        <p>
          Use the <code>ACE_SINGLETON_DECLARE</code> macro to declare
          a class as a singleton.  Declare exported (i.e. default
          visibility)  singleton templates prior to typedefs that
          reference them.  This prevents g++ 4.0 from silently making
          their visibility hidden (see <a
            href="http://bugzilla.dre.vanderbilt.edu/show_bug.cgi?id=2260">Bug 2260</a> for details).
        </p>
      </li>
      <li>
        <p>
          Avoid inlining virtual functions in classes that must be
          exported since doing so can cause RTTI related problems
          (e.g. <code>dynamic_cast&lt;&gt; failures</code>) when using
          g++ &gt;= 4.0 due to our use of that compiler's "visibility
          attribute" support that is tied in to the export macros.
          This includes virtual destructors automatically created by
          the compiler when you don't declare one.  Make sure you
          define a no-op out-of-line virtual destructor if your base
          class has a virtual destructor since you may otherwise run
          into the mentioned RTTI problems.
        </p>
      </li>
    </ul>


<hr>
<h3><a href="http://www.cs.wustl.edu/~schmidt/ACE-overview.html">ACE</a>
  Usage Guidelines</h3>
<ul>
  <li>Always use the <strong><code>ACE_OS</code></strong>
      namespace functions instead of bare OS system calls.<p>

  <li>As a general rule, the only functions that should go into the
      <strong><code>ACE_OS</code></strong> namespace are ones that
        have direct equivalents on some OS platform.  Functions that
        are extensions should go in the
        <strong><code>ACE</code></strong> namespace.<p>

  <li>Use the <strong><code>ACE_SYNCH_MUTEX</code></strong> macro,
      instead of using one of the specific mutexes, such as
      <strong><code>ACE_Thread_Mutex</code></strong>.  This provides
      portability between threaded and non-threaded platforms.<p>

  <li>Avoid creating a static instance of user-defined (class) type.
      Instead, either create it as an
      <strong><code>ACE_Singleton</code></strong>,
      <strong><code>ACE_TSS_Singleton</code></strong>, or as an
      <strong><code>ACE_Cleanup</code></strong> object.  See the
      <strong>ACE</strong>
      <a href="../ace/Singleton.h"><code>Singleton.h</code></a>,
      <a href="../ace/Object_Manager.h"><code>Object_Manager.h</code></a>, and
      <a href="../ace/Managed_Object.h"><code>Managed_Object.h</code></a>
      header files for more information.<p>

      Static instances of built-in types, such as
      <strong><code>int</code></strong> or any pointer type, are fine.<p>

      Construction of static instance of a user-defined type should
      <em>never</em> spawn threads.  Because order of construction of
      statics across files is not defined by the language, it is usually
      assumed that only one thread exists during static construction.
      This allows statics suchs as locks to be safely created.  We do not
      want to violate this assumption.<p>

  <li>Do not use C++ exception handling directly.  Some platforms do
      not support it.  And, it can impose an execution speed penalty.
      Instead use the TAO/ACE try/catch macros.<p>

  <li>Because ACE does not use exception handling, dealing with
      failures requires a bit of care.  This is especially true
      in constructors.  Consider the following approach:

      <pre>
      ACE_NEW_RETURN (this-&gt;name_space_, LOCAL_NAME_SPACE, -1);

      if (ACE_LOG_MSG-&gt;op_status () != 0)
      ....
      </pre>

      This snip of code is from
      <a href="../ace/Naming_Context.cpp"><code>ACE_Naming_Context</code></a>.
      All failed constructors in ACE (should) call ACE_ERROR.  This sets
      the thread-specific <strong>op_status</strong>, which can be checked
      by the caller.  This mechanism allows the caller to check for a failed
      constructor without the requiring the constructor to throw
      exceptions.<p>

  <LI>Another consequence of ACE's avoidance of exception handling is
      that you should use <CODE>open()</CODE> methods on classes that
      perform initializations that can fail.  This is because <CODE>open()</CODE>
      returns an error code that's easily checked by the caller,
      rather than relying on constructor and thread-specific status
      values. <P>

  <li>Avoid using the C++ Standard Template Library (STL) in our
      applications.  Some platforms do not support it yet. It is
      safe to use the STL generic algoritms. The following have been
      used already and don't seem to cause any portability issues:
      <pre>
  std::swap
  std::for_each
  std::fill
  std::generate
  std::transform
  std::copy
      </pre><p>

  <li>Be <em>very</em> careful with <code>ACE_ASSERT</code>.  It
      must only be used to check values; it may never be used to
      wrap a function call, or contain any other side effect.  That's
      because the statement will disappear when ACE_NDEBUG is enabled.
      For example, this code is BAD:
      <pre>
      ACE_ASSERT (this-&gt;next (retv) != 0);  // BAD CODE!
      </pre>

      Instead, the above should be coded this way:

      <pre>
      int const result = this-&gt;next (retv);
      ACE_ASSERT (result != 0);
      ACE_UNUSED_ARG (result);
      </pre><p>

  <li>Never put side effects in <code>ACE_DEBUG</code> code:
      <pre>
      ACE_DEBUG ((LM_DEBUG,
                 "handling signal: %d iterations left\n",
                 --this-&gt;iterations_));        // BAD CODE!
      </pre>

      Note that this won't work correctly if <code>ACE_NDEBUG</code> is
      defined, for the same reason that having side-effects in
      <code>ACE_ASSERT</code>s won't work either, <em>i.e.</em>, because
      the code is removed.<p>

  <li>Be <strong>very</strong> careful with the code that you put
      in a signal handler.  On Solaris, the man pages document systems
      calls as being Async-Signal-Safe if they can be called from signal
      handlers.  In general, it's best to just set a flag in a signal
      handler and take appropriate action elsewhere.  It's also best
      to avoid using signals, especially asynchronous signals.<p>

  <li>Immediately after opening a temporary file, unlink it.  For
      example:
      <pre><code>
      ACE_HANDLE h = open the file (filename);

      ACE_OS::unlink (filename);
      </code></pre><p>

      This avoids leaving the temporary file even if the program crashes.<p>

  <li>Be sure to specify the <code>THR_BOUND</code> thread creation
    flag for time-critical threads.  This ensures that the thread competes
    for resources globally on Solaris.  It is harmless on other platforms.<p>
</ul>


<hr>
<h3><a href="http://www.cs.wustl.edu/~schmidt/ACE-overview.html">Other
  ACE</a> and
  <a href="http://www.cs.wustl.edu/~schmidt/TAO-overview.html">TAO</a>
  Guidelines</h3>
<ul>
  <li>When enhancing, updating, or fixing ACE or TAO, always:
  <ol>
    <li>Test your change on at least Windows and Linux before commiting.
      After commiting watch the scoreboard to catch errors your change
      may be related to on other platforms.
    <li>Add an entry to the appropriate ChangeLog.  TAO and some
      ACE subdirectories, such as <a href="../ASNMP">ASNMP</a>,
      <a href="../apps/JAWS">JAWS</a>, and
      <a href="../apps/gperf">gperf,</a> have their
      own ChangeLogs.  If you don't use one of those, use the
      <a href="../ChangeLog">ChangeLog</a> in the top-level
      <a href="..">ACE_wrappers</a> directory. A ChangeLog entry should
      have the form:
      <pre>&lt;tab&gt; * dir/file.ext [(methods)]: description...</pre>
      If you have a number of files, the names should be on separate lines.
      In this case, it's also ok to start the description on a new line
      indented to "dir."
    <li>Commit your change using a message of this form:<p>
<code>
ChangeLogTag: Thu Jul 22 09:55:10 UTC 1999  David L. Levine
 &lt;levine@cs.wustl.edu&gt;
</code>
    <li>If the change is in response to a request by someone else:
    <ol>
      <li>Make sure that person is acknowledged in
        <a href="../THANKS">ACE_wrappers/THANKS</a>, and<p>
      <li>Respond to that person.<p>
    </ol>
  </ol>

  <li><strong>Never</strong> add copyrighted, confidential, or otherwise
      restricted code to the ACE or TAO distributions without reviewing
      the situation with DOC management (i.e. Doug Schmidt). You will also
      most likely need to get written permission from the owner. The
      particular language and form needed will be relayed to you after
      discussing it with DOC management.<p>
</ul>


<hr>
<h3>SVN Usage Guidelines</h3>
<ul>
  <li>Always make sure that a change builds and executes correctly
    on at least one platform before checking it into the SVN repository.
    All changes <strong>must</strong> be tested with g++ before commiting.
    That means you may need to test on at least two platforms.<p>
</ul>


<hr>
<h3>Script Guidelines</h3>
<ul>
  <li>In general, it's best to write scripts in Perl.  It's
    OK to use Bourne shell.  Never, never, never use csh, ksh,
    bash, or any other kind of shell.<p>

  <li>Follow the Perl style guide guide as closely as
    possible.  <code>man perlstyle</code> to view it.

  <li>Don't specify a hard-coded path to Perl itself.  Use
    the following code at the top of the script to pick up
    perl from the users <code>PATH</code>:<br>
      <pre>
eval '(exit $?0)' && eval 'exec perl -S $0 ${1+"$@"}'
    & eval 'exec perl -S $0 $argv:q'
    if 0;
      </pre><p>

  <li>Never, never, never start the first line of a script
    with "<code>#</code>", unless the first line is "<code>#! /bin/sh</code>".
    With just "<code>#</code>", t/csh users will spawn a new shell.
    That will cause their <code>.[t]cshrc</code> to be
    processed, possibly clobbering a necessary part of
    their environment.<p>

  <li>If your Perl script relies on features only available
    in newer versions of Perl, include the a statement similar
    to the following:<br>
      <pre>
        require 5.003;
      </pre>

  <li>Don't depend on <strong><code>.</code></strong> being
    in the user's path.  If the script spawns another executable
    that is supposed to be in the current directory, be sure the
    prefix its filename with <strong><code>.</code></strong>.<p>
</ul>


<hr>
<h3>Software Engineering Guidelines</h3>
<ul>
  <li><strong>Advise</strong>:  Keep other developers informed of problems
      and progress.<p>

  <li><strong>Authorize</strong>:  We have contractual obligations to not
      unilaterally change interfaces.  If you need to change or remove an
      interface, get an OK.<p>

  <li><strong>Minimize</strong> risk:  Test all changes.  Solicit review of
      changes.<p>

  <li><strong>Revise</strong> only when necessary:  Every change has risk,
      so avoid making any change unless there is a good reason for it.<p>

  <li><strong>Normalize</strong>:  Factor out commonality.  For example,
      maintain a data value in only one place.<p>

  <li><strong>Synthesize</strong>:  Build stubs and scaffolding early to
      simulate the complete system.  Maintain a checked-in version of the
      system that cleanly builds and tests at all times.<p>

  <li><strong>Be available</strong>:  Breaking compilation in one
      platform or another should be avoided (see above),
      but it is bound to happen when so many platforms are in use.
      Be available after making a change,
      if you won't be available for at least 48 hours after the change
      is made then don't make it!<p>
</ul>



<hr>
<h3><a href="http://www.cs.wustl.edu/~schmidt/rules.html">ACE
  Design Rules</a></h3>


<hr><p>
  <font size=-1>
<!-- hhmts start -->
Last modified: Wed Nov 23 11:00:44 CST 2005
<!-- hhmts end -->
  </font><p>



Back to <A HREF="index.html">ACE Documentation Home</A>.

</body>
</html>