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
|
<!-- $Id$ -->
<html>
<head>
<title>ACE Implementation Guidelines</title>
<link rev=made href="mailto:levine@cs.wustl.edu">
</head>
<body>
<center>
<h1>ACE Implementation Guidelines</h1>
<font size=-1>
Last modified <!--#echo var="LAST_MODIFIED" -->.<p>
</font>
</center>
<h2> </h2>
Thanks to Graham Dumpleton <grahamd@nms.otc.com.au> for providing
corrections to the OSE Classtools link and description. Thanks also
to Graham for providing the OSE tools!<p>
<h3>Coding 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>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>The program <strong><code>main</code></strong> function should
always be declared with arguments, e.g.,
<pre>
int
main (int argc, char *argv[])
{
[...]
return 0;
}
</pre><p>
It should also return 0 on successful termination, and non-zero
otherwise.<p>
</ul>
<li><strong>Code Documentation</strong><p>
<ul>
<li>Use comments and whitespace (:-) liberally.<p>
<li>Insert a CVS/RCS 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. CVS
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>Comments, especially in header files, must follow the
<a href=http://www.dscpl.com.au>OSE</a> Tools format requirements.
Please see the ``Classinfo Tools'' section of the
<a href=http://www.dscpl.com.au>OSE</a> ``Tools Manual''
for these requirements.<p>
Please note that the Classinfo tools in OSE have been developed
independently since the copies in ACE were made and thus they
support new features not supported in the ACE version of the tools.
Certain subtle changes were also made in the ACE copies for
indicating sections, <em>etc.</em>, which makes them different
from the OSE documentation. Please see the
<a href=http://www.cs.wustl.edu/~schmidt/ACE-doctools.html>ACE-doctools
page</a> for descriptions of these changes.<p>
</ul>
<li><strong>Preprocessor</strong><p>
<ul>
<li>Always follow a preprocessor <strong><code>#endif</code></strong>
with a <strong><code>/* */</code></strong> C-style comment. 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 /**/ <synch.h>
# include /**/ <thread.h>
# 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>Always insert a <strong><code>/**/</code></strong> between an
<strong><code>#include</code></strong> and
<strong><code>filename</code></strong>, as shown in the above
example. This avoids dependency problems with Visual C++.<p>
</ul>
<li><strong>C++ Syntax and Constructs</strong><p>
<ul>
<li><strong><code>for</code></strong> loops should look like:
<pre>
for (size_t i = 0; i < Options::instance ()->spawn_count (); i++)
spawn ();
</pre>
(though I prefer to always wrap the body of the loop in braces,
to avoid surprises when other code or debugging statements are
added, and to maintain sanity when the body consists of a macro,
such as ACE_ASSERT:)
<pre>
for (size_t i = 0; i < Options::instance ()->spawn_count (); i++)
{
ACE_ASSERT (spawn () == 0);
}
</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>
<li>Put inline member functions in a <strong><code>.i</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.i"
#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.i"
#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 .i 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>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>. Ideally,
<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>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>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>
</ul>
<li><strong>I/O</strong><p>
<ul>
<li>Use <strong><code>ACE_DEBUG</code></strong> for printouts,
and <strong><code>ACE_OS::scanf/fprintf ()</code></strong> for
file I/O. Avoid using iostreams because of implementation
differences across platforms.<p>
</ul>
</ul><p>
<h3><a href="http://www.cs.wustl.edu/~schmidt/ACE-overview.html">ACE</a>
Usage Guidelines</h3>
<ul>
<li>Always use <strong><code>ACE_OS</code></strong> (static)
member functions instead of bare OS system calls.<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 run-time type identification (RTTI). Some platforms
do not support it.<p>
<li>Do not use exception handling. Some platforms do not support it.
And, it imposes an execution speed penalty.<p>
<li>Avoid using STL in our applications. Some platforms do not
support it yet.<p>
</ul><p>
<h3><a href="http://www.cs.wustl.edu/~levine/CVS.html">CVS</a>
Usage Guidelines</h3>
<ul>
<li>Always make sure that a change builds and executes correctly
before checking it into the CVS repository.<p>
</ul><p>
</body>
</html>
|
