developed and tested on Unix systems only. It can be used positively on
<ul>
<li>Linux ELF with egcs 1.1.x and gcc 2.95.x;
- <li>Sun Solaris 2.5, 2.6, and 7, with egcs 1.1.x and gcc 2.95.x.
+ <li>Sun Solaris 2.5, 2.6, and 7, with egcs 1.1.x and gcc 2.95.x;
+ <li>IBM AIX 4.2, with gcc 2.95.x (with some restrictions on
+ the use of shared libraries).
</ul>
<acronym>deal.II</acronym> uses only very few features of an
operating system. It should therefore be rather simple to port it
<code>$(wildcard ...)</code> function which prevented us
from compiling some parts of the library (most of our
Makefiles use a workaround, though). Other make programs
- (i.e. non-GNU) will
- probably fail to work.
+ (i.e. non-GNU) will fail to work.
<li> In case you want to generate the documentation from the
header files, you only need Perl installed.
suffix <code>.g.a</code> instead of <code>.a</code>. The
difference between the two sets of libraries is the following:
<ul>
- <li> The <code>.g.a</code> versions contain debugging
+ <li>
+ <p>
+ The <code>.g.a</code> versions contain debugging
information. In fact the <code>.g</code> reminds us of the fact
that gcc is called using the option <code>-g</code> to include
debugging information into its output.
+ </p>
<p>
-
Besides the debugging output the compiler puts into the output,
the library contains a great number of assertions (presently
about 2000) checking the validity of parameters to functions and
parameters (such as vectors having the wrong size, etc) and they
are usually found almost instantaneously using the file name and
line number of where the problem occurred.
+ </p>
<p>
-
You will want to link your programs against the
<code>.g.a</code> versions of the libraries while developing
your programs.
+ </p>
- <li> The <code>.a</code> libraries do not contain debugging
+ <li>
+ <p>
+ The <code>.a</code> libraries do not contain debugging
information nor the assertions. For these reasons, they are much
smaller and your program will run significantly faster (the
performance penalty of the <code>.g.a</code> libraries is
between a factor of two and four, depending on which parts of
the libraries you use). Furthermore, these libraries are
compiled with optimization options of the compiler.
+ </p>
<p>
-
You will want to link your programs against these libraries when
your application runs stably and are used in production mode.
+ </p>
</ul>
You can give several flags to ./configure:
<ul>
<li>
+ <p>
<code>--enable-shared</code>: Compile the files of deal.II
into shared libraries, rather than statically linked
libraries. Enabling this option saves disk space, link time and
start-up time, so this is the default. However, some systems
might not support shared libraries, in which case you should
call ./configure with the parameter
- <code>--disable-shared</code>.
+ <code>--disable-shared</code>. (Since on AIX we could not get
+ shared libraries right immediately, they are disabled by default
+ on this system. Probably, there is a simple work-around, but
+ since we do not regularly test on AIX, we did not try very
+ hard.)
+ </p>
<p>
-
It is important to note that the actual size of the executable
program in memory will be larger than when linked statically,
since the dynamic linker does not remove symbols which are not
used, in contrast to the static linker. Therefore, more main
memory will be used when running your applications, but link
time is significantly reduced.
+ </p>
<li>
+ <p>
<code>--enable-multithreading</code>: This sets compiler
variables such that the resulting program supports
multithreading. Basically, for this different system include
multi-threaded programs are working well and routinely) and that
gcc's runtime library is not thread-safe unless you configure gcc
with <code>--enable-threads</code> and recompile it.
+ </p>
<li>
- <code>--with-multithreading=ACE-path</code>: enabling
- multithreading as shown above does not enable multithreading
- inside the library itself. However, there are several places
- where multithreading can be used (in some parts of the graphical
- output routines, the KellyErrorEstimator class and some other
- places), and you can switch to multithreading using this
- configure option.
-
- <p>
-
- To support multithreading in a cross-platform way, we use the
- <a href="http://www.cs.wustl.edu/~schmidt/ACE.html" target="_top">ACE
- (Adaptive Communications Environment)</a> library. This needs
- to be installed separately, and the path to its installation
- directory needs to be given to this option.
-
- <p>
+ <p>
+ <code>--with-multithreading=ACE-path</code>: enabling
+ multithreading as shown above does not enable multithreading
+ inside the library itself. However, there are several places
+ where multithreading can be used (in some parts of the graphical
+ output routines, the KellyErrorEstimator class and some other
+ places), and you can switch to multithreading using this
+ configure option.
+ </p>
- In our experience, if you want to use ACE on Sun, you should
- compile it for pthreads rather than Solaris threads.
+ <p>
+ To support multithreading in a cross-platform way, we use the
+ <a href="http://www.cs.wustl.edu/~schmidt/ACE.html" target="_top">ACE
+ (Adaptive Communications Environment)</a> library. This needs
+ to be installed separately, and the path to its installation
+ directory needs to be given to this option.
+ </p>
- <p>
+ <p>
+ In our experience, if you want to use ACE on Sun, you should
+ compile it for pthreads rather than Solaris threads.
+ </p>
- Note that the multi-thread support in the library is still
- experimental.
+ <p>
+ Note that the multi-thread support in the library is still
+ experimental.
+ </p>
</ul>
<p>
projects / dealii-svn.git / commitdiff