[Quickfix-developers] HELP - linux shared library - and now ???

[Mustafa R. <m....@ka...>]

Hi there,

I am new to that group, but like the approch of how this fix-library is 
generated. Thats why
I started to create the shared library today. Well, I have now a working 
shared library under
linux <quickfix.so> and can start tha java-application
"Banzai".java - no problems with the shared library but, as soon as I 
want to access a native method I get "java.lang.UnsatisfiedLinkError" 
which occures because the c++-sources in the
directory src/java is not compiled and linked to the library generated 
in src/C++.

Thats fine so lets try to compile the directory src/java with all the 
generated classes from javah ...
I created a Makefile since the existing once are ignored but
URGS - this is no "ansi-C" standard but seems to be BorlandC++ code. 
There are includefiles
that are NOT available under unix and all conversion-methods as well as 
operators are
not compatible to g++. Even the build.xml file with ant is only 
available for windows because
it uses several windows executeables ...
Now I am realy frustrated - after hours of work with the shared library 
- no satisfaction in the end - sometimes I don't like computers ;-)

But perhaps sombody out there can help to solve these final problems 
now. Here is what must
be done to get a shared library that resolves all symbols and manages 
exeptiopns:

(1) first of all you have to compile with the option -fPIC (this makes 
address-independent code which is necessary for shared libraries)
        ==> to do that change the line in configure.in from
                 < CFLAGS="-D_XOPEN_SOURCE=500 $XML_CFLAGS"
                  to
                 > CFLAGS="-D_XOPEN_SOURCE=500 -fPIC $XML_CFLAGS"

(2) change the line in src/C++/Makefile.in from
                   
                   < libquickfix_la_LDFLAGS = -static
                    to
                    >  libquickfix_la_LDFLAGS = -shared

(3) call ./bootstrap
              ./configure --enable-shared

(4) this will generate a shared library but because exceptions are used 
there are still some
symbols not linked to the library :-(
If you look at the output of the link commands you will see, a line like

gcc -shared  Session.lo SessionFactory.lo Parser.lo Settings.lo 
ConfigLexer.lo MessageStore.lo SocketServer.lo SocketConnector.lo 
SocketStream.lo Acceptor.lo Initiator.lo SocketAcceptor.lo 
SocketInitiator.lo SocketMonitor.lo SocketConnection.lo 
ThreadedSocketAcceptor.lo ThreadedSocketInitiator.lo 
ThreadedSocketConnection.lo FileStore.lo Dictionary.lo DataDictionary.lo 
SessionSettings.lo MessageSorters.lo Utility.lo  -L/usr/lib 
/usr/lib/libxml2.so -lz -lm -liberty  -Wl,-soname -Wl,libquickfix.so.0 
-o .libs/libquickfix.so.0.0.0


the problem is, that gcc is using the c-link library and NOT c++ 
link-library - thus exceptions
are NOT handled correctly in libraries. To achieve a working library you 
must copy the complete
line and replace gcc with g++ in the directory src/C++ >> that's it !!!

g++ -shared  Session.lo SessionFactory.lo Parser.lo Settings.lo 
ConfigLexer.lo MessageStore.lo SocketServer.lo SocketConnector.lo 
SocketStream.lo Acceptor.lo Initiator.lo SocketAcceptor.lo 
SocketInitiator.lo SocketMonitor.lo SocketConnection.lo 
ThreadedSocketAcceptor.lo ThreadedSocketInitiator.lo 
ThreadedSocketConnection.lo FileStore.lo Dictionary.lo DataDictionary.lo 
SessionSettings.lo MessageSorters.lo Utility.lo  -L/usr/lib 
/usr/lib/libxml2.so -lz -lm -liberty  -Wl,-soname -Wl,libquickfix.so.0 
-o .libs/libquickfix.so.0.0.0

===> yeahhhh - we have a shared library

(5) unfortunatelly java doesn't know anything about our new library - 
thus  insert in your main class
 public class myMain {
    static {
        System.loadLibrary("quickfix");
    }
    static public Main(String args[]) {
        ... blabla ...
    }
}

and don't forget to start java with the option -Djava.library.path


e.g. java -Djava.library.path=/usr/local/lib myTest

That's all.


I hope I could help to get towards a java-library under linux - I really 
need that, but
currently there seems to be no chance instead of developing the complete 
access-layer
in the directory src/java completly new - that sounds ugly !

with best regards

P.S. by the way - great job thoughtworks.COM - will there be a fix for 
the java-code ? soon ???