Dynamic Link at Actor Start-up

The following dynamic program uses a custom dynamic library which will be loaded and linked at actor start-up. It uses a function foo() which is defined in the dynamic library. This function calls a function bar() defined in the main program.

This is the dynamic program progdyn.c:

#include <chorus.h> 

extern void foo();

main() {
    foo();              /* calling foo defined in the library */
}

void bar() {
    printf ("bar called\n");
}

This is the dynamic library libdyn.c:

#include <chorus.h> 

extern void bar();

void foo() {
    printf ("Calling bar\n");
    bar();              /* calling bar defined in the main program */
}

Building the Dynamic Library

Create a directory libdyndir in $WORK, containing libdyn.c and the following Imakefile:

SRCS = libdyn.c
DynamicLibraryTarget (libdyn.so, libdyn.o, , , ,-Xlinker -soname=libdyn.so )
Depend(libdyn.c)

In the libdyndir directory, build the dynamic library libdyn.so using the ChorusOSMkMf, make depend, and make commands.

Building the Dynamic Program

Create a directory progdyndir in $WORK, containing progdyn.c and the following Imakefile:

SRCS = progdyn.c
DynamicUserTarget (progdyn, progdyn.o, , 
        $(WORK)/libdyndir/libdyn.so,
        $(WORK)/libdyndir/libdyn.so, )
Depend()

In the progdyndir directory, build the dynamic program progdyn using the ChorusOSMkMf, make depend and make commands.

% ChorusOSMkMf $WORK
% make depend
% make

Running the Dynamic Program

Copy the dynamic program into the /bin subdirectory of the chorus_root_directory directory:

% cp $WORK/progdyndir/progdyn chorus_root_directory/bin 

Copy the dynamic library into the /lib subdirectory of the chorus_root_directory directory:

% cp $WORK/libdyndir/libdyn.so chorus_root_directory/lib 

Then, the following command will tell the runtime linker where to find the libdyn.so dynamic library:

% rsh jericho setenv LD_LIBRARY_PATH /lib 

Alternatively, set the runpath to /lib in the ldopts argument of the program macro (-rpath /lib).

Finally, the following command will start the program and dynamically load the libdyn.so library:

% rsh jericho arun /bin/progdyn