Hi there,

I am trying to implement a load balancing module and need to use some c++ codes in it. I tried to run a demo as follows:

I have a cpp_library.h, a cpp_library.cpp and my_load_balancer_module.c.

cpp_library.h

#ifndef C_BASE_CPP_LIBRARY_H
#define C_BASE_CPP_LIBRARY_H

#ifdef __cplusplus
extern "C" {
#endif

int cpp_hello_world();

#ifdef __cplusplus
}
#endif

#endif //C_BASE_CPP_LIBRARY_H

cpp_library.cpp

#include <iostream>
#include "cpp_library.h"

int cpp_hello_world() {
return 0;
}

my_load_balancer_module.c

#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_http.h>
#include "cpp_library.h"
........................................
........................................
........................................
........................................

And I enabled --with-ld-opt="-lstdc++". It complied without any errors. But when I loaded the my_load_balancer_module in the nginx.conf and tried to start nginx, I am getting the following error:

nginx: [emerg] dlopen() "/usr/local/Cellar/nginx/1.21.0/modules/my_load_balancer_module.so" failed
(dlopen(/usr/local/Cellar/nginx/1.21.0/modules/my_load_balancer_module.so, 10): Symbol not found: _cpp_hello_world
Referenced from: /usr/local/Cellar/nginx/1.21.0/modules/my_load_balancer_module.so
Expected in: flat namespace
in /usr/local/Cellar/nginx/1.21.0/modules/my_load_balancer_module.so) in /usr/local/etc/nginx/nginx.conf:4


I think I am messing up something since I have very limited knowledge of C/C++. Can you please help to figure out how to do it correctly? Thanks in advance.