Undefined registerKernelFactories in Plugin

[Andrea Zonca]

Hi,

I've created the CPU platform for my plugin, at runtime it finds the plugin ".so" library but `dlsym` returns a NULL handle for registerKernelFactories.

I defined the function as:

Code: Select all

extern "C" OPENMM_EXPORT void registerKernelFactories() {                                                                       std::cout << "Executing registerKernelFactories of CPU MBPol" << std::endl;                                             
    for( int ii = 0; ii < Platform::getNumPlatforms(); ii++ ){                                                              
        Platform& platform = Platform::getPlatform(ii);                                                                     
        if( platform.getName() == "CPU" ){                                                                                  
                                                                                                                            
             MBPolCpuKernelFactory* factory = new MBPolCpuKernelFactory();                                                             
             std::cout << "Registered CPU CalcMBPolElectrostaticsForceKernel::Name" << std::endl;                           
        }                                                                                                                   
    }                                                                                                                       
} 

I see that it is exported in the library:

Code: Select all

nm -gC /usr/local/openmm/lib/plugins/libOpenMMMBPolCPU.so | grep registerKernelFactories
00000000000237b7 T registerKernelFactories

all of the code is here: https://github.com/paesanilab/mbpol_ope ... n/pull/115

Do you have suggestions on how to debug this?
Thanks!

[Peter Eastman]

That's strange. You've declared it as extern "C", and it looks like it's spelled correctly, so it should be found. Are you certain that /usr/local/openmm/lib/plugins/libOpenMMMBPolCPU.so is actually the library that it's loading when it fails to find the function?

[Andrea Zonca]

yes, it is the only location where that is available beside the build folder.

[Peter Eastman]

That's not quite what I meant. How did you determine that dlsym() was returning NULL? Did you modify the code for initializePlugins() and have it print out the result? If so, then have it also print out the full path to the plugin it's loading to make sure it's really what you expect. If not, then what leads you to believe it's returning NULL?

[Andrea Zonca]

Nevermind, I found the issue, I misread the logs, it was actually failing to load the plugin due to a linking error.