moduleExample_Mod.cpp

This is a simple example of how to define a module of code that Aria's ArModuleLoader class can dynamically load at runtime. On Windows, loadable modules are DLL files. On Linux, they are shared object (.so) files (ARIA's Makefiles can compile any source file ending in "Mod.cpp" into a .so, so to build this module, run "make moduleExample_Mod.so"). ArModuleLoader knows about these platform conventions, so only the base name (without the .dll or .so suffix) is used to load it. To implement a loadable module, you derive a class from ArModule, instantiate the pure virtual functions init() and exit(), and create an instance of that class. The two functions simply print out the equivalent of Hello World. An important part is the global instance of the class and the call to the macro ARDEF_MODULE(). Without that macro invocation, Aria will never be able to invoke those two functions.

The program moduleExample.cpp is designed to load this module and check the error return.

See also:

moduleExample.cpp.

ArModule in the reference manual.

#include "Aria.h"


class SimpleMod : public ArModule
{
public:

  bool init(ArRobot *robot, void *argument = NULL);
  bool exit();
};

SimpleMod aModule;
ARDEF_MODULE(aModule);

bool SimpleMod::init(ArRobot *robot, void *argument)
{
  ArLog::log(ArLog::Terse, "module: init(%p) called in the loaded module!", robot);
  if (argument != NULL)
    ArLog::log(ArLog::Terse, "module: Argument given to ArModuleLoader::load was the string '%s'.", 
       (char *)argument);
  else
    ArLog::log(ArLog::Terse, "module: No argument was given to ArModuleLoader (this is OK).");
    
  // Do stuff here...
    
  return(true);
}

bool SimpleMod::exit()
{
  ArLog::log(ArLog::Terse, "module: exit() called.");

  // Do stuff here...

  return(true);
}

---