DynamicLibraryLoader Class Reference

Wrapper class to facilitate loading and lifetime management of dynamic libraries and obtaining pointers to exported functions. More...

#include <DynamicLibraryLoader.h>

Public Member Functions
	DynamicLibraryLoader (const std::string &library_file)
	~DynamicLibraryLoader ()
template<typename T >
T	getFunction (std::string func, bool hard_fail=true)
	Get a function/data pointer of type T to a function exported from the loaded library.

Private Attributes
void *	_handle
	Library handle returned by dlopen.
const std::string	_library_file
	Library file name.

Detailed Description

Wrapper class to facilitate loading and lifetime management of dynamic libraries and obtaining pointers to exported functions.

Definition at line 24 of file DynamicLibraryLoader.h.

Constructor & Destructor Documentation

DynamicLibraryLoader()

DynamicLibraryLoader::DynamicLibraryLoader

(

const std::string &

library_file

)

Definition at line 13 of file DynamicLibraryLoader.C.

  : _library_file(library_file)
{
  MooseUtils::checkFileReadable(_library_file, false, /*throw_on_unreadable=*/true);
#ifdef LIBMESH_HAVE_DLOPEN
  _handle = dlopen(_library_file.c_str(), RTLD_LAZY);
  if (!_handle)
    mooseError("Failed to load library '", _library_file, "' in DynamicLibraryLoader: ", dlerror());
 
  dlerror();
#else
  // support for the POSIX function 'dlopen' to dynamically load libraries is missing
  mooseError("Dynamic library loading is not supported on this operating system.");
#endif
}

~DynamicLibraryLoader()

DynamicLibraryLoader::~DynamicLibraryLoader

(

)

Definition at line 29 of file DynamicLibraryLoader.C.

{
#ifdef LIBMESH_HAVE_DLOPEN
  dlclose(_handle);
#endif
}

Member Function Documentation

getFunction()

template<typename T >

T DynamicLibraryLoader::getFunction	(	std::string	func,
		bool	hard_fail = true
	)

Get a function/data pointer of type T to a function exported from the loaded library.

Parameters

hard_fail

Set this to false to return a nullptr if a symbol was not found.

Definition at line 47 of file DynamicLibraryLoader.h.

{
#ifdef LIBMESH_HAVE_DLOPEN
  // clear error
  dlerror();
 
  // Snag the function pointers from the library
  void * pointer = dlsym(_handle, func.c_str());
 
  // Catch errors
  const char * dlsym_error = dlerror();
  if (dlsym_error && hard_fail)
  {
    dlclose(_handle);
    mooseError("DynamicLibraryLoader error: Unable to find symbol '",
               func,
               "' in library '",
               _library_file,
               "'. ",
               std::string(dlsym_error));
  }
 
  return *reinterpret_cast<T *>(&pointer);
#else
  // this can never be reached as the object instantiation would have already failed
  return nullptr;
#endif
}

Member Data Documentation

_handle

void* DynamicLibraryLoader::_handle

private

Library handle returned by dlopen.

Definition at line 39 of file DynamicLibraryLoader.h.

Referenced by DynamicLibraryLoader(), getFunction(), and ~DynamicLibraryLoader().

_library_file

const std::string DynamicLibraryLoader::_library_file

private

Library file name.

Definition at line 42 of file DynamicLibraryLoader.h.

Referenced by DynamicLibraryLoader(), and getFunction().

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The documentation for this class was generated from the following files:

• solid_mechanics/include/utils/DynamicLibraryLoader.h
• solid_mechanics/src/utils/DynamicLibraryLoader.C