Dynamic module loader for Linux, FreeBSD, and MacOS X. More...

#include <>>

Public Types
enum	ModuleFlags { MODULE_FLAGS_NONE = 0, MODULE_FLAGS_DEFAULT = 0x000E, MODULE_BIND_LAZY = 0x0001, MODULE_BIND_NOW = 0x0002, MODULE_BIND_LOCAL = 0x0000, MODULE_BIND_GLOBAL = 0x0004, MODULE_BIND_MASK = 0x0003, MODULE_BIND_DEEP = 0x0008, MODULE_NODELETE = 0x1000 }
	Flags for the loading process. More...

Public Member Functions
	Module (std::string filename, ModuleFlags flags=MODULE_FLAGS_DEFAULT)
	Constructor.
virtual	~Module ()
	Destructor.
virtual void	open ()
	Open the module.
virtual bool	close ()
	Close the module.
virtual void	ref ()
	Increment the reference count of this module.
virtual void	unref ()
	Decrease the reference count of this module.
virtual bool	notref ()
	Check if there are no reference to this module.
virtual unsigned int	get_ref_count ()
	Get the reference count of this module.
virtual bool	has_symbol (const char *symbol_name)
	Check if the module has the given symbol.
virtual void *	get_symbol (const char *symbol_name)
	Get a symbol from the module.
virtual std::string	get_filename ()
	Get the full file name of the module.
virtual std::string	get_base_filename ()
	Get the base file name of the module.
virtual bool	operator== (const Module &cmod)
	Compare to another Module instance.

Static Public Member Functions
static const char *	get_file_extension ()
	Get file extension for dl modules.

Detailed Description

Dynamic module loader for Linux, FreeBSD, and MacOS X.

A Module implementation for the dl dynamic loader library that comes with glibc, applicable for Linux, FreeBSD, and MacOS X Systems.

For nice reading and hints about using dynamic module loading with C++ you should have a look at http://www.isotton.com/howtos/C++-dlopen-mini-HOWTO/C++-dlopen-mini-HOWTO.html

Author:: Tim Niemueller

Definition at line 40 of file module.h.

Member Enumeration Documentation

enum fawkes::Module::ModuleFlags

Flags for the loading process.

Enumerator:

MODULE_FLAGS_NONE	No flags.
MODULE_FLAGS_DEFAULT	Default flags, these are MODULE_BIND_GLOBAL, MODULE_BIND_NOW and MODULE_BIND_DEEP.
MODULE_BIND_LAZY	Perform lazy binding. Only resolve symbols as thecode that references them is executed. If the symbol is never referenced,then it is never resolved. (Lazy binding is only performed for function references; references to variables are always immediately bound when the library is loaded.)
MODULE_BIND_NOW	Resolve all symbols immediately when loading the library. It's the opposite of MODULE_BIND_LAZY. It shall be the the default (makes sense for the framework robotics).
MODULE_BIND_LOCAL	Symbols defined in this library are not made available to resolve references in subsequently loaded libraries. It's the opposite of MODULE_BIND_GLOBAL. It shall be the default and MODULE_BIND_GLOBAL shall automatically override it.
MODULE_BIND_GLOBAL	Symbols defined in this library are not made available to resolve references in subsequently loaded libraries.
MODULE_BIND_MASK	Can be used to encode flags in a longer data field.
MODULE_BIND_DEEP	Place the lookup scope of the symbols in this library ahead of the global scope. This means that a self-contained library will use its own symbols in preference to global symbols with the same name contained in libraries that have already been loaded.
MODULE_NODELETE	Do not unload the library during dlclose(). Consequently, the library's static variables are not reinitialized if the library is reloaded with dlopen() at a later time.

Definition at line 44 of file module.h.

Constructor & Destructor Documentation

fawkes::Module::Module	(	std::string	filename,
		Module::ModuleFlags	flags = `MODULE_FLAGS_DEFAULT`
	)

Constructor.

Parameters:

filename	full filename of the module
flags	module flags

Definition at line 64 of file module.cpp.

fawkes::Module::~Module ( )

virtual

Destructor.

Closes the module.

Definition at line 78 of file module.cpp.

References close().

Member Function Documentation

bool fawkes::Module::close ( )

virtual

Close the module.

Returns:: Returns true if the module could be closed, false otherwise

Definition at line 151 of file module.cpp.

Referenced by ~Module().

std::string fawkes::Module::get_base_filename ( )

virtual

Get the base file name of the module.

Returns:: Returns the base file name of the module. On Unix systems this is everything after the last slash

Definition at line 289 of file module.cpp.

Referenced by fawkes::ModuleManager::close_module(), and fawkes::ModuleManager::open_module().

const char * fawkes::Module::get_file_extension ( )

static

Get file extension for dl modules.

Returns:: Returns the file extension for dl modules, this is "so" on Linux and FreeBSD systems, and dylib on MacOS X. It is defined at compile time in config.mk.

Definition at line 268 of file module.cpp.

std::string fawkes::Module::get_filename ( )

virtual

Get the full file name of the module.

Returns:: Returns a string with the full file name of the module

Definition at line 278 of file module.cpp.

unsigned int fawkes::Module::get_ref_count ( )

virtual

Get the reference count of this module.

Returns:: Returns the number of references to this module

Definition at line 202 of file module.cpp.

void * fawkes::Module::get_symbol ( const char * symbol_name )

virtual

Get a symbol from the module.

Parameters:

symbol_name The name of the symbol. NOTE: C++ symbols are mangled with type info and thus are not plainly available as symbol name. Use extern "C" to avoid this. Read http://www.isotton.com/howtos/C++-dlopen-mini-HOWTO/C++-dlopen-mini-HOWTO.html for more information on this topic.

Returns:: Returns a pointer to the symbol or NULL if symbol was not found

Definition at line 253 of file module.cpp.

Referenced by fawkes::BlackBoardInstanceFactory::delete_interface_instance(), fawkes::PluginLoader::get_description(), and fawkes::BlackBoardInstanceFactory::new_interface_instance().

bool fawkes::Module::has_symbol ( const char * symbol_name )

virtual

Check if the module has the given symbol.

Parameters:

symbol_name The name of the symbol. NOTE: C++ symbols are mangled with type info and thus are not plainly available as symbol name. Use extern "C" to avoid this. Read http://www.isotton.com/howtos/C++-dlopen-mini-HOWTO/C++-dlopen-mini-HOWTO.html for more information on this topic.

Returns:: Returns true if the symbol was found, false otherwise

Definition at line 230 of file module.cpp.

Referenced by fawkes::BlackBoardInstanceFactory::delete_interface_instance(), fawkes::PluginLoader::get_description(), and fawkes::BlackBoardInstanceFactory::new_interface_instance().

bool fawkes::Module::notref ( )

virtual

Check if there are no reference to this module.

Returns:: Returns true if there are no references to this module, false if there is at least one reference

Definition at line 192 of file module.cpp.

void fawkes::Module::open ( )

virtual

Open the module.

Returns:: true if the module could be opened, false otherwise

Exceptions:

ModuleOpenException thrown if there was any problem while loading the module

Definition at line 89 of file module.cpp.

References fawkes::Exception::append(), fawkes::File::is_regular(), MODULE_BIND_DEEP, MODULE_BIND_GLOBAL, MODULE_BIND_LAZY, MODULE_BIND_LOCAL, MODULE_BIND_NOW, and MODULE_NODELETE.

Referenced by fawkes::ModuleManager::open_module().

bool fawkes::Module::operator== ( const Module & cmod )

virtual

Compare to another Module instance.

Parameters:

cmod	a reference to the other comparison instance

Returns:: Returns true, if the full file names of both modules are the same, false otherwise

Definition at line 214 of file module.cpp.

void fawkes::Module::ref ( )

virtual

Increment the reference count of this module.

Definition at line 171 of file module.cpp.

Referenced by fawkes::ModuleManager::open_module().

void fawkes::Module::unref ( )

virtual

Decrease the reference count of this module.

Definition at line 179 of file module.cpp.

Referenced by fawkes::ModuleManager::close_module(), and fawkes::BlackBoardInstanceFactory::delete_interface_instance().

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

src/libs/utils/system/dynamic_module/module.h
src/libs/utils/system/dynamic_module/module.cpp

Public Types

Public Member Functions

Static Public Member Functions

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation