glibmm: Glib::Module Class Reference

Dynamic Loading of Modules These functions provide a portable way to dynamically load object files (commonly known as 'plug-ins'). More...

#include <glibmm/module.h>

Public Types

Public Member Functions

 Module (const std::string& file_name, Flags flags=Flags(0))
 Opens a module. More...

 
 Module (const Module&)=delete
 
Moduleoperator= (const Module&)=delete
 
 Module (Module&& other) noexcept
 
Moduleoperator= (Module&& other) noexcept
 
virtual ~Module ()
 Close a module. More...

 
 operator bool () const
 Check whether the module was found. More...

 
void make_resident ()
 Ensures that a module will never be unloaded. More...

 
bool get_symbol (const std::string& symbol_name, void*& symbol) const
 Gets a symbol pointer from the module. More...

 
std::string get_name () const
 Get the name of the module. More...

 
GModule* gobj ()
 
const GModule* gobj () const
 

Static Public Member Functions

static bool get_supported ()
 Checks if modules are supported on the current platform. More...

 
static std::string get_last_error ()
 Gets a string describing the last module error. More...

 
static std::string build_path (const std::string& directory, const std::string& module_name)
 A portable way to build the filename of a module. More...

 

Protected Attributes

GModule* gobject_
 

Detailed Description

Dynamic Loading of Modules These functions provide a portable way to dynamically load object files (commonly known as 'plug-ins').

The current implementation supports all systems that provide an implementation of dlopen() (e.g. Linux/Sun), as well as HP-UX via its shl_load() mechanism, and Windows platforms via DLLs.

Constructor & Destructor Documentation

Glib::Module::Module ( const std::string file_name,
Flags  flags = Flags(0) 
)
explicit

Opens a module.

First of all it tries to open file_name as a module. If that fails and file_name has the ".la"-suffix (and is a libtool archive) it tries to open the corresponding module. If that fails and it doesn't have the proper module suffix for the platform (G_MODULE_SUFFIX), this suffix will be appended and the corresponding module will be opended. If that fails and file_name doesn't have the ".la"-suffix, this suffix is appended and it tries to open the corresponding module.

Use operator bool() to see whether the operation succeeded. For instance,

Glib::Module module("plugins/helloworld");
if(module)
{
void* func = nullptr;
bool found = get_symbol("some_function", func);
}
Parameters
file_nameThe library filename to open
flagsFlags to configure the load process
Glib::Module::Module ( const Module )
delete
Glib::Module::Module ( Module&&  other)
noexcept
virtual Glib::Module::~Module ( )
virtual

Close a module.

The module will be removed from memory, unless make_resident has been called.

Member Function Documentation

static std::string Glib::Module::build_path ( const std::string directory,
const std::string module_name 
)
static

A portable way to build the filename of a module.

The platform-specific prefix and suffix are added to the filename, if needed, and the result is added to the directory, using the correct separator character.

The directory should specify the directory where the module can be found. It can be an empty string to indicate that the module is in a standard platform-specific directory, though this is not recommended since the wrong module may be found.

For example, calling build_path() on a Linux system with a directory of /lib and a module_name of "mylibrary" will return /lib/libmylibrary.so. On a Windows system, using \Windows as the directory it will return \Windows\mylibrary.dll.

Parameters
directoryThe directory the module is in
module_nameThe name of the module
Returns
The system-specific filename of the module
static std::string Glib::Module::get_last_error ( )
static

Gets a string describing the last module error.

Returns
The error string
std::string Glib::Module::get_name ( ) const

Get the name of the module.

Returns
The name of the module
static bool Glib::Module::get_supported ( )
static

Checks if modules are supported on the current platform.

Returns
true if available, false otherwise
bool Glib::Module::get_symbol ( const std::string symbol_name,
void *&  symbol 
) const

Gets a symbol pointer from the module.

Parameters
symbol_nameThe name of the symbol to lookup
symbolA pointer to set to the symbol
Returns
True if the symbol was found, false otherwise.
GModule* Glib::Module::gobj ( )
inline
const GModule* Glib::Module::gobj ( ) const
inline
void Glib::Module::make_resident ( )

Ensures that a module will never be unloaded.

Any calls to the Glib::Module destructor will not unload the module.

Glib::Module::operator bool ( ) const
explicit

Check whether the module was found.

Module& Glib::Module::operator= ( const Module )
delete
Module& Glib::Module::operator= ( Module&&  other)
noexcept

Member Data Documentation

GModule* Glib::Module::gobject_
protected