Name
Dynamic Loading of Modules -- portable method for dynamically loading 'plug-ins'.
Description
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.
To use them you must first determine whether dynamic loading
is supported on the platform by calling g_module_supported().
If it is, you can open a module with g_module_open(),
find the module's symbols (e.g. function names) with g_module_symbol(),
and later close the module with g_module_close().
g_module_name() will return the file name of a currently opened module.
If any of the above functions fail, the error status can be found with
g_module_error().
The gmodule implementation features reference counting for opened modules,
and supports hook functions within a module which are called when the
module is loaded and unloaded (see GModuleCheckInit and GModuleUnload).
If your module introduces static data to common subsystems in the running
program, e.g. through calling g_quark_from_static_string ("my-module-stuff"),
it must ensure that it is never unloaded, by calling g_module_make_resident().
Details
g_module_supported ()
Checks if modules are supported on the current platform.
g_module_build_path ()
gchar* g_module_build_path (const gchar *directory,
const gchar *module_name); |
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 NULL or an empty string to indicate that the module is in a standard
operating-system specific directory, though this is not recommended since the
wrong module may be found.
For example, calling g_module_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".
g_module_open ()
Opens a module.
If the module has already been opened, its reference count is incremented.
enum GModuleFlags
typedef enum
{
G_MODULE_BIND_LAZY = 1 << 0,
G_MODULE_BIND_MASK = 0x01
} GModuleFlags; |
Flags passed to g_module_open().
G_MODULE_BIND_LAZY specifies that symbols are only resolved when needed.
The default action is to bind all symbols when the module is loaded.
(G_MODULE_BIND_LAZY is not supported on all platforms.)
g_module_symbol ()
Gets a symbol pointer from a module.
g_module_name ()
Gets the file name from a GModule.
g_module_make_resident ()
void g_module_make_resident (GModule *module); |
Ensures that a module will never be unloaded.
Any future g_module_close() calls on the module will be ignored.
g_module_close ()
Closes a module.
g_module_error ()
gchar* g_module_error (void); |
Gets a string describing the last module error.
GModuleCheckInit ()
Specifies the type of the module initialization function.
If a module contains a function named g_module_check_init() it is called
automatically when the module is loaded. It is passed the GModule structure
and should return NULL on success or a string describing the initialization
error.
GModuleUnload ()
void (*GModuleUnload) (GModule *module); |
Specifies the type of the module function called when it is unloaded.
If a module contains a function named g_module_unload() it is called
automatically when the module is unloaded.
It is passed the GModule structure.
G_MODULE_EXPORT
Used to declare functions exported by modules.
G_MODULE_IMPORT
#define G_MODULE_IMPORT extern |
Used to declare functions imported from modules.