Module
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Eina module provides some helpers over POSIX dlopen(). More...

Defines

#define EINA_MODULE_INIT(f)   EAPI Eina_Module_Init __eina_module_init = &f
 declares the given function as the module initializer (__eina_module_init).
#define EINA_MODULE_SHUTDOWN(f)   EAPI Eina_Module_Shutdown __eina_module_shutdown = &f
 declares the given function as the module shutdownializer (__eina_module_shutdown).

Typedefs

typedef struct _Eina_Module Eina_Module
 Dynamic module loader handle.
typedef Eina_Bool(* Eina_Module_Cb )(Eina_Module *m, void *data)
typedef Eina_Bool(* Eina_Module_Init )(void)
 If a function with such signature is exported by module as __eina_module_init, it will be called on the first load after dlopen() and if EINA_FALSE is returned, load will fail, EINA_TRUE means the module was successfully initialized.
typedef void(* Eina_Module_Shutdown )(void)
 If a function with such signature is exported by module as __eina_module_shutdown, it will be called before calling dlclose().

Functions

Eina_Module * eina_module_new (const char *file)
 Return a new module.
Eina_Bool eina_module_free (Eina_Module *m)
 Delete a module.
Eina_Bool eina_module_load (Eina_Module *m)
 Load a module.
Eina_Bool eina_module_unload (Eina_Module *m)
 Unload a module.
void * eina_module_symbol_get (const Eina_Module *m, const char *symbol)
 Retrive the data associated to a symbol.
const char * eina_module_file_get (const Eina_Module *m)
 Return the file name associated to the module.
char * eina_module_symbol_path_get (const void *symbol, const char *sub_dir)
 Return the path built from the location of a library and a given sub directory.
char * eina_module_environment_path_get (const char *env, const char *sub_dir)
 Return the path built from the value of an environment varialbe and a given sub directory.
Eina_Array * eina_module_arch_list_get (Eina_Array *array, const char *path, const char *arch)
 Get an array of modules found on the directory path matching an arch type.
Eina_Array * eina_module_list_get (Eina_Array *array, const char *path, Eina_Bool recursive, Eina_Module_Cb cb, void *data)
 Get a list of modules found on the directory path.
void eina_module_list_load (Eina_Array *array)
 Load every module on the list of modules.
void eina_module_list_unload (Eina_Array *array)
 Unload every module on the list of modules.
void eina_module_list_free (Eina_Array *array)
 Free every module on the list of modules.
Eina_Module * eina_module_find (const Eina_Array *array, const char *module)
 Find an module in array.

Variables

Eina_Error EINA_ERROR_WRONG_MODULE
 Error identifier corresponding to a wrong module.
Eina_Error EINA_ERROR_MODULE_INIT_FAILED
 Error identifier corresponding to a failure during the initialisation of a module.

Detailed Description

Eina module provides some helpers over POSIX dlopen().

These functions provide module management.

It is not meant to replace, abstract or make a "portable" version of the POSIX, but enhance its usage by defining some good practices.

Modules are created with eina_module_new() and later loaded with eina_module_load(). Loads are reference counted and there must be the same number of eina_module_unload() in order to have it to call dlclose(). This makes simple to have different users for the same module.

The loaded shared objects may have two visible functions that will be called and might provide initialization and shutdown proceedures. The symbols are __eina_module_init and __eina_module_shutdown and will be defined by the macros EINA_MODULE_INIT() and EINA_MODULE_SHUTDOWN().

There are some helpers to automatically create modules based on directory listing. See eina_module_arch_list_get(), eina_module_list_get() and eina_module_find().

Define Documentation

#define EINA_MODULE_INIT ( f   )     EAPI Eina_Module_Init __eina_module_init = &f

declares the given function as the module initializer (__eina_module_init).

It must be of signature Eina_Module_Init

#define EINA_MODULE_SHUTDOWN ( f   )     EAPI Eina_Module_Shutdown __eina_module_shutdown = &f

declares the given function as the module shutdownializer (__eina_module_shutdown).

It must be of signature Eina_Module_Shutdown

Typedef Documentation

Eina_Module_Init

If a function with such signature is exported by module as __eina_module_init, it will be called on the first load after dlopen() and if EINA_FALSE is returned, load will fail, EINA_TRUE means the module was successfully initialized.

See also:
Eina_Module_Shutdown
Eina_Module_Shutdown

If a function with such signature is exported by module as __eina_module_shutdown, it will be called before calling dlclose().

See also:
Eina_Module_Init

Function Documentation

Eina_Module * eina_module_new ( const char *  file  ) 

Return a new module.

Parameters:
file The name of the file module to load.

This function returns a new module. If file is NULL, the function returns NULL, otherwise, it allocates an Eina_Module, stores a duplicate string of file, sets its reference to 0 and its handle to NULL.

When the new module is not needed anymore, use eina_module_free() to free the allocated memory.

See also:
eina_module_load
Eina_Bool eina_module_free ( Eina_Module *  m  ) 

Delete a module.

Parameters:
m The module to delete.
Returns:
EINA_TRUE on success, EINA_FALSE otherwise.

This function calls eina_module_unload() if m has been previously loaded and frees the allocated memory. On success this function returns EINA_TRUE and EINA_FALSE otherwise. If m is NULL, the function returns immediately.

Eina_Bool eina_module_load ( Eina_Module *  m  ) 

Load a module.

Parameters:
m The module to load.
Returns:
EINA_TRUE on success, EINA_FALSE otherwise.

This function load the shared file object passed in eina_module_new(). If it is a internal Eina module (like the mempools), it also initialize it. It the shared file object can not be loaded, the error EINA_ERROR_WRONG_MODULE is set and EINA_FALSE is returned. If it is a internal Eina module and the module can not be initialized, the error EINA_ERROR_MODULE_INIT_FAILED is set and EINA_FALSE is returned. If the module has already been loaded, it's refeence counter is increased by one and EINA_TRUE is returned. If m is NULL, the function returns immediately EINA_FALSE.

When the symbols of the shared file objetcts are not needed anymore, call eina_module_unload() to unload the module.

Eina_Bool eina_module_unload ( Eina_Module *  m  ) 

Unload a module.

Parameters:
m The module to load.
Returns:
EINA_TRUE on success, EINA_FALSE otherwise.

This function unload the module m that has been previously loaded by eina_module_load(). If the reference counter of m is strictly greater than 1, EINA_FALSE is returned. Otherwise, the shared object file is closed and if it is a internal Eina module, it is shutted down just before. In that case, EINA_TRUE is returned. In all case, the reference counter is decreased. If m is NULL, the function returns immediately EINA_FALSE.

void * eina_module_symbol_get ( const Eina_Module *  m,
const char *  symbol 
)

Retrive the data associated to a symbol.

Parameters:
m The module.
symbol The symbol.
Returns:
The data associated to the symbol, or NULL on failure.

This function returns the data associated to symbol of m. m must have been loaded before with eina_module_load(). If m is NULL, or if it has not been correctly loaded before, the function returns immediately NULL.

const char * eina_module_file_get ( const Eina_Module *  m  ) 

Return the file name associated to the module.

Parameters:
m The module.
Returns:
The file name.

This function returns the file name passed in eina_module_new(). If m is NULL, the function returns immediately NULL. The returned value must no be freed.

char * eina_module_symbol_path_get ( const void *  symbol,
const char *  sub_dir 
)

Return the path built from the location of a library and a given sub directory.

Parameters:
symbol The symbol to search for.
sub_dir The subdirectory to append.
Returns:
The built path on success, NULL otherwise.

This function returns the path built by concatenating the path of the library containing the symbol symbol and sub_dir. sub_dir can be NULL. The returned path must be freed when not used anymore. If the symbol is not found, or dl_addr() is not supported, or allocation fails, this function returns NULL.

char * eina_module_environment_path_get ( const char *  env,
const char *  sub_dir 
)

Return the path built from the value of an environment varialbe and a given sub directory.

Parameters:
env The environment variable to expand.
sub_dir The subdirectory to append.
Returns:
The built path on success, NULL otherwise.

This function returns the path built by concatenating the value of the environment variable named env and sub_dir. sub_dir can be NULL. The returned path must be freed when not used anymore. If the symbol is not found, or env does not exist, or allocation fails, this function returns NULL.

Eina_Array * eina_module_arch_list_get ( Eina_Array *  array,
const char *  path,
const char *  arch 
)

Get an array of modules found on the directory path matching an arch type.

Parameters:
array The array that stores the list of the modules.
path The directory's path to search for modules.
arch The architecture string.

This function adds to array the module names found in path which match the cpu architecture arch. If path or arch is NULL, the function returns immediately array. array can be NULL. In that case, it is created with 4 elements.

Eina_Array * eina_module_list_get ( Eina_Array *  array,
const char *  path,
Eina_Bool  recursive,
Eina_Module_Cb  cb,
void *  data 
)

Get a list of modules found on the directory path.

Parameters:
array The array that stores the list of the modules.
path The directory's path to search for modules.
recursive Iterate recursively on the path.
cb Callback function to call on each module.
data Data passed to the callback function.

This function adds to array the list of modules found in path. If recursive is EINA_TRUE, then recursive search is done. The callback cb is called on each module found, and data is passed to cb. If path is NULL, the function returns immediately array. If the returned value of cb is 0, the module will not be added to the list, otherwise it will be added. array can be NULL. In that case, it is created with 4 elements. cb can be NULL.

void eina_module_list_load ( Eina_Array *  array  ) 

Load every module on the list of modules.

Parameters:
array The array of modules to load.

This function calls eina_module_load() on each element found in array. If array is NULL, this function does nothing.

void eina_module_list_unload ( Eina_Array *  array  ) 

Unload every module on the list of modules.

Parameters:
array The array of modules to unload.

This function calls eina_module_unload() on each element found in array. If array is NULL, this function does nothing.

void eina_module_list_free ( Eina_Array *  array  ) 

Free every module on the list of modules.

Parameters:
array The array of modules to free.

This function calls eina_module_free() on each element found in array. If array is NULL, this function does nothing.

Eina_Module * eina_module_find ( const Eina_Array *  array,
const char *  module 
)

Find an module in array.

Parameters:
array The array to find the module.
module The name of module to be searched.

This function finds an module in array. If the element is found the function returns the module, else NULL is returned.